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Xing C, Lei C, Yang Y, Zhou D, Liu S, Xu J, Liu Z, Wu T, Zhou X, Huang S, Liu W. Drought responses and population differentiation of Calohypnum plumiforme inferred from comparative transcriptome analysis. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2024; 208:108456. [PMID: 38417308 DOI: 10.1016/j.plaphy.2024.108456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 01/16/2024] [Accepted: 02/20/2024] [Indexed: 03/01/2024]
Abstract
Bryophytes, known as poikilohydric plants, possess vegetative desiccation-tolerant (DT) ability to withstand water deficit stress. Consequently, they offer valuable genetic resources for enhancing resistance to water scarcity stress. In this research, we examined the physiological, phytohormonal, and transcriptomic changes in DT mosses Calohypnum plumiforme from two populations, with and without desiccation treatment. Comparative analysis revealed population differentiation at physiological, gene sequence, and expression levels. Under desiccation stress, the activities of superoxide dismutase (SOD) and peroxidase (POD) showed significant increases, along with elevation of soluble sugars and proteins, consistent with the transcriptome changes. Notable activation of the bypass pathway of JA biosynthesis suggested their roles in compensating for JA accumulation. Furthermore, our analysis revealed significant correlations among phytohormones and DEGs in their respective signaling pathway, indicating potential complex interplays of hormones in C plumiforme. Protein phosphatase 2C (PP2C) in the abscisic acid signaling pathway emerged as the pivotal hub in the phytohormone crosstalk regulation network. Overall, this study was one of the first comprehensive transcriptome analyses of moss C. plumiforme under slow desiccation rates, expanding our knowledge of bryophyte transcriptomes and shedding light on the gene regulatory network involved in response to desiccation, as well as the evolutionary processes of local adaptation across moss populations.
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Affiliation(s)
- Chengguang Xing
- Guangdong Key Laboratory of Plant Resources, School of Ecology, Sun Yat-sen University, Shenzhen, 518100, China.
| | - Chunyi Lei
- Department of Scientific Research and Education, Heishiding Nature Reserve, Zhaoqing, 526536, China.
| | - Yuchen Yang
- Guangdong Key Laboratory of Plant Resources, School of Ecology, Sun Yat-sen University, Shenzhen, 518100, China.
| | - Dandan Zhou
- School of Marine Sciences, Sun Yat-sen University, Zhuhai, 519000, China.
| | - Shanshan Liu
- Guangdong Key Laboratory of Plant Resources, School of Ecology, Sun Yat-sen University, Shenzhen, 518100, China.
| | - Jianqu Xu
- School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China.
| | - Zhiwei Liu
- Guangdong Key Laboratory of Plant Resources, School of Ecology, Sun Yat-sen University, Shenzhen, 518100, China.
| | - Tao Wu
- Guangdong Key Laboratory of Plant Resources, School of Ecology, Sun Yat-sen University, Shenzhen, 518100, China.
| | - Xiaohang Zhou
- School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China.
| | - Shuzhen Huang
- Guangdong Key Laboratory of Plant Resources, School of Ecology, Sun Yat-sen University, Shenzhen, 518100, China.
| | - Weiqiu Liu
- Guangdong Key Laboratory of Plant Resources, School of Ecology, Sun Yat-sen University, Shenzhen, 518100, China.
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Sheng X, Qiying C, Shifeng S, Liu Yizhen, Bicai G, Lan W, Gang G. The trait co-variation regulates the response of bryophytes to nitrogen deposition: A meta-analysis. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 339:122739. [PMID: 37852313 DOI: 10.1016/j.envpol.2023.122739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 10/11/2023] [Accepted: 10/12/2023] [Indexed: 10/20/2023]
Abstract
The nitrogen deposition has the potential to alter the trait composition of plant communities by affecting the fitness and physiological adaptation of species, consequently exerting an influence on ecosystem processes. Despite the importance of bryophytes in nutrient and carbon dynamics across different ecosystems, there is a lack of research examining the relationship between nitrogen deposition and the co-variation of bryophyte traits. To address this gap, a meta-analysis was conducted using data from 27 independent studies to investigate potential associations between trait co-variation of bryophytes and nitrogen deposition. The results revealed that interspecific variability regulates the influence of nitrogen deposition on bryophytes by affecting trait co-variation. Multiple correspondence analysis identified six combinations of closely related traits. For example, species with unbranched main stems frequently exhibit robust leaf midribs, leading to leaf wrinkling and leaf clasping around the stem as a response to water loss. Some weft or mat species tend to obtain resources (nitrogen) through their scale hairs on the main stem. Some species with narrow leaves require leaf teeth to maintain a normal leaf shape. The subgroup analyses indicated that certain traits, including unbranched main stem, changes in leaf morphology, robust leaf midrib, main stem without scale hairs, narrow leaf, leaf margin with teeth, undeveloped apophysis, and erect capsule minimize interaction with pollutants and represent a resource strategy. Conversely, functional traits representing a resource acquisition strategy, such as branched main stem, no changes in leaf morphology, short and weak leaf midrib, main stem with scale hairs, broad leaf, leaf margin without teeth, developed apophysis, and non-erect capsule increase pollutant exposure. Overall, our results suggest that anthropogenic global change may significantly impact bryophytes due to changes in their individual physiology and colony ecological indicators caused by increased nitrogen deposition.
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Affiliation(s)
- Xu Sheng
- School of Life Sciences, Nanchang University, Nanchang, 330031, China
| | - Cai Qiying
- School of Life Sciences, Nanchang University, Nanchang, 330031, China
| | - Sun Shifeng
- School of Life Sciences, Nanchang University, Nanchang, 330031, China
| | - Liu Yizhen
- School of Life Sciences, Nanchang University, Nanchang, 330031, China
| | - Guan Bicai
- School of Life Sciences, Nanchang University, Nanchang, 330031, China
| | - Wu Lan
- School of Life Sciences, Nanchang University, Nanchang, 330031, China; Key Laboratory of Poyang Lake Environment and Resource Utilization Ministry of Education, Nanchang University, Nanchang, 330031, China
| | - Ge Gang
- School of Life Sciences, Nanchang University, Nanchang, 330031, China; Key Laboratory of Poyang Lake Environment and Resource Utilization Ministry of Education, Nanchang University, Nanchang, 330031, China.
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Jaszczuk I, Kotowski W, Kozub Ł, Kreyling J, Jabłońska E. Physiological responses of fen mosses along a nitrogen gradient point to competition restricting their fundamental niches. OIKOS 2022. [DOI: 10.1111/oik.09336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Izabela Jaszczuk
- Inst. of Environmental Biology, Faculty of Biology, Univ. of Warsaw, Biological and Chemical Research Centre Warsaw Poland
| | - Wiktor Kotowski
- Inst. of Environmental Biology, Faculty of Biology, Univ. of Warsaw, Biological and Chemical Research Centre Warsaw Poland
| | - Łukasz Kozub
- Inst. of Environmental Biology, Faculty of Biology, Univ. of Warsaw, Biological and Chemical Research Centre Warsaw Poland
| | - Jürgen Kreyling
- Experimental Plant Ecology, Inst. of Botany and Landscape Ecology, Univ. of Greifswald Greifswald Germany
| | - Ewa Jabłońska
- Inst. of Environmental Biology, Faculty of Biology, Univ. of Warsaw, Biological and Chemical Research Centre Warsaw Poland
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Perera-Castro AV, Waterman MJ, Robinson SA, Flexas J. Limitations to photosynthesis in bryophytes: certainties and uncertainties regarding methodology. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:4592-4604. [PMID: 35524766 DOI: 10.1093/jxb/erac189] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 05/05/2022] [Indexed: 06/14/2023]
Abstract
Bryophytes are the group of land plants with the lowest photosynthetic rates, which was considered to be a consequence of their higher anatomical CO2 diffusional limitation compared with tracheophytes. However, the most recent studies assessing limitations due to biochemistry and mesophyll conductance in bryophytes reveal discrepancies based on the methodology used. In this study, we compared data calculated from two different methodologies for estimating mesophyll conductance: variable J and the curve-fitting method. Although correlated, mesophyll conductance estimated by the curve-fitting method was on average 4-fold higher than the conductance obtained by the variable J method; a large enough difference to account for the scale of differences previously shown between the biochemical and diffusional limitations to photosynthesis. Biochemical limitations were predominant when the curve-fitting method was used. We also demonstrated that variations in bryophyte relative water content during measurements can also introduce errors in the estimation of mesophyll conductance, especially for samples which are overly desiccated. Furthermore, total chlorophyll concentration and soluble proteins were significantly lower in bryophytes than in tracheophytes, and the percentage of proteins quantified as Rubisco was also significantly lower in bryophytes (<6.3% in all studied species) than in angiosperms (>16% in all non-stressed cases). Photosynthetic rates normalized by Rubisco were not significantly different between bryophytes and angiosperms. Our data suggest that the biochemical limitation to photosynthesis in bryophytes is more relevant than so far assumed.
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Affiliation(s)
- Alicia V Perera-Castro
- Universitat de les Illes Balears, Department of Biology, INAGEA, Carretera de Valldemossa Km 7.5, 07122, Palma de Mallorca, Illes Balears, Spain
- Universidad de La Laguna, Department of Botany, Ecology and Plant Physiology, Av. Astrofísico Francisco Sánchez, S/N, 38200 La Laguna, Canary Islands, Spain
| | - Melinda J Waterman
- Centre for Sustainable Ecosystem Solutions, School of Earth, Atmosphere and Life Sciences, University of Wollongong, Wollongong, NSW, Australia
- Securing Antarctica's Environmental Future, University of Wollongong, Wollongong, NSW, Australia
| | - Sharon A Robinson
- Centre for Sustainable Ecosystem Solutions, School of Earth, Atmosphere and Life Sciences, University of Wollongong, Wollongong, NSW, Australia
- Securing Antarctica's Environmental Future, University of Wollongong, Wollongong, NSW, Australia
| | - Jaume Flexas
- Universitat de les Illes Balears, Department of Biology, INAGEA, Carretera de Valldemossa Km 7.5, 07122, Palma de Mallorca, Illes Balears, Spain
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Oishi Y. Biomonitoring of transboundary pollutants using moss in Japan's mountains. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:15018-15025. [PMID: 34625899 DOI: 10.1007/s11356-021-16746-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 09/22/2021] [Indexed: 06/13/2023]
Abstract
Long-range transported atmospheric pollutants (or transboundary pollutants) include trace metals with isotope ratios and compositions that vary from those of domestic pollutants, which threaten mountain ecosystems. These differences can be applied as indices to evaluate the influence of transboundary pollutants on mountain ecosystems. Mosses play important ecological functions in mountains and are sensitive to atmospheric deposition. Therefore, using these indices for moss biomonitoring can provide a more accurate indication of ecosystem health. However, studies on indices that are appropriate for moss biomonitoring are limited. Here, the effectiveness of moss biomonitoring using trace metal indices was examined to evaluate transboundary pollutants in mountainous areas in Japan. Transboundary pollutants in these areas originate from mainland Asia and are characterized by high lead isotope ratios, lead-to-zinc (Pb/Zn) ratios, and arsenic-to-vanadium (As/V) ratios. Given that the abundance of transboundary pollutants decreases with distance from mainland Asia, these three indices are also expected to vary with distance. The Pb isotope ratios were found to decrease with distance from mainland Asia; in contrast, the Pb/Zn and As/V ratios did not display any notable relationship with distance. These results are likely attributed to biological and environmental factors that affect trace metal content in moss. Thus, moss Pb isotope ratios are useful indicators of transboundary pollutants in Japan's mountains, offering an important tool for comparable moss biomonitoring studies in East Asia.
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Affiliation(s)
- Yoshitaka Oishi
- Fukui Prefectural University, Center for Arts and Sciences, 4-1-1 Kenjojima, Matsuoka, Eiheiji-cho, Yoshida-gun, Fukui, 910-1195, Japan.
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6
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Selecting Biomonitors of Atmospheric Nitrogen Deposition: Guidelines for Practitioners and Decision Makers. NITROGEN 2021. [DOI: 10.3390/nitrogen2030021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Environmental pollution is a major threat to public health and is the cause of important economic losses worldwide. Atmospheric nitrogen deposition is one of the most significant components of environmental pollution, which, in addition to being a health risk, is one of the leading drivers of global biodiversity loss. However, monitoring pollution is not possible in many regions of the world because the instrumentation, deployment, operation, and maintenance of automated systems is onerous. An affordable alternative is the use of biomonitors, naturally occurring or transplanted organisms that respond to environmental pollution with a consistent and measurable ecophysiological response. This policy brief advocates for the use of biomonitors of atmospheric nitrogen deposition. Descriptions of the biological and monitoring particularities of commonly utilized biomonitor lichens, bryophytes, vascular epiphytes, herbs, and woody plants, are followed by a discussion of the principal ecophysiological parameters that have been shown to respond to the different nitrogen emissions and their rate of deposition.
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Woods CL, Maleta K, Ortmann K. Plant-plant interactions change during succession on nurse logs in a northern temperate rainforest. Ecol Evol 2021; 11:9631-9641. [PMID: 34306649 PMCID: PMC8293789 DOI: 10.1002/ece3.7786] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 05/22/2021] [Accepted: 05/26/2021] [Indexed: 11/08/2022] Open
Abstract
Plant-plant interactions change through succession from facilitative to competitive. At early stages of succession, early-colonizing plants can increase the survival and reproductive output of other plants by ameliorating disturbance and stressful conditions. At later stages of succession, plant interactions are more competitive as plants put more energy toward growth and reproduction. In northern temperate rainforests, gap dynamics result in tree falls that facilitate tree regeneration (nurse logs) and bryophyte succession. How bryophyte-tree seedling interactions vary through log succession remains unclear. We examined the relationships of tree seedlings, bryophyte community composition, bryophyte depth, and percent canopy cover in 166 1.0 m2 plots on nurse logs and the forest floor in the Hoh rainforest in Washington, USA, to test the hypothesis that bryophyte-tree seedling interactions change from facilitative to competitive as the log decays. Tree seedling density was highest on young logs with early-colonizing bryophyte species (e.g., Rhizomnium glabrescens) and lowest on decayed logs with Hylocomium splendens, a long-lived moss that reaches depths >20 cm. As a result, bryophyte depth increased with nurse log decay and was negatively associated with tree seedling density. Tree seedling density was 4.6× higher on nurse logs than on the forest floor, which was likely due to competitive exclusion by forest floor plants, such as H. splendens. Nurse logs had 17 species of bryophytes while the forest floor had six, indicating that nurse logs contribute to maintaining bryophyte diversity. Nurse logs enable both tree seedlings and smaller bryophyte species to avoid competition with forest floor plants, including the dominant bryophyte, H. splendens. H. splendens is likely a widespread driver of plant community structure given its dominance in northern temperate forests. Our findings indicate that plant-plant interactions shift with succession on nurse logs from facilitative to competitive and, thus, influence forest community structure and dynamics.
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Affiliation(s)
| | - Katy Maleta
- Biology DepartmentUniversity of Puget SoundTacomaWAUSA
| | - Kimmy Ortmann
- Biology DepartmentUniversity of Puget SoundTacomaWAUSA
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Shen H, Dong S, DiTommaso A, Li S, Xiao J, Yang M, Zhang J, Gao X, Xu Y, Zhi Y, Liu S, Dong Q, Wang W, Liu P, Xu J. Eco-physiological processes are more sensitive to simulated N deposition in leguminous forbs than non-leguminous forbs in an alpine meadow of the Qinghai-Tibetan Plateau. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 744:140612. [PMID: 32711302 DOI: 10.1016/j.scitotenv.2020.140612] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 06/27/2020] [Accepted: 06/28/2020] [Indexed: 06/11/2023]
Abstract
Increased nitrogen (N) deposition can affect ecosystem processes and thus influence plant eco-physiological processes in grasslands. However, how N deposition affects eco-physiological processes of leguminous and non-leguminous forbs in alpine grasslands is understudied. A long-term field experiment using a range of simulated N deposition rates (0, 8, 24, 40, 56, and 72 kg N ha-1 year-1) was established to examine the effects of N deposition on various eco-physiological parameters in leguminous and non-leguminous forbs in an alpine meadow of the Qinghai-Tibetan Plateau. We found that the responses of leguminous and non-leguminous forbs to simulated N deposition varied. Net photosynthetic rate of leguminous and non-leguminous forbs exhibited different response patterns, but chronic increases in simulated N deposition rates may lead to negative effects in both functional groups. Neither functional group responded differently in aboveground biomass under the highest N addition level (72 kg N ha-1 year-1) compared to the control. Differences in aboveground biomass of leguminous forbs were observed at intermediate N levels. Short-term simulated N deposition significantly promoted N uptake of both functional groups. In leguminous forbs, simulated N deposition affected net photosynthetic rates (PN) and aboveground biomass (AGB) mainly via stomatal conductance (gs), water use efficiency (WUE), and plant N uptake. In non-leguminous forbs, simulated N deposition affected PN and AGB mainly through WUE and plant N uptake. Our findings suggest that leguminous and non-leguminous forbs have differential response mechanisms to N deposition, and compared with non-leguminous forbs, leguminous forbs are more sensitive to continuing increased N deposition. The obvious decline trend in photosynthetic capacity in leguminous forbs is likely to exacerbate the already divergent ecological processes between leguminous and non-leguminous forbs. More importantly, these changes are likely to alter the future composition, function, and stability of alpine meadow ecosystems.
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Affiliation(s)
- Hao Shen
- School of Environment, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Beijing Normal University, Beijing 100875, China; Soil and Crop Sciences, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853, United States
| | - Shikui Dong
- School of Environment, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Beijing Normal University, Beijing 100875, China; College of Grassland Sciences, Beijing Forestry University, Beijing 100083, China; Department of Natural Resources, Cornell University, Ithaca, NY 14853, United States.
| | - Antonio DiTommaso
- Soil and Crop Sciences, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853, United States
| | - Shuai Li
- School of Environment, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Beijing Normal University, Beijing 100875, China
| | - Jiannan Xiao
- School of Environment, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Beijing Normal University, Beijing 100875, China
| | - Mingyue Yang
- School of Environment, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Beijing Normal University, Beijing 100875, China
| | - Jing Zhang
- School of Environment, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Beijing Normal University, Beijing 100875, China
| | - Xiaoxia Gao
- School of Environment, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Beijing Normal University, Beijing 100875, China
| | - Yudan Xu
- School of Environment, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Beijing Normal University, Beijing 100875, China
| | - Yangliu Zhi
- School of Environment, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Beijing Normal University, Beijing 100875, China
| | - Shiliang Liu
- School of Environment, State Key Joint Laboratory of Environmental Simulation and Pollution Control, Beijing Normal University, Beijing 100875, China
| | - Quanming Dong
- Qinghai Academy of Animal Husbandry and Veterinary Science, Qinghai University, Xining 810003, China
| | - Wenying Wang
- School of Life and Geographic Sciences, Qinghai Normal University, Xining 810008, China
| | - Pan Liu
- School of Life and Geographic Sciences, Qinghai Normal University, Xining 810008, China
| | - Jiyu Xu
- School of Life and Geographic Sciences, Qinghai Normal University, Xining 810008, China
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Ewing SR, Baxter A, Wilson JD, Hayhow DB, Gordon J, Thompson DBA, Whitfield DP, van der Wal R. Clinging on to alpine life: Investigating factors driving the uphill range contraction and population decline of a mountain breeding bird. GLOBAL CHANGE BIOLOGY 2020; 26:3771-3787. [PMID: 32350939 DOI: 10.1111/gcb.15064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 01/16/2020] [Accepted: 02/01/2020] [Indexed: 06/11/2023]
Abstract
Climate change and anthropogenic nitrogen deposition are widely regarded as important drivers of environmental change in alpine habitats. However, due to the difficulties working in high-elevation mountain systems, the impacts of these drivers on alpine breeding species have rarely been investigated. The Eurasian dotterel (Charadrius morinellus) is a migratory wader, which has been the subject of uniquely long-term and spatially widespread monitoring effort in Scotland, where it breeds in alpine areas in dwindling numbers. Here we analyse data sets spanning three decades, to investigate whether key potential drivers of environmental change in Scottish mountains (snow lie, elevated summer temperatures and nitrogen deposition) have contributed to the population decline of dotterel. We also consider the role of rainfall on the species' wintering grounds in North Africa. We found that dotterel declines-in both density and site occupancy of breeding males-primarily occurred on low and intermediate elevation sites. High-elevation sites mostly continued to be occupied, but males occurred at lower densities in years following snow-rich winters, suggesting that high-elevation snow cover displaced dotterel to lower sites. Wintering ground rainfall was positively associated with densities of breeding males two springs later. Dotterel densities were reduced at low and intermediate sites where nitrogen deposition was greatest, but not at high-elevation sites. While climatic factors explained variation in breeding density between years, they did not seem to explain the species' uphill retreat and decline. We cannot rule out the possibility that dotterel have increasingly settled on higher sites previously unavailable due to extensive snow cover, while changes associated with nitrogen deposition may also have rendered lower lying sites less suitable for breeding. Causes of population and range changes in mountain-breeding species are thus liable to be complex, involving multiple anthropogenic drivers of environmental change acting widely across annual and migratory life cycles.
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Affiliation(s)
- Steven R Ewing
- RSPB Centre for Conservation Science, RSPB Scotland, Edinburgh, UK
| | - Alistair Baxter
- School of Biological Sciences, University of Aberdeen, Aberdeen, UK
| | - Jeremy D Wilson
- RSPB Centre for Conservation Science, RSPB Scotland, Edinburgh, UK
| | - Daniel B Hayhow
- RSPB Centre for Conservation Science, RSPB, The Lodge, Bedfordshire, UK
| | - James Gordon
- RSPB Centre for Conservation Science, RSPB Scotland, Edinburgh, UK
| | | | | | - René van der Wal
- School of Biological Sciences, University of Aberdeen, Aberdeen, UK
- Department of Ecology, Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden
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Benvenutto‐Vargas VP, Ochoa‐Hueso R. Effects of nitrogen deposition on the spatial pattern of biocrusts and soil microbial activity in a semi‐arid Mediterranean shrubland. Funct Ecol 2020. [DOI: 10.1111/1365-2435.13512] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Raúl Ochoa‐Hueso
- Department of Ecology Universidad Autónoma de Madrid Madrid Spain
- Department of Biology IVAGROUniversity of CádizCampus de Excelencia Internacional Agroalimentario (ceiA3) Puerto Real Cádiz Spain
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11
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Alves Negrini AC, Evans JR, Kaiser BN, Millar AH, Kariyawasam BC, Atkin OK. Effect of N supply on the carbon economy of barley when accounting for plant size. FUNCTIONAL PLANT BIOLOGY : FPB 2020; 47:368-381. [PMID: 32135075 DOI: 10.1071/fp19025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Accepted: 12/02/2019] [Indexed: 06/10/2023]
Abstract
Nitrogen availability and ontogeny both affect the relative growth rate (RGR) of plants. In this study of barley (Hordeum vulgare L.) we determined which growth parameters are affected by nitrate (N) availability, and whether these were confounded by differences in plant size, reflecting differences in growth. Plants were hydroponically grown on six different nitrate (N) concentrations for 28 days, and nine harvests were performed to assess the effect of N on growth parameters. Most growth parameters showed similar patterns of responses to N supply whether compared at common time points or common plant sizes. N had a significant effect on the biomass allocation: increasing N increased leaf mass ratio (LMR) and decreased root mass ratio (RMR). Specific leaf area (SLA) was not significantly affected by N. RGR increased with increasing N supply up to 1 mM, associated with increases in both LMR and net assimilation rate (NAR). Increases in N supply above 1 mM did not increase RGR as increases in LMR were offset by decreases in NAR. The high RGR at suboptimal N supply suggest a higher nitrogen use efficiency (biomass/N supply). The reasons for the homeostasis of growth under suboptimal N levels are discussed.
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Affiliation(s)
- Ana Clarissa Alves Negrini
- Australian Research Council Centre of Excellence in Plant Energy Biology, Research School of Biology, Building 134, The Australian National University, Canberra, ACT 2601, Australia; and Corresponding author.
| | - John R Evans
- Australian Research Council Centre of Excellence for Translational Photosynthesis, Building 134, The Australian National University, Canberra, ACT 2601, Australia
| | - Brent N Kaiser
- Centre for Carbon, Water and Food, School of Life and Environmental Science, The University of Sydney, Brownlow Hill, New South Wales 2070, Australia
| | - A Harvey Millar
- Australian Research Council Centre of Excellence in Plant Energy Biology, School of Molecular Sciences, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Buddhima C Kariyawasam
- Australian Research Council Centre of Excellence in Plant Energy Biology, Research School of Biology, Building 134, The Australian National University, Canberra, ACT 2601, Australia
| | - Owen K Atkin
- Australian Research Council Centre of Excellence in Plant Energy Biology, Research School of Biology, Building 134, The Australian National University, Canberra, ACT 2601, Australia
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Fernández-Martínez M, Corbera J, Domene X, Sayol F, Sabater F, Preece C. Nitrate pollution reduces bryophyte diversity in Mediterranean springs. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 705:135823. [PMID: 31972951 DOI: 10.1016/j.scitotenv.2019.135823] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 11/26/2019] [Accepted: 11/26/2019] [Indexed: 06/10/2023]
Abstract
Anthropogenic activities and intensive farming are causing nitrate pollution in groundwater bodies. These aquifers are drained by springs which, in the Mediterranean region, act as refugia for preserving biodiversity of species that need continuous water. Some springs are also used for drinking water for wild animals, livestock and humans, so if their water quality is compromised it can become a threat to public health. However, the impact of nitrate pollution on these biotic communities remains unknown. We sampled 338 assemblages of aquatic and semi-aquatic bryophytes (i.e., hygrophytic mosses and liverworts) growing in springs in a gradient of water conductivity, nitrate concentration and climate and distributed across the north-east of the Iberian Peninsula to investigate the impact of nitrate pollution on the diversity of bryophytes and moss functional traits in Mediterranean springs. Based on previous literature suggesting that increased nitrogen load decreases biodiversity in grasslands and freshwater ecosystems, we hypothesised that water nitrate pollution in springs decreases bryophyte diversity at the local and regional scales. Our results indicated that, at the local scale (spring), nitrate pollution reduced the number and the likelihood of finding a rare species in springs. Rare species were found in 4% of the springs with nitrate above 50 mg L-1 but in 32% of the springs with nitrate below 50 mg L-1. Moss, liverwort and overall bryophyte diversity were not directly affected by nitrate at the local scale but nitrate consistently decreased diversity of mosses, liverworts and rare bryophyte species at the regional scale. We also found that warmer and drier springs presented fewer bryophyte species. Our results show that the combination of nitrate pollution, increasing temperature and drought could severely threaten bryophyte diversity in Mediterranean springs. Our results indicate that the absence of rare bryophytes could be used as a bioindicator of nitrate pollution in springs.
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Affiliation(s)
- M Fernández-Martínez
- PLECO (Plants and Ecosystems), Department of Biology, University of Antwerp, 2610 Wilrijk, Belgium; Delegació de la Serralada Litoral Central (ICHN), Mataró, Catalonia, Spain.
| | - J Corbera
- Delegació de la Serralada Litoral Central (ICHN), Mataró, Catalonia, Spain
| | - X Domene
- CREAF, Bellaterra, 08193 Barcelona, Catalonia, Spain
| | - F Sayol
- Department of Biological and Environmental Sciences, University of Gothenburg, 405-30 Gothenburg, Sweden; Gothenburg Global Biodiversity Centre (GGBC), 405-30 Gothenburg, Sweden
| | - F Sabater
- Delegació de la Serralada Litoral Central (ICHN), Mataró, Catalonia, Spain; Department of Ecology, University of Barcelona, Barcelona, Catalonia, Spain
| | - C Preece
- CREAF, Bellaterra, 08193 Barcelona, Catalonia, Spain; CSIC, Global Ecology Unit, CREAF-CSIC-UAB, Bellaterra, 08193 Barcelona, Catalonia, Spain
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13
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Boch S, Allan E, Humbert JY, Kurtogullari Y, Lessard-Therrien M, Müller J, Prati D, Rieder NS, Arlettaz R, Fischer M. Direct and indirect effects of land use on bryophytes in grasslands. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 644:60-67. [PMID: 29980086 DOI: 10.1016/j.scitotenv.2018.06.323] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 05/26/2018] [Accepted: 06/26/2018] [Indexed: 06/08/2023]
Abstract
Land-use intensification is the major threat for biodiversity in agricultural grasslands, and fertilization has been suggested as the most important driver. A common explanation for the decline of bryophyte diversity with higher land-use intensity is an indirect negative effect via the increase in vascular plant productivity, which reduces light levels for bryophytes. However, direct negative effects of land-use intensification may also be important. Here, we disentangle direct and vascular plant biomass mediated indirect effects of land use on bryophytes. We analyzed two complementary datasets from agricultural grasslands, an observational study across 144 differently managed grasslands in Germany and an experimental fertilization and irrigation study of eleven grasslands in the Swiss Alps. We found that bryophyte richness and cover strongly declined with land-use intensity and in particular with fertilization. However, structural equation modelling revealed that although both direct and indirect effects were important, the direct negative effect of fertilization was even stronger than the indirect effect mediated by increased plant biomass. Thus, our results challenge the widespread view that the negative effects of fertilization are mostly indirect and mediated via increased light competition with vascular plants. Our study shows that land use intensification reduces bryophyte diversity through several different mechanisms. Therefore, only low-intensity management with limited fertilizer inputs will allow the maintenance of bryophyte-rich grasslands.
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Affiliation(s)
- Steffen Boch
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland; Institute of Plant Sciences, University of Bern, Altenbergrain 21, 3013 Bern, Switzerland.
| | - Eric Allan
- Institute of Plant Sciences, University of Bern, Altenbergrain 21, 3013 Bern, Switzerland
| | - Jean-Yves Humbert
- Division of Conservation Biology, Institute of Ecology and Evolution, University of Bern, Baltzerstrasse 6, 3012 Bern, Switzerland
| | - Yasemin Kurtogullari
- Institute of Plant Sciences, University of Bern, Altenbergrain 21, 3013 Bern, Switzerland; Division of Conservation Biology, Institute of Ecology and Evolution, University of Bern, Baltzerstrasse 6, 3012 Bern, Switzerland
| | - Malie Lessard-Therrien
- Division of Conservation Biology, Institute of Ecology and Evolution, University of Bern, Baltzerstrasse 6, 3012 Bern, Switzerland; College of Biological Science, University of Guelph, 50 Stone Road East, Guelph, Ontario, Canada
| | - Jörg Müller
- Department of Nature Conservation, Heinz Sielmann Foundation, Unter den Kiefern 9, 14641 Wustermark, Germany
| | - Daniel Prati
- Institute of Plant Sciences, University of Bern, Altenbergrain 21, 3013 Bern, Switzerland
| | - Nora Simone Rieder
- Institute of Plant Sciences, University of Bern, Altenbergrain 21, 3013 Bern, Switzerland; Division of Conservation Biology, Institute of Ecology and Evolution, University of Bern, Baltzerstrasse 6, 3012 Bern, Switzerland
| | - Raphaël Arlettaz
- Division of Conservation Biology, Institute of Ecology and Evolution, University of Bern, Baltzerstrasse 6, 3012 Bern, Switzerland; Swiss Ornithological Institute, Valais Field Station, Rue du Rhône 11, 1950 Sion, Switzerland
| | - Markus Fischer
- Institute of Plant Sciences, University of Bern, Altenbergrain 21, 3013 Bern, Switzerland
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Zhang H, Li W, Adams HD, Wang A, Wu J, Jin C, Guan D, Yuan F. Responses of Woody Plant Functional Traits to Nitrogen Addition: A Meta-Analysis of Leaf Economics, Gas Exchange, and Hydraulic Traits. FRONTIERS IN PLANT SCIENCE 2018; 9:683. [PMID: 29875787 PMCID: PMC5974508 DOI: 10.3389/fpls.2018.00683] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 05/04/2018] [Indexed: 05/26/2023]
Abstract
Atmospheric nitrogen (N) deposition has been found to significantly affect plant growth and physiological performance in terrestrial ecosystems. Many individual studies have investigated how N addition influences plant functional traits, however these investigations have usually been limited to a single species, and thereby do not allow derivation of general patterns or underlying mechanisms. We synthesized data from 56 papers and conducted a meta-analysis to assess the general responses of 15 variables related to leaf economics, gas exchange, and hydraulic traits to N addition among 61 woody plant species, primarily from temperate and subtropical regions. Results showed that under N addition, leaf area index (+10.3%), foliar N content (+7.3%), intrinsic water-use efficiency (+3.1%) and net photosynthetic rate (+16.1%) significantly increased, while specific leaf area, stomatal conductance, and transpiration rate did not change. For plant hydraulics, N addition significantly increased vessel diameter (+7.0%), hydraulic conductance in stems/shoots (+6.7%), and water potential corresponding to 50% loss of hydraulic conductivity (P50, +21.5%; i.e., P50 became less negative), while water potential in leaves (-6.7%) decreased (became more negative). N addition had little effect on vessel density, hydraulic conductance in leaves and roots, or water potential in stems/shoots. N addition had greater effects on gymnosperms than angiosperms and ammonium nitrate fertilization had larger effects than fertilization with urea, and high levels of N addition affected more traits than low levels. Our results demonstrate that N addition has coupled effects on both carbon and water dynamics of woody plants. Increased leaf N, likely fixed in photosynthetic enzymes and pigments leads to higher photosynthesis and water use efficiency, which may increase leaf growth, as reflected in LAI results. These changes appear to have downstream effects on hydraulic function through increases in vessel diameter, which leads to higher hydraulic conductance, but lower water potential and increased vulnerability to embolism. Overall, our results suggest that N addition will shift plant function along a tradeoff between C and hydraulic economies by enhancing C uptake while simultaneously increasing the risk of hydraulic dysfunction.
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Affiliation(s)
- Hongxia Zhang
- Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Weibin Li
- State Key Laboratory of Grassland and Agro-Ecosystems, Key Laboratory of Grassland Livestock Industry Innovation, Ministry of Agriculture and Rural Affairs, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, China
| | - Henry D. Adams
- Department of Plant Biology, Ecology and Evolution, Oklahoma State University, Stillwater, OK, United States
| | - Anzhi Wang
- Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
| | - Jiabing Wu
- Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
| | - Changjie Jin
- Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
| | - Dexin Guan
- Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
| | - Fenghui Yuan
- Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, China
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15
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Izquieta-Rojano S, López-Aizpún M, Irigoyen JJ, Santamaría JM, Santamaría C, Lasheras E, Ochoa-Hueso R, Elustondo D. Eco-physiological response of Hypnum cupressiforme Hedw. to increased atmospheric ammonia concentrations in a forest agrosystem. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 619-620:883-895. [PMID: 29734634 DOI: 10.1016/j.scitotenv.2017.11.139] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 10/20/2017] [Accepted: 11/13/2017] [Indexed: 06/08/2023]
Abstract
Ammonia (NH3) emissions are linked to eutrophication, plant toxicity and ecosystem shifts from N to P limitation. Bryophytes are key components of terrestrial ecosystems, yet highly sensitive to N deposition. Hence, physiological responses of mosses may be indicative of NH3-related impacts, and thus useful to foresee future ecosystem damages and establish atmospheric Critical Levels (CLEs). In this work, samples of Hypnum cupressiforme Hedw. were seasonally collected along a well-defined NH3 concentration gradient in an oak woodland during a one-year period. We performed a comprehensive evaluation of tissue chemistry, stoichiometry, metabolic enzymes, antioxidant response, membrane damages, photosynthetic pigments, soluble protein content and N and C isotopic fractionation. Our results showed that all the physiological parameters studied (except P, K, Ca and C) responded to the NH3 gradient in predictable ways, although the magnitude and significance of the response were dependent on the sampling season, especially for enzymatic activities and pigments content. Nutritional imbalances, membrane damages and disturbance of cellular C and N metabolism were found as a consequence to NH3 exposure, being more affected the mosses more exposed to the barn atmosphere. These findings suggested significant implications of intensive farming for the correct functioning of oak woodlands and highlighted the importance of seasonal dynamics in the study of key physiological processes related to photosynthesis, mosses nutrition and responses to oxidative stress. Finally, tissue N showed the greatest potential for the identification of NH3-related ecological end points (estimated CLE=3.5μgm-3), whereas highly scattered physiological responses, although highly sensitive, were not suitable to that end.
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Affiliation(s)
- S Izquieta-Rojano
- Universidad de Navarra, Facultad de Ciencias, Departamento de Química, Laboratorio Integrado de Calidad Ambiental (LICA), Campus Universitario, Irunlarrea 1, 31008 Pamplona, Spain
| | - M López-Aizpún
- Universidad de Navarra, Facultad de Ciencias, Departamento de Química, Laboratorio Integrado de Calidad Ambiental (LICA), Campus Universitario, Irunlarrea 1, 31008 Pamplona, Spain
| | - J J Irigoyen
- Universidad de Navarra, Facultad de Ciencias, Departamento de Biología Ambiental, Campus Universitario, Irunlarrea 1, 31008 Pamplona, Spain
| | - J M Santamaría
- Universidad de Navarra, Facultad de Ciencias, Departamento de Química, Laboratorio Integrado de Calidad Ambiental (LICA), Campus Universitario, Irunlarrea 1, 31008 Pamplona, Spain.
| | - C Santamaría
- Universidad de Navarra, Facultad de Ciencias, Departamento de Química, Laboratorio Integrado de Calidad Ambiental (LICA), Campus Universitario, Irunlarrea 1, 31008 Pamplona, Spain
| | - E Lasheras
- Universidad de Navarra, Facultad de Ciencias, Departamento de Química, Laboratorio Integrado de Calidad Ambiental (LICA), Campus Universitario, Irunlarrea 1, 31008 Pamplona, Spain
| | - R Ochoa-Hueso
- Universidad Autónoma de Madrid, Departmento de Ecología, Darwin 2, 28049 Madrid, Spain
| | - D Elustondo
- Universidad de Navarra, Facultad de Ciencias, Departamento de Química, Laboratorio Integrado de Calidad Ambiental (LICA), Campus Universitario, Irunlarrea 1, 31008 Pamplona, Spain
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Ochoa-Hueso R, Mondragon-Cortés T, Concostrina-Zubiri L, Serrano-Grijalva L, Estébanez B. Nitrogen deposition reduces the cover of biocrust-forming lichens and soil pigment content in a semiarid Mediterranean shrubland. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:26172-26184. [PMID: 29103122 DOI: 10.1007/s11356-017-0482-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 10/16/2017] [Indexed: 06/07/2023]
Abstract
Biocrusts are key drivers of the structure and functioning of drylands and are very sensitive to disturbance, including atmospheric nitrogen (N) deposition. We studied the impacts of simulated N deposition on biocrust community composition and soil photosynthetic and photoprotective pigment content after five years of N application in a European semiarid Mediterranean shrubland. The experiment consisted in six experimental blocks with four plots, each receiving 0, 10, 20, or 50 kg NH4NO3-N ha-1 year-1 + 6-7 kg N ha-1 year-1 background. After 5 years of N application, total lichen cover decreased up to 50% compared to control conditions and these changes were only clearly evident when evaluated from a temporal perspective (i.e. as the percentage of change from the first survey in 2008 to the last survey in 2012). In contrast, moss cover did not change in response to N, suggesting that biocrust community alterations operate via species- and functional group-specific effects. Interestingly, between-year variations in biocrust cover tracked variations in autumnal precipitation, showing that these communities are more dynamic than previously thought. Biocrust species alterations in response to N were, however, often secondary when compared to the role of ecologically relevant drivers such as soil pH and shrub cover, which greatly determined the composition and inter-annual dynamics of the biocrust community. Similarly, cyanobacterial abundance and soil pigment concentration were greatly determined by biotic and abiotic interactions, soil pH for pigments, and organic matter content and shrub cover for cyanobacteria. Biocrusts, and particularly the lichen component, are highly sensitive to N deposition and their responses to pollutant N can be best understood when evaluated from a temporal and multivariate perspective, including impacts mediated by interactions with biotic and abiotic drivers.
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Affiliation(s)
- Raúl Ochoa-Hueso
- Department of Ecology, Autonomous University of Madrid, 2 Darwin Street, 28049, Madrid, Spain.
| | - Tatiana Mondragon-Cortés
- Department of Biology, Botany Unit, Autonomous University of Madrid, 2 Darwin Street, 28049, Madrid, Spain
| | - Laura Concostrina-Zubiri
- Centre for Ecology, Evolution and Environmental Changes (CE3C), Faculdade de Ciências, Universidade de Lisboa, Campo Grande, Bloco C2, 6° Piso, Sala 11, 1749-016, Lisbon, Portugal
| | - Lilia Serrano-Grijalva
- Department of Ecology, Autonomous University of Madrid, 2 Darwin Street, 28049, Madrid, Spain
| | - Belén Estébanez
- Department of Biology, Botany Unit, Autonomous University of Madrid, 2 Darwin Street, 28049, Madrid, Spain
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17
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Shi XM, Song L, Liu WY, Lu HZ, Qi JH, Li S, Chen X, Wu JF, Liu S, Wu CS. Epiphytic bryophytes as bio-indicators of atmospheric nitrogen deposition in a subtropical montane cloud forest: Response patterns, mechanism, and critical load. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2017; 229:932-941. [PMID: 28784334 DOI: 10.1016/j.envpol.2017.07.077] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 07/18/2017] [Accepted: 07/19/2017] [Indexed: 06/07/2023]
Abstract
Increasing trends of atmospheric nitrogen (N) deposition due to pollution and land-use changes are dramatically altering global biogeochemical cycles. Bryophytes, which are extremely vulnerable to N deposition, often play essential roles in these cycles by contributing to large nutrient pools in boreal and montane forest ecosystems. To interpret the sensitivity of epiphytic bryophytes for N deposition and to determine their critical load (CL) in a subtropical montane cloud forest, community-level, physiological and chemical responses of epiphytic bryophytes were tested in a 2-year field experiment of N additions. The results showed a significant decrease in the cover of the bryophyte communities at an N addition level of 7.4 kg ha-1 yr-1, which is consistent with declines in the biomass production, vitality, and net photosynthetic rate responses of two dominant bryophyte species. Given the background N deposition rate of 10.5 kg ha-1yr-1 for the study site, a CL of N deposition is therefore estimated as ca. 18 kg N ha-1 yr-1. A disordered cellular carbon (C) metabolism, including photosynthesis inhibition and ensuing chlorophyll degradation, due to the leakage of magnesium and potassium and corresponding downstream effects, along with direct toxic effects of excessive N additions is suggested as the main mechanism driving the decline of epiphytic bryophytes. Our results confirmed the process of C metabolism and the chemical stability of epiphytic bryophytes are strongly influenced by N addition levels; when coupled to the strong correlations found with the loss of bryophytes, this study provides important and timely evidence on the response mechanisms of bryophytes in an increasingly N-polluted world. In addition, this study underlines a general decline in community heterogeneity and biomass production of epiphytic bryophytes induced by increasing N deposition.
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Affiliation(s)
- Xian-Meng Shi
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan 650223, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Liang Song
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan 650223, PR China.
| | - Wen-Yao Liu
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan 650223, PR China
| | - Hua-Zheng Lu
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan 650223, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Jin-Hua Qi
- Ailaoshan Station for Subtropical Forest Ecosystem Studies, Jingdong 676209, PR China
| | - Su Li
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan 650223, PR China
| | - Xi Chen
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan 650223, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Jia-Fu Wu
- Yunnan Provincial Appraisal Center for Environmental Engineering, Kunming, Yunnan 650032, PR China
| | - Shuai Liu
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan 650223, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Chuan-Sheng Wu
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan 650223, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China; Ailaoshan Station for Subtropical Forest Ecosystem Studies, Jingdong 676209, PR China
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18
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Liu BY, Lei CY, Liu WQ. Nitrogen Addition Exacerbates the Negative Effects of Low Temperature Stress on Carbon and Nitrogen Metabolism in Moss. FRONTIERS IN PLANT SCIENCE 2017; 8:1328. [PMID: 28824666 PMCID: PMC5539086 DOI: 10.3389/fpls.2017.01328] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Accepted: 07/14/2017] [Indexed: 06/01/2023]
Abstract
Global environmental changes are leading to an increase in localized abnormally low temperatures and increasing nitrogen (N) deposition is a phenomenon recognized worldwide. Both low temperature stress (LTS) and excess N induce oxidative stress in plants, and excess N also reduces their resistance to LTS. Mosses are primitive plants that are generally more sensitive to alterations in environmental factors than vascular species. To study the combined effects of N deposition and LTS on carbon (C) and N metabolism in moss, two moss species, Pogonatum cirratum subsp. fuscatum, and Hypnum plumaeforme, exposed to various concentrations of nitrate (KNO3) or ammonium (NH4Cl), were treated with or without LTS. C/N metabolism indices were then monitored, both immediately after the stress and after a short recovery period (10 days). LTS decreased the photosystem II (PSII) performance index and inhibited non-cyclic photophosphorylation, ribulose-1,5-bisphosphate carboxylase, and glutamine synthetase activities, indicating damage to PSII and reductions in C/N assimilation in these mosses. LTS did not affect cyclic photophosphorylation, sucrose synthase, sucrose-phosphate synthase, and NADP-isocitrate dehydrogenase activities, suggesting a certain level of energy and C skeleton generation were maintained in the mosses to combat LTS; however, LTS inhibited the activity of glycolate oxidase. As predicted, N supply increased the sensitivity of the mosses to LTS, resulting in greater damage to PSII and a sharper decrease in C/N assimilation. After the recovery period, the performance of PSII and C/N metabolism, which were inhibited by LTS increased significantly, and were generally higher than those of control samples not exposed to LTS, suggesting overcompensation effects; however, N application reduced the extent of compensation effects. Both C and N metabolism exhibited stronger compensation effects in H. plumaeforme than in P. cirratum subsp. fuscatum. The difference was especially pronounced after addition of N, indicating that H. plumaeforme may be more resilient to temperature and N variation, which could explain its wider distribution in the natural environment.
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Affiliation(s)
- Bin-Yang Liu
- Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen UniversityGuangzhou, China
- State Key Laboratory of Vegetation and Environment Change, Institute of Botany, Chinese Academy of SciencesBeijing, China
| | - Chun-Yi Lei
- Department of Scientific Research and Education, Heishiding Nature ReserveZhaoqing, China
| | - Wei-Qiu Liu
- Guangdong Key Laboratory of Plant Resources, School of Life Sciences, Sun Yat-sen UniversityGuangzhou, China
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19
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Virtanen R, Eskelinen A, Harrison S. Comparing the responses of bryophytes and short‐statured vascular plants to climate shifts and eutrophication. Funct Ecol 2016. [DOI: 10.1111/1365-2435.12788] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Risto Virtanen
- Department of Ecology University of Oulu PO Box 3000 FI‐90014 Oulu Finland
- Department of Physiological Diversity Helmholtz Center for Environmental Research – UFZ Permoserstr. 15 Leipzig04318 Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐Leipzig Deutscher Platz 5e LeipzigD‐04103 Germany
| | - Anu Eskelinen
- Department of Ecology University of Oulu PO Box 3000 FI‐90014 Oulu Finland
- Department of Physiological Diversity Helmholtz Center for Environmental Research – UFZ Permoserstr. 15 Leipzig04318 Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐Leipzig Deutscher Platz 5e LeipzigD‐04103 Germany
- Department of Environmental Science and Policy University of California One Shields Avenue Davis CA95616 USA
| | - Susan Harrison
- Department of Environmental Science and Policy University of California One Shields Avenue Davis CA95616 USA
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Liu B, Lei C, Jin J, Guan Y, Li S, Zhang Y, Liu W. Physiological responses of two moss species to the combined stress of water deficit and elevated N deposition (II): Carbon and nitrogen metabolism. Ecol Evol 2016; 6:7596-7609. [PMID: 30128114 PMCID: PMC6093146 DOI: 10.1002/ece3.2521] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 08/30/2016] [Accepted: 09/04/2016] [Indexed: 11/08/2022] Open
Abstract
Nitrogen (N) deposition levels and frequencies of extreme drought events are increasing globally. In efforts to improve understanding of plants' responses to associated stresses, we have investigated responses of mosses to drought under elevated nitrogen conditions. More specifically, we exposed Pogonatum cirratum subsp. fuscatum and Hypnum plumaeforme to various nitrate (KNO 3) or ammonium (NH 4Cl) treatments, with and without water deficit stress and monitored indices related to carbon (C) and N metabolism both immediately after the stress and after a short recovery period. The results show that N application stimulated both C and N assimilation activities, including ribulose-1,5-bisphosphate carboxylase, glutamine synthetase/glutamate synthase (GS/GOGAT), and glutamate dehydrogenase (GDH) activities, while water deficit inhibited C and N assimilation. The mosses could resist stress caused by excess N and water deficit by increasing their photorespiration activity and proline (Pro) contents. However, N supply increased their sensitivity to water stress, causing sharper reductions in C and N assimilation rates, and further increases in photorespiration and Pro contents, indicating more serious oxidative or osmotic stress in the mosses. In addition, there were interspecific differences in N assimilation pathways, as the GS/GOGAT and GDH pathways were the preferentially used ammonium assimilation pathways in P. cirratum and H. plumaeforme when stressed, respectively. After rehydration, both mosses exhibited overcompensation effects for most C and N assimilation activities, but when supplied with N, the activities were generally restored to previous levels (or less), indicating that N supply reduced their ability to recover from water deficit stress. In conclusion, mosses can tolerate a certain degree of water deficit stress and possess some resilience to environmental fluctuations, but elevated N deposition reduces their tolerance and ability to recover.
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Affiliation(s)
- Bin‐yang Liu
- Guangdong Key Laboratory of Plant ResourcesSchool of Life SciencesSun Yat‐sen UniversityGuangzhouChina
- The State Key Laboratory of Vegetation and Environment ChangeInstitute of BotanyThe Chinese Academy of SciencesBeijingChina
| | - Chun‐yi Lei
- Heishiding Nature Reserve of Guangdong ProvinceZhaoqingChina
| | - Jian‐hua Jin
- Guangdong Key Laboratory of Plant ResourcesSchool of Life SciencesSun Yat‐sen UniversityGuangzhouChina
| | - Yi‐yun Guan
- Guangdong Key Laboratory of Plant ResourcesSchool of Life SciencesSun Yat‐sen UniversityGuangzhouChina
| | - Shan Li
- Guangdong Key Laboratory of Plant ResourcesSchool of Life SciencesSun Yat‐sen UniversityGuangzhouChina
| | - Yi‐shun Zhang
- Guangdong Key Laboratory of Plant ResourcesSchool of Life SciencesSun Yat‐sen UniversityGuangzhouChina
| | - Wei‐qiu Liu
- Guangdong Key Laboratory of Plant ResourcesSchool of Life SciencesSun Yat‐sen UniversityGuangzhouChina
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Chen X, Liu WY, Song L, Li S, Wu Y, Shi XM, Huang JB, Wu CS. Physiological Responses of Two Epiphytic Bryophytes to Nitrogen, Phosphorus and Sulfur Addition in a Subtropical Montane Cloud Forest. PLoS One 2016; 11:e0161492. [PMID: 27560190 PMCID: PMC4999294 DOI: 10.1371/journal.pone.0161492] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 08/05/2016] [Indexed: 11/19/2022] Open
Abstract
Atmospheric depositions pose significant threats to biodiversity and ecosystem function. However, the underlying physiological mechanisms are not well understood, and few studies have considered the combined effects and interactions of multiple pollutants. This in situ study explored the physiological responses of two epiphytic bryophytes to combined addition of nitrogen, phosphorus and sulfur. We investigated the electrical conductivity (EC), total chlorophyll concentration (Chl), nutrient stoichiometry and chlorophyll fluorescence signals in a subtropical montane cloud forest in south-west China. The results showed that enhanced fertilizer additions imposed detrimental effects on bryophytes, and the combined enrichment of simulated fertilization exerted limited synergistic effects in their natural environments. On the whole, EC, Chl, the effective quantum yield of photosystem II (ΦPSII) and photochemical quenching (qP) were the more reliable indicators of increased artificial fertilization. However, conclusions on nutrient stoichiometry should be drawn cautiously concerning the saturation uptake and nutrient interactions in bryophytes. Finally, we discuss the limitations of prevailing fertilization experiments and emphasize the importance of long-term data available for future investigations.
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Affiliation(s)
- Xi Chen
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Wen-yao Liu
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, China
| | - Liang Song
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, China
| | - Su Li
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, China
| | - Yi Wu
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Xian-meng Shi
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Jun-biao Huang
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Chuan-sheng Wu
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, China
- University of Chinese Academy of Sciences, Beijing, China
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22
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Song L, Lu HZ, Xu XL, Li S, Shi XM, Chen X, Wu Y, Huang JB, Chen Q, Liu S, Wu CS, Liu WY. Organic nitrogen uptake is a significant contributor to nitrogen economy of subtropical epiphytic bryophytes. Sci Rep 2016; 6:30408. [PMID: 27460310 PMCID: PMC4961951 DOI: 10.1038/srep30408] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Accepted: 07/05/2016] [Indexed: 11/20/2022] Open
Abstract
Without any root contact with the soil, epiphytic bryophytes must experience and explore poor, patchy, and heterogeneous habitats; while, the nitrogen (N) uptake and use strategies of these organisms remain uncharacterized, which obscures their roles in the N cycle. To investigate the N sources, N preferences, and responses to enhanced N deposition in epiphytic bryophytes, we carried out an in situ manipulation experiment via the (15)N labelling technique in an Asian cloud forest. Epiphytic bryophytes obtained more N from air deposition than from the bark, but the contribution of N from the bark was non-negligible. Glycine accounted for 28.4% to 44.5% of the total N in bryophyte tissue, which implies that organic N might serve as an important N source. Increased N deposition increased the total N uptake, but did not alter the N preference of the epiphytic bryophytes. This study provides sound evidence that epiphytic bryophytes could take up N from the bark and wet deposition in both organic and inorganic N forms. It is thus important to consider organic N and bark N sources, which were usually neglected, when estimating the role of epiphytic bryophytes in N cycling and the impacts of N deposition on epiphytic bryophytes in cloud forests.
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Affiliation(s)
- Liang Song
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan 650223, P. R. China
| | - Hua-Zheng Lu
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan 650223, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Xing-Liang Xu
- Key Laboratory of Ecosystem Network Observation and Modelling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, P. R. China
| | - Su Li
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan 650223, P. R. China
| | - Xian-Meng Shi
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan 650223, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Xi Chen
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan 650223, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Yi Wu
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan 650223, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Jun-Biao Huang
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan 650223, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Quan Chen
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan 650223, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Shuai Liu
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan 650223, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Chuan-Sheng Wu
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan 650223, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
- Ailaoshan Station for Subtropical Forest Ecosystem Studies, Jingdong 676209, P. R. China
| | - Wen-Yao Liu
- Key Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, Yunnan 650223, P. R. China
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23
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Welch D. The floristic changes of Scottish moorland dominated by heather (Calluna vulgaris, Ericaceae) but unburnt for 50 years and kept checked by moderate grazing. ACTA ACUST UNITED AC 2016. [DOI: 10.1080/20423489.2016.1178061] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- D. Welch
- Centre for Ecology & Hydrology, Edinburgh Research Station, Bush Estate, Penicuik, Midlothian, EH26 0QB, UK
- East Fernbank, Woodside Road, Banchory, Kincardineshire AB31 5XL, Scotland, UK
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24
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Varela Z, García-Seoane R, Arróniz-Crespo M, Carballeira A, Fernández JA, Aboal JR. Evaluation of the use of moss transplants (Pseudoscleropodium purum) for biomonitoring different forms of air pollutant nitrogen compounds. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2016; 213:841-849. [PMID: 27038571 DOI: 10.1016/j.envpol.2016.03.056] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2016] [Revised: 03/19/2016] [Accepted: 03/21/2016] [Indexed: 06/05/2023]
Abstract
We investigated whether three different types of moss transplants (devitalized moss bags with and without cover and auto-irrigated moss transplants) are suitable for use as biomonitors of the deposition of oxidised and/or reduced forms of N. For this purpose, we determined whether the concentration of atmospheric NO2 was related to the % N, δ(15)N and the activity of the enzyme biomarkers phosphomonoesterase (PME) and nitrate reductase (NR) in the tissues of moss transplants. We exposed the transplants in 5 different environments of Galicia (NW Spain) and Cataluña (NE Spain): industrial environments, urban and periurban environments, the surroundings of a cattle farm and in a monitoring site included in the sampling network of the European Monitoring Programme. The results showed that the moss in the auto-irrigated transplants was able of incorporating the N in its tissues because it was metabolically active, whereas in devitalized moss bags transplants, moss simply intercepts physically the N compounds that reached it in particulate or gaseous form. In addition, this devitalization could limit the capacity of moss to capture gaseous compounds (i.e. reduced N) and to reduce the oxidised compounds that reach the specimens. These findings indicate that devitalized moss transplants cannot be used to monitor either oxidised or reduced N compounds, whereas transplants of metabolically active moss can be used for this purpose. Finally, the NR and PME biomarkers should be used with caution because of the high variability in their activities and the limits of quantification should be evaluated in each case.
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Affiliation(s)
- Z Varela
- Área de Ecología, Facultad de Biología, Campus Vida, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain.
| | - R García-Seoane
- Área de Ecología, Facultad de Biología, Campus Vida, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain
| | - M Arróniz-Crespo
- School of Environment, Natural Resources and Geography, Deniol Road, Bangor, Gwynedd, LL572UN, United Kingdom
| | - A Carballeira
- Área de Ecología, Facultad de Biología, Campus Vida, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain
| | - J A Fernández
- Área de Ecología, Facultad de Biología, Campus Vida, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain
| | - J R Aboal
- Área de Ecología, Facultad de Biología, Campus Vida, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain
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25
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Zhang Y, Zhou X, Yin B, Downing A. Sensitivity of the xerophytic moss Syntrichia caninervis to prolonged simulated nitrogen deposition. ANNALS OF BOTANY 2016; 117:1153-61. [PMID: 27085182 PMCID: PMC4904175 DOI: 10.1093/aob/mcw058] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Revised: 11/29/2015] [Accepted: 02/18/2016] [Indexed: 05/09/2023]
Abstract
BACKGROUND AND AIMS Biological soil crusts, comprising assemblages of cyanobacteria, fungi, lichens and mosses, are common in dryland areas and are important elements in these ecosystems. Increasing N deposition has led to great changes in community structure and function in desert ecosystems worldwide. However, it is unclear how moss crusts respond to increased atmospheric N deposition, especially in terms of growth and physiological parameters. The aim of this study was to understand how Syntrichia caninervis, a dominant species in moss crusts in many northern hemisphere desert ecosystems, responds to added N. METHODS The population and shoot growth, and physiological responses of S. caninervis to six different doses of simulated N deposition (0, 0·3, 0·5, 1·0, 1·5 and 3·0 g N m(-2) year(-1)) were studied over a 3 year period. KEY RESULTS Low amounts of added N increased shoot length and leaf size, whereas high doses reduced almost all growth parameters. Moss shoot density increased, but population biomass decreased with high N. Low N augmented chlorophyll b, total chlorophyll content and soluble protein concentrations, but not chlorophyll a or chlorophyll fluorescence. High N was detrimental to all these indices. Soluble sugar concentration declined with increased N, but proline concentration was not affected significantly. Antioxidant enzyme activities generally decreased with low N additions and increased with high doses of simulated N deposition. CONCLUSIONS Low amounts of added N (0-0·5 g N m(-2) year(-1)) may enhance moss growth and vitality, while higher amounts have detrimental effects.
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Affiliation(s)
- Yuanming Zhang
- Xinjiang Institute of Ecology and Geography, Key Laboratory of Biogeography and Bioresource in Arid Land, Chinese Academy of Sciences, Urumqi 830011, China
| | - Xiaobing Zhou
- Xinjiang Institute of Ecology and Geography, Key Laboratory of Biogeography and Bioresource in Arid Land, Chinese Academy of Sciences, Urumqi 830011, China
| | - Benfeng Yin
- Xinjiang Institute of Ecology and Geography, Key Laboratory of Biogeography and Bioresource in Arid Land, Chinese Academy of Sciences, Urumqi 830011, China State Key Laboratory of Earth Surface Processes and Resource Ecology, College of life sciences of Beijing Normal University, Beijing 100875, China
| | - Alison Downing
- Department of Biological Sciences, Macquarie University, NSW 2109, Australia
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26
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Zong S, Jin Y, Xu J, Wu Z, He H, Du H, Wang L. Nitrogen deposition but not climate warming promotes Deyeuxia angustifolia encroachment in alpine tundra of the Changbai Mountains, Northeast China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 544:85-93. [PMID: 26657251 DOI: 10.1016/j.scitotenv.2015.11.144] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Revised: 11/26/2015] [Accepted: 11/26/2015] [Indexed: 06/05/2023]
Abstract
Vegetation in the alpine tundra area of the Changbai Mountains, one of two alpine tundra areas in China, has undergone great changes in recent decades. The aggressive herb species Deyeuxia angustifolia (Komarov) Y. L. Chang, a narrow-leaf small reed, was currently encroaching upon the alpine landscape and threatening tundra biota. The alpine tundra of the Changbai Mountains has been experiencing a warmer climate and receiving a high load of atmospheric nitrogen deposition. In this study, we aimed to assess the respective roles of climate warming and atmospheric nitrogen deposition in promoting the upward encroachment of D. angustifolia. We conducted experiments for three years to examine the response of D. angustifolia and a native alpine shrub, Rhododendron chrysanthum, to the conditions in which temperature and nitrogen were increased. Treatments consisting of temperature increase, nitrogen addition, temperature increase combined with nitrogen addition, and controls were conducted on the D. angustifolia communities with three encroachment levels (low, medium, and high levels). Results showed that 1) D. angustifolia grew in response to added nutrients but did not grow well when temperature increased. R. chrysanthum showed negligible responses to the simulated environmental changes. 2) Compared to R. chrysanthum, D. angustifolia could effectively occupy the above-ground space by increasing tillers and growing rapidly by efficiently using nitrogen. The difference in nitrogen uptake abilities between the two species contributed to expansion of D. angustifolia. 3) D. angustifolia encroachment could deeply change the biodiversity of tundra vegetation and may eventually result in the replacement of native biota, especially with nitrogen addition. Our research indicated that nutrient perturbation may be more important than temperature perturbation in promoting D. angustifolia encroachment upon the nutrient- and species-poor alpine tundra ecosystem in the Changbai Mountains.
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Affiliation(s)
- Shengwei Zong
- School of Geographical Sciences, Northeast Normal University, 130024 Changchun, China
| | - Yinghua Jin
- School of Geographical Sciences, Northeast Normal University, 130024 Changchun, China
| | - Jiawei Xu
- School of Geographical Sciences, Northeast Normal University, 130024 Changchun, China.
| | - Zhengfang Wu
- School of Geographical Sciences, Northeast Normal University, 130024 Changchun, China
| | - Hongshi He
- School of Geographical Sciences, Northeast Normal University, 130024 Changchun, China; School of Natural Resources, University of Missouri, Columbia, MO, USA
| | - Haibo Du
- School of Geographical Sciences, Northeast Normal University, 130024 Changchun, China
| | - Lei Wang
- School of Geographical Sciences, Northeast Normal University, 130024 Changchun, China
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27
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Stevens CJ, Payne RJ, Kimberley A, Smart SM. How will the semi-natural vegetation of the UK have changed by 2030 given likely changes in nitrogen deposition? ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2016; 208:879-89. [PMID: 26439678 DOI: 10.1016/j.envpol.2015.09.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 09/02/2015] [Indexed: 05/22/2023]
Abstract
Nitrogen deposition is known to have major impacts on contemporary ecosystems but few studies have addressed how these impacts will develop over coming decades. We consider likely changes to British semi-natural vegetation up to the year 2030 both qualitatively, based on knowledge of species responses from experimental and gradient studies, and quantitatively, based on modelling of species relationships in national monitoring data. We used historical N deposition trends and national predictions of changing deposition to calculate cumulative deposition from 1900 to 2030. Data from the Countryside Survey (1978, 1990 and 1998) was used to parameterise models relating cumulative N deposition to Ellenberg N which were then applied to expected future deposition trends. Changes to habitat suitability for key species of grassland, heathland and bog, and broadleaved woodland to 2030 were predicted using the MultiMOVE model. In UK woodlands by 2030 there is likely to be reduced occurrence of lichens, increased grass cover and a shift towards more nitrophilic vascular plant species. In grasslands we expect changing species composition with reduced occurrence of terricolous lichens and, at least in acid grasslands, reduced species richness. In heaths and bogs we project overall reductions in species richness with decreased occurrence of terricolous lichens and some bryophytes, reduced cover of dwarf shrubs and small increases in grasses. Our study clearly suggests that changes in vegetation due to nitrogen deposition are likely to continue through coming decades.
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Affiliation(s)
- Carly J Stevens
- Lancaster Environment Centre, Lancaster University, Bailrigg, Lancaster LA1 4QQ, UK.
| | - Richard J Payne
- Environment Department, University of York, Heslington, York YO10 5DD, UK
| | - Adam Kimberley
- Lancaster Environment Centre, Lancaster University, Bailrigg, Lancaster LA1 4QQ, UK; Centre for Ecology & Hydrology, Lancaster Environment Centre, Bailrigg, Lancaster LA1 4AP, UK
| | - Simon M Smart
- Centre for Ecology & Hydrology, Lancaster Environment Centre, Bailrigg, Lancaster LA1 4AP, UK
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28
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Wipf S, Sommerkorn M, Stutter MI, Wubs ERJ, van der Wal R. Snow cover, freeze-thaw, and the retention of nutrients in an oceanic mountain ecosystem. Ecosphere 2015. [DOI: 10.1890/es15-00099.1] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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29
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Pescott OL, Simkin JM, August TA, Randle Z, Dore AJ, Botham MS. Air pollution and its effects on lichens, bryophytes, and lichen-feeding Lepidoptera: review and evidence from biological records. Biol J Linn Soc Lond 2015. [DOI: 10.1111/bij.12541] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Oliver L. Pescott
- Centre for Ecology & Hydrology; Maclean Building Benson Lane Crowmarsh Gifford Wallingford Oxfordshire OX10 8BB UK
| | - Janet M. Simkin
- Department of Life Sciences; Natural History Museum; The British Lichen Society; c/o Lichen Herbarium Cromwell Road London SW7 5BD UK
| | - Tom A. August
- Centre for Ecology & Hydrology; Maclean Building Benson Lane Crowmarsh Gifford Wallingford Oxfordshire OX10 8BB UK
| | - Zoe Randle
- Butterfly Conservation; Wareham Dorset BH20 5QP UK
| | - Anthony J. Dore
- Centre for Ecology & Hydrology; Bush Estate Penicuik Midlothian EH26 0QB UK
| | - Marc S. Botham
- Centre for Ecology & Hydrology; Maclean Building Benson Lane Crowmarsh Gifford Wallingford Oxfordshire OX10 8BB UK
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30
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Vegetation Composition in Bogs is Sensitive to Both Load and Concentration of Deposited Nitrogen: A Modeling Analysis. Ecosystems 2014. [DOI: 10.1007/s10021-014-9820-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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31
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Harmens H, Schnyder E, Thöni L, Cooper DM, Mills G, Leblond S, Mohr K, Poikolainen J, Santamaria J, Skudnik M, Zechmeister HG, Lindroos AJ, Hanus-Illnar A. Relationship between site-specific nitrogen concentrations in mosses and measured wet bulk atmospheric nitrogen deposition across Europe. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2014; 194:50-59. [PMID: 25094057 DOI: 10.1016/j.envpol.2014.07.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Revised: 07/03/2014] [Accepted: 07/09/2014] [Indexed: 06/03/2023]
Abstract
To assess the relationship between nitrogen concentrations in mosses and wet bulk nitrogen deposition or concentrations in precipitation, moss tissue and deposition were sampled within a distance of 1 km of each other in seven European countries. Relationships for various forms of nitrogen appeared to be asymptotic, with data for different countries being positioned at different locations along the asymptotic relationship and saturation occurring at a wet bulk nitrogen deposition of ca. 20 kg N ha(-1) yr(-1). The asymptotic behaviour was more pronounced for ammonium-N than nitrate-N, with high ammonium deposition at German sites being most influential in providing evidence of the asymptotic behaviour. Within countries, relationships were only significant for Finland and Switzerland and were more or less linear. The results confirm previous relationships described for modelled total deposition. Nitrogen concentration in mosses can be applied to identify areas at risk of high nitrogen deposition at European scale.
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Affiliation(s)
- Harry Harmens
- Centre for Ecology and Hydrology, Environment Centre Wales, Deiniol Road, Bangor, Gwynedd LL57 2UW, UK.
| | - Elvira Schnyder
- FUB-Research Group for Environmental Monitoring, Alte Jonastrasse 83, CH-8640 Rapperswil, Switzerland (1)
| | - Lotti Thöni
- FUB-Research Group for Environmental Monitoring, Alte Jonastrasse 83, CH-8640 Rapperswil, Switzerland (1)
| | - David M Cooper
- Centre for Ecology and Hydrology, Environment Centre Wales, Deiniol Road, Bangor, Gwynedd LL57 2UW, UK.
| | - Gina Mills
- Centre for Ecology and Hydrology, Environment Centre Wales, Deiniol Road, Bangor, Gwynedd LL57 2UW, UK.
| | - Sébastien Leblond
- Muséum National d'Histoire Naturelle, 57 rue Cuvier, Case 39, 75005 Paris, France.
| | - Karsten Mohr
- Landwirtschaftskammer Niedersachsen, Mars-la-Tour Str. 1-13, 26121 Oldenburg, Germany.
| | - Jarmo Poikolainen
- Finnish Forest Research Institute, P.O. Box 413, FI-90014 University of Oulu, Finland.
| | | | - Mitja Skudnik
- Slovenian Forestry Institute, Vecna pot 2, 1000 Ljubljana, Slovenia.
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32
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Ochoa-Hueso R, Arróniz-Crespo M, Bowker MA, Maestre FT, Pérez-Corona ME, Theobald MR, Vivanco MG, Manrique E. Biogeochemical indicators of elevated nitrogen deposition in semiarid Mediterranean ecosystems. ENVIRONMENTAL MONITORING AND ASSESSMENT 2014; 186:5831-42. [PMID: 24894911 PMCID: PMC4427508 DOI: 10.1007/s10661-014-3822-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Accepted: 05/09/2014] [Indexed: 05/24/2023]
Abstract
Nitrogen (N) deposition has doubled the natural N inputs received by ecosystems through biological N fixation and is currently a global problem that is affecting the Mediterranean regions. We evaluated the existing relationships between increased atmospheric N deposition and biogeochemical indicators related to soil chemical factors and cryptogam species across semiarid central, southern, and eastern Spain. The cryptogam species studied were the biocrust-forming species Pleurochaete squarrosa (moss) and Cladonia foliacea (lichen). Sampling sites were chosen in Quercus coccifera (kermes oak) shrublands and Pinus halepensis (Aleppo pine) forests to cover a range of inorganic N deposition representative of the levels found in the Iberian Peninsula (between 4.4 and 8.1 kg N ha(-1) year(-1)). We extended the ambient N deposition gradient by including experimental plots to which N had been added for 3 years at rates of 10, 20, and 50 kg N ha(-1) year(-1). Overall, N deposition (extant plus simulated) increased soil inorganic N availability and caused soil acidification. Nitrogen deposition increased phosphomonoesterase (PME) enzyme activity and PME/nitrate reductase (NR) ratio in both species, whereas the NR activity was reduced only in the moss. Responses of PME and NR activities were attributed to an induced N to phosphorus imbalance and to N saturation, respectively. When only considering the ambient N deposition, soil organic C and N contents were positively related to N deposition, a response driven by pine forests. The PME/NR ratios of the moss were better predictors of N deposition rates than PME or NR activities alone in shrublands, whereas no correlation between N deposition and the lichen physiology was observed. We conclude that integrative physiological measurements, such as PME/NR ratios, measured on sensitive species such as P. squarrosa, can provide useful data for national-scale biomonitoring programs, whereas soil acidification and soil C and N storage could be useful as additional corroborating ecosystem indicators of chronic N pollution.
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Affiliation(s)
- Raúl Ochoa-Hueso
- Hawkesbury Institute for the Environment, University of Western Sydney, Locked Bag 1797, Penrith, New South Wales, 2751, Australia,
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Fritz C, Lamers LPM, Riaz M, van den Berg LJL, Elzenga TJTM. Sphagnum mosses--masters of efficient N-uptake while avoiding intoxication. PLoS One 2014; 9:e79991. [PMID: 24416125 PMCID: PMC3886977 DOI: 10.1371/journal.pone.0079991] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Accepted: 10/01/2013] [Indexed: 11/29/2022] Open
Abstract
Peat forming Sphagnum mosses are able to prevent the dominance of vascular plants under ombrotrophic conditions by efficiently scavenging atmospherically deposited nitrogen (N). N-uptake kinetics of these mosses are therefore expected to play a key role in differential N availability, plant competition, and carbon sequestration in Sphagnum peatlands. The interacting effects of rain N concentration and exposure time on moss N-uptake rates are, however, poorly understood. We investigated the effects of N-concentration (1, 5, 10, 50, 100, 500 µM), N-form ((15)N-ammonium or nitrate) and exposure time (0.5, 2, 72 h) on uptake kinetics for Sphagnum magellanicum from a pristine bog in Patagonia (Argentina) and from a Dutch bog exposed to decades of N-pollution. Uptake rates for ammonium were higher than for nitrate, and N-binding at adsorption sites was negligible. During the first 0.5 h, N-uptake followed saturation kinetics revealing a high affinity (Km 3.5-6.5 µM). Ammonium was taken up 8 times faster than nitrate, whereas over 72 hours this was only 2 times. Uptake rates decreased drastically with increasing exposure times, which implies that many short-term N-uptake experiments in literature may well have overestimated long-term uptake rates and ecosystem retention. Sphagnum from the polluted site (i.e. long-term N exposure) showed lower uptake rates than mosses from the pristine site, indicating an adaptive response. Sphagnum therefore appears to be highly efficient in using short N pulses (e.g. rainfall in pristine areas). This strategy has important ecological and evolutionary implications: at high N input rates, the risk of N-toxicity seems to be reduced by lower uptake rates of Sphagnum, at the expense of its long-term filter capacity and related competitive advantage over vascular plants. As shown by our conceptual model, interacting effects of N-deposition and climate change (changes in rainfall) will seriously alter the functioning of Sphagnum peatlands.
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Affiliation(s)
- Christian Fritz
- Department of Aquatic Ecology and Environmental Biology, Radboud University Nijmegen, Nijmegen, The Netherlands
- Centre for Energy and Environmental Studies, University of Groningen, Groningen, The Netherlands
| | - Leon P. M. Lamers
- Department of Aquatic Ecology and Environmental Biology, Radboud University Nijmegen, Nijmegen, The Netherlands
| | - Muhammad Riaz
- Department of Environmental Science, GC University, Faisalabad, Pakistan
- Environment Department, University of York, York, United Kingdom
| | - Leon J. L. van den Berg
- Department of Aquatic Ecology and Environmental Biology, Radboud University Nijmegen, Nijmegen, The Netherlands
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Liu XY, Koba K, Makabe A, Li XD, Yoh M, Liu CQ. Ammonium first: natural mosses prefer atmospheric ammonium but vary utilization of dissolved organic nitrogen depending on habitat and nitrogen deposition. THE NEW PHYTOLOGIST 2013; 199:407-419. [PMID: 23692546 DOI: 10.1111/nph.12284] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Accepted: 03/18/2013] [Indexed: 05/03/2023]
Abstract
Mosses, among all types of terrestrial vegetation, are excellent scavengers of anthropogenic nitrogen (N), but their utilization of dissolved organic N (DON) and their reliance on atmospheric N remain uncharacterized in natural environments, which obscures their roles in N cycles. Natural (15) N abundance of N sources (nitrate (NO(3)(-)), ammonium (NH(4)(+)) and DON in deposition and soil) for epilithic and terricolous mosses was analyzed at sites with different N depositions at Guiyang, China. Moss NO(3)(-) assimilation was inhibited substantially by the high supply of NH(4)(+) and DON. Therefore, contributions of NH(4)(+) and DON to moss N were partitioned using isotopic mass-balance methods. The N contributions averaged 56% and 46% from atmospheric NH(4)(+), and 44% and 17% from atmospheric DON in epilithic and terricolous mosses, respectively. In terricolous mosses, soil NH(4)(+) and soil DON accounted for 16% and 21% of bulk N, which are higher than current estimations obtained using (15) N-labeling methods. Moreover, anthropogenic NH(4)(+) deposition suppressed utilization of DON and soil N because of the preference of moss for NH(4)(+) under elevated NH(4)(+) deposition. These results underscore the dominance of, and preference for, atmospheric NH(4)(+) in moss N utilization, and highlight the importance of considering DON and soil N sources when estimating moss N sequestration and the impacts of N deposition on mosses.
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Affiliation(s)
- Xue-Yan Liu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550002, China
- Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, 1838509, Japan
| | - Keisuke Koba
- Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, 1838509, Japan
| | - Akiko Makabe
- Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, 1838509, Japan
| | - Xiao-Dong Li
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550002, China
| | - Muneoki Yoh
- Institute of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, 1838509, Japan
| | - Cong-Qiang Liu
- State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang, 550002, China
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Munzi S, Paoli L, Fiorini E, Loppi S. Physiological response of the epiphytic lichen Evernia prunastri (L.) Ach. to ecologically relevant nitrogen concentrations. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2012; 171:25-29. [PMID: 22868343 DOI: 10.1016/j.envpol.2012.07.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Revised: 06/12/2012] [Accepted: 07/01/2012] [Indexed: 06/01/2023]
Abstract
This study investigated the physiological response of the epiphytic lichen Evernia prunastri to ecologically relevant concentrations of nitrogen compounds. Lichen samples were sprayed for 4 weeks either with water or 50, 150 and 500 μM NH(4)Cl. The integrity of cell membranes and chlorophyll a fluorescence emission (F(V)/F(M) and PI(ABS)) were analyzed. No membrane damage occurred after the exposure period. F(V)/F(M), a classical fluorescence indicator, decreased during the second week of treatment with 500 μM NH(4)Cl and the third week with 50 and 150 μM NH(4)Cl. PI(ABS), an overall index of the photosynthetic performance, was more sensitive and decreased already during the first week with 500 μM NH(4)Cl and the second week with 150 μM NH(4)Cl. Since E. prunastri has been exposed to ammonium loads corresponding to real environmental conditions, these findings open the way to an effective use of this species as early indicators of environmental nitrogen excess.
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Affiliation(s)
- S Munzi
- Center for Environmental Biology, University of Lisbon, Campo Grande, Bloco C2, 1749-016 Lisbon, Portugal.
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Ge J, Li J, Zhang J, Yang Z. Time-dependent oxidative stress responses of submerged macrophyte Vallisneria natans seedlings exposed to ammonia in combination with microcystin under laboratory conditions. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2012; 89:67-72. [PMID: 22484329 DOI: 10.1007/s00128-012-0633-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2011] [Accepted: 03/29/2012] [Indexed: 05/31/2023]
Abstract
We studied the antioxidant responses of macrophyte Vallisnerria natans seedlings to combined ammonia (0, 0.21, and 0.85 mg L(-1)) and microcystin-LR (MC-LR) (0, 10, and 50 μg L(-1)) for 7 days. Results showed that superoxide dismutase, catalase (CAT), peroxidase, and glutathione were significantly induced by the mixtures of ammonia and MC-LR, and there were significant interactions between ammonia and MC-LR. Specially, CAT increased about fivefold at ammonia 0.85 mg L(-1) and MC-LR 50 μg L(-1) on day 3. Malondialdehyde fluctuated with both ammonia and MC-LR, and significant interactions were detected between the two stressors. Changes in all the measured variables were time-dependent.
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Affiliation(s)
- Juan Ge
- Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210046, China
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Song L, Liu WY, Ma WZ, Qi JH. Response of epiphytic bryophytes to simulated N deposition in a subtropical montane cloud forest in southwestern China. Oecologia 2012; 170:847-56. [DOI: 10.1007/s00442-012-2341-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Accepted: 04/16/2012] [Indexed: 11/28/2022]
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Fritz C, van Dijk G, Smolders AJP, Pancotto VA, Elzenga TJTM, Roelofs JGM, Grootjans AP. Nutrient additions in pristine Patagonian Sphagnum bog vegetation: can phosphorus addition alleviate (the effects of) increased nitrogen loads. PLANT BIOLOGY (STUTTGART, GERMANY) 2012; 14:491-499. [PMID: 22221295 DOI: 10.1111/j.1438-8677.2011.00527.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Sphagnum-bog ecosystems have a limited capability to retain carbon and nutrients when subjected to increased nitrogen (N) deposition. Although it has been proposed that phosphorus (P) can dilute negative effects of nitrogen by increasing biomass production of Sphagnum mosses, it is still unclear whether P-addition can alleviate physiological N-stress in Sphagnum plants. A 3-year fertilisation experiment was conducted in lawns of a pristine Sphagnum magellanicum bog in Patagonia, where competing vascular plants were practically absent. Background wet deposition of nitrogen was low (≈ 0.1-0.2 g · N · m(-2) · year(-1)). Nitrogen (4 g · N · m(-2) · year(-1)) and phosphorus (1 g · P · m(-2) · year(-1)) were applied, separately and in combination, six times during the growing season. P-addition substantially increased biomass production of Sphagnum. Nitrogen and phosphorus changed the morphology of Sphagnum mosses by enhancing height increment, but lowering moss stem density. In contrast to expectations, phosphorus failed to alleviate physiological stress imposed by excess nitrogen (e.g. amino acid accumulation, N-saturation and decline in photosynthetic rates). We conclude that despite improving growth conditions by P-addition, Sphagnum-bog ecosystems remain highly susceptible to nitrogen additions. Increased susceptibility to desiccation by nutrients may even worsen the negative effects of excess nitrogen especially in windy climates like in Patagonia.
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Affiliation(s)
- C Fritz
- Aquatic Ecology, Institute for Water and Wetland Research, Radboud University, Nijmegen, The Netherlands.
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Stevens CJ, Manning P, van den Berg LJL, de Graaf MCC, Wamelink GWW, Boxman AW, Bleeker A, Vergeer P, Arroniz-Crespo M, Limpens J, Lamers LPM, Bobbink R, Dorland E. Ecosystem responses to reduced and oxidised nitrogen inputs in European terrestrial habitats. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2011; 159:665-76. [PMID: 21215502 DOI: 10.1016/j.envpol.2010.12.008] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2010] [Revised: 11/29/2010] [Accepted: 12/09/2010] [Indexed: 05/06/2023]
Abstract
While it is well established that ecosystems display strong responses to elevated nitrogen deposition, the importance of the ratio between the dominant forms of deposited nitrogen (NH(x) and NO(y)) in determining ecosystem response is poorly understood. As large changes in the ratio of oxidised and reduced nitrogen inputs are occurring, this oversight requires attention. One reason for this knowledge gap is that plants experience a different NH(x):NO(y) ratio in soil to that seen in atmospheric deposits because atmospheric inputs are modified by soil transformations, mediated by soil pH. Consequently species of neutral and alkaline habitats are less likely to encounter high NH(4)(+) concentrations than species from acid soils. We suggest that the response of vascular plant species to changing ratios of NH(x):NO(y) deposits will be driven primarily by a combination of soil pH and nitrification rates. Testing this hypothesis requires a combination of experimental and survey work in a range of systems.
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Affiliation(s)
- Carly J Stevens
- Department of Life Sciences, The Open University, Walton Hall, Milton Keynes MK7 6AA, UK.
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Gornall JL, Woodin SJ, Jónsdóttir IS, van der Wal R. Balancing positive and negative plant interactions: how mosses structure vascular plant communities. Oecologia 2011; 166:769-82. [DOI: 10.1007/s00442-011-1911-6] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2009] [Accepted: 01/06/2011] [Indexed: 11/29/2022]
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41
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Armitage HF, Britton AJ, Woodin SJ, van der Wal R. Assessing the recovery potential of alpine moss-sedge heath: reciprocal transplants along a nitrogen deposition gradient. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2011; 159:140-147. [PMID: 20888678 DOI: 10.1016/j.envpol.2010.09.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2010] [Revised: 09/07/2010] [Accepted: 09/09/2010] [Indexed: 05/29/2023]
Abstract
The potential of alpine moss-sedge heath to recover from elevated nitrogen (N) deposition was assessed by transplanting Racomitrium lanuginosum shoots and vegetation turfs between 10 elevated N deposition sites (8.2-32.9 kg ha(-1) yr(-1)) and a low N deposition site, Ben Wyvis (7.2 kg ha(-1) yr(-1)). After two years, tissue N of Racomitrium shoots transplanted from higher N sites to Ben Wyvis only partially equilibrated to reduced N deposition whereas reciprocal transplants almost matched the tissue N of indigenous moss. Unexpectedly, moss shoot growth was stimulated at higher N deposition sites. However, moss depth and biomass increased in turfs transplanted to Ben Wyvis, apparently due to slower shoot turnover (suggested to result partly from decreased tissue C:N slowing decomposition), whilst abundance of vascular species declined. Racomitrium heath has the potential to recover from the impacts of N deposition; however, this is constrained by the persistence of enhanced moss tissue N contents.
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Affiliation(s)
- Heather F Armitage
- Macaulay Institute, Craigiebuckler, Aberdeen AB15 8QH, UK; Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 3UU, UK.
| | | | - Sarah J Woodin
- Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen AB24 3UU, UK
| | - René van der Wal
- Aberdeen Centre for Environmental Sustainability (ACES), School of Biological Sciences, University of Aberdeen, Aberdeen AB24 3UU, UK
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Pearce ISK, Britton AJ, Armitage HF, Jones B. Additive impacts of nitrogen deposition and grazing on a mountain moss-sedge heath. ACTA ACUST UNITED AC 2010. [DOI: 10.1007/s00035-010-0075-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Vieira AR, Gonzalez C, Martins-Loução MA, Branquinho C. Intracellular and extracellular ammonium (NH4(+)) uptake and its toxic effects on the aquatic biomonitor Fontinalis antipyretica. ECOTOXICOLOGY (LONDON, ENGLAND) 2009; 18:1087-1094. [PMID: 19609671 DOI: 10.1007/s10646-009-0374-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2009] [Accepted: 06/24/2009] [Indexed: 05/28/2023]
Abstract
The objective of this work is to validate the use of the aquatic moss Fontinalis antipyretica as biomonitor of NH(4)(+) aquatic pollution. In order to achieve this objective we needed to understand the pattern of uptake of NH(4)(+) by the moss and evaluate the impact of high concentrations on its physiological performance. The cellular location of NH(4)(+) in the moss is crucial for understanding its monitoring capacity. We were able to show that a sequential elution technique, based on the use of NiCl(2) as an efficient displacing agent, allowed the quantification of the cellular location of NH(4)(+). This was done along a concentration gradient and time of exposure. The extracellular and intracellular NH(4)(+) concentrations that caused significant physiological impact in membrane permeability of F. antipyretica were the same that caused significant decreasing in the photosynthetic capacity of the same moss. The former NH(4)(+) concentration thresholds were shown to decrease with increasing exposure time. These results are important since under natural conditions lower concentration of NH(4)(+) are present in waters but for very long periods of time. The importance of applying this knowledge in biomonitoring studies to fulfil the requirements of the Water Framework Directive is discussed.
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Affiliation(s)
- Ana Rute Vieira
- Faculty of Sciences, Centre for Environmental Biology (CBA), University of Lisbon, Campo Grande, Bloco C2, Piso 5, sala 2.5.37, 1749-016, Lisbon, Portugal
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Pirintsos SA, Munzi S, Loppi S, Kotzabasis K. Do polyamines alter the sensitivity of lichens to nitrogen stress? ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2009; 72:1331-1336. [PMID: 19376578 DOI: 10.1016/j.ecoenv.2009.03.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2008] [Revised: 03/02/2009] [Accepted: 03/02/2009] [Indexed: 05/27/2023]
Abstract
The sensitivity of lichens measuring photosynthetic efficiency and polyamines as modulator of nitrogen stress tolerance was investigated. Two lichen species with a markedly different tolerance to nitrogen compounds, namely Evernia prunastri (L.) Ach. and Xanthoria parietina (L.) Th.Fr., were incubated with deionized water (control) and solutions of KNO(3), NH(4)NO(3) and (NH(4))(2)SO(4) and then exposed to different light conditions. The F(v)/F(m) parameter (maximum quantum efficiency of photosystem II) was used as stress indicator. The results showed that F(v)/F(m) values, in the produced experimental conditions, were independent from the light gradient. Photosynthetic efficiency of E. prunastri was impaired by high ammonium concentrations, while nitrate had no effect; X. parietina was hardly influenced by nitrogen compounds. External supply of polyamines reduced the sensitivity of E. prunastri, while polyamine inhibitors reduced the tolerance of X. parietina to NH(4)(+), suggesting that polyamines play an important role in modulating the sensitivity/tolerance to nitrogen stress.
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Affiliation(s)
- S A Pirintsos
- Department of Biology, University of Crete, Heraklion, Greece.
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45
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Leith ID, Mitchell RJ, Truscott AM, Cape JN, van Dijk N, Smith RI, Fowler D, Sutton MA. The influence of nitrogen in stemflow and precipitation on epiphytic bryophytes, Isothecium myosuroides Brid., Dicranum scoparium Hewd. and Thuidium tamariscinum (Hewd.) Schimp of Atlantic oakwoods. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2008; 155:237-246. [PMID: 18343004 DOI: 10.1016/j.envpol.2007.11.031] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2007] [Revised: 11/23/2007] [Accepted: 11/26/2007] [Indexed: 05/26/2023]
Abstract
The spatial relationship between the concentration and deposition of the major ions in precipitation and stemflow and their influence on the tissue nitrogen concentration of three epiphytic bryophytes on Quercus petraea (Matt) Liebl. and Q. robur L. was investigated at seven UK Atlantic oak woodland sites with a range of total N deposition of 55-250 mmol m(-2). The main driver of change in tissue N concentrations of three epiphytic bryophytes (Isothecium myosuroides Brid. (Eurhynchium myosuroides (Brid.) Schp.), Dicranum scoparium Hewd. and Thuidium tamariscinum (Hewd.) Schimp.) was total N deposition in stemflow, dominated by ammonium deposition. The three epiphytic species also showed strong relationships between tissue N concentration and total N deposition in rainfall but a poor correlation with total N ion concentration in rainfall. This study shows that epiphytic bryophytes utilise stemflow N and thus increase their risk from inputs of total N deposition compared to terricolous species at the same site.
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Affiliation(s)
- I D Leith
- Centre for Ecology and Hydrology Edinburgh, Bush Estate, Penicuik, Midlothian, EH26 0QB, UK.
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46
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Britton AJ, Fisher JM. Growth responses of low-alpine dwarf-shrub heath species to nitrogen deposition and management. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2008; 153:564-573. [PMID: 17988771 DOI: 10.1016/j.envpol.2007.09.022] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2007] [Revised: 09/05/2007] [Accepted: 09/12/2007] [Indexed: 05/25/2023]
Abstract
Nitrogen deposition is a continuing problem in European alpine regions. We hypothesised that, despite climatic limitations, low-alpine Calluna heathland would respond to nitrogen addition with increased shoot growth and flowering and that fire and grazing would modify responses. In a five-year study, 0-50kgNha(-1)y(-1) were added, combined with burning (+/-) and clipping (+/-). Calluna vulgaris responded with increased shoot extension, but effects on flowering were variable. Burning enhanced the positive effect of nitrogen addition and negative effects of clipping. Sub-dominant shrubs generally did not respond to nitrogen. C. vulgaris shoot extension was stimulated by nitrogen addition of 10kgNha(-1)y(-1) (above background) supporting suggestions that alpine heathlands are sensitive to low levels of nitrogen deposition. Increased C. vulgaris growth could negatively impact on important lichen components of this vegetation through increased shading and competition. Climatic factors constrain productivity in this community, but do not prevent rapid responses to nitrogen deposition by some species.
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Pearce ISK, Van der Wal R. Interpreting nitrogen pollution thresholds for sensitive habitats: the importance of concentration versus dose. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2008; 152:253-6. [PMID: 17614169 DOI: 10.1016/j.envpol.2007.04.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2006] [Revised: 04/17/2007] [Accepted: 04/24/2007] [Indexed: 05/16/2023]
Abstract
Nitrate and ammonium concentration in wet deposition detrimentally impacted a sensitive pollution indicator species irrespective of the nitrogen dose.
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Affiliation(s)
- I S K Pearce
- Centre for Ecology and Hydrology, Glassel, Banchory, Aberdeenshire AB31 4BY, UK.
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48
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Arróniz-Crespo M, Leake JR, Horton P, Phoenix GK. Bryophyte physiological responses to, and recovery from, long-term nitrogen deposition and phosphorus fertilisation in acidic grassland. THE NEW PHYTOLOGIST 2008; 180:864-74. [PMID: 18801005 DOI: 10.1111/j.1469-8137.2008.02617.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Atmospheric nitrogen deposition can cause major declines in bryophyte abundance yet the physiological basis for such declines is not fully understood. Bryophyte physiological responses may also be sensitive bioindicators of both the impacts of, and recovery from, N deposition. Here, responses of tissue nutrients (nitrogen (N), phosphorus (P) and potassium (K): NPK), N and P metabolism enzymes (nitrate reductase and phosphomonoesterase), photosynthetic pigments, chlorophyll fluorescence, sclerophylly and percentage cover of two common bryophytes (Pseudoscleropodium purum and Rhytidiadelphus squarrosus) to long-term (11 yr) enhanced N deposition (+3.5 and +14 g N m(-2) yr(-1)) are reported in factorial combination with P addition. Recovery of responses 22 months after treatment cessation were also assessed. Enhanced N deposition caused up to 90% loss of bryophyte cover but no recovery was observed. Phosphomonoesterase activity and tissue N:P ratios increased up to threefold in response to N loading and showed clear recovery, particularly in P. purum. Smaller responses and recovery were also seen in all chlorophyll fluorescence measurements and altered photosynthetic pigment composition. The P limitation of growth appears to be a key mechanism driving bryophyte loss along with damage to photosystem II. Physiological measurements are more sensitive than measurements of abundance as bioindicators of N deposition impact and of recovery in particular.
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Affiliation(s)
- María Arróniz-Crespo
- University of Sheffield, Department of Animal and Plant Sciences, Western Bank, Sheffield, S10 2TN, UK.
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49
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Pilkington MG, Caporn SJM, Carroll JA, Cresswell N, Lee JA, Emmett BA, Bagchi R. Phosphorus supply influences heathland responses to atmospheric nitrogen deposition. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2007; 148:191-200. [PMID: 17182158 DOI: 10.1016/j.envpol.2006.10.034] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2005] [Revised: 10/17/2006] [Accepted: 10/20/2006] [Indexed: 05/13/2023]
Abstract
On an upland moor dominated by pioneer Calluna vulgaris and with an understorey of mosses and lichens, experimental plots were treated with factorial combinations of nitrogen (N) at +0 and +20kg Nha(-1)yr(-1), and phosphorus (P) at +0 and +5kg Pha(-1)yr(-1). Over the 4-year duration of the experiment, the cover of the Calluna canopy increased in density over time as part of normal phenological development. Moss cover increased initially in response to N addition but then remained static; increases in cover in response to P addition became stronger over time, eventually causing reductions in the cover of the dominant Calluna canopy. Lichen cover virtually disappeared within 4 years in plots receiving +20kg Nha(-1)yr(-1) and also in separate plots receiving +10kg Nha(-1)yr(-1), but this effect was reversed by the addition of P.
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Affiliation(s)
- M G Pilkington
- Department of Environmental and Leisure Studies, Manchester Metropolitan University, MMU Cheshire, Crewe, Cheshire, UK.
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50
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Nimptsch J, Pflugmacher S. Ammonia triggers the promotion of oxidative stress in the aquatic macrophyte Myriophyllum mattogrossense. CHEMOSPHERE 2007; 66:708-14. [PMID: 16962634 DOI: 10.1016/j.chemosphere.2006.07.064] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2006] [Revised: 07/19/2006] [Accepted: 07/22/2006] [Indexed: 05/11/2023]
Abstract
The effect of increased ammonia content on sub-acute biochemical responses was assessed in the rooted submersed aquatic macrophyte Myriophyllum mattogrossense (common name: "Brazil Milfoil" or "Matogrosso Milfoil"), in a seven day aquarium experiment. The pH and temperature were monitored in order to determine the proportions of both ionized (NH4+) and un-ionized (NH3) forms of ammonia. Specific activities of several enzymes such as catalase (CAT), guaiacol peroxidase (POD), glutathione peroxidase (GPx) and glutathione S-transferase (GST's) were measured as well as the content of the soluble antioxidant glutathione and lipid peroxidation were determined as these parameters are considered as indicators of cell-level disorder. The results showed that ammonia is able to generate oxidative stress, expressed through an elevated GSH content and the enhancement of CAT, POD, GPx and GST's activities in treatments with elevated ammonia content. As the toxic mechanism of ammonia is a complex phenomenon, this work adds an additional point of view to explain in parts the oxidative stress generating effect of ammonia promoting oxidative stress. Additionally the different modes of action proposed by other research groups are discussed, thus trying to combine the various points of view.
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Affiliation(s)
- Jorge Nimptsch
- Leibniz-Institute of Freshwater Ecology and Inland Fisheries, RG Biochemical Regulation, Müggelseedamm 301, D-12587 Berlin, Germany
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