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Barberis D, Lombardi G, Ravetto Enri S, Pittarello M, Viglietti D, Freppaz M, Lonati M. Nitrogen fertilizer enhances vegetation establishment of a high‐altitude machine‐graded ski slope. Restor Ecol 2022. [DOI: 10.1111/rec.13777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Davide Barberis
- Department of Agricultural, Forest and Food Sciences University of Turin, Largo Paolo Braccini 2 10095 Grugliasco TO Italy
| | - Giampiero Lombardi
- Department of Agricultural, Forest and Food Sciences University of Turin, Largo Paolo Braccini 2 10095 Grugliasco TO Italy
| | - Simone Ravetto Enri
- Department of Agricultural, Forest and Food Sciences University of Turin, Largo Paolo Braccini 2 10095 Grugliasco TO Italy
| | - Marco Pittarello
- Department of Agricultural, Forest and Food Sciences University of Turin, Largo Paolo Braccini 2 10095 Grugliasco TO Italy
| | - Davide Viglietti
- Department of Agricultural, Forest and Food Sciences University of Turin, Largo Paolo Braccini 2 10095 Grugliasco TO Italy
| | - Michele Freppaz
- Department of Agricultural, Forest and Food Sciences University of Turin, Largo Paolo Braccini 2 10095 Grugliasco TO Italy
| | - Michele Lonati
- Department of Agricultural, Forest and Food Sciences University of Turin, Largo Paolo Braccini 2 10095 Grugliasco TO Italy
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2
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Walker JB, Rinehart S, Greenberg‐Pines G, White WK, DeSantiago R, Lipson DA, Long JD. Aboveground competition influences density‐dependent effects of cordgrass on sediment biogeochemistry. Ecol Evol 2022; 12:e8722. [PMID: 35356584 PMCID: PMC8939245 DOI: 10.1002/ece3.8722] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 02/08/2022] [Accepted: 02/22/2022] [Indexed: 11/06/2022] Open
Abstract
Interspecific interactions between plants influence plant phenotype, distribution, abundance, and community structure. Each of these can, in turn, impact sediment biogeochemistry. Although the population and community level impacts of these interactions have been extensively studied, less is known about their effect on sediment biogeochemistry. This is surprising given that many plants are categorized as foundation species that exert strong control on community structure. In southern California salt marshes, we used clipping experiments to manipulate aboveground neighbor presence to study interactions between two dominant plants, Pacific cordgrass (Spartina foliosa) and perennial pickleweed (Sarcocornia pacifica). We also measured how changes in cordgrass stem density influenced sediment biogeochemistry. Pickleweed suppressed cordgrass stem density but had no effect on aboveground biomass. For every cordgrass stem lost per square meter, porewater ammonium increased 0.3–1.0 µM. Thus, aboveground competition with pickleweed weakened the effects of cordgrass on sediment biogeochemistry. Predictions about plant–soil feedbacks, especially under future climate scenarios, will be improved when plant–plant interactions are considered, particularly those containing dominant and foundation species.
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Affiliation(s)
- Janet B. Walker
- Department of Biology San Diego State University San Diego California USA
- Coastal and Marine Institute San Diego State University San Diego California USA
- Southern California Coastal Water Research Project Costa Mesa California USA
| | - Shelby Rinehart
- Department of Biology San Diego State University San Diego California USA
- Coastal and Marine Institute San Diego State University San Diego California USA
- Department of Biological Sciences University of Alabama Tuscaloosa Alabama USA
| | - Gabriel Greenberg‐Pines
- Department of Biology San Diego State University San Diego California USA
- Coastal and Marine Institute San Diego State University San Diego California USA
- Department of Zoology and Biodiversity Research Centre University of British Columbia Vancouver BC Canada
| | - Wendi K. White
- Department of Biology San Diego State University San Diego California USA
- Coastal and Marine Institute San Diego State University San Diego California USA
- Department of Biology University of Massachusetts Boston Boston Massachusetts USA
| | - Ric DeSantiago
- Department of Biology San Diego State University San Diego California USA
- Coastal and Marine Institute San Diego State University San Diego California USA
- Department of Environmental Science and Policy University of California Davis Davis California USA
| | - David A. Lipson
- Department of Biology San Diego State University San Diego California USA
| | - Jeremy D. Long
- Department of Biology San Diego State University San Diego California USA
- Coastal and Marine Institute San Diego State University San Diego California USA
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3
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Mao Q, Chen H, Gurmesa GA, Gundersen P, Ellsworth DS, Gilliam FS, Wang C, Zhu F, Ye Q, Mo J, Lu X. Negative effects of long-term phosphorus additions on understory plants in a primary tropical forest. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 798:149306. [PMID: 34340072 DOI: 10.1016/j.scitotenv.2021.149306] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 07/23/2021] [Accepted: 07/23/2021] [Indexed: 06/13/2023]
Abstract
Human activities have disturbed global phosphorus (P) cycling by introducing substantial amounts of P to natural ecosystems. Although natural P gradients and fertilization studies have found that plant community traits are closely related to P availability, it remains unclear how increased P supply affects plant growth and diversity in P-deficient tropical forests. We used a decadal P-addition experiment (2007-2017) to study the effects of increased P input on plant growth and diversity in understory layer in tropical forests. We monitored the dynamics of seedling growth, survival rate, and diversity of understory plants throughout the fertilization period under control and P addition at 15 g P m-2 yr-1. To identify the drivers of responses, P concentration, photosynthesis rate and nonstructural carbon were analyzed. Results showed that long-term P addition significantly increased P concentrations both in soil pools and plant tissues. However, P addition did not increase the light-saturated photosynthesis rate or growth rate of the understory plants. Furthermore, P addition significantly decreased the survival rate of seedlings and reduced the species richness and density of understory plants. The negative effects of P addition may be attributed to an increased carbon cost due to the tissue maintenance of plants with higher P concentrations. These findings indicate that increased P supply alone is not necessary to benefit the growth of plants in ecosystems with low P availability, and P inputs can inhibit understory plants and may alter community composition. Therefore, we appeal to a need for caution when inputting P to tropical forests ecosystems.
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Affiliation(s)
- Qinggong Mao
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China; Center of Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou 510650, China
| | - Hao Chen
- School of Ecology, Sun Yat-sen University, Shenzhen 510006, China
| | | | - Per Gundersen
- Department of Geosciences and Natural Resource Management, University of Copenhagen, 1958 Frederiksberg C, Denmark
| | - David Scott Ellsworth
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales 2751, Australia
| | - Frank S Gilliam
- Department of Biology, University of West Florida, Pensacola, FL 32514, USA
| | - Cong Wang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Fiefei Zhu
- Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110164, China
| | - Qing Ye
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China; Center of Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou 510650, China
| | - Jiangming Mo
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China; Center of Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou 510650, China.
| | - Xiankai Lu
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China; Center of Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou 510650, China.
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4
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Bowd EJ, Banks SC, Bissett A, May TW, Lindenmayer DB. Direct and indirect disturbance impacts in forests. Ecol Lett 2021; 24:1225-1236. [PMID: 33830614 DOI: 10.1111/ele.13741] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 02/01/2021] [Accepted: 02/22/2021] [Indexed: 01/16/2023]
Abstract
Human and natural disturbances are key drivers of change in forest ecosystems. Yet, the direct and indirect mechanisms which underpin these changes remain poorly understood at the ecosystem level. Here, using structural equation modelling across a 150+ year chronosequence, we disentangle the direct and indirect effects of major disturbances in a temperate forest ecosystem. We show that wildfires, logging and post-fire (salvage) logging can affect plant and microbial communities and abiotic soil properties both directly and indirectly through plant-soil-microbial interactions. We quantified 68 direct and indirect disturbance effects across these components, with the majority resulting in ecosystem-wide adverse effects. Indirect disturbance effects accounted for 43% of total disturbance effects, with some amplifying or partially mitigating direct disturbance effects. Overall, human disturbances were associated with more negative effects than natural disturbances. Our analyses provide novel insights into the multifaceted dynamics of forest disturbances and the mechanisms which underpin their relative impacts.
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Affiliation(s)
- Elle J Bowd
- Fenner School of Environment and Society, The Australian National University, Canberra, ACT, 2601, Australia
| | - Sam C Banks
- Fenner School of Environment and Society, The Australian National University, Canberra, ACT, 2601, Australia.,Research Institute for Environment and Livelihoods, College of Engineering, IT and the Environment, Charles Darwin University, Darwin, NT, 0909, Australia
| | - Andrew Bissett
- The Commonwealth Scientific and Industrial Research Organization, CSIRO Oceans and Atmosphere, Hobart, TAS, 700, Australia
| | - Tom W May
- Royal Botanic Gardens Victoria, Birdwood Ave, Melbourne, Vic., 3004, Australia
| | - David B Lindenmayer
- Fenner School of Environment and Society, The Australian National University, Canberra, ACT, 2601, Australia
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5
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Oono R, Black D, Slessarev E, Sickler B, Strom A, Apigo A. Species diversity of fungal endophytes across a stress gradient for plants. THE NEW PHYTOLOGIST 2020; 228:210-225. [PMID: 32472573 DOI: 10.1111/nph.16709] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Accepted: 05/11/2020] [Indexed: 06/11/2023]
Abstract
Foliar fungal endophytes are one of the most diverse guilds of symbiotic fungi found in the photosynthetic tissues of every plant lineage, but it is unclear how plant environments and leaf resource availability shape their diversity. We explored correlations between leaf nutrient availability and endophyte diversity among Pinus muricata and Vaccinium ovatum plants growing across a soil nutrient gradient spanning a series of coastal terraces in Mendocino, California. Endophyte richness decreased in plants with higher leaf nitrogen-to-phosphorus ratios for both host species, but increased with sodium, which may be toxic to fungi at high concentrations. Isolation frequency, a proxy of fungal biomass, was not significantly predicted by any of the same leaf constituents in the two plant species. We propose that stressed plants can exhibit both low foliar nutrients or high levels of toxic compounds, and that both of these stress responses predict endophyte species richness. Stressful conditions that limit growth of fungi may increase their diversity due to the suppression of otherwise dominating species. Differences between the host species in their endophyte communities may be explained by host specificity, leaf phenology, or microclimates.
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Affiliation(s)
- Ryoko Oono
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA, 93106, USA
| | - Danielle Black
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA, 93106, USA
| | - Eric Slessarev
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Burton Sickler
- Materials Research Laboratory, University of California, Santa Barbara, CA, 93106, USA
| | - Amanda Strom
- Materials Research Laboratory, University of California, Santa Barbara, CA, 93106, USA
| | - Austen Apigo
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA, 93106, USA
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6
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Lin TC, Hogan JA, Chang CT. Tropical Cyclone Ecology: A Scale-Link Perspective. Trends Ecol Evol 2020; 35:594-604. [PMID: 32521243 DOI: 10.1016/j.tree.2020.02.012] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 02/17/2020] [Accepted: 02/24/2020] [Indexed: 11/25/2022]
Abstract
Tropical cyclones are increasing in intensity and size and, thus, are poised to increase in importance as disturbance agents. Our understanding of cyclone ecology is biased towards the North Atlantic Basin, because cyclone effects do differ across oceanic basins. Cyclones have both short and long-term effects across the levels of biological organization, but we lack a scale-perspective of cyclone ecology. Effects on individual trees, such as defoliation or branch stripping and uprooting, are mechanistically linked to effects at the community and ecosystem levels, including forest productivity and stand regeneration time. Forest dwarfing via the gradual removal of taller trees by cyclones over many generations illustrates that cyclones shape forest structure through the accumulation of short-term effects over longer timescales.
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Affiliation(s)
- Teng-Chiu Lin
- Department of Life Science, National Taiwan Normal University, Taipei, 11677, Taiwan.
| | - J Aaron Hogan
- Department of Biological Sciences, Florida International University, Miami, FL 33199, USA; Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA
| | - Chung-Te Chang
- Center for Ecology and Environment, Tunghai University, Taichung, 40704, Taiwan; Department of Life Science, Tunghai University, Taichung, 40704, Taiwan
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7
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Rafique M, Ortas I, Rizwan M, Chaudhary HJ, Gurmani AR, Hussain Munis MF. Residual effects of biochar and phosphorus on growth and nutrient accumulation by maize (Zea mays L.) amended with microbes in texturally different soils. CHEMOSPHERE 2020; 238:124710. [PMID: 31545216 DOI: 10.1016/j.chemosphere.2019.124710] [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: 07/13/2019] [Revised: 08/24/2019] [Accepted: 08/29/2019] [Indexed: 05/26/2023]
Abstract
The purpose of study was to examine the residual effects of two types of biochar amendments, two phosphorus (P) fertilizer levels, phosphorus solubilizing bacteria (PSB) and arbuscular mycorrhizal fungs (AMF) on plant growth, nutrients absorption and root architecture of Zea mays L. in texturally different soils. Biochar signficantly increased nutrients absorption and plant biomass production with P-fertilization and microbial inoculantion. Texturally different soils enhanced the plant biomass and nutrients absorption in their independent capacity on addition of biochar, microbial inoculants and P-fertilization. It was shown that mycorrhizal inoculation had positive influence on plant root and shoot biomass in both soils irrespective to the biochar type used. Root colonization was notably increased in biochar + mycorrhizae (B + M) inocultaed plants. It was shown that mycorrhizal inoculation had positive influence on nutrients absorption by plant roots and it had high content of P, potassium, calcium and magnesium in plants at all biochar and P levels. Without P fertilization, biochar amendments significantly promoted shoot P content and root colonization. The P application significantly influenced soil microbial activity in terms of nutrient concentration and plant growth. Root attributes were significantly inclined by microbial inoculation. Residual effects of biochar and P significantly enhanced the nutreints absorption and maize plant growth. Thus, we concluded that residual biochar and P fertilizer showed positive effects on nutrients absorption and maize plant growth promotion in differently textured soils. Microbial inoculants further stimulated the plant biomass production and nutrients absorption due to effective root colonization.
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Affiliation(s)
- Mazhar Rafique
- Department of Plant Sciences, Quaid-i-Azam University, Islamabad, 45320, Pakistan; Department of Soil Science and Plant Nutrition, Cukurova University, Adana, 1150, Turkey; Department of Soil Science, The University of Haripur, Haripur, 22630, Khyber Pakhtunkhwa, Pakistan
| | - Ibrahim Ortas
- Department of Soil Science and Plant Nutrition, Cukurova University, Adana, 1150, Turkey
| | - Muhammad Rizwan
- Department of Environmental Sciences and Engineering, Government College University, Allama Iqbal Road, Faisalabad, 38000, Pakistan.
| | | | - Ali Raza Gurmani
- Department of Soil Science, The University of Haripur, Haripur, 22630, Khyber Pakhtunkhwa, Pakistan
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8
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Is Phylogeny More Useful than Functional Traits for Assessing Diversity Patterns Under Community Assembly Processes? FORESTS 2019. [DOI: 10.3390/f10121159] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Phylogenetic and functional diversities and their relationship are important for understanding community assembly, which relates to forest sustainability. Thus, both diversities have been used in ecological studies evaluating community responses to environmental changes. However, it is unclear whether these diversity measures can uncover the actual community assembly processes. Herein, we examined their utility to assess such assembly processes by analyzing similarities in phylogenetic, functional, and taxonomic α- and β-diversities along an elevational gradient. Additionally, we examined the relationships among environment, phylogeny, and functional traits within the community. Based on our results, we evaluated whether phylogenetic or functional diversity could better reveal the actual community assembly processes. We found that taxonomic, phylogenetic, and functional α-diversities were correlated with one another. Although the functional α-diversity showed a linear correlation with the elevational gradient, taxonomic and phylogenetic α-diversities showed unimodal patterns. Both phylogenetic and functional β-diversities correlated with taxonomic β-diversity, but there was no significant relationship between the former. Overall, our results evidenced that phylogenetic diversity and taxonomic diversity showed similar patterns, whereas functional diversity showed a relatively independent pattern, which may be due to limitations in the functional trait dimensions used in the present study. Although it is difficult to unravel whether the environment shapes phylogeny or functional traits within a community, phylogenetic diversity is a good proxy for assessing the assembly processes, whereas functional diversity may improve knowledge on the community by maximizing information about the functional trait dimensions.
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9
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Roberts JW, Seastedt TR. Effects on vegetative restoration of two treatments: erosion matting and supplemental rock cover in the alpine ecosystem. Restor Ecol 2019. [DOI: 10.1111/rec.13010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jarret W. Roberts
- Department of Ecology and Evolutionary Biology and INSTAARUniversity of Colorado Boulder CO 80309‐0450 U.S.A
| | - Tim R. Seastedt
- Department of Ecology and Evolutionary Biology and INSTAARUniversity of Colorado Boulder CO 80309‐0450 U.S.A
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10
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Li S, Dong S, Shen H, Han Y, Zhang J, Xu Y, Gao X, Yang M, Li Y, Zhao Z, Liu S, Zhou H, Dong Q, Yeomans JC. Different responses of multifaceted plant diversities of alpine meadow and alpine steppe to nitrogen addition gradients on Qinghai-Tibetan Plateau. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 688:1405-1412. [PMID: 31726568 DOI: 10.1016/j.scitotenv.2019.06.211] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 06/05/2019] [Accepted: 06/13/2019] [Indexed: 05/25/2023]
Abstract
Qinghai-Tibetan Plateau (QTP), >4000 m known as the "third pole of the earth" and is highly sensitive to nitrogen (N) deposition, understanding the effects of N deposition on multifaceted plant diversity (taxonomy diversity, functional diversity and phylogenetic diversity) in the alpine grasslands of Qinghai-Tibet Plateau are vital for the conservation of alpine plant diversity and the sustainability of alpine grasslands ecosystem services. We added N of different gradients to test the effects of soil acidification, soil eutrophication, and phosphorus limitation independently, and interactively on the multifaceted plant richness and evenness in both an alpine meadow and an alpine steppe of the QTP. We found that all the p-value of taxonomy diversity, functional diversity and phylogenetic diversity were >0.05 and values of R2 of fixed factors by nitrogen addition gradients was low (<0.10). In contrast to the alpine steppe, diversity of alpine meadow is more sensitive to soil factors than alpine steppe. Soil acidification caused by nitrogen deposition changed taxonomic evenness (p < 0.05), while eutrophication associated with nitrogen deposition altered taxonomic richness and phylogenetic evenness (p < 0.05) in the alpine meadow and functional richness (p < 0.05) in the alpine steppe. These findings suggest that the effects of N deposition on the multifaceted plant diversity (taxonomic, functional and phylogenetic diversity) varied with N deposition gradients and ecosystem types. Rational adaptation and mitigation techniques should be considered for different types of alpine grasslands on the QTP according to their different responses to the nitrogen deposition gradients in the future.
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Affiliation(s)
- Shuai Li
- School of Environment, Beijing Normal University, Beijing 100875, China
| | - Shikui Dong
- School of Environment, Beijing Normal University, Beijing 100875, China.
| | - Hao Shen
- School of Environment, Beijing Normal University, Beijing 100875, China
| | - Yuhui Han
- School of Environment, Beijing Normal University, Beijing 100875, China
| | - Jing Zhang
- School of Environment, Beijing Normal University, Beijing 100875, China
| | - Yudan Xu
- School of Environment, Beijing Normal University, Beijing 100875, China
| | - Xiaoxia Gao
- School of Environment, Beijing Normal University, Beijing 100875, China
| | - Mingyue Yang
- School of Environment, Beijing Normal University, Beijing 100875, China
| | - Yu Li
- School of Environment, Beijing Normal University, Beijing 100875, China
| | - Zhenzhen Zhao
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China
| | - Shiliang Liu
- School of Environment, Beijing Normal University, Beijing 100875, China
| | - Huakun Zhou
- Northwest Institute of Plateau Biology, Chinese Academy of Science, Key Laboratory of Restoration Ecology of Cold Are in Qinghai Province, Xining 810008, China
| | - Quanming Dong
- Qinghai Academy of Animal Husbandry and Veterinary Science, Qinghai University, Xining 810003, China
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11
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Zong N, Zhao G, Shi P. Different sensitivity and threshold in response to nitrogen addition in four alpine grasslands along a precipitation transect on the Northern Tibetan Plateau. Ecol Evol 2019; 9:9782-9793. [PMID: 31534693 PMCID: PMC6745826 DOI: 10.1002/ece3.5514] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 07/10/2019] [Accepted: 07/10/2019] [Indexed: 11/29/2022] Open
Abstract
The increase in atmospheric nitrogen (N) deposition has resulted in some terrestrial ecological changes. In order to identify the response of sensitive indicators to N input and estimate the sensitivity and saturation thresholds in alpine grasslands, we set up a series of multilevel N addition experiments in four types of alpine grasslands (alpine meadow [AM], alpine meadow-steppe [AMS], alpine steppe [AS], and alpine desert-steppe [ADS]) along with a decreasing precipitation gradient from east to west on the Northern Tibetan Plateau. N addition only had significant effects on species diversity in AMS, while had no effects on the other three alpine grasslands. Aboveground biomass of grasses and overall community in ADS were enhanced with increasing N addition, but such effects did not occur in AS. Legume biomass in ADS and AS showed similar unimodal patterns and exhibited a decreasing tend in AM. Regression fitting showed that the most sensitive functional groups were grasses, and the N saturation thresholds were 103, 115, 136, and 156 kg N hm-2 year-1 in AM, AMS, AS, and ADS, respectively. This suggests that alpine grasslands become more and more insensitive to N input with precipitation decrease. N saturation thresholds also negatively correlated with soil N availability. N sensitivity differences caused by precipitation and nutrient availability suggest that alpine grasslands along the precipitation gradient will respond differently to atmospheric N deposition in the future global change scenario. This different sensitivity should also be taken into consideration when using N fertilization to restore degraded grasslands.
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Affiliation(s)
- Ning Zong
- Lhasa National Ecological Research Station, Key Laboratory of Ecosystem Network Observation and Modelling, Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijingChina
| | - Guangshuai Zhao
- Lhasa National Ecological Research Station, Key Laboratory of Ecosystem Network Observation and Modelling, Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijingChina
- China National Forestry Economics and Development Research CenterBeijingChina
| | - Peili Shi
- Lhasa National Ecological Research Station, Key Laboratory of Ecosystem Network Observation and Modelling, Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijingChina
- University of Chinese Academy of SciencesBeijingChina
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12
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Sitters J, Cherif M, Egelkraut D, Giesler R, Olofsson J. Long‐term heavy reindeer grazing promotes plant phosphorus limitation in arctic tundra. Funct Ecol 2019. [DOI: 10.1111/1365-2435.13342] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Judith Sitters
- Department of Ecology and Environmental Science Umeå University Umeå Sweden
- Ecology and Biodiversity, Department Biology Vrije Universiteit Brussel Brussels Belgium
| | - Mehdi Cherif
- Department of Ecology and Environmental Science Umeå University Umeå Sweden
- Climate Impacts Research Centre, Department of Ecology and Environmental Science Umeå University Abisko Sweden
| | - Dagmar Egelkraut
- Department of Ecology and Environmental Science Umeå University Umeå Sweden
- Department of Biological Sciences University of Bergen Bergen Norway
| | - Reiner Giesler
- Department of Ecology and Environmental Science Umeå University Umeå Sweden
- Climate Impacts Research Centre, Department of Ecology and Environmental Science Umeå University Abisko Sweden
| | - Johan Olofsson
- Department of Ecology and Environmental Science Umeå University Umeå Sweden
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13
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Wentz KF, Neff JC, Suding KN. Leaf temperatures mediate alpine plant communities' response to a simulated extended summer. Ecol Evol 2019; 9:1227-1243. [PMID: 30805155 PMCID: PMC6374730 DOI: 10.1002/ece3.4816] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 09/26/2018] [Accepted: 11/20/2018] [Indexed: 11/10/2022] Open
Abstract
We use a quantitative model of photosynthesis to explore leaf-level limitations to plant growth in an alpine tundra ecosystem that is expected to have longer, warmer, and drier growing seasons. The model is parameterized with abiotic and leaf trait data that is characteristic of two dominant plant communities in the alpine tundra and specifically at the Niwot Ridge Long Term Ecological Research Site: the dry and wet meadows. Model results produce realistic estimates of photosynthesis, nitrogen-use efficiency, water-use efficiency, and other gas exchange processes in the alpine tundra. Model simulations suggest that dry and wet meadow plant species do not significantly respond to changes in the volumetric soil moisture content but are sensitive to variation in foliar nitrogen content. In addition, model simulations indicate that dry and wet meadow species have different maximum rates of assimilation (normalized for leaf nitrogen content) because of differences in leaf temperature. These differences arise from the interaction of plant height and the abiotic environment characteristic of each plant community. The leaf temperature of dry meadow species is higher than wet meadow species and close to the optimal temperature for photosynthesis under current conditions. As a result, 2°C higher air temperatures in the future will likely lead to declines in dry meadow species' carbon assimilation. On the other hand, a longer and warmer growing season could increase nitrogen availability and assimilation rates in both plant communities. Nonetheless, a temperature increase of 4°C may lower rates of assimilation in both dry and wet meadow plant communities because of higher, and suboptimal, leaf temperatures.
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Affiliation(s)
| | - Jason C. Neff
- Environmental Studies DepartmentUniversity of ColoradoBoulderColorado
| | - Katharine N. Suding
- Institute of Arctic & Alpine Research, Ecology & Evolutionary Biology DepartmentUniversity of ColoradoBoulderColorado
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14
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Langley JA, Chapman SK, La Pierre KJ, Avolio M, Bowman WD, Johnson DS, Isbell F, Wilcox KR, Foster BL, Hovenden MJ, Knapp AK, Koerner SE, Lortie CJ, Megonigal JP, Newton PCD, Reich PB, Smith MD, Suttle KB, Tilman D. Ambient changes exceed treatment effects on plant species abundance in global change experiments. GLOBAL CHANGE BIOLOGY 2018; 24:5668-5679. [PMID: 30369019 DOI: 10.1111/gcb.14442] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2018] [Accepted: 08/02/2018] [Indexed: 06/08/2023]
Abstract
The responses of species to environmental changes will determine future community composition and ecosystem function. Many syntheses of global change experiments examine the magnitude of treatment effect sizes, but we lack an understanding of how plant responses to treatments compare to ongoing changes in the unmanipulated (ambient or background) system. We used a database of long-term global change studies manipulating CO2 , nutrients, water, and temperature to answer three questions: (a) How do changes in plant species abundance in ambient plots relate to those in treated plots? (b) How does the magnitude of ambient change in species-level abundance over time relate to responsiveness to global change treatments? (c) Does the direction of species-level responses to global change treatments differ from the direction of ambient change? We estimated temporal trends in plant abundance for 791 plant species in ambient and treated plots across 16 long-term global change experiments yielding 2,116 experiment-species-treatment combinations. Surprisingly, for most species (57%) the magnitude of ambient change was greater than the magnitude of treatment effects. However, the direction of ambient change, whether a species was increasing or decreasing in abundance under ambient conditions, had no bearing on the direction of treatment effects. Although ambient communities are inherently dynamic, there is now widespread evidence that anthropogenic drivers are directionally altering plant communities in many ecosystems. Thus, global change treatment effects must be interpreted in the context of plant species trajectories that are likely driven by ongoing environmental changes.
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Affiliation(s)
- J Adam Langley
- Department of Biology, Villanova University, Villanova, Pennsylvania
| | | | | | - Meghan Avolio
- Department of Earth & Planetary Sciences, Johns Hopkins University, Baltimore, Maryland
| | - William D Bowman
- Department of Ecology and Evolutionary Biology and Mountain Research Station, University of Colorado, Boulder, Colorado
| | - David S Johnson
- Virginia Institute of Marine Science, Gloucester Point, Virginia
| | - Forest Isbell
- Department of Ecology, Evolution and Behavior, University of Minnesota, Saint Paul, Minnesota
| | - Kevin R Wilcox
- U.S. Department of Agriculture, Agriculture Research Service, Fort Collins, Colorado
| | - Bryan L Foster
- Ecology and Evolutionary Biology and Kansas Biological Survey, University of Kansas, Lawrence, Kansas
| | - Mark J Hovenden
- Biological Sciences, School of Natural Sciences, University of Tasmania, Hobart, Tasmania, Australia
| | - Alan K Knapp
- Department of Biology and Graduate Degree Program in Ecology, Fort Collins, Colorado
| | - Sally E Koerner
- Department of Biology, University of North Carolina Greensboro, Greensboro, North Carolina
| | - Christopher J Lortie
- The National Center for Ecological Analysis and Synthesis, UCSB, Santa Barbara, California
| | | | | | - Peter B Reich
- Department of Forest Resources, University of Minnesota, St. Paul, Minnesota
- Hawkesbury Institute for the Environment, Western Sydney University, Penrith, New South Wales, Australia
| | - Melinda D Smith
- Department of Biology and Graduate Degree Program in Ecology, Fort Collins, Colorado
| | - Kenwyn B Suttle
- Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, California
| | - David Tilman
- Department of Ecology, Evolution and Behavior, University of Minnesota, Saint Paul, Minnesota
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15
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LaPlante E, Souza L. Plant dominance in a subalpine montane meadow: biotic vs. abiotic controls of subordinate diversity within and across sites. PeerJ 2018; 6:e5619. [PMID: 30258717 PMCID: PMC6152469 DOI: 10.7717/peerj.5619] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 08/18/2018] [Indexed: 11/26/2022] Open
Abstract
Background Understanding the underlying factors that determine the relative abundance of plant species is critical to predict both biodiversity and ecosystem function. Biotic and abiotic factors can shape the distribution and the relative abundance of species across natural communities, greatly influencing local biodiversity. Methods Using a combination of an observational study and a five-year plant removal experiment we: (1) documented how plant diversity and composition of montane meadow assemblages vary along a plant dominance gradient using an observational study; (2) tracked above- and belowground functional traits of co-dominant plant species Potentilla and Festuca along a plant dominance gradient in an observational study; (3) determined whether plant species diversity and composition was directly influenced by commonly occurring species Potentilla and Festuca with the use of a randomized plot design, 5-year plant removal experiment (no removal control, Potentilla removed, Festuca removed, n = 10). Results We found that subordinate species diversity and compositional dissimilarity were greatest in Potentilla and Festuca co-dominated sites, where neither Potentilla nor Festuca dominated, rather than at sites where either species became dominant. Further, while above- and belowground plant functional traits varied along a dominance gradient, they did so in a way that inconsistently predicted plant species relative abundance. Also, neither variation in plant functional traits of Festuca and Potentilla nor variation in resources and conditions (such as soil nitrogen and temperature) explained our subordinate diversity patterns. Finally, neither Potentilla nor Festuca influenced subordinate diversity or composition when we directly tested for their impacts in a plant removal experiment. Discussion Taken together, patterns of subordinate diversity and composition were likely driven by abiotic factors rather than biotic interactions. As a result, the role of abiotic factors influencing local-level species interactions can be just as important as biotic interactions themselves in structuring plant communities.
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Affiliation(s)
- Erika LaPlante
- Department of Plant Biology, Michigan State University, East Lansing, MI, United States of America.,Department of Integrative Biology, University of Californnia Berkeley, Berkeley, CA, United States of America
| | - Lara Souza
- Oklahoma Biological Survey & Department of Microbiology and Plant Biology, The University of Oklahoma, Norman, OK, United States of America
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16
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Baruah G, Molau U, Jägerbrand AK, Alatalo JM. Impacts of seven years of experimental warming and nutrient addition on neighbourhood species interactions and community structure in two contrasting alpine plant communities. ECOLOGICAL COMPLEXITY 2018. [DOI: 10.1016/j.ecocom.2017.11.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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17
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Cline LC, Hobbie SE, Madritch MD, Buyarski CR, Tilman D, Cavender‐Bares JM. Resource availability underlies the plant‐fungal diversity relationship in a grassland ecosystem. Ecology 2017; 99:204-216. [DOI: 10.1002/ecy.2075] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 09/14/2017] [Accepted: 10/23/2017] [Indexed: 11/07/2022]
Affiliation(s)
- Lauren C. Cline
- Department of Plant and Microbial Biology University of Minnesota 123 Snyder Hall, 1475 Gortner Ave. St. Paul Minnesota 55108 USA
| | - Sarah E. Hobbie
- Department of Ecology, Evolution, and Behavior University of Minnesota 123 Snyder Hall, 1475 Gortner Ave. St. Paul Minnesota 55108 USA
| | - Michael D. Madritch
- Department of Biology Appalachian State University 572 Rivers Street., ASU Box 32027 Boone North Carolina 28608 USA
| | - Christopher R. Buyarski
- Department of Ecology, Evolution, and Behavior University of Minnesota 123 Snyder Hall, 1475 Gortner Ave. St. Paul Minnesota 55108 USA
- Department of Forest Resources University of Minnesota 115 Green Hall, 1530 Cleveland Ave N. St. PaulMinnesota 55108 USA
| | - David Tilman
- Department of Ecology, Evolution, and Behavior University of Minnesota 123 Snyder Hall, 1475 Gortner Ave. St. Paul Minnesota 55108 USA
- Bren School University of California‐Santa Barbara Santa Barbara, Bren Hall, 2400 University of California California 93117 USA
| | - Jeannine M. Cavender‐Bares
- Department of Ecology, Evolution, and Behavior University of Minnesota 123 Snyder Hall, 1475 Gortner Ave. St. Paul Minnesota 55108 USA
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18
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Bracewell SA, Johnston EL, Clark GF. Latitudinal variation in the competition‐colonisation trade‐off reveals rate‐mediated mechanisms of coexistence. Ecol Lett 2017. [DOI: 10.1111/ele.12791] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Sally A. Bracewell
- Applied Marine and Estuarine Ecology Lab Evolution and Ecology Research Centre University of New South Wales Sydney2052 NSW Australia
| | - Emma L. Johnston
- Applied Marine and Estuarine Ecology Lab Evolution and Ecology Research Centre University of New South Wales Sydney2052 NSW Australia
| | - Graeme F. Clark
- Applied Marine and Estuarine Ecology Lab Evolution and Ecology Research Centre University of New South Wales Sydney2052 NSW Australia
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19
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Song M, Yu L, Jiang Y, Lei Y, Korpelainen H, Niinemets Ü, Li C. Nitrogen-controlled intra- and interspecific competition between Populus purdomii and Salix rehderiana drive primary succession in the Gongga Mountain glacier retreat area. TREE PHYSIOLOGY 2017; 37:799-814. [PMID: 28338926 DOI: 10.1093/treephys/tpx017] [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: 10/15/2016] [Accepted: 02/19/2017] [Indexed: 06/06/2023]
Abstract
In this study, intra- and interspecific competition were investigated in early successional Salix rehderiana Schneider and later-appearing Populus purdomii Rehder under non-fertilized (control) and nitrogen (N)-fertilized conditions in the Hailuogou glacier retreat area. Our aim was to discover whether N is a key factor in plant-plant competition and whether N drives the primary succession process in a glacier retreat area. We analyzed differences in responses to intra- and interspecific competition and N fertilization between P. purdomii and S. rehderiana, including parameters such as biomass accumulation, nutrient absorption, non-structural carbohydrates, photosynthetic capacity, hydrolysable amino acids and leaf ultrastructure. In the control treatments, S. rehderiana individuals subjected to interspecific competition benefited from the presence of P. purdomii plants, as indicated by higher levels of biomass accumulation, photosynthetic capacity, N absorption, amino acid contents and photosynthetic N-use efficiency. However, in the N-fertilized treatments, P. purdomii individuals exposed to interspecific competition benefited from the presence of S. rehderiana plants, as shown by a higher growth rate, enhanced carbon gain capacity, greater amino acid contents, and elevated water-use efficiency, whereas the growth of S. rehderiana was significantly reduced. Our results demonstrate that N plays a pivotal role in determining the asymmetric competition pattern among Salicaceae species during primary succession. We argue that the interactive effects of plant-plant competition and N availability are key mechanisms that drive primary succession in the Gongga Mountain glacier retreat area.
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Affiliation(s)
- Mengya Song
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, Sichuan, China
- University of Chinese Academy of Sciences, Beijing 100039, China
| | - Lei Yu
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, Sichuan, China
- University of Chinese Academy of Sciences, Beijing 100039, China
| | - Yonglei Jiang
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, Sichuan, China
- University of Chinese Academy of Sciences, Beijing 100039, China
| | - Yanbao Lei
- Key Laboratory of Mountain Surface Processes and Ecological Regulation, Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, Sichuan, China
| | - Helena Korpelainen
- Department of Agricultural Sciences, Viikki Plant Science Centre, P.O. Box 27,University of Helsinki, HelsinkiFI-00014, Finland
| | - Ülo Niinemets
- Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 1, 51014 Tartu, Estonia
| | - Chunyang Li
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 310036, Zhejiang, China
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20
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Iturrate‐Garcia M, O'Brien MJ, Khitun O, Abiven S, Niklaus PA, Schaepman‐Strub G. Interactive effects between plant functional types and soil factors on tundra species diversity and community composition. Ecol Evol 2016; 6:8126-8137. [PMID: 27878083 PMCID: PMC5108264 DOI: 10.1002/ece3.2548] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 09/13/2016] [Accepted: 09/19/2016] [Indexed: 01/15/2023] Open
Abstract
Plant communities are coupled with abiotic factors, as species diversity and community composition both respond to and influence climate and soil characteristics. Interactions between vegetation and abiotic factors depend on plant functional types (PFT) as different growth forms will have differential responses to and effects on site characteristics. However, despite the importance of different PFT for community assembly and ecosystem functioning, research has mainly focused on vascular plants. Here, we established a set of observational plots in two contrasting habitats in northeastern Siberia in order to assess the relationship between species diversity and community composition with soil variables, as well as the relationship between vegetation cover and species diversity for two PFT (nonvascular and vascular). We found that nonvascular species diversity decreased with soil acidity and moisture and, to a lesser extent, with soil temperature and active layer thickness. In contrast, no such correlation was found for vascular species diversity. Differences in community composition were found mainly along soil acidity and moisture gradients. However, the proportion of variation in composition explained by the measured soil variables was much lower for nonvascular than for vascular species when considering the PFT separately. We also found different relationships between vegetation cover and species diversity according the PFT and habitat. In support of niche differentiation theory, species diversity and community composition were related to edaphic factors. The distinct relationships found for nonvascular and vascular species suggest the importance of considering multiple PFT when assessing species diversity and composition and their interaction with edaphic factors. Synthesis: Identifying vegetation responses to edaphic factors is a first step toward a better understanding of vegetation-soil feedbacks under climate change. Our results suggest that incorporating differential responses of PFT is important for predicting vegetation shifts, primary productivity, and in turn, ecosystem functioning in a changing climate.
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Affiliation(s)
- Maitane Iturrate‐Garcia
- Department of Evolutionary Biology and Environmental StudiesUniversity of ZurichZurichSwitzerland
| | - Michael J. O'Brien
- Department of Evolutionary Biology and Environmental StudiesUniversity of ZurichZurichSwitzerland
- Estación Experimental de Zonas ÁridasConsejo Superior de Investigaciones CientíficasAlmeríaSpain
| | - Olga Khitun
- Komarov Botanical InstituteRussian Academy of ScienceSt. PetersburgRussia
| | - Samuel Abiven
- Department of GeographyUniversity of ZurichZurichSwitzerland
| | - Pascal A. Niklaus
- Department of Evolutionary Biology and Environmental StudiesUniversity of ZurichZurichSwitzerland
| | - Gabriela Schaepman‐Strub
- Department of Evolutionary Biology and Environmental StudiesUniversity of ZurichZurichSwitzerland
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21
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Yuan X, Knelman JE, Gasarch E, Wang D, Nemergut DR, Seastedt TR. Plant community and soil chemistry responses to long-term nitrogen inputs drive changes in alpine bacterial communities. Ecology 2016; 97:1543-54. [PMID: 27459784 DOI: 10.1890/15-1160.1] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Bacterial community composition and diversity was studied in alpine tundra soils across a plant species and moisture gradient in 20 y-old experimental plots with four nutrient addition regimes (control, nitrogen (N), phosphorus (P) or both nutrients). Different bacterial communities inhabited different alpine meadows, reflecting differences in moisture, nutrients and plant species. Bacterial community alpha-diversity metrics were strongly correlated with plant richness and the production of forbs. After meadow type, N addition proved the strongest determinant of bacterial community structure. Structural Equation Modeling demonstrated that tundra bacterial community responses to N addition occur via changes in plant community composition and soil pH resulting from N inputs, thus disentangling the influence of direct (resource availability) vs. indirect (changes in plant community structure and soil pH) N effects that have remained unexplored in past work examining bacterial responses to long-term N inputs in these vulnerable environments. Across meadow types, the relative influence of these indirect N effects on bacterial community structure varied. In explicitly evaluating the relative importance of direct and indirect effects of long-term N addition on bacterial communities, this study provides new mechanistic understandings of the interaction between plant and microbial community responses to N inputs amidst environmental change.
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22
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Sandvik SM, Heegaard E, Elven R, Vandvik V. Responses of alpine snowbed vegetation to long-term experimental warming. ECOSCIENCE 2016. [DOI: 10.1080/11956860.2004.11682819] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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23
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Zong N, Shi P, Song M, Zhang X, Jiang J, Chai X. Nitrogen Critical Loads for an Alpine Meadow Ecosystem on the Tibetan Plateau. ENVIRONMENTAL MANAGEMENT 2016; 57:531-42. [PMID: 26475686 DOI: 10.1007/s00267-015-0626-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2015] [Accepted: 09/29/2015] [Indexed: 05/23/2023]
Abstract
Increasing atmospheric nitrogen (N) deposition has the potential to alter plant diversity and thus the function and stability of terrestrial ecosystems. N-limited alpine ecosystems are expected to be particularly susceptible to increasing N deposition. However, little is known about the critical loads and saturation thresholds of ecosystem responses to increasing N deposition on the Tibetan Plateau, despite its importance to ecosystem management. To evaluate the N critical loads and N saturation thresholds in an alpine ecosystem, in 2010, we treated an alpine meadow with five levels of N addition (0, 10, 20, 40, and 80 kg N ha(-1) year(-1)) and characterized plant and soil responses. The results showed that plant species richness and diversity index did not statistically vary with N addition treatments, but they both changed with years. N addition affected plant cover and aboveground productivity, especially for grasses, and soil chemical features. The N critical loads and saturation thresholds, in terms of plant cover and biomass change at the community level, were 8.8-12.7 and 50 kg N ha(-1) year(-1) (including the ambient N deposition rate), respectively. However, pronounced changes in soil inorganic N and net N mineralization occurred under the 20 and 40 kg N ha(-1) year(-1) treatments. Our results indicate that plant community cover and biomass are more sensitive than soil to increasing N inputs. The plant community composition in alpine ecosystems on the Qinghai-Tibetan Plateau may change under increasing N deposition in the future.
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Affiliation(s)
- Ning Zong
- Lhasa National Ecological Research Station, Key Laboratory of Ecosystem Network Observation and Modelling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, 11A, Datun Road, Chaoyang District, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Peili Shi
- Lhasa National Ecological Research Station, Key Laboratory of Ecosystem Network Observation and Modelling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, 11A, Datun Road, Chaoyang District, Beijing, 100101, China.
| | - Minghua Song
- Key Laboratory of Ecosystem Network Observation and Modelling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China
| | - Xianzhou Zhang
- Lhasa National Ecological Research Station, Key Laboratory of Ecosystem Network Observation and Modelling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, 11A, Datun Road, Chaoyang District, Beijing, 100101, China
| | - Jing Jiang
- Nanjing Agricultural Institute of Jiangsu Hilly Region, Nanjing, 210046, Jiangsu, China
| | - Xi Chai
- Lhasa National Ecological Research Station, Key Laboratory of Ecosystem Network Observation and Modelling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, 11A, Datun Road, Chaoyang District, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
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24
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Humbert JY, Dwyer JM, Andrey A, Arlettaz R. Impacts of nitrogen addition on plant biodiversity in mountain grasslands depend on dose, application duration and climate: a systematic review. GLOBAL CHANGE BIOLOGY 2016; 22:110-120. [PMID: 26010833 DOI: 10.1111/gcb.12986] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Revised: 04/15/2015] [Accepted: 05/17/2015] [Indexed: 05/28/2023]
Abstract
Although the influence of nitrogen (N) addition on grassland plant communities has been widely studied, it is still unclear whether observed patterns and underlying mechanisms are constant across biomes. In this systematic review, we use meta-analysis and metaregression to investigate the influence of N addition (here referring mostly to fertilization) upon the biodiversity of temperate mountain grasslands (including montane, subalpine and alpine zones). Forty-two studies met our criteria of inclusion, resulting in 134 measures of effect size. The main general responses of mountain grasslands to N addition were increases in phytomass and reductions in plant species richness, as observed in lowland grasslands. More specifically, the analysis reveals that negative effects on species richness were exacerbated by dose (ha(-1) year(-1) ) and duration of N application (years) in an additive manner. Thus, sustained application of low to moderate levels of N over time had effects similar to short-term application of high N doses. The climatic context also played an important role: the overall effects of N addition on plant species richness and diversity (Shannon index) were less pronounced in mountain grasslands experiencing cool rather than warm summers. Furthermore, the relative negative effect of N addition on species richness was more pronounced in managed communities and was strongly negatively related to N-induced increases in phytomass, that is the greater the phytomass response to N addition, the greater the decline in richness. Altogether, this review not only establishes that plant biodiversity of mountain grasslands is negatively affected by N addition, but also demonstrates that several local management and abiotic factors interact with N addition to drive plant community changes. This synthesis yields essential information for a more sustainable management of mountain grasslands, emphasizing the importance of preserving and restoring grasslands with both low agricultural N application and limited exposure to N atmospheric deposition.
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Affiliation(s)
- Jean-Yves Humbert
- Division of Conservation Biology, Institute of Ecology and Evolution, University of Bern, Baltzerstrasse 6, 3012, Bern, Switzerland
- School of Biological Sciences, The University of Queensland, St Lucia, Qld, 4072, Australia
| | - John M Dwyer
- Division of Conservation Biology, Institute of Ecology and Evolution, University of Bern, Baltzerstrasse 6, 3012, Bern, Switzerland
- School of Biological Sciences, The University of Queensland, St Lucia, Qld, 4072, Australia
- CSIRO Land and Water Flagship, EcoSciences Precinct, Dutton Park, Qld, 4102, Australia
| | - Aline Andrey
- 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
- Instituto Argentino de Investigaciones de las Zonas Áridas, CONICET, CC 507, 5500, Mendoza, Argentina
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25
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Xu D, Fang X, Zhang R, Gao T, Bu H, Du G. Influences of nitrogen, phosphorus and silicon addition on plant productivity and species richness in an alpine meadow. AOB PLANTS 2015; 7:plv125. [PMID: 26574603 PMCID: PMC4676797 DOI: 10.1093/aobpla/plv125] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 10/20/2015] [Indexed: 05/09/2023]
Abstract
Fertilization, especially with nitrogen (N), increases aboveground primary productivity (APP), but reduces plant species richness at some level. Silicon (Si) fertilization alone, or with addition of N or phosphorus (P), has multiple direct and indirect beneficial effects on plant growth and development, both for individuals and the whole community. This study aimed to examine the effects of Si, N, P, NSi and PSi combinations on APP and species richness of the community and of four functional groups in an alpine meadow. The results showed that plots fertilized with Si in combination with either N or P had higher APP than when fertilized with N or P alone. Addition of N or P increased APP, and the higher APP occurred when the highest level of N was added, indicating co-limitation of N and P, with N being most limiting. Silicon fertilization alone or with addition of N increased the APP of grasses and forbs. Nitrogen addition decreased the community species richness; Si with addition of N alleviated the loss of species richness of the whole community and the forbs group. For the four functional groups, N or P addition increased the species richness of grasses and decreased that of forbs. Our findings highlight the importance of Si in improving APP and alleviating N fertilization-induced biodiversity loss in grasslands, and will help improve our ability to predict community composition and biomass dynamics in alpine meadow ecosystems subject to changing nutrient availability.
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Affiliation(s)
- Danghui Xu
- State Key Laboratory of Grassland Agro-ecosystems/School of Life Science, Lanzhou University, No. 222, South Tianshui Road, Lanzhou, Gansu 730000, China
| | - Xiangwen Fang
- State Key Laboratory of Grassland Agro-ecosystems/School of Life Science, Lanzhou University, No. 222, South Tianshui Road, Lanzhou, Gansu 730000, China
| | - Renyi Zhang
- State Key Laboratory of Grassland Agro-ecosystems/School of Life Science, Lanzhou University, No. 222, South Tianshui Road, Lanzhou, Gansu 730000, China
| | - Tianpeng Gao
- Centre of Urban Ecology and Environmental Biotechnology, Lanzhou City University, Lanzhou 730070, China
| | - Haiyan Bu
- State Key Laboratory of Grassland Agro-ecosystems/School of Life Science, Lanzhou University, No. 222, South Tianshui Road, Lanzhou, Gansu 730000, China
| | - Guozhen Du
- State Key Laboratory of Grassland Agro-ecosystems/School of Life Science, Lanzhou University, No. 222, South Tianshui Road, Lanzhou, Gansu 730000, China
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26
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Little CJ, Jägerbrand AK, Molau U, Alatalo JM. Community and species-specific responses to simulated global change in two subarctic-alpine plant communities. Ecosphere 2015. [DOI: 10.1890/es14-00427.1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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27
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Cui N, Wu J, Zhong F, Yang L, Xiang D, Cheng S, Zhou Q. Seed banks and their implications of rivers with different trophic levels in Chaohu Lake Basin, China. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2015; 22:2247-2257. [PMID: 25178861 DOI: 10.1007/s11356-014-3501-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Accepted: 08/20/2014] [Indexed: 06/03/2023]
Abstract
The seed banks of three rivers, with different trophic levels in Chaohu Lake Basin, China, were investigated to explore the dynamics of seed bank under the pressure of eutrophication. A total of 60 species from 25 family 43 genera were identified from the seed banks of the three rivers. In the eutrophic Paihe River, the species richness and mean seed density were the highest, followed by the oligotrophic Hangbuhe River and the hypereutrophic Nanfeihe River. Various compositions of three functional group assemblage of hydro-ecotypes were found in different rivers. The dominant and endemic species were aquatic, wetland, and terrestrial species in Hangbuhe River, Paihe River, and Nanfeihe River, respectively. The shift trend of seed bank in three rivers probably presented past vegetation dynamics under the trophic process in the rivers of Chaohu Lake Basin. Seed bank in the river bed might be quickly assessed by its trophic level. Additionally, it might imply that the seed bank with more aquatic species in the oligotrophic river would be a potential seed resource for vegetation restoration of severely degraded river ecosystems.
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Affiliation(s)
- Naxin Cui
- Key Laboratory of Yangtze River Water Environment, Ministry of Education, Tongji University, Shanghai, 200092, China
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28
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Laiolo P, Illera JC, Meléndez L, Segura A, Obeso JR. Abiotic, biotic, and evolutionary control of the distribution of C and N isotopes in food webs. Am Nat 2014; 185:169-82. [PMID: 25616137 DOI: 10.1086/679348] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Ecosystem functioning depends on nutrient cycles and their responses to abiotic and biotic determinants, with the influence of evolutionary legacies being generally overlooked in ecosystem ecology. Along a broad elevation gradient characterized by shifting climatic and grazing environments, we addressed clines of plant N and C∶N content and of δ(13)C and δ(15)N in producers (herbs) and in primary (grasshoppers) and secondary (birds) consumers, both within and between species in phylogenetically controlled scenarios. We found parallel and significant intra- and interspecific trends of isotopic variation with elevation in the three groups. In primary producers, nutrient and isotope distributions had a detectable phylogenetic signal that constrained their variation along the environmental gradient. The influence of the environment could not be ascribed to any single factor, and both grazing and climate had an effect on leaf stoichiometry and, thus, on the resources available to consumers. Trends in consumers matched those in plants but often became nonsignificant after controlling for isotopic values of their direct resources, revealing direct bottom-up control and little phylogenetic dependence. By integrating ecosystem and mechanistic perspectives, we found that nutrient dynamics in food webs are governed at the base by the complex interaction between local determinants and evolutionary factors.
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Affiliation(s)
- Paola Laiolo
- Research Unit of Biodiversity (Universidad de Oviedo [UO], Consejo Superior de Investigaciones Científicas [CSIC], Principado de Asturias [PA]), Oviedo University, 33600 Mieres, Spain
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Alatalo JM, Little CJ, Jägerbrand AK, Molau U. Dominance hierarchies, diversity and species richness of vascular plants in an alpine meadow: contrasting short and medium term responses to simulated global change. PeerJ 2014; 2:e406. [PMID: 24883260 PMCID: PMC4034599 DOI: 10.7717/peerj.406] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Accepted: 05/08/2014] [Indexed: 11/20/2022] Open
Abstract
We studied the impact of simulated global change on a high alpine meadow plant community. Specifically, we examined whether short-term (5 years) responses are good predictors for medium-term (7 years) changes in the system by applying a factorial warming and nutrient manipulation to 20 plots in Latnjajaure, subarctic Sweden. Seven years of experimental warming and nutrient enhancement caused dramatic shifts in dominance hierarchies in response to the nutrient and the combined warming and nutrient enhancement treatments. Dominance hierarchies in the meadow moved from a community being dominated by cushion plants, deciduous, and evergreen shrubs to a community being dominated by grasses, sedges, and forbs. Short-term responses were shown to be inconsistent in their ability to predict medium-term responses for most functional groups, however, grasses showed a consistent and very substantial increase in response to nutrient addition over the seven years. The non-linear responses over time point out the importance of longer-term studies with repeated measurements to be able to better predict future changes. Forecasted changes to temperature and nutrient availability have implications for trophic interactions, and may ultimately influence the access to and palatability of the forage for grazers. Depending on what anthropogenic change will be most pronounced in the future (increase in nutrient deposits, warming, or a combination of them both), different shifts in community dominance hierarchies may occur. Generally, this study supports the productivity-diversity relationship found across arctic habitats, with community diversity peaking in mid-productivity systems and degrading as nutrient availability increases further. This is likely due the increasing competition in plant-plant interactions and the shifting dominance structure with grasses taking over the experimental plots, suggesting that global change could have high costs to biodiversity in the Arctic.
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Affiliation(s)
- Juha M. Alatalo
- Department of Ecology and Genetics, Uppsala University, Visby, Sweden
| | - Chelsea J. Little
- Department of Ecology and Genetics, Uppsala University, Visby, Sweden
| | | | - Ulf Molau
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden
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Increasing Soil Nutrient Loads of European Semi-natural Grasslands Strongly Alter Plant Functional Diversity Independently of Species Loss. Ecosystems 2013. [DOI: 10.1007/s10021-013-9714-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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31
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Variability of polar scurvygrass Cochlearia groenlandica individual traits along a seabird influenced gradient across Spitsbergen tundra. Polar Biol 2013. [DOI: 10.1007/s00300-013-1385-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Olofsson J, te Beest M, Ericson L. Complex biotic interactions drive long-term vegetation dynamics in a subarctic ecosystem. Philos Trans R Soc Lond B Biol Sci 2013; 368:20120486. [PMID: 23836791 PMCID: PMC3720058 DOI: 10.1098/rstb.2012.0486] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Predicting impacts of global warming requires understanding of the extent to which plant biomass and production are controlled by bottom-up and top-down drivers. By annually monitoring community composition in grazed control plots and herbivore-free exclosures at an Arctic location for 15 years, we detected multiple biotic interactions. Regular rodent cycles acted as pulses driving synchronous fluctuations in the biomass of field-layer vegetation; reindeer influenced the biomass of taller shrubs, and the abundance of plant pathogenic fungi increased when densities of their host plants increased in exclosures. Two outbreaks of geometrid moths occurred during the study period, with contrasting effects on the field layer: one in 2004 had marginal effects, while one in 2012 severely reduced biomass in the control plots and eliminated biomass that had accumulated over 15 years in the exclosures. The latter was followed by a dramatic decline of the dominant understory dwarf-shrub Empetrum hermaphroditum, driven by an interaction between moth herbivory on top buds and leaves, and increased disease severity of a pathogenic fungus. We show that the climate has important direct and indirect effects on all these biotic interactions. We conclude that long time series are essential to identify key biotic interactions in ecosystems, since their importance will be influenced by climatic conditions, and that manipulative treatments are needed in order to obtain the mechanistic understanding needed for robust predictions of future ecosystem changes and their feedback effects.
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Affiliation(s)
- Johan Olofsson
- Department of Ecology and Environmental Science, Umeå University, 901 87 Umeå, Sweden.
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Clark CM, Morefield PE, Gilliam FS, Pardo LH. Estimated losses of plant biodiversity in the United States from historical N deposition (1985–2010). Ecology 2013; 94:1441-8. [DOI: 10.1890/12-2016.1] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Kaarlejärvi E, Eskelinen A, Olofsson J. Herbivory prevents positive responses of lowland plants to warmer and more fertile conditions at high altitudes. Funct Ecol 2013. [DOI: 10.1111/1365-2435.12113] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Elina Kaarlejärvi
- Department of Ecology and Environmental Sciences; Umeå University; SE-90187; Umeå; Sweden
| | | | - Johan Olofsson
- Department of Ecology and Environmental Sciences; Umeå University; SE-90187; Umeå; Sweden
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Species Composition of Subalpine Grassland is Sensitive to Nitrogen Deposition, but Not to Ozone, After Seven Years of Treatment. Ecosystems 2013. [DOI: 10.1007/s10021-013-9670-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Bowman WD, Murgel J, Blett T, Porter E. Nitrogen critical loads for alpine vegetation and soils in Rocky Mountain National Park. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2012; 103:165-171. [PMID: 22516810 DOI: 10.1016/j.jenvman.2012.03.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2011] [Revised: 12/27/2011] [Accepted: 03/02/2012] [Indexed: 05/31/2023]
Abstract
We evaluated the ecological thresholds associated with vegetation and soil responses to nitrogen (N) deposition, by adding NH(4)NO(3) in solution at rates of 5, 10 and 30 kg N ha(-1) yr(-1) to plots in a species rich dry meadow alpine community in Rocky Mountain National Park receiving ambient N deposition of 4 kg N ha(-1) yr(-1). To determine the levels of N input that elicited changes, we measured plant species composition annually, and performed one-time measurements of aboveground biomass and N concentrations, soil solution and resin bag inorganic N, soil pH, and soil extractable cations after 3 years of N additions. Our goal was to use these dose-response relationships to provide N critical loads for vegetation and soils for the alpine in Rocky Mountain National Park. Species richness and diversity did not change in response to the treatments, but one indicator species, Carex rupestris increased in cover from 34 to 125% in response to the treatments. Using the rate of change in cover for C. rupestris in the treatment and the ambient plots, and assuming the change in cover was due solely to N deposition, we estimated a N critical load for vegetation at 3 kg N ha(-1) yr(-1). Inorganic N concentrations in soil solution increased above ambient levels at input rates between 9 kg N ha(-1) yr(-1) (resin bags) and 14 kg N ha(-1) yr(-1) (lysimeters), indicating biotic and abiotic sinks for N deposition are exhausted at these levels. No changes in soil pH or extractable cations occurred in the treatment plots, indicating acidification had not occurred after 3 years. We conclude that N critical loads under 10 kg ha(-1) yr(-1) are needed to prevent future acidification of soils and surface waters, and recommend N critical loads for vegetation at 3 kg N ha(-1) yr(-1) as important for protecting natural plant communities and ecosystem services in Rocky Mountain National Park.
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Affiliation(s)
- William D Bowman
- Mountain Research Station, Institute of Arctic and Alpine Research, University of Colorado, Boulder, CO 80309, USA.
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Ashton IW, Miller AE, Bowman WD, Suding KN. Niche complementarity due to plasticity in resource use: plant partitioning of chemical N forms. Ecology 2010; 91:3252-60. [DOI: 10.1890/09-1849.1] [Citation(s) in RCA: 253] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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38
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Burkle L, Irwin R. The importance of interannual variation and bottomâup nitrogen enrichment for plantâpollinator networks. OIKOS 2009. [DOI: 10.1111/j.1600-0706.2009.17740.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Mitchell MGE, Cahill JF, Hik DS. Plant interactions are unimportant in a subarctic-alpine plant community. Ecology 2009; 90:2360-7. [PMID: 19769114 DOI: 10.1890/08-0924.1] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
We investigated whether plant interaction intensity in a subarctic-alpine meadow is important for determining community structure and species abundance. Using two common species as phytometers, we measured interaction intensity using a neighbor removal approach. Eight biotic and abiotic variables known to influence species abundance and community structure were measured, with regression trees used to examine how plant interactions and the biotic and abiotic variables were related to species evenness, richness, and phytometer spatial cover. A range of interactions was present, with both strong competition and facilitation present over small-scale abiotic and biotic gradients. Despite the variation in interaction intensity, it was generally unrelated to either community structure or phytometer cover. In other words, plant interactions were intense in many cases but were not important to community structure. This may be due to the prevalence of clonal species in this system and the influence of previous year's interactions on plant survival and patterns of community structure. These results also suggest how conflicting theories of the role of competition in unproductive environments may be resolved. Our findings suggest that plant interactions may be intense in reducing individual growth, while simultaneously not important in the context of community structure. Plant interactions need to be viewed and tested relative to other factors and stresses to accurately evaluate their importance in plant communities, with continued differentiation between the intensity of plant interactions and their relative importance in communities.
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Affiliation(s)
- Matthew G E Mitchell
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G2E9, Canada
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Spiegelberger T, Müller-Schärer H, Matthies D, Schaffner U. Sawdust Addition Reduces the Productivity of Nitrogen-Enriched Mountain Grasslands. Restor Ecol 2009. [DOI: 10.1111/j.1526-100x.2008.00424.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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41
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Baptist F, Tcherkez G, Aubert S, Pontailler JY, Choler P, Nogués S. 13C and 15N allocations of two alpine species from early and late snowmelt locations reflect their different growth strategies. JOURNAL OF EXPERIMENTAL BOTANY 2009; 60:2725-35. [PMID: 19401411 PMCID: PMC2692016 DOI: 10.1093/jxb/erp128] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2008] [Revised: 03/25/2009] [Accepted: 03/25/2009] [Indexed: 05/10/2023]
Abstract
Intense efforts are currently devoted to disentangling the relationships between plant carbon (C) allocation patterns and soil nitrogen (N) availability because of their consequences for growth and more generally for C sequestration. In cold ecosystems, only a few studies have addressed whole-plant C and/or N allocation along natural elevational or topographical gradients. (12)C/(13)C and (14)N/(15)N isotope techniques have been used to elucidate C and N partitioning in two alpine graminoids characterized by contrasted nutrient economies: a slow-growing species, Kobresia myosuroides (KM), and a fast-growing species, Carex foetida (CF), located in early and late snowmelt habitats, respectively, within the alpine tundra (French Alps). CF allocated higher labelling-related (13)C content belowground and produced more root biomass. Furthermore, assimilates transferred to the roots were preferentially used for growth rather than respiration and tended to favour N reduction in this compartment. Accordingly, this species had higher (15)N uptake efficiency than KM and a higher translocation of reduced (15)N to aboveground organs. These results suggest that at the whole-plant level, there is a compromise between N acquisition/reduction and C allocation patterns for optimized growth.
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Affiliation(s)
- Florence Baptist
- Laboratoire d'Ecologie Alpine, UMR CNRS-UJF 5553, Université de Grenoble, BP 53, F-38041 Grenoble Cedex 09, France.
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42
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Suding KN, Ashton IW, Bechtold H, Bowman WD, Mobley ML, Winkleman R. PLANT AND MICROBE CONTRIBUTION TO COMMUNITY RESILIENCE IN A DIRECTIONALLY CHANGING ENVIRONMENT. ECOL MONOGR 2008. [DOI: 10.1890/07-1092.1] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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43
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Abstract
The importance of interspecific competition as a cause of resource partitioning among species has been widely assumed but rarely tested. Using neighbor removals in combination with 15N tracer additions in the field, we examined variation among three alpine species in the uptake of 15N-NH4+, 15N-NO3-, and 15N-13C-[2]-glycine in intact neighborhoods, when paired with a specific neighbor, and when all neighbors were removed. Species varied in the capacity to take up 15N-labeled NH4+, NO3-, and glycine in intact neighborhoods and in interspecific pairs. When interspecific neighbor pairs were compared with no neighbor controls, neighbors reduced 15N uptake in target species by as much as 50%, indicating competition for N. Furthermore, neighbor identity influenced the capacity of species to take up different forms of N. Thus, competition within interspecific neighbor pairs often caused reduced uptake of a particular form of N, as well as shifts to uptake of an alternative form of N. Such shifts in resource use as a result of competition are an implicit assumption in studies of resource partitioning but have rarely been documented. Our study suggests that plasticity in the uptake of different forms of N may be a mechanism by which cooccurring plants reduce competition for N.
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Affiliation(s)
- Amy E Miller
- Mountain Research Station, Institute of Arctic and Alpine Research, and Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, Colorado 80309, USA.
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44
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Murakami M, Ichie T, Hirao T. Beta-diversity of lepidopteran larval communities in a Japanese temperate forest: effects of phenology and tree species. Ecol Res 2007. [DOI: 10.1007/s11284-007-0353-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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45
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Bassin S, Volk M, Suter M, Buchmann N, Fuhrer J. Nitrogen deposition but not ozone affects productivity and community composition of subalpine grassland after 3 yr of treatment. THE NEW PHYTOLOGIST 2007; 175:523-534. [PMID: 17635227 DOI: 10.1111/j.1469-8137.2007.02140.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
A field experiment was established at 2000 m above sea level (asl) in the central Swiss Alps with the aim of investigating the effects of elevated ozone (O(3)) and nitrogen deposition (N), and of their combination, on above-ground productivity and species composition of subalpine grassland. One hundred and eighty monoliths were extracted from a species-rich Geo-Montani-Nardetum pasture and exposed in a free-air O(3)-fumigation system to one of three concentrations of O(3) (ambient, 1.2 x ambient, 1.6 x ambient) and five concentrations of additional N. Above-ground biomass, proportion of functional groups and normalized difference vegetation index (NDVI) were measured annually. After 3 yr of treatment, the vegetation responded to the N input with an increase in above-ground productivity and altered species composition, but without changes resulting from elevated O(3). N input > 10 kg N ha(-1) yr(-1) was sufficient to affect the composition of functional groups, with sedges benefiting over-proportionally. No interaction of O(3) x N was observed, except for NDVI; positive effects of N addition on canopy greenness were counteracted by accelerated leaf senescence in the highest O(3) treatment. The results suggest that effects of elevated O(3) on the productivity and floristic composition of subalpine grassland may develop slowly, regardless of the sensitive response to increasing N.
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Affiliation(s)
- Seraina Bassin
- Air Pollution and Climate Group, Agroscope Research Station ART, CH-8046 Zurich, Switzerland
| | - Matthias Volk
- Air Pollution and Climate Group, Agroscope Research Station ART, CH-8046 Zurich, Switzerland
| | - Matthias Suter
- Institute of Integrative Biology, ETH Zurich, CH-8092 Zurich, Switzerland
| | - Nina Buchmann
- Institute of Plant Sciences, ETH Zurich, CH-8092 Zurich, Switzerland
| | - Jürg Fuhrer
- Air Pollution and Climate Group, Agroscope Research Station ART, CH-8046 Zurich, Switzerland
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Bowman WD, Gartner JR, Holland K, Wiedermann M. Nitrogen critical loads for alpine vegetation and terrestrial ecosystem response: are we there yet? ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2006; 16:1183-93. [PMID: 16827011 DOI: 10.1890/1051-0761(2006)016[1183:nclfav]2.0.co;2] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Increases in the deposition of anthropogenic nitrogen (N) have been linked to several terrestrial ecological changes, including soil biogeochemistry, plant stress susceptibility, and community diversity. Recognizing the need to identify sensitive indicators of biotic response to N deposition, we empirically estimated the N critical load for changes in alpine plant community composition and compared this with the estimated critical load for soil indicators of ecological change. We also measured the degree to which alpine vegetation may serve as a sink for anthropogenic N and how much plant sequestration is related to changes in species composition. We addressed these research goals by adding 20, 40, or 60 kg N x ha(-1) x yr(-1), along with an ambient control (6 kg N x ha(-1) x yr(-1) total deposition), to a species-rich alpine dry meadow for an eight-year period. Change in plant species composition associated with the treatments occurred within three years of the initiation of the experiment and were significant at all levels of N addition. Using individual species abundance changes and ordination scores, we estimated the N critical loads (total deposition) for (1) change in individual species to be 4 kg N x ha(-1) yr(-1) and (2) for overall community change to be 10 kg N x ha(-1) x yr(-1). In contrast, increases in NO3- leaching, soil solution inorganic NO3-, and net N nitrification occurred at levels above 20 kg N x ha(-1) x yr(-1). Increases in total aboveground biomass were modest and transient, occurring in only one of the three years measured. Vegetative uptake of N increased significantly, primarily as a result of increasing tissue N concentrations and biomass increases in subdominant species. Aboveground vegetative uptake of N accounted for <40% of the N added. The results of this experiment indicate that changes in vegetation composition will precede detectable changes in more traditionally used soil indicators of ecosystem responses to N deposition and that changes in species composition are probably ongoing in alpine dry meadows of the Front Range of the Colorado Rocky Mountains. Feedbacks to soil N cycling associated with changes in litter quality and species composition may result in only short-term increases in vegetation N pools.
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Affiliation(s)
- William D Bowman
- Mountain Research Station, Institute of Arctic and Alpine Research, and Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, Colorado 80309-0334, USA.
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47
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Pennings SC, Clark CM, Cleland EE, Collins SL, Gough L, Gross KL, Milchunas DG, Suding KN. Do individual plant species show predictable responses to nitrogen addition across multiple experiments? OIKOS 2005. [DOI: 10.1111/j.0030-1299.2005.13792.x] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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48
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Klanderud K, Totland Ø. SIMULATED CLIMATE CHANGE ALTERED DOMINANCE HIERARCHIES AND DIVERSITY OF AN ALPINE BIODIVERSITY HOTSPOT. Ecology 2005. [DOI: 10.1890/04-1563] [Citation(s) in RCA: 179] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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49
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Traut BH. Effects of nitrogen addition and salt grass (Distichlis spicata) upon high salt marsh vegetation in Northern California, USA. ACTA ACUST UNITED AC 2005. [DOI: 10.1007/bf02732862] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Muñoz AA, Celedon-Neghme C, Cavieres LA, Arroyo MTK. Bottom-up effects of nutrient availability on flower production, pollinator visitation, and seed output in a high-Andean shrub. Oecologia 2004; 143:126-35. [PMID: 15583940 DOI: 10.1007/s00442-004-1780-3] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2004] [Accepted: 11/09/2004] [Indexed: 11/25/2022]
Abstract
Soil nutrient availability directly enhances vegetative growth, flowering, and fruiting in alpine ecosystems. However, the impacts of nutrient addition on pollinator visitation, which could affect seed output indirectly, are unknown. In a nutrient addition experiment, we tested the hypothesis that seed output in the insect-pollinated, self-incompatible shrub, Chuquiraga oppositifolia (Asteraceae) of the Andes of central Chile, is enhanced by soil nitrogen (N) availability. We aimed to monitor total shrub floral display, size of flower heads (capitula), pollinator visitation patterns, and seed output during three growing seasons on control and N addition shrubs. N addition did not augment floral display, size of capitula, pollinator visitation, or seed output during the first growing season. Seed mass and viability were 25-40% lower in fertilised shrubs. During the second growing season only 33% of the N addition shrubs flowered compared to 71% of controls, and a significant (50%) enhancement in vegetative growth occurred in fertilised shrubs. During the third growing season, floral display in N addition shrubs was more than double that of controls, received more than twice the number of insect pollinator visits, and seed output was three- to four-fold higher compared to controls. A significant (50%) enhancement in vegetative growth again occurred in N addition shrubs. Results of this study strongly suggest that soil N availability produces strong positive bottom-up effects on the reproductive output of the alpine shrub C. oppositifolia. Despite taking considerably longer to be manifest in comparison to the previously reported top-down indirect negative effects of lizard predators in the same study system, our results suggest that both bottom-up and top-down forces are important in controlling the reproductive output of an alpine shrub.
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Affiliation(s)
- Alejandro A Muñoz
- ECOBIOSIS, Departamento de Botánica, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Casilla 160-C, Concepción, Chile.
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