1
|
Wang X, Li J, Ge H, Pan S, Li P, Guo L, Yang L, Peng Z, Wang B, Wang Z, Wang C, Liu L. Plant traits mediate foliar uptake of deposited nitrogen by mature woody plants. PLANT, CELL & ENVIRONMENT 2024; 47:4870-4885. [PMID: 39101480 DOI: 10.1111/pce.15073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2024] [Revised: 07/22/2024] [Accepted: 07/25/2024] [Indexed: 08/06/2024]
Abstract
Increased atmospheric nitrogen (N) deposition significantly disturbs ecosystem N cycle. Although foliar interception and uptake of N deposition can provide an important alternative N supply to forest ecosystems, the mechanisms regulating foliar N uptake from wet deposition are not fully understood. Here, we selected 19 woody species with a wide range of plant traits from different functional groups and conducted a 15N isotope labelling experiment through brushing 15NH4 + and 15NO3 - solution on canopy leaves. Our findings demonstrate that leaves can directly absorb N from wet deposition within a few hours. The average leaf 15N recoveries were 10% and 28% under 15NH4 + and 15NO3 - treatments across species, respectively, while twig N recoveries were only 1%-7% of leaf N recoveries. Differences in foliar N uptake efficiency among species were closely associated with leaf traits but were little influenced by meteorological conditions or soil nutrient status. Specifically, plants with higher leaf N concentration, larger specific leaf area and lower wax concentration exhibited higher leaf N recovery. Our results indicated that tree canopies could directly absorb N from atmospheric deposition. We highlight the critical role of leaf traits in determining canopy foliar N uptake, which may consequently influence plant competition under elevated N deposition.
Collapse
Affiliation(s)
- Xin Wang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- China National Botanical Garden, Beijing, China
| | - Jing Li
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- China National Botanical Garden, Beijing, China
- College of Resources and Environment, University of the Chinese Academy of Sciences, Beijing, China
| | - Heng Ge
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- China National Botanical Garden, Beijing, China
- College of Resources and Environment, University of the Chinese Academy of Sciences, Beijing, China
| | - Shengnan Pan
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- China National Botanical Garden, Beijing, China
- College of Resources and Environment, University of the Chinese Academy of Sciences, Beijing, China
| | - Ping Li
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- China National Botanical Garden, Beijing, China
- College of Resources and Environment, University of the Chinese Academy of Sciences, Beijing, China
| | - Lulu Guo
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- China National Botanical Garden, Beijing, China
- College of Resources and Environment, University of the Chinese Academy of Sciences, Beijing, China
| | - Lu Yang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- China National Botanical Garden, Beijing, China
- College of Resources and Environment, University of the Chinese Academy of Sciences, Beijing, China
| | - Ziyang Peng
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- China National Botanical Garden, Beijing, China
- College of Resources and Environment, University of the Chinese Academy of Sciences, Beijing, China
| | - Bin Wang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- China National Botanical Garden, Beijing, China
- College of Resources and Environment, University of the Chinese Academy of Sciences, Beijing, China
- College of Life Science, Zhejiang University, Hangzhou, Zhejiang, China
| | - Zhenhua Wang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- China National Botanical Garden, Beijing, China
- College of Resources and Environment, University of the Chinese Academy of Sciences, Beijing, China
- The Engineering Technology Research Center of Characteristic Medicinal Plants of Fujian, School of Life Sciences, Ningde Normal University, Ningde, Fujian, China
| | - Chengzhang Wang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- China National Botanical Garden, Beijing, China
- College of Resources and Environment, University of the Chinese Academy of Sciences, Beijing, China
| | - Lingli Liu
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- China National Botanical Garden, Beijing, China
- College of Resources and Environment, University of the Chinese Academy of Sciences, Beijing, China
| |
Collapse
|
2
|
Cai Z, Fu M, Yao Y, Chen Y, Song H, Zhang S. Differences in phytohormone and flavonoid metabolism explain the sex differences in responses of Salix rehderiana to drought and nitrogen deposition. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2023; 114:534-553. [PMID: 36790349 DOI: 10.1111/tpj.16152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 02/08/2023] [Indexed: 05/10/2023]
Abstract
Due to global warming and the increase in nitrogen oxide emissions, plants experience drought and nitrogen (N) deposition. However, little is known about the acclimation to drought and N deposition of Salix species, which are dioecious woody plants. Here, an investigation into foliar N deposition combined with drought was conducted by assessing integrated phenotypes, phytohormones, transcriptomics, and metabolomics of male and female Salix rehderiana. The results indicated that there was greater transcriptional regulation in males than in females. Foliar N deposition induced an increase in foliar abscisic acid (ABA) levels in males, resulting in the inhibition of stomatal conductance, photosynthesis, carbon (C) and N accumulation, and growth, whereas more N was assimilated in females. Growth as well as C and N accumulation in drought-stressed S. rehderiana females increased after N deposition. Interestingly, drought decreased flavonoid biosynthesis whereas N deposition increased it in females. Both drought and N deposition increased flavonoid methylation in males and glycosylation in females. However, in drought-exposed S. rehderiana, N deposition increased the biosynthesis and glycosylation of flavonoids in females but decreased glycosylation in males. Therefore, foliar N deposition affects the growth and drought tolerance of S. rehderiana by altering the foliar ABA levels and the biosynthesis and modification of flavonoids. This work provides a basis for understanding how S. rehderiana may acclimate to N deposition and drought in the future.
Collapse
Affiliation(s)
- Zeyu Cai
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China
| | - Mingyue Fu
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China
| | - Yuan Yao
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China
| | - Yao Chen
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China
| | - Haifeng Song
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China
| | - Sheng Zhang
- Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China
| |
Collapse
|
3
|
Tian Y, Wang J, Zhou L, Tao L, Lin Y, Hui D, Ren H, Lu H. Nitrogen budgets of a lower subtropical forest as affected by 6 years of over-canopy and understory nitrogen additions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 852:158546. [PMID: 36067860 DOI: 10.1016/j.scitotenv.2022.158546] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Revised: 08/31/2022] [Accepted: 09/01/2022] [Indexed: 06/15/2023]
Abstract
Although tropical and subtropical regions have replaced temperate regions as the global-change hotspots for increased atmosphere nitrogen (N) deposition, whether the regional forests reach N saturation is still unclear. Understory or floor N addition has been commonly used in N-deposition studies, but the results of such studies have recently been challenged because they fail to account for canopy interception, assimilation, and leaching processes. Here, we conducted a field experiment to quantify the effects of over-canopy and understory N addition on N budgets in a lower subtropical monsoon evergreen broadleaved (LSMEB) forest. We found that the LSMEB forest was not N saturated after receiving additional N at 25 and 50 kg ha-1 yr-1 for 6 years. Plants were able to absorb the added N by increasing the N concentrations in their organs, with 120-412 % increasing trend of plant N pools under N-addition treatments. Canopy absorption of N resulting from over-canopy N addition led to increases in N concentrations in tree organs but not to increases in tree biomass. Understory N addition could underestimate the effects of N deposition in forests due to neglecting canopy N interception and canopy effects on N redistribution. Additional experiments using over-canopy N addition are needed to assess the true effects of N deposition on different forest ecosystems in different climate zones.
Collapse
Affiliation(s)
- Yang Tian
- CAS Engineering Laboratory for Vegetation Ecosystem Restoration on Islands and Coastal Zones & Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China
| | - Jun Wang
- CAS Engineering Laboratory for Vegetation Ecosystem Restoration on Islands and Coastal Zones & Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China
| | - Lang Zhou
- CAS Engineering Laboratory for Vegetation Ecosystem Restoration on Islands and Coastal Zones & Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China; Forestry Comprehensive Affairs Center of Baiyun District, Guangzhou 510540, China
| | - Libin Tao
- CAS Engineering Laboratory for Vegetation Ecosystem Restoration on Islands and Coastal Zones & Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China; Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions, Ministry of Education, College of Geography and Environmental Science, Henan University, Jinming Avenue, Kaifeng 475004, China
| | - Yongbiao Lin
- CAS Engineering Laboratory for Vegetation Ecosystem Restoration on Islands and Coastal Zones & Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China
| | - Dafeng Hui
- Department of Biological Sciences, Tennessee State University, Nashville, TN 37209, USA
| | - Hai Ren
- CAS Engineering Laboratory for Vegetation Ecosystem Restoration on Islands and Coastal Zones & Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China.
| | - Hongfang Lu
- CAS Engineering Laboratory for Vegetation Ecosystem Restoration on Islands and Coastal Zones & Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China.
| |
Collapse
|
4
|
Hu CC, Liu XY. Plant nitrogen-use strategies and their responses to the urban elevation of atmospheric nitrogen deposition in southwestern China. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 311:119969. [PMID: 35981639 DOI: 10.1016/j.envpol.2022.119969] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 08/09/2022] [Accepted: 08/10/2022] [Indexed: 06/15/2023]
Abstract
The elevation of nitrogen (N) deposition by urbanization profoundly impacts the structure and function of surrounding forest ecosystems. Plants are major biomass sinks of external N inputs into forests. Yet, the N-use strategies of forest plants in many areas remain unconstrained in city areas, so their responses and adapting mechanisms to the elevated N deposition are open questions. Here we investigated concentrations and N isotope (δ15N) of total N (TN) and nitrate (NO3-) in leaves and roots of four plant species in subtropical shrubberies and pine forests under N deposition levels of 13 kg-N ha-1 yr-1 and 29 kg-N ha-1 yr-1 at the Guiyang area of southwestern China, respectively. The δ15N differences between plant NO3- and soil NO3- revealed a meager NO3- reduction in leaves but a preferentially high NO3- reduction in roots. δ15N mass-balance analyses between plant TN and soil dissolved N suggested that soil NO3- contributed more than reduced N, and dissolved organic N contributed comparably with ammonium to plant TN, and the study plants preferred NO3- over reduced N. The elevation of N deposition induced root but not leaf NO3- reduction and enhanced the contribution of soil NO3- to plant TN, but plant NO3- preference decreased due to much higher magnitudes of soil NO3- enrichment than plant NO3- utilization. We conclude that plants in subtropical forests of southwestern China preferred NO3- over reduced N, and NO3- was reduced more in roots than in leaves, anthropogenic N pollution enhanced soil NO3- enrichment and plant NO3- utilization but reduced plant NO3- preference.
Collapse
Affiliation(s)
- Chao-Chen Hu
- School of Earth System Science, Tianjin University, Tianjin, 300072, China
| | - Xue-Yan Liu
- School of Earth System Science, Tianjin University, Tianjin, 300072, China.
| |
Collapse
|
5
|
Xie H, Li X, Tang Y, Pile Knapp LS, Jin S. Multi-nutrient stoichiometry of Chinese hickory (Carya cathayensis) saplings: plant organs vary in their response to nitrogen fertilization. TREE PHYSIOLOGY 2022; 42:1786-1798. [PMID: 35313354 DOI: 10.1093/treephys/tpac030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 03/08/2022] [Indexed: 06/14/2023]
Abstract
Nitrogen (N) enrichment from excessive fertilization in managed forests affects biogeochemical cycles on multiple scales, but our knowledge of how N availability shifts multi-nutrient stoichiometries (including macronutrients: N, phosphorus, potassium, calcium, magnesium and micronutrients: manganese, iron and zinc) within and among organs (root, stem and leaf) remains limited. To understand the difference among organs in terms of multi-nutrient stoichiometric homeostasis responding to N fertilization, a six-level N supply experiment was conducted through a hydroponic system to examine stem growth, multi-nutrient concentrations and stoichiometric ratios in roots, stems and leaves of 2-year-old Chinese hickory (Carya cathayensis Sarg.) saplings. Results showed that N supply significantly enhanced leaf length, width, basal diameter and sapling height. Increasing the rates of N also significantly altered multi-nutrient concentrations in roots, stems and leaves. Macronutrients generally respond more positively than micronutrients within organs. Among organs, leaves and stems generally responded more actively to N supply than roots. The stoichiometric ratios of nutrients within different organs changed significantly with N supply, but their direction and degree of change varied by organ. Specifically, increased N supply reduced the ratios of both macronutrients and micronutrients to N in plant organs, while increased N supply elevated the ratios of P to other nutrients. With N fertilization, ratios of micronutrients decreased in leaves and stems and increased in roots. In particular, leaf N and stem Mn stoichiometries responded strongly to N availability, indicating stimulated N uptake but a decreased risk of Mn2+ accumulation to excessive N. Overall, Chinese hickory saplings responded positively to increasing N availability in terms of stem growth, but the multi-nutrient stoichiometric homeostasis was distinctively organ-dependent. These results are expected to enhance our understanding of N-induced changes in homeostasis of multiple nutrients at the organ level and may offer new insights into how plants adapt to increasing N fertilization.
Collapse
Affiliation(s)
- Hongtao Xie
- Jiyang College, Zhejiang A&F University, Zhuji 311800, China
| | - Xueqin Li
- Jiyang College, Zhejiang A&F University, Zhuji 311800, China
| | - Yu Tang
- Jiyang College, Zhejiang A&F University, Zhuji 311800, China
| | - Lauren S Pile Knapp
- USDA Forest Service, Northern Research Station, 202 ABNR Building, University of Missouri-Columbia, Columbia, MO 65211, USA
| | - Songheng Jin
- Jiyang College, Zhejiang A&F University, Zhuji 311800, China
| |
Collapse
|
6
|
Snyder KA, Robinson SA, Schmidt S, Hultine KR. Stable isotope approaches and opportunities for improving plant conservation. CONSERVATION PHYSIOLOGY 2022; 10:coac056. [PMID: 35966756 PMCID: PMC9367551 DOI: 10.1093/conphys/coac056] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 04/15/2021] [Accepted: 08/01/2022] [Indexed: 06/01/2023]
Abstract
Successful conservation of threatened species and ecosystems in a rapidly changing world requires scientifically sound decision-making tools that are readily accessible to conservation practitioners. Physiological applications that examine how plants and animals interact with their environment are now widely used when planning, implementing and monitoring conservation. Among these tools, stable-isotope physiology is a potentially powerful, yet under-utilized cornerstone of current and future conservation efforts of threatened and endangered plants. We review the underlying concepts and theory of stable-isotope physiology and describe how stable-isotope applications can support plant conservation. We focus on stable isotopes of carbon, hydrogen, oxygen and nitrogen to address plant ecophysiological responses to changing environmental conditions across temporal scales from hours to centuries. We review examples from a broad range of plant taxa, life forms and habitats and provide specific examples where stable-isotope analysis can directly improve conservation, in part by helping identify resilient, locally adapted genotypes or populations. Our review aims to provide a guide for practitioners to easily access and evaluate the information that can be derived from stable-isotope signatures, their limitations and how stable isotopes can improve conservation efforts.
Collapse
Affiliation(s)
- Keirith A Snyder
- Corresponding author: USDA Agricultural Research Service, Great Basin Rangelands Research Unit, Reno,
920 Valley Road, NV 89512, USA.
| | - Sharon A Robinson
- School of Earth, Atmospheric and Life Sciences, University of Wollongong, Wollongong, New South Wales 2522, Australia
- Securing Antarctica’s Environmental Future, University of Wollongong, Wollongong, New South Wales 2522, Australia
| | - Susanne Schmidt
- School of Agriculture and Food Sciences, The University of Queensland, Building 62, Brisbane Queensland 4075, Australia
| | - Kevin R Hultine
- Department of Research, Conservation and Collections, Desert Botanical Garden, 1201 Galvin Parkway, Phoenix, AZ 85008, USA
| |
Collapse
|
7
|
Manninen S, Zverev V, Kozlov MV. Foliar stable isotope ratios of carbon and nitrogen in boreal forest plants exposed to long-term pollution from the nickel-copper smelter at Monchegorsk, Russia. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:48880-48892. [PMID: 35199271 PMCID: PMC9252950 DOI: 10.1007/s11356-022-19261-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 02/13/2022] [Indexed: 06/14/2023]
Abstract
Long-term exposure to primary air pollutants, such as sulphur dioxide (SO2) and nitrogen oxides (NOx), alters the structure and functions of forest ecosystems. Many biochemical and biogeochemical processes discriminate against the heavier isotopes in a mixture; thus, the values of δ13C and δ15N (i.e. the ratio of stable isotopes 13C to 12C and that of 15 N to 14 N, respectively) may give insights into changes in ecosystem processes and identify the immediate drivers of these changes. We studied sources of variation in the δ13C and δ15N values in the foliage of eight boreal forest C3 plants at 10 sites located at the distance of 1-40 km from the Monchegorsk nickel-copper smelter in Russia. From 1939‒2019, this smelter emitted over 14,000,000 metric tons (t) of SO2, 250,000 t of metals, primarily nickel and copper, and 140,000 t of NOx. The δ13C value in evergreen plants and the δ15N value in all plants increased near the smelter independently of the plant mycorrhizal type. We attribute the pollution-related increase in the foliar δ13C values of evergreen species mainly to direct effects of SO2 on stomatal conductance, in combination with pollution-related water stress, which jointly override the potential opposite effect of increasing ambient CO2 concentration on δ13C values. Stomatal uptake of NOx and root uptake of 15N-enriched organic N compounds and NH4+ may explain the increased foliar δ15N values and elevated foliar N concentrations, especially in the evergreen trees (Pinus sylvestris), close to Monchegorsk, where the soil inorganic N supply is reduced due to the impact of long-term SO2 and heavy metal emissions on plant biomass. We conclude that, despite the uncertainties in interpreting δ13C and δ15N responses to pollution, the Monchegorsk smelter has imposed and still imposes a great impact on C and N cycling in the surrounding N-limited subarctic forest ecosystems.
Collapse
Affiliation(s)
- Sirkku Manninen
- Faculty of Biological and Environmental Sciences, University of Helsinki, Viikinkaari 1, P.O. Box 65 , 00014, Helsinki, Finland
| | - Vitali Zverev
- Department of Biology, University of Turku, 20014, Turku, Finland
| | - Mikhail V Kozlov
- Department of Biology, University of Turku, 20014, Turku, Finland.
| |
Collapse
|
8
|
Wang X, Wang B, Wang C, Wang Z, Li J, Jia Z, Yang S, Li P, Wu Y, Pan S, Liu L. Canopy processing of N deposition increases short-term leaf N uptake and photosynthesis, but not long-term N retention for aspen seedlings. THE NEW PHYTOLOGIST 2021; 229:2601-2610. [PMID: 33112419 DOI: 10.1111/nph.17041] [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: 08/19/2020] [Accepted: 10/19/2020] [Indexed: 06/11/2023]
Abstract
Forest canopies can retain nitrogen (N) from atmospheric deposition. However, most empirical and modeling studies do not consider the processing of the N deposited in the canopy. To assess whether N deposition through canopy will alter the plant's N uptake and retention, we conducted a 3-yr mesocosm experiment by applying (15 NH4 )2 SO4 solution to aspen sapling canopies or directly to the soil. We found that 15 N-NH4+ applied to the canopy was directly taken up by leaves. Compared with the soil N application, the canopy N application resulted in higher photosynthesis but lower N retention of the plant-soil system in the first growing season. Plant biomass, N concentration, and leaf N resorption were not significantly different between the canopy and soil N applications. The partitioning of retained 15 N among plant components and soil layers was similar between the two treatments 3 yr after the N application. Our findings indicated that the canopy N processing could alter leaf N supply and photosynthesis in the short term but not N retention in the long term. Under natural conditions, the chronic N deposition could continuously refill the canopy N pool, causing a sustained increase in canopy carbon uptake. Canopy N processing needs to be considered for accurately predicting the impact of N deposition.
Collapse
Affiliation(s)
- Xin Wang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Bin Wang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Chengzhang Wang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhenhua Wang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jing Li
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhou Jia
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Sen Yang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ping Li
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yuntao Wu
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Shengnan Pan
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Lingli Liu
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
- College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China
| |
Collapse
|
9
|
Tracing plant–environment interactions from organismal to planetary scales using stable isotopes: a mini review. Emerg Top Life Sci 2021; 5:301-316. [DOI: 10.1042/etls20200277] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Revised: 01/28/2021] [Accepted: 01/29/2021] [Indexed: 01/09/2023]
Abstract
Natural isotope variation forms a mosaic of isotopically distinct pools across the biosphere and flows between pools integrate plant ecology with global biogeochemical cycling. Carbon, nitrogen, and water isotopic ratios (among others) can be measured in plant tissues, at root and foliar interfaces, and in adjacent atmospheric, water, and soil environments. Natural abundance isotopes provide ecological insight to complement and enhance biogeochemical research, such as understanding the physiological conditions during photosynthetic assimilation (e.g. water stress) or the contribution of unusual plant water or nutrient sources (e.g. fog, foliar deposition). While foundational concepts and methods have endured through four decades of research, technological improvements that enable measurement at fine spatiotemporal scales, of multiple isotopes, and of isotopomers, are advancing the field of stable isotope ecology. For example, isotope studies now benefit from the maturation of field-portable infrared spectroscopy, which allows the exploration of plant–environment sensitivity at physiological timescales. Isotope ecology is also benefiting from, and contributing to, new understanding of the plant–soil–atmosphere system, such as improving the representation of soil carbon pools and turnover in land surface models. At larger Earth-system scales, a maturing global coverage of isotope data and new data from site networks offer exciting synthesis opportunities to merge the insights of single-or multi-isotope analysis with ecosystem and remote sensing data in a data-driven modeling framework, to create geospatial isotope products essential for studies of global environmental change.
Collapse
|
10
|
Hu Y, Peuke AD, Zhao X, Yan J, Li C. Effects of simulated atmospheric nitrogen deposition on foliar chemistry and physiology of hybrid poplar seedlings. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2019; 143:94-108. [PMID: 31491704 DOI: 10.1016/j.plaphy.2019.08.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 08/27/2019] [Accepted: 08/27/2019] [Indexed: 05/27/2023]
Abstract
During recent decades, the southern and eastern regions of Asia have experienced high levels of atmospheric N deposition. Excess N deposition is predicted to influence tree growth and species composition in the regions, but visual or physiological assessments alone are not sufficient to determine the real effects of atmospheric N deposition. In this study, we simulated atmospheric wet deposition of inorganic N by spraying a NO3- solution (20 mmol⋅L-1) or a mixture of NO3- (20 mmol⋅L-1) plus NO2- (100 or 300 μmol⋅L-1) on leaves of hybrid poplar (Populus alba × Populus berolinensis) seedlings and examined morphoanatomical traits and physiological processes. Leaves of seedlings sprayed with single or mixed N solutions developed marginal necrosis, curling, and small cracks on the adaxial surface. The silicon (Si)-rich crystals were larger (about 100% increase in crystal diameter compared to untreated seedlings) on the adaxial leaf surface, with a significant positive correlation between the atomic percentage of N and Si on the crystal areas of the surface. Leaves were sensitive to NO2- compared with NO3- even at a low concentration; water content, dry mass, and photochemical variables significantly declined and dark respiration increased only in leaves treated with mixed N form. Mixed N foliar applications significantly increased leaf concentrations of the free amino acids Glu, Gln, and Asn and organic acids oxaloacetic acid and citric acid. Besides, mixed N treatment stimulated leaf transamination, as indicated by significant increases in Ala and Asp concentrations and activities of glutamic oxalacetic transaminase and glutamic pyruvic transaminase. However, mixed N applications led to declines in leaf concentrations of putrescine (by 65%, p = 0.01) and spermine (by 53%, p = 0.01). A higher proportion of NO2- (300 μmol⋅L-1) in mixed N solution was inhibitory to key N-metabolic enzymes and N translocation via the phloem. Our results showed that wet deposition of airborne N pollutants modified surface properties and induced additional detrimental effects related to N-compound foliar absorption. Furthermore, our findings indicate that detoxification of reactive N is apparently related to N assimilation and export from the treated leaves via the phloem.
Collapse
Affiliation(s)
- Yanbo Hu
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, College of Life Sciences, Northeast Forestry University, Harbin City, 150040, PR China; State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin City, 150040, PR China.
| | - Andreas D Peuke
- ADP International Plant Science Consulting, Talstrasse 8, D-79194, Gundelfingen, Germany
| | - Xiyang Zhao
- State Key Laboratory of Tree Genetics and Breeding, Northeast Forestry University, Harbin City, 150040, PR China
| | - Junxin Yan
- College of Landscape Architecture, Northeast Forestry University, Harbin City, 150040, PR China
| | - Chunming Li
- Heilongjiang Academy of Forestry, Harbin City, 150081, PR China
| |
Collapse
|
11
|
Soper FM. Three's a crowd: triple-isotope analysis traces alternate plant nitrogen nutrition pathways. THE NEW PHYTOLOGIST 2019; 223:1687-1689. [PMID: 31328280 DOI: 10.1111/nph.16025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Affiliation(s)
- Fiona M Soper
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, 14850, USA
| |
Collapse
|