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Lu C, van Groenigen KJ, Gillespie MAK, Hollister RD, Post E, Cooper EJ, Welker JM, Huang Y, Min X, Chen J, Jónsdóttir IS, Mauritz M, Cannone N, Natali SM, Schuur E, Molau U, Yan T, Wang H, He JS, Liu H. Diminishing warming effects on plant phenology over time. THE NEW PHYTOLOGIST 2024. [PMID: 39103987 DOI: 10.1111/nph.20019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2023] [Accepted: 07/06/2024] [Indexed: 08/07/2024]
Abstract
Plant phenology, the timing of recurrent biological events, shows key and complex response to climate warming, with consequences for ecosystem functions and services. A key challenge for predicting plant phenology under future climates is to determine whether the phenological changes will persist with more intensive and long-term warming. Here, we conducted a meta-analysis of 103 experimental warming studies around the globe to investigate the responses of four phenophases - leaf-out, first flowering, last flowering, and leaf coloring. We showed that warming advanced leaf-out and flowering but delayed leaf coloring across herbaceous and woody plants. As the magnitude of warming increased, the response of most plant phenophases gradually leveled off for herbaceous plants, while phenology responded in proportion to warming in woody plants. We also found that the experimental effects of warming on plant phenology diminished over time across all phenophases. Specifically, the rate of changes in first flowering for herbaceous species, as well as leaf-out and leaf coloring for woody species, decreased as the experimental duration extended. Together, these results suggest that the real-world impact of global warming on plant phenology will diminish over time as temperatures continue to increase.
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Affiliation(s)
- Chunyan Lu
- Tiantong National Station for Forest Ecosystem Research, The Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, 200241, China
- Institute of Eco-Chongming (IEC), Shanghai, 202162, China
| | - Kees Jan van Groenigen
- Department of Geography, Faculty of Environment, Science and Economy, University of Exeter, Exeter, EX4 4RJ, UK
| | - Mark A K Gillespie
- Department of Arctic and Marine Biology, UiT - The Arctic University of Norway, Tromsø, N-9037, Norway
- Department of Civil Engineering and Environmental Sciences, Western Norway University of Applied Sciences, Sogndal, 6856, Norway
| | - Robert D Hollister
- Biology Department, Grand Valley State University, Allendale, MI, 49401-9403, USA
| | - Eric Post
- Department of Wildlife, Fish and Conservation Biology, University of California, Davis, CA, 95616, USA
| | - Elisabeth J Cooper
- Department of Arctic and Marine Biology, UiT - The Arctic University of Norway, Tromsø, N-9037, Norway
| | - Jeffrey M Welker
- Ecology and Genetics Research Group, University of Oulu, Oulu, 90014, Finland
- The University of the Arctic (UArctic), Rovaniemi, 96300, Finland
- Department of Biological Sciences, University of Alaska, Anchorage, AK, 99508, USA
| | - Yixuan Huang
- Tiantong National Station for Forest Ecosystem Research, The Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, 200241, China
| | - Xueting Min
- Tiantong National Station for Forest Ecosystem Research, The Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, 200241, China
| | - Jianghui Chen
- Tiantong National Station for Forest Ecosystem Research, The Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, 200241, China
| | - Ingibjörg Svala Jónsdóttir
- Institute of Life and Environmental Sciences, University of Iceland, Reykjavík, 102, Iceland
- University Centre in Svalbard, Longyearbyen, N-9171, Norway
| | - Marguerite Mauritz
- Biological Sciences, University of Texas at El Paso, El Paso, TX, 79968, USA
| | - Nicoletta Cannone
- Department of Theoretical and Applied Sciences, University of Insubria, Via J.H. Dunant, 3, Varese, 21100, Italy
- Climate Change Research Centre, Via Valleggio 11, Como, 22100, Italy
| | - Susan M Natali
- Woods Hole Research Center, Falmouth, MA, 02540-1644, USA
| | - Edward Schuur
- Center for Ecosystem Science and Society, Northern Arizona University, Flagstaff, AZ, 86011, USA
| | - Ulf Molau
- Department of Biology and Environmental Sciences, University of Gothenburg, Gothenburg, 405 30, Sweden
| | - Tao Yan
- State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, 730000, China
| | - Hao Wang
- State Key Laboratory of Grassland Agro-ecosystems, College of Ecology, Lanzhou University, Lanzhou, 730000, China
| | - Jin-Sheng He
- State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, 730000, China
- Institute of Ecology, College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China
| | - Huiying Liu
- Tiantong National Station for Forest Ecosystem Research, The Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Shanghai, 200241, China
- Institute of Eco-Chongming (IEC), Shanghai, 202162, China
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Qiao M, Sun R, Wang Z, Dumack K, Xie X, Dai C, Wang E, Zhou J, Sun B, Peng X, Bonkowski M, Chen Y. Legume rhizodeposition promotes nitrogen fixation by soil microbiota under crop diversification. Nat Commun 2024; 15:2924. [PMID: 38575565 PMCID: PMC10995168 DOI: 10.1038/s41467-024-47159-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 03/22/2024] [Indexed: 04/06/2024] Open
Abstract
Biological nitrogen fixation by free-living bacteria and rhizobial symbiosis with legumes plays a key role in sustainable crop production. Here, we study how different crop combinations influence the interaction between peanut plants and their rhizosphere microbiota via metabolite deposition and functional responses of free-living and symbiotic nitrogen-fixing bacteria. Based on a long-term (8 year) diversified cropping field experiment, we find that peanut co-cultured with maize and oilseed rape lead to specific changes in peanut rhizosphere metabolite profiles and bacterial functions and nodulation. Flavonoids and coumarins accumulate due to the activation of phenylpropanoid biosynthesis pathways in peanuts. These changes enhance the growth and nitrogen fixation activity of free-living bacterial isolates, and root nodulation by symbiotic Bradyrhizobium isolates. Peanut plant root metabolites interact with Bradyrhizobium isolates contributing to initiate nodulation. Our findings demonstrate that tailored intercropping could be used to improve soil nitrogen availability through changes in the rhizosphere microbiome and its functions.
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Affiliation(s)
- Mengjie Qiao
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ruibo Sun
- Anhui Province Key Lab of Farmland Ecological Conservation and Nutrient Utilization, College of Resources and Environment, Anhui Agricultural University, Hefei, 230036, China
| | - Zixuan Wang
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
- College of Land Resource and Environment, Jiangxi Agricultural University, Nanchang, 330045, China
| | - Kenneth Dumack
- Terrestrial Ecology, Institute of Zoology, University of Cologne, Zülpicher Str 47b, Cologne, 50674, Germany
| | - Xingguang Xie
- National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Chuanchao Dai
- College of Life Sciences, Nanjing Normal University, Nanjing, 210023, China
| | - Ertao Wang
- National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Jizhong Zhou
- Institute for Environmental Genomics and Department of Microbiology and Plant Biology, University of Oklahoma, Norman, 73019, USA
| | - Bo Sun
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Xinhua Peng
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Michael Bonkowski
- Terrestrial Ecology, Institute of Zoology, University of Cologne, Zülpicher Str 47b, Cologne, 50674, Germany
- Cluster of Excellence on Plant Sciences (CEPLAS), University of Cologne, Cologne, 50674, Germany
| | - Yan Chen
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China.
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Niu B, Fu G. Response of plant diversity and soil microbial diversity to warming and increased precipitation in alpine grasslands on the Qinghai-Xizang Plateau - A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 912:168878. [PMID: 38029973 DOI: 10.1016/j.scitotenv.2023.168878] [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: 10/19/2023] [Revised: 11/15/2023] [Accepted: 11/23/2023] [Indexed: 12/01/2023]
Abstract
Plant diversity and soil microbial diversity are closely related, and they maintain the health and stability of terrestrial ecosystems. As a hotspot region of global biodiversity research, both air temperature and precipitation of the Qinghai-Xizang Plateau tend to increase in future. Based on an overview of the responses of grassland/alpine ecosystems to seasonal asymmetric warming and increased precipitation worldwide, we elaborated the advancements and uncertainties on the responses of plant diversity and soil microbial diversity to warming and increased precipitation in alpine grasslands on the Qinghai-Xizang Plateau. The future research focus of plant diversity and soil microbial diversity in the alpine grasslands of the Qinghai-Xizang Plateau under climate warming and increased precipitation was proposed. Generally, previous studies found that the responses of plant species diversity and soil microbial species diversity to warming and increased precipitation differed between alpine meadows and alpine steppes, but few studies focused on their responses to warming and increased precipitation in alpine desert steppes. Previous studies mainly focused on species diversity, although phylogenetic and functional diversities are also important aspects of biodiversity. Previous studies mainly explained responses of plant diversity and soil microbial diversity to warming and increased precipitation based on niche theory, although neutral theory is also the other important mechanism in regulating biodiversity. Moreover, previous studies almost ignored the coupling relationship between plant diversity and soil microbial diversity. Therefore, the following four aspects need to be strengthened, including the responses of plant diversity and soil microbial diversity to warming and increased precipitation in alpine desert steppes, the responses of plant and soil microbial phylogenetic diversity and functional diversity to warming and increased precipitation, combining the niche theory and neutral theory to examining the mechanism of biodiversity, and the coupling relationships between plant diversity and soil microbial diversity under warming and increased precipitation.
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Affiliation(s)
- Ben Niu
- Lhasa Plateau Ecosystem Research Station, Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China
| | - Gang Fu
- Lhasa Plateau Ecosystem Research Station, Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.
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Fang C, Verbrigghe N, Sigurdsson BD, Ostonen I, Leblans NIW, Marañón-Jiménez S, Fuchslueger L, Sigurðsson P, Meeran K, Portillo-Estrada M, Verbruggen E, Richter A, Sardans J, Peñuelas J, Bahn M, Vicca S, Janssens IA. Decadal soil warming decreased vascular plant above and belowground production in a subarctic grassland by inducing nitrogen limitation. THE NEW PHYTOLOGIST 2023; 240:565-576. [PMID: 37545200 DOI: 10.1111/nph.19177] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Accepted: 07/10/2023] [Indexed: 08/08/2023]
Abstract
Below and aboveground vegetation dynamics are crucial in understanding how climate warming may affect terrestrial ecosystem carbon cycling. In contrast to aboveground biomass, the response of belowground biomass to long-term warming has been poorly studied. Here, we characterized the impacts of decadal geothermal warming at two levels (on average +3.3°C and +7.9°C) on below and aboveground plant biomass stocks and production in a subarctic grassland. Soil warming did not change standing root biomass and even decreased fine root production and reduced aboveground biomass and production. Decadal soil warming also did not significantly alter the root-shoot ratio. The linear stepwise regression model suggested that following 10 yr of soil warming, temperature was no longer the direct driver of these responses, but losses of soil N were. Soil N losses, due to warming-induced decreases in organic matter and water retention capacity, were identified as key driver of the decreased above and belowground production. The reduction in fine root production was accompanied by thinner roots with increased specific root area. These results indicate that after a decade of soil warming, plant productivity in the studied subarctic grassland was affected by soil warming mainly by the reduction in soil N.
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Affiliation(s)
- Chao Fang
- Research Center for Global Changes and Ecosystem Carbon Sequestration & Mitigation, School of Applied Meteorology, Nanjing University of Information Science and Technology, Nanjing, 210044, China
- PLECO (Plants and Ecosystems), Department of Biology, University of Antwerp, Universiteitsplein 1, Wilrijk, 2610, Belgium
| | - Niel Verbrigghe
- Flanders Research Institute for Agriculture, Fisheries and Food, Caritasstraat 39, Melle, 9090, Belgium
| | | | - Ivika Ostonen
- Institute of Ecology and Earth Sciences, University of Tartu, Tartu, 51003, Estonia
| | - Niki I W Leblans
- Climate Impacts Research Centre, Umeå University, Umeå, 90333, Sweden
| | - Sara Marañón-Jiménez
- CREAF, Cerdanyola del Vallès, Barcelona, 08193, Catalonia, Spain
- CSIC, Global Ecology Unit CREAF-CSIC-UAB, Bellaterra, Barcelona, 08193, Catalonia, Spain
- Universitat Autònoma de Barcelona, Cerdanyola del Vallès, 08193, Spain
| | - Lucia Fuchslueger
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Djerassiplatz 1, 1030, Vienna, Austria
| | - Páll Sigurðsson
- Agricultural University of Iceland, Hvanneyri, Borgarnes, IS-311, Iceland
| | - Kathiravan Meeran
- Department of Ecology, University of Innsbruck, 6020, Innsbruck, Austria
| | - Miguel Portillo-Estrada
- PLECO (Plants and Ecosystems), Department of Biology, University of Antwerp, Universiteitsplein 1, Wilrijk, 2610, Belgium
| | - Erik Verbruggen
- PLECO (Plants and Ecosystems), Department of Biology, University of Antwerp, Universiteitsplein 1, Wilrijk, 2610, Belgium
| | - Andreas Richter
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Djerassiplatz 1, 1030, Vienna, Austria
| | - Jordi Sardans
- CREAF, Cerdanyola del Vallès, Barcelona, 08193, Catalonia, Spain
- CSIC, Global Ecology Unit CREAF-CSIC-UAB, Bellaterra, Barcelona, 08193, Catalonia, Spain
| | - Josep Peñuelas
- CREAF, Cerdanyola del Vallès, Barcelona, 08193, Catalonia, Spain
- CSIC, Global Ecology Unit CREAF-CSIC-UAB, Bellaterra, Barcelona, 08193, Catalonia, Spain
| | - Michael Bahn
- Department of Ecology, University of Innsbruck, 6020, Innsbruck, Austria
| | - Sara Vicca
- PLECO (Plants and Ecosystems), Department of Biology, University of Antwerp, Universiteitsplein 1, Wilrijk, 2610, Belgium
| | - Ivan A Janssens
- PLECO (Plants and Ecosystems), Department of Biology, University of Antwerp, Universiteitsplein 1, Wilrijk, 2610, Belgium
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Bai T, Wang P, Qiu Y, Zhang Y, Hu S. Nitrogen availability mediates soil carbon cycling response to climate warming: A meta-analysis. GLOBAL CHANGE BIOLOGY 2023; 29:2608-2626. [PMID: 36744998 DOI: 10.1111/gcb.16627] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Accepted: 01/10/2023] [Indexed: 05/31/2023]
Abstract
Global climate warming may induce a positive feedback through increasing soil carbon (C) release to the atmosphere. Although warming can affect both C input to and output from soil, direct and convincing evidence illustrating that warming induces a net change in soil C is still lacking. We synthesized the results from field warming experiments at 165 sites across the globe and found that climate warming had no significant effect on soil C stock. On average, warming significantly increased root biomass and soil respiration, but warming effects on root biomass and soil respiration strongly depended on soil nitrogen (N) availability. Under high N availability (soil C:N ratio < 15), warming had no significant effect on root biomass, but promoted the coupling between effect sizes of root biomass and soil C stock. Under relative N limitation (soil C:N ratio > 15), warming significantly enhanced root biomass. However, the enhancement of root biomass did not induce a corresponding C accumulation in soil, possibly because warming promoted microbial CO2 release that offset the increased root C input. Also, reactive N input alleviated warming-induced C loss from soil, but elevated atmospheric CO2 or precipitation increase/reduction did not. Together, our findings indicate that the relative availability of soil C to N (i.e., soil C:N ratio) critically mediates warming effects on soil C dynamics, suggesting that its incorporation into C-climate models may improve the prediction of soil C cycling under future global warming scenarios.
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Affiliation(s)
- Tongshuo Bai
- Ecosystem Ecology Laboratory, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | - Peng Wang
- Ecosystem Ecology Laboratory, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | - Yunpeng Qiu
- Ecosystem Ecology Laboratory, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | - Yi Zhang
- Ecosystem Ecology Laboratory, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
| | - Shuijin Hu
- Ecosystem Ecology Laboratory, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, China
- Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, North Carolina, USA
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Lee J, Yun J, Yang Y, Jung JY, Lee YK, Yuan J, Ding W, Freeman C, Kang H. Attenuation of Methane Oxidation by Nitrogen Availability in Arctic Tundra Soils. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:2647-2659. [PMID: 36719133 DOI: 10.1021/acs.est.2c05228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
CH4 emission in the Arctic has large uncertainty due to the lack of mechanistic understanding of the processes. CH4 oxidation in Arctic soil plays a critical role in the process, whereby removal of up to 90% of CH4 produced in soils by methanotrophs can occur before it reaches the atmosphere. Previous studies have reported on the importance of rising temperatures in CH4 oxidation, but because the Arctic is typically an N-limited system, fewer studies on the effects of inorganic nitrogen (N) have been reported. However, climate change and an increase of available N caused by anthropogenic activities have recently been reported, which may cause a drastic change in CH4 oxidation in Arctic soils. In this study, we demonstrate that excessive levels of available N in soil cause an increase in net CH4 emissions via the reduction of CH4 oxidation in surface soil in the Arctic tundra. In vitro experiments suggested that N in the form of NO3- is responsible for the decrease in CH4 oxidation via influencing soil bacterial and methanotrophic communities. The findings of our meta-analysis suggest that CH4 oxidation in the boreal biome is more susceptible to the addition of N than in other biomes. We provide evidence that CH4 emissions in Arctic tundra can be enhanced by an increase of available N, with profound implications for modeling CH4 dynamics in Arctic regions.
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Affiliation(s)
- Jaehyun Lee
- School of Civil and Environmental Engineering, Yonsei University, Seoul03722, South Korea
| | - Jeongeun Yun
- School of Civil and Environmental Engineering, Yonsei University, Seoul03722, South Korea
| | - Yerang Yang
- School of Civil and Environmental Engineering, Yonsei University, Seoul03722, South Korea
| | - Ji Young Jung
- Korea Polar Research Institute, Incheon21990, South Korea
| | - Yoo Kyung Lee
- Korea Polar Research Institute, Incheon21990, South Korea
| | - Junji Yuan
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing210008, China
| | - Weixin Ding
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing210008, China
| | - Chris Freeman
- School of Natural Sciences, Bangor University, BangorLL57 2UW, U.K
| | - Hojeong Kang
- School of Civil and Environmental Engineering, Yonsei University, Seoul03722, South Korea
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Newsham KK, Danielsen BK, Biersma EM, Elberling B, Hillyard G, Kumari P, Priemé A, Woo C, Yamamoto N. Rapid Response to Experimental Warming of a Microbial Community Inhabiting High Arctic Patterned Ground Soil. BIOLOGY 2022; 11:biology11121819. [PMID: 36552329 PMCID: PMC9775327 DOI: 10.3390/biology11121819] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 12/06/2022] [Accepted: 12/08/2022] [Indexed: 12/23/2022]
Abstract
The influence of climate change on microbial communities inhabiting the sparsely vegetated patterned ground soils that are widespread across the High Arctic is poorly understood. Here, in a four-year experiment on Svalbard, we warmed patterned ground soil with open top chambers and biannually irrigated the soil to predict the responses of its microbial community to rising temperatures and precipitation. A 1 °C rise in summertime soil temperature caused 44% and 78% increases in CO2 efflux and CH4 consumption, respectively, and a 32% increase in the frequency of bacterial 16S ribosomal RNA genes. Bacterial alpha diversity was unaffected by the treatments, but, of the 40 most frequent bacterial taxa, warming caused 44-45% reductions in the relative abundances of a Sphingomonas sp. and Ferruginibacter sp. and 33-91% increases in those of a Phenylobacterium sp. and a member of the Acetobacteraceae. Warming did not influence the frequency of fungal internal transcribed spacer 2 copies, and irrigation had no effects on the measured variables. Our study suggests rapid changes to the activities and abundances of microbes, and particularly bacteria, in High Arctic patterned ground soils as they warm. At current rates of soil warming on Svalbard (0.8 °C per decade), we anticipate that similar effects to those reported here will manifest themselves in the natural environment by approximately the mid 2030s.
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Affiliation(s)
- Kevin K. Newsham
- British Antarctic Survey, NERC, High Cross, Madingley Road, Cambridge CB3 0ET, UK
- Correspondence:
| | - Birgitte Kortegaard Danielsen
- Center for Permafrost, Department of Geosciences and Natural Resource Management, University of Copenhagen, Øster Volgade 10, DK-1350 Copenhagen, Denmark
| | | | - Bo Elberling
- Center for Permafrost, Department of Geosciences and Natural Resource Management, University of Copenhagen, Øster Volgade 10, DK-1350 Copenhagen, Denmark
| | - Guy Hillyard
- British Antarctic Survey, NERC, High Cross, Madingley Road, Cambridge CB3 0ET, UK
| | - Priyanka Kumari
- Department of Environmental Health Sciences, Graduate School of Public Health, Seoul National University, Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Anders Priemé
- Center for Permafrost, Department of Geosciences and Natural Resource Management, University of Copenhagen, Øster Volgade 10, DK-1350 Copenhagen, Denmark
- Department of Biology, University of Copenhagen, Universitetsparken 15, DK-2100 Copenhagen, Denmark
| | - Cheolwoon Woo
- Department of Environmental Health Sciences, Graduate School of Public Health, Seoul National University, Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
| | - Naomichi Yamamoto
- Department of Environmental Health Sciences, Graduate School of Public Health, Seoul National University, Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea
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Microbiogeochemical Traits to Identify Nitrogen Hotspots in Permafrost Regions. NITROGEN 2022. [DOI: 10.3390/nitrogen3030031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Permafrost-affected tundra soils are large carbon (C) and nitrogen (N) reservoirs. However, N is largely bound in soil organic matter (SOM), and ecosystems generally have low N availability. Therefore, microbial induced N-cycling processes and N losses were considered negligible. Recent studies show that microbial N processing rates, inorganic N availability, and lateral N losses from thawing permafrost increase when vegetation cover is disturbed, resulting in reduced N uptake or increased N input from thawing permafrost. In this review, we describe currently known N hotspots, particularly bare patches in permafrost peatland or permafrost soils affected by thermokarst, and their microbiogeochemical characteristics, and present evidence for previously unrecorded N hotspots in the tundra. We summarize the current understanding of microbial N cycling processes that promote the release of the potent greenhouse gas (GHG) nitrous oxide (N2O) and the translocation of inorganic N from terrestrial into aquatic ecosystems. We suggest that certain soil characteristics and microbial traits can be used as indicators of N availability and N losses. Identifying N hotspots in permafrost soils is key to assessing the potential for N release from permafrost-affected soils under global warming, as well as the impact of increased N availability on emissions of carbon-containing GHGs.
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Yun J, Jung JY, Kwon MJ, Seo J, Nam S, Lee YK, Kang H. Temporal Variations Rather than Long-Term Warming Control Extracellular Enzyme Activities and Microbial Community Structures in the High Arctic Soil. MICROBIAL ECOLOGY 2022; 84:168-181. [PMID: 34498119 DOI: 10.1007/s00248-021-01859-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Accepted: 09/02/2021] [Indexed: 06/13/2023]
Abstract
In Arctic soils, warming accelerates decomposition of organic matter and increases emission of greenhouse gases (GHGs), contributing to a positive feedback to climate change. Although microorganisms play a key role in the processes between decomposition of organic matter and GHGs emission, the effects of warming on temporal responses of microbial activity are still elusive. In this study, treatments of warming and precipitation were conducted from 2012 to 2018 in Cambridge Bay, Canada. Soils of organic and mineral layers were collected monthly from June to September in 2018 and analyzed for extracellular enzyme activities and bacterial community structures. The activity of hydrolases was the highest in June and decreased thereafter over summer in both organic and mineral layers. Bacterial community structures changed gradually over summer, and the responses were distinct depending on soil layers and environmental factors; water content and soil temperature affected the shift of bacterial community structures in both layers, whereas bacterial abundance, dissolved organic carbon, and inorganic nitrogen did so in the organic layer only. The activity of hydrolases and bacterial community structures did not differ significantly among treatments but among months. Our results demonstrate that temporal variations may control extracellular enzyme activities and microbial community structure rather than the small effect of warming over a long period in high Arctic soil. Although the effects of the treatments on microbial activity were minor, our study provides insight that microbial activity may increase due to an increase in carbon availability, if the growing season is prolonged in the Arctic.
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Affiliation(s)
- Jeongeun Yun
- School of Civil and Environmental Engineering, Yonsei University, Seoul, 03722, Korea
| | - Ji Young Jung
- Korea Polar Research Institute, Incheon, 21990, Korea
| | - Min Jung Kwon
- Laboratoire Des Sciences du Climat Et de I'Environnement, LSCE, 91191, Gif sur Yvette, France
| | - Juyoung Seo
- School of Civil and Environmental Engineering, Yonsei University, Seoul, 03722, Korea
| | - Sungjin Nam
- Korea Polar Research Institute, Incheon, 21990, Korea
| | - Yoo Kyung Lee
- Korea Polar Research Institute, Incheon, 21990, Korea
| | - Hojeong Kang
- School of Civil and Environmental Engineering, Yonsei University, Seoul, 03722, Korea.
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Leffler AJ, Becker HA, Kelsey KC, Spalinger DA, Welker JM. Short‐term effects of summer warming on caribou forage quality are mitigated by long‐term warming. Ecosphere 2022. [DOI: 10.1002/ecs2.4104] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- A. Joshua Leffler
- Department of Natural Resource Management South Dakota State University Brookings South Dakota USA
| | - Heidi A. Becker
- Department of Natural Resource Management South Dakota State University Brookings South Dakota USA
| | - Katharine C. Kelsey
- Department of Geography and Environmental Science University of Colorado‐Denver Denver Colorado USA
| | - Donald A. Spalinger
- Department of Biological Sciences University of Alaska‐Anchorage Anchorage Alaska USA
| | - Jeffrey M. Welker
- Department of Biological Sciences University of Alaska‐Anchorage Anchorage Alaska USA
- Ecology and Genetics Research Unit and UArctic University of Oulu Oulu Finland
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11
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Jespersen RG, Leffler AJ, Väisänen M, Welker JM. Resistance and change in a High Arctic ecosystem, NW Greenland: Differential sensitivity of ecosystem metrics to 15 years of experimental warming and wetting. GLOBAL CHANGE BIOLOGY 2022; 28:1853-1869. [PMID: 34870887 DOI: 10.1111/gcb.16027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 09/23/2021] [Accepted: 11/11/2021] [Indexed: 06/13/2023]
Abstract
Dramatic increases in air temperature and precipitation are occurring in the High Arctic (>70°N), yet few studies have characterized the long-term responses of High Arctic ecosystems to the interactive effects of experimental warming and increased rain. Beginning in 2003, we applied a factorial summer warming and wetting experiment to a polar semidesert in northwest Greenland. In summer 2018, we assessed several metrics of ecosystem structure and function, including plant cover, greenness, ecosystem CO2 exchange, aboveground (leaf, stem) and belowground (litter, root, soil) carbon (C) and nitrogen (N) concentrations (%) and pools, as well as leaf and soil stable isotopes (δ13 C and δ15 N). Wetting induced the most pronounced changes in ecosystem structure, accelerating the expansion of Salix arctica cover by 370% and increasing aboveground C, N, and biomass pools by 94%-101% and root C, N, and biomass pools by 60%-122%, increases which coincided with enhanced net ecosystem CO2 uptake. Further, wetting combined with warming enhanced plot-level greenness, whereas in isolation neither wetting nor warming had an effect. At the plant level, the effects of warming and wetting differed among species and included warming-linked decreases in leaf N and δ15 N in S. arctica, whereas leaf N and δ15 N in Dryas integrifolia did not respond to the climate treatments. Finally, neither plant- nor plot-level C and N allocation patterns nor soil C, N, δ13 C, or δ15 N concentrations changed in response to our manipulations, indicating that these ecosystem metrics may resist climate change, even in the longer term. In sum, our results highlight the importance of summer precipitation in regulating ecosystem structure and function in arid parts of the High Arctic, but they do not completely refute previous findings of resistance in some High Arctic ecosystem properties to climate change.
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Affiliation(s)
- Robert Gus Jespersen
- Department of Biological Sciences, University of Alaska-Anchorage, Anchorage, Alaska, USA
| | - Alan Joshua Leffler
- Department of Natural Resource Management, South Dakota State University, Brookings, South Dakota, USA
| | - Maria Väisänen
- Ecology and Genetics Research Unit, University of Oulu, Oulu, Finland
- Arctic Centre, University of Lapland, Rovaniemi, Finland
| | - Jeffrey M Welker
- UArctic Research Chair, Department of Arctic Ecology & Biogeochemistry, University of Oulu, Oulu, Finland
- University of Alaska-Anchorage, Anchorage, Alaska, USA
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12
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Burnett MS, Schütte UM, Harms TK. WIDESPREAD CAPACITY FOR DENITRIFICATION ACROSS A BOREAL FOREST LANDSCAPE. BIOGEOCHEMISTRY 2022; 158:215-232. [PMID: 36186670 PMCID: PMC9518932 DOI: 10.1007/s10533-022-00895-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 01/18/2022] [Indexed: 06/16/2023]
Abstract
A warming climate combined with frequent and severe fires cause permafrost to thaw, especially in the region of discontinuous permafrost, where soil temperatures may only be a few degrees below 0 °C. Soil thaw releases carbon (C) and nitrogen (N) into the actively cycling pools, and whereas C emissions following permafrost thaw are well documented, the fates of N remain unclear. Denitrification could release N from ecosystems as nitrous oxide (N2O) or nitrogen gas (N2), but the contributions of these processes to the high-latitude N cycle remain uncertain. We quantified microbial capacity for denitrification and N2O production in boreal soils, lakes, and streams using anoxic C- and N-amended assays, and assessed correlates of denitrifying enzyme activity (DEA) in Interior Alaska. Riparian soils and stream sediments supported the highest potential rates of denitrification, upland soils were intermediate, and lakes supported lower rates, whereas deep permafrost soils supported little denitrification. Time since fire had no effect on denitrification potential in upland soils. Across all landscape positions, DEA was negatively correlated with ammonium pools. Within each landscape position, potential rate of denitrification increased with soil or sediment organic matter content. Widespread N loss to denitrification in boreal forests could constrain the capacity for N-limited primary producers to maintain C stocks in soils following permafrost thaw.
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Affiliation(s)
- Melanie S. Burnett
- Institute of Arctic Biology and Department of Biology & Wildlife, University of Alaska Fairbanks, Fairbanks, Alaska 99775, United States of America
- Department of Earth and Planetary Science, McGill University, Montréal, Quebec H3A 2A7, Canada
| | - Ursel M.E. Schütte
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska 99775, United States of America
| | - Tamara K. Harms
- Institute of Arctic Biology and Department of Biology & Wildlife, University of Alaska Fairbanks, Fairbanks, Alaska 99775, United States of America
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13
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Li X, Yan Y, Fu L. Effects of Rainfall Manipulation on Ecosystem Respiration and Soil Respiration in an Alpine Steppe in Northern Tibet Plateau. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.708761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The response mechanism of ecosystem respiration (Re) and soil respiration (Rs) to different water conditions is of great significance for understanding the carbon cycle under future changes in the precipitation patterns. We used seven precipitation treatments to investigate the effects of precipitation on Re and Rs on a typical alpine steppe in Northern Tibet. Precipitation was captured and relocated to simulate the precipitation rates of −25, −50, −75, 0 (CK), +25, +50, and +75%. The soil moisture was influenced by all the precipitation treatments. There was a positive linear relationship between the soil moisture and Re, Rs in the study area during the experiment (July–October). Soil volumetric water content (VWC), absolute water content (AWC), soil temperature (ST), aboveground biomass (AGB), bulk density, soil total nitrogen (TN), and alkaline hydrolysis nitrogen (AHN) were the predictors of Re and Rs. The multiple linear regression analysis showed that ST and AWC could explain 90.6% of Rs, and ST, AWC, and AHN could explain 89.4% of Re. Ecosystem respiration was more sensitive to the increased precipitation (+29.5%) whereas Rs was more sensitive to the decreased precipitation (−23.8%). An appropriate increase in water (+25 and +50%) could improve the Re and Rs, but a greater increase (+75%) would not have a significant effect; it could have an effect even lower than those of the first two. Our study highlights the importance of increased precipitation and the disadvantage of decreased precipitation on Re and Rs in an arid region. The precipitation changes will lead to significant changes in the soil properties and AGB, and affect Re and Rs, to change the climate of the alpine steppe in Northern Tibet in the future. These findings contribute to our understanding of the regional patterns of environmental C exchange and soil C flux under the climate change scenarios and highlight the importance of water availability to the regulating ecosystem processes in semi-arid steppe ecosystems. In view of these findings, we urge future researchers to focus on manipulating the precipitation over longer time scales, seasonality, and incorporating more environmental factors to improve our ability to predict and model Re and Rs and feedback from climate change.
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14
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A multimillion-year-old record of Greenland vegetation and glacial history preserved in sediment beneath 1.4 km of ice at Camp Century. Proc Natl Acad Sci U S A 2021; 118:2021442118. [PMID: 33723012 DOI: 10.1073/pnas.2021442118] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Understanding the history of the Greenland Ice Sheet (GrIS) is critical for determining its sensitivity to warming and contribution to sea level; however, that history is poorly known before the last interglacial. Most knowledge comes from interpretation of marine sediment, an indirect record of past ice-sheet extent and behavior. Subglacial sediment and rock, retrieved at the base of ice cores, provide terrestrial evidence for GrIS behavior during the Pleistocene. Here, we use multiple methods to determine GrIS history from subglacial sediment at the base of the Camp Century ice core collected in 1966. This material contains a stratigraphic record of glaciation and vegetation in northwestern Greenland spanning the Pleistocene. Enriched stable isotopes of pore-ice suggest precipitation at lower elevations implying ice-sheet absence. Plant macrofossils and biomarkers in the sediment indicate that paleo-ecosystems from previous interglacial periods are preserved beneath the GrIS. Cosmogenic 26Al/10Be and luminescence data bracket the burial of the lower-most sediment between <3.2 ± 0.4 Ma and >0.7 to 1.4 Ma. In the upper-most sediment, cosmogenic 26Al/10Be data require exposure within the last 1.0 ± 0.1 My. The unique subglacial sedimentary record from Camp Century documents at least two episodes of ice-free, vegetated conditions, each followed by glaciation. The lower sediment derives from an Early Pleistocene GrIS advance. 26Al/10Be ratios in the upper-most sediment match those in subglacial bedrock from central Greenland, suggesting similar ice-cover histories across the GrIS. We conclude that the GrIS persisted through much of the Pleistocene but melted and reformed at least once since 1.1 Ma.
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Lie Z, Huang W, Liu X, Zhou G, Yan J, Li Y, Huang C, Wu T, Fang X, Zhao M, Liu S, Chu G, Kadowaki K, Pan X, Liu J. Warming leads to more closed nitrogen cycling in nitrogen-rich tropical forests. GLOBAL CHANGE BIOLOGY 2021; 27:664-674. [PMID: 33140554 DOI: 10.1111/gcb.15432] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 10/07/2020] [Indexed: 06/11/2023]
Abstract
Warming may have profound effects on nitrogen (N) cycling by changing plant N demand and underground N supply. However, large uncertainty exists regarding how warming affects the integrated N dynamic in tropical forests. We translocated model plant-soil ecosystems from a high-altitude site (600 m) to low-altitude sites at 300 and 30 m to simulate warming by 1.0°C and 2.1°C, respectively, in tropical China. The effects of experimental warming on N components in plant, soil, leaching, and gas were studied over 6 years. Our results showed that foliar δ15 N values and inorganic N (NH4 -N and NO3 -N) leaching were decreased under warming, with greater decreases under 2.1°C of warming than under 1.0°C of warming. The 2.1°C of warming enhanced plant growth, plant N uptake, N resorption, and fine root biomass, suggesting higher plant N demand. Soil total N concentrations, NO3 -N concentrations, microbial biomass N and arbuscular mycorrhizal fungal abundance were decreased under 2.1°C of warming, which probably restricted bioavailable N supply and arbuscular mycorrhizal contribution of N supply to plants. These changes in plants, soils and leaching indicated more closed N cycling under warming, the magnitude of which varied over time. The closed N cycling became pronounced during the first 3 years of warming where the sustained reductions in soil inorganic N could not meet plant N demand. Subsequently, the closed N cycling gradually mitigated, as observed by attenuated positive responses of plant growth and less negative responses of microbial biomass N to warming during the last 3 years. Overall, the more closed N cycling under warming could facilitate ecosystem N retention and affect production in these tropical forests, but these effects would be eventually mitigated with long-term warming probably due to the restricted plant growth and microbial acclimation.
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Affiliation(s)
- Zhiyang Lie
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- Center of Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
- Field Science Education and Research Center, Kyoto University, Kyoto, Japan
| | - Wenjuan Huang
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, USA
| | - Xujun Liu
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- Center of Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Guoyi Zhou
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Junhua Yan
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Yuelin Li
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- Center of Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, China
| | - Chumin Huang
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- Center of Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Ting Wu
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- Center of Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Xiong Fang
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
| | - Mengdi Zhao
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- Center of Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Shizhong Liu
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- Center of Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, China
| | - Guowei Chu
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- Center of Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, China
| | - Kohmei Kadowaki
- Field Science Education and Research Center, Kyoto University, Kyoto, Japan
| | - Xiaoping Pan
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- Center of Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, China
| | - Juxiu Liu
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, China
- Center of Plant Ecology, Core Botanical Gardens, Chinese Academy of Sciences, Guangzhou, China
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16
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Salazar A, Rousk K, Jónsdóttir IS, Bellenger J, Andrésson ÓS. Faster nitrogen cycling and more fungal and root biomass in cold ecosystems under experimental warming: a meta-analysis. Ecology 2020; 101:e02938. [PMID: 31750541 PMCID: PMC7027553 DOI: 10.1002/ecy.2938] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 10/01/2019] [Accepted: 10/18/2019] [Indexed: 11/13/2022]
Abstract
Warming can alter the biogeochemistry and ecology of soils. These alterations can be particularly large in high northern latitude ecosystems, which are experiencing the most intense warming globally. In this meta-analysis, we investigated global trends in how experimental warming is altering the biogeochemistry of the most common limiting nutrient for biological processes in cold ecosystems of high northern latitudes (>50°): nitrogen (N). For comparison, we also analyzed cold ecosystems at intermediate and high southern latitudes. In addition, we examined N-relevant genes and enzymes, and the abundance of belowground organisms. Together, our findings suggest that warming in cold ecosystems increases N mineralization rates and N2 O emissions and does not affect N fixation, at least not in a consistent way across biomes and conditions. Changes in belowground N fluxes caused by warming lead to an accumulation of N in the forms of dissolved organic and root N. These changes seem to be more closely linked to increases in enzyme activity that target relatively labile N sources, than to changes in the abundance of N-relevant genes (e.g., amoA and nosZ). Finally, our analysis suggests that warming in cold ecosystems leads to an increase in plant roots, fungi, and (likely in an indirect way) fungivores, and does not affect the abundance of archaea, bacteria, or bacterivores. In summary, our findings highlight global trends in the ways warming is altering the biogeochemistry and ecology of soils in cold ecosystems, and provide information that can be valuable for prediction of changes and for management of such ecosystems.
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Affiliation(s)
- Alejandro Salazar
- Faculty of Life and Environmental SciencesUniversity of IcelandSturlugata 7101ReykjavíkIceland
| | - Kathrin Rousk
- Department of BiologyTerrestrial Ecology SectionUniversity of CopenhagenUniversitetsparken 152100CopenhagenDenmark
- Center for Permafrost (CENPERM)University of CopenhagenØster Voldgade 101350CopenhagenDenmark
| | - Ingibjörg S. Jónsdóttir
- Faculty of Life and Environmental SciencesUniversity of IcelandSturlugata 7101ReykjavíkIceland
| | - Jean‐Philippe Bellenger
- Centre SeveDepartment of ChemistryFaculty of SciencesUniversite de SherbrookeJ1K2R1SherbrookeQuebecCanada
| | - Ólafur S. Andrésson
- Faculty of Life and Environmental SciencesUniversity of IcelandSturlugata 7101ReykjavíkIceland
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17
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Asynchronous nitrogen supply and demand produce nonlinear plant allocation responses to warming and elevated CO 2. Proc Natl Acad Sci U S A 2019; 116:21623-21628. [PMID: 31591204 DOI: 10.1073/pnas.1904990116] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Terrestrial ecosystem responses to climate change are mediated by complex plant-soil feedbacks that are poorly understood, but often driven by the balance of nutrient supply and demand. We actively increased aboveground plant-surface temperature, belowground soil temperature, and atmospheric CO2 in a brackish marsh and found nonlinear and nonadditive feedbacks in plant responses. Changes in root-to-shoot allocation by sedges were nonlinear, with peak belowground allocation occurring at +1.7 °C in both years. Above 1.7 °C, allocation to root versus shoot production decreased with increasing warming such that there were no differences in root biomass between ambient and +5.1 °C plots in either year. Elevated CO2 altered this response when crossed with +5.1 °C, increasing root-to-shoot allocation due to increased plant nitrogen demand and, consequently, root production. We suggest these nonlinear responses to warming are caused by asynchrony between the thresholds that trigger increased plant nitrogen (N) demand versus increased N mineralization rates. The resulting shifts in biomass allocation between roots and shoots have important consequences for forecasting terrestrial ecosystem responses to climate change and understanding global trends.
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18
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Beard KH, Choi RT, Leffler AJ, Carlson LG, Kelsey KC, Schmutz JA, Welker JM. Migratory goose arrival time plays a larger role in influencing forage quality than advancing springs in an Arctic coastal wetland. PLoS One 2019; 14:e0213037. [PMID: 30865725 PMCID: PMC6415786 DOI: 10.1371/journal.pone.0213037] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Accepted: 02/13/2019] [Indexed: 11/18/2022] Open
Abstract
With warmer springs, herbivores migrating to Arctic breeding grounds may experience phenological mismatches between their energy demands and the availability of high quality forage. Yet, how the timing of the start of the season and herbivore arrival influences forage quality is often unknown. In coastal western Alaska, approximately one million migratory geese arrive each spring to breed, where foliar %N and C:N ratios are linked to gosling survival and population growth. We conducted a three-year experiment where we manipulated the start of the growing season using warming chambers and grazing times using captive Pacific black brant (Branta bernicla nigricans) to examine how the timing of these events influences the quality of an important forage species. Our results suggest that grazing timing plays a much greater role than an advanced growing season in determining forage quality. All top models included grazing timing, and suggested that compared to typical grazing timing, early grazing significantly reduced foliar %C by 6% and C:N ratios by 16%, while late goose grazing significantly reduced foliar %N by 15% and increased foliar C:N ratios by 21%. While second-ranking top models included the effect of season, the advanced growing season effect was not significant and only reduced %N by 4%, increased %C by <1%, and increased C:N ratios by 5% compared to an ambient growing season. In summary, in years where geese arrive early, they will consume higher quality forage when they arrive and throughout the season, while in years that geese arrive late they will consume lower quality forage when they arrive and for the remainder of the season. When the growing season starts has only a minor influence on this pattern. Our findings suggest that cues determining migration and arrival times to breeding areas are important factors influencing forage quality for geese in western Alaska.
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Affiliation(s)
- Karen H. Beard
- Department of Wildland Resources, Utah State University and the Ecology Center, Logan, UT, United States of America
| | - Ryan T. Choi
- Department of Wildland Resources, Utah State University and the Ecology Center, Logan, UT, United States of America
| | - A. Joshua Leffler
- Department of Natural Resource Management, South Dakota State University, Brookings, SD, United States of America
| | - Lindsay G. Carlson
- Department of Wildland Resources, Utah State University and the Ecology Center, Logan, UT, United States of America
| | - Katharine C. Kelsey
- Department of Biological Sciences, University of Alaska-Anchorage, Anchorage, AK, United States of America
| | - Joel A. Schmutz
- US Geological Survey Alaska Science Center, Anchorage, AK, United States of America
| | - Jeffrey M. Welker
- Department of Biological Sciences, University of Alaska-Anchorage, Anchorage, AK, United States of America
- UArctic, Ecology and Genetics Research Unit, University of Oulu, Oulu, Finland
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19
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Mei L, Yang X, Cao H, Zhang T, Guo J. Arbuscular Mycorrhizal Fungi Alter Plant and Soil C:N:P Stoichiometries Under Warming and Nitrogen Input in a Semiarid Meadow of China. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:E397. [PMID: 30708940 PMCID: PMC6388220 DOI: 10.3390/ijerph16030397] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 01/27/2019] [Accepted: 01/29/2019] [Indexed: 11/29/2022]
Abstract
Ecological stoichiometry has been widely used to determine how plant-soil systems respond to global change and to reveal which factors limit plant growth. Arbuscular mycorrhizal fungi (AMF) can increase plants' uptake of nutrients such as nitrogen (N) and phosphorus (P), thereby altering plant and soil stoichiometries. To understand the regulatory effect of AMF feedback on plants and soil stoichiometry under global change, a microcosm experiment was conducted with warming and N input. The C₄ grass Setaria viridis, C₃ grass Leymus chinensis, and Chenopodiaceae species Suaeda corniculata were studied. The results showed that the mycorrhizal benefits for the C₄ grass S. viridis were greater than those for the C₃ grass L. chinensis, whereas for the Chenopodiaceae species S. corniculata, AMF symbiosis was antagonistic. Under N input and a combination of warming and N input, AMF significantly decreased the N:P ratios of all three species. Under N input, the soil N content and the N:P ratio were decreased significantly in the presence of AMF, whereas the soil C:N ratio was increased. These results showed that AMF can reduce the P limitation caused by N input and improve the efficiency of nutrient utilization, slow the negative influence of global change on plant growth, and promote grassland sustainability.
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Affiliation(s)
- Linlin Mei
- Institute of Grassland Science, Northeast Normal University, Key Laboratory of Vegetation Ecology, Ministry of Education, Changchun 130024, China.
| | - Xue Yang
- Institute of Grassland Science, Northeast Normal University, Key Laboratory of Vegetation Ecology, Ministry of Education, Changchun 130024, China.
| | - Hongbing Cao
- Institute of Grassland Science, Northeast Normal University, Key Laboratory of Vegetation Ecology, Ministry of Education, Changchun 130024, China.
| | - Tao Zhang
- Institute of Grassland Science, Northeast Normal University, Key Laboratory of Vegetation Ecology, Ministry of Education, Changchun 130024, China.
| | - Jixun Guo
- Institute of Grassland Science, Northeast Normal University, Key Laboratory of Vegetation Ecology, Ministry of Education, Changchun 130024, China.
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20
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Moreira X, Abdala-Roberts L, Pérez-Ramos IM, Knops JMH, Pesendorfer MB, Koenig WD, Mooney KA. Weather cues associated with masting behavior dampen the negative autocorrelation between past and current reproduction in oaks. AMERICAN JOURNAL OF BOTANY 2019; 106:51-60. [PMID: 30633821 DOI: 10.1002/ajb2.1210] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 10/17/2018] [Indexed: 06/09/2023]
Abstract
PREMISE OF THE STUDY The influence of weather conditions on masting and the ecological advantages of this reproductive behavior have been the subject of much interest. Weather conditions act as cues influencing reproduction of individual plants, and similar responses expressed across many individuals lead to population-level synchrony in reproductive output. In turn, synchrony leads to benefits from economies of scale such as enhanced pollination success and seed predator satiation. However, there may also be individual-level benefits from reproductive responses to weather cues, which may explain the origin of masting in the absence of economies of scale. In a previous study, we found support for a mechanism whereby individual responses to weather cues attenuate the negative autocorrelation between past and current annual seed production-a pattern typically attributed to resource limitation and reproductive tradeoffs among years. METHODS Here we provide a follow-up and more robust evaluation of this hypothesis in 12 species of oaks (Quercus spp.), testing for a negative autocorrelation (tradeoff) between past and current reproduction and whether responses to weather cues associated with masting reduce the strength of this negative autocorrelation. KEY RESULTS Our results showed a strong negative autocorrelation for 11 of the species, and that species-specific reproductive responses to weather cues dampened this negative autocorrelation in 10 of them. CONCLUSIONS This dampening effect presumably reflects a reduction in resource limitation or increased resource use associated with weather conditions, and suggests that responses to weather cues conferring these advantages should be selected for based on individual benefits.
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Affiliation(s)
- Xoaquín Moreira
- Misión Biológica de Galicia (MBG-CSIC), Apdo. 28, 36080, Pontevedra, Galicia, Spain
| | - Luis Abdala-Roberts
- Departamento de Ecología Tropical, Universidad Autónoma de Yucatán, Apartado Postal 4-116, Itzimna, 97000, Mérida, Yucatán, Mexico
| | - Ignacio M Pérez-Ramos
- Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS-CSIC), P.O. Box 1052, 41080, Sevilla, Andalucía, Spain
| | - Johannes M H Knops
- Department of Health and Environmental Sciences, Xi'an Jiaotong Liverpool University, Suzhou, 215123, China
| | - Mario B Pesendorfer
- Cornell Lab of Ornithology, 159 Sapsucker Woods Road, Ithaca, New York, 14850, USA
| | - Walter D Koenig
- Cornell Lab of Ornithology, 159 Sapsucker Woods Road, Ithaca, New York, 14850, USA
| | - Kailen A Mooney
- Department of Ecology and Evolutionary Biology, University of California, Irvine, California, USA, 92697
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21
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Jespersen RG, Leffler AJ, Oberbauer SF, Welker JM. Arctic plant ecophysiology and water source utilization in response to altered snow: isotopic (δ18O and δ2H) evidence for meltwater subsidies to deciduous shrubs. Oecologia 2018; 187:1009-1023. [DOI: 10.1007/s00442-018-4196-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Accepted: 06/05/2018] [Indexed: 11/29/2022]
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22
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Schmidt JH, Rexstad EA, Roland CA, McIntyre CL, MacCluskie MC, Flamme MJ. Weather-driven change in primary productivity explains variation in the amplitude of two herbivore population cycles in a boreal system. Oecologia 2017; 186:435-446. [PMID: 29170821 DOI: 10.1007/s00442-017-4004-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 11/06/2017] [Indexed: 11/29/2022]
Abstract
Vertebrate populations throughout the circumpolar north often exhibit cyclic dynamics, and predation is generally considered to be a primary driver of these cycles in a variety of herbivore species. However, weather and climate play a role in entraining cycles over broad landscapes and may alter cyclic dynamics, although the mechanism by which these processes operate is uncertain. Experimental and observational work has suggested that weather influences primary productivity over multi-year time periods, suggesting a pathway through which weather and climate may influence cyclic herbivore dynamics. Using long-term monitoring data, we investigated the relationships among multi-year weather conditions, measures of primary productivity, and the abundance of two cyclic herbivore species: snowshoe hare and northern red-backed vole. We found that precipitation (rain and snow) and growing season temperatures were strongly associated with variation in primary productivity over multi-year time horizons. In turn, fourfold variation in the amplitude of both the hare and vole cycles observed in our study area corresponded to long-term changes in primary productivity. The congruence of our results for these two species suggests a general mechanism by which weather and climate might influence cyclic herbivore population dynamics. Our findings also suggested that the association between climate warming and the disappearance of cycles might be initiated by changes in primary productivity. This work provides an explanation for observed influences of weather and climate on primary productivity and population cycles and will help our collective understanding of how future climate warming may influence these ecological phenomena in the future.
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Affiliation(s)
- Joshua H Schmidt
- US National Park Service, Central Alaska Network, 4175 Geist Road, Fairbanks, AK, 99709, USA.
| | - Eric A Rexstad
- Research Unit for Wildlife Population Assessment, Centre for Research into Ecological and Environmental Modelling, University of St. Andrews, St Andrews, KY16 9LZ, UK
| | - Carl A Roland
- US National Park Service, Central Alaska Network, 4175 Geist Road, Fairbanks, AK, 99709, USA.,US National Park Service, Denali National Park and Preserve, 4175 Geist Road, Fairbanks, AK, 99709, USA
| | - Carol L McIntyre
- US National Park Service, Denali National Park and Preserve, 4175 Geist Road, Fairbanks, AK, 99709, USA
| | - Margaret C MacCluskie
- US National Park Service, Central Alaska Network, 4175 Geist Road, Fairbanks, AK, 99709, USA
| | - Melanie J Flamme
- US National Park Service, Yukon-Charley Rivers Preserve and Gates of the Arctic National Park and Preserve, 4175 Geist Road, Fairbanks, AK, 99709, USA
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23
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Geml J, Semenova TA, Morgado LN, Welker JM. Changes in composition and abundance of functional groups of arctic fungi in response to long-term summer warming. Biol Lett 2017; 12:rsbl.2016.0503. [PMID: 27881760 PMCID: PMC5134034 DOI: 10.1098/rsbl.2016.0503] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 10/28/2016] [Indexed: 11/12/2022] Open
Abstract
We characterized fungal communities in dry and moist tundra and investigated the effect of long-term experimental summer warming on three aspects of functional groups of arctic fungi: richness, community composition and species abundance. Warming had profound effects on community composition, abundance, and, to a lesser extent, on richness of fungal functional groups. In addition, our data show that even within functional groups, the direction and extent of response to warming tend to be species-specific and we recommend that studies on fungal communities and their roles in nutrient cycling take into account species-level responses.
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Affiliation(s)
- József Geml
- Naturalis Biodiversity Center, PO Box 9517, 2300 RA Leiden, The Netherlands .,Faculty of Science, Leiden University, PO Box 9502, 2300 RA Leiden, The Netherlands
| | - Tatiana A Semenova
- Naturalis Biodiversity Center, PO Box 9517, 2300 RA Leiden, The Netherlands.,Faculty of Science, Leiden University, PO Box 9502, 2300 RA Leiden, The Netherlands
| | - Luis N Morgado
- Naturalis Biodiversity Center, PO Box 9517, 2300 RA Leiden, The Netherlands
| | - Jeffrey M Welker
- Department of Biological Sciences, University of Alaska Anchorage, Anchorage, AK 99508, USA
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24
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Song X, Zhu J, He N, Huang J, Tian J, Zhao X, Liu Y, Wang C. Asynchronous pulse responses of soil carbon and nitrogen mineralization to rewetting events at a short-term: Regulation by microbes. Sci Rep 2017; 7:7492. [PMID: 28790341 PMCID: PMC5548802 DOI: 10.1038/s41598-017-07744-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 07/03/2017] [Indexed: 11/25/2022] Open
Abstract
Rewetting after precipitation events plays an important role in regulating soil carbon (C) and nitrogen (N) turnover processes in arid and semiarid ecosystems. Here, we conducted a 48-h rewetting simulation experiment with measurements of soil C and N mineralization rates (RC and RN, respectively) and microbial biomass N (MBN) at high temporal resolution to explore the pulse responses of RC and RN. RC and RN responded strongly and rapidly to rewetting over the short term. The maximum RC value (because of pulse effects) ranged from 16.53 to 19.33 µg C gsoil−1 h−1, observed 10 min after rewetting. The maximum RN varied from 22.86 to 40.87 µg N gsoil−1 h−1, appearing 5–6 h after rewetting. The responses of soil microbial growth to rewetting were rapid, and the maximum MBN was observed 2–3 h after rewetting. Unexpectedly, there was no correlation between RC, RN, and MBN during the process of rewetting, and RC and RN were uncoupled. In sum, the pulse responses of RC, RN, and microbial growth to simulated rewetting were rapid, strong, and asynchronous, which offers insights into the different responses of microbes to rewetting and mechanisms behind microbes.
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Affiliation(s)
- Xiaoli Song
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China.,State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, the Chinese Academy of Sciences, Beijing, 100093, China.,College of Animal Science and Veterinary Medicine, Shanxi Agricultural University, Taigu, 030801, China
| | - Jianxing Zhu
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China.
| | - Nianpeng He
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China
| | - Jianhui Huang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, the Chinese Academy of Sciences, Beijing, 100093, China
| | - Jing Tian
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China
| | - Xiang Zhao
- College of Animal Science and Veterinary Medicine, Shanxi Agricultural University, Taigu, 030801, China
| | - Yuan Liu
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing, 100101, China
| | - Changhui Wang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, the Chinese Academy of Sciences, Beijing, 100093, China.
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25
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Winkler DE, Chapin KJ, Kueppers LM. Soil moisture mediates alpine life form and community productivity responses to warming. Ecology 2016; 97:1553-1563. [DOI: 10.1890/15-1197.1] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 01/04/2016] [Accepted: 01/11/2016] [Indexed: 11/18/2022]
Affiliation(s)
- Daniel E. Winkler
- School of Engineering University of California, Merced 5200 North Lake Road Merced CA 95343 USA
| | - Kenneth J. Chapin
- Department of Ecology and Evolutionary Biology University of California, Los Angeles 612 Charles E. Young Drive East Los Angeles CA 90095‐7246 USA
| | - Lara M. Kueppers
- Sierra Nevada Research Institute University of California, Merced 5200 North Lake Road Merced CA 95343 USA
- Climate and Ecosystem Sciences Division Lawrence Berkeley National Laboratory One Cyclotron Road Berkeley CA 94720 USA
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26
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Wild B, Gentsch N, Čapek P, Diáková K, Alves RJE, Bárta J, Gittel A, Hugelius G, Knoltsch A, Kuhry P, Lashchinskiy N, Mikutta R, Palmtag J, Schleper C, Schnecker J, Shibistova O, Takriti M, Torsvik VL, Urich T, Watzka M, Šantrůčková H, Guggenberger G, Richter A. Plant-derived compounds stimulate the decomposition of organic matter in arctic permafrost soils. Sci Rep 2016; 6:25607. [PMID: 27157964 PMCID: PMC4860603 DOI: 10.1038/srep25607] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 04/18/2016] [Indexed: 11/30/2022] Open
Abstract
Arctic ecosystems are warming rapidly, which is expected to promote soil organic matter (SOM) decomposition. In addition to the direct warming effect, decomposition can also be indirectly stimulated via increased plant productivity and plant-soil C allocation, and this so called “priming effect” might significantly alter the ecosystem C balance. In this study, we provide first mechanistic insights into the susceptibility of SOM decomposition in arctic permafrost soils to priming. By comparing 119 soils from four locations across the Siberian Arctic that cover all horizons of active layer and upper permafrost, we found that an increased availability of plant-derived organic C particularly stimulated decomposition in subsoil horizons where most of the arctic soil carbon is located. Considering the 1,035 Pg of arctic soil carbon, such an additional stimulation of decomposition beyond the direct temperature effect can accelerate net ecosystem C losses, and amplify the positive feedback to global warming.
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Affiliation(s)
- Birgit Wild
- Department of Microbiology and Ecosystem Science, University of Vienna, Vienna, Austria.,Austrian Polar Research Institute, Vienna, Austria.,Department of Earth Sciences, University of Gothenburg, Gothenburg, Sweden
| | - Norman Gentsch
- Institute of Soil Science, Leibniz Universität Hannover, Hannover, Germany
| | - Petr Čapek
- Department of Ecosystem Biology, University of South Bohemia, České Budějovice, Czech Republic
| | - Kateřina Diáková
- Department of Ecosystem Biology, University of South Bohemia, České Budějovice, Czech Republic
| | - Ricardo J Eloy Alves
- Austrian Polar Research Institute, Vienna, Austria.,Department of Ecogenomics and Systems Biology, University of Vienna, Vienna, Austria
| | - Jiři Bárta
- Department of Ecosystem Biology, University of South Bohemia, České Budějovice, Czech Republic
| | - Antje Gittel
- Department of Biology, Centre for Geobiology, University of Bergen, Bergen, Norway.,Department of Bioscience, Center for Geomicrobiology, Aarhus, Denmark
| | - Gustaf Hugelius
- Department of Physical Geography, Stockholm University, Stockholm, Sweden
| | - Anna Knoltsch
- Department of Microbiology and Ecosystem Science, University of Vienna, Vienna, Austria.,Austrian Polar Research Institute, Vienna, Austria
| | - Peter Kuhry
- Department of Physical Geography, Stockholm University, Stockholm, Sweden
| | - Nikolay Lashchinskiy
- Central Siberian Botanical Garden, Siberian Branch of Russian Academy of Sciences, Novosibirsk, Russia
| | - Robert Mikutta
- Institute of Soil Science, Leibniz Universität Hannover, Hannover, Germany.,Soil Science and Soil Protection, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany
| | - Juri Palmtag
- Department of Physical Geography, Stockholm University, Stockholm, Sweden
| | - Christa Schleper
- Austrian Polar Research Institute, Vienna, Austria.,Department of Ecogenomics and Systems Biology, University of Vienna, Vienna, Austria
| | - Jörg Schnecker
- Department of Microbiology and Ecosystem Science, University of Vienna, Vienna, Austria.,Austrian Polar Research Institute, Vienna, Austria.,Department of Natural Resources and the Environment, University of New Hampshire, Durham, NH, USA
| | - Olga Shibistova
- Institute of Soil Science, Leibniz Universität Hannover, Hannover, Germany.,VN Sukachev Institute of Forest, Siberian Branch of Russian Academy of Sciences, Krasnoyarsk, Russia
| | - Mounir Takriti
- Department of Microbiology and Ecosystem Science, University of Vienna, Vienna, Austria.,Austrian Polar Research Institute, Vienna, Austria.,Lancaster Environment Centre, Lancaster University, Lancaster, UK
| | - Vigdis L Torsvik
- Department of Biology, Centre for Geobiology, University of Bergen, Bergen, Norway
| | - Tim Urich
- Austrian Polar Research Institute, Vienna, Austria.,Department of Ecogenomics and Systems Biology, University of Vienna, Vienna, Austria.,Institute of Microbiology, Ernst-Moritz-Arndt University, Greifswald, Germany
| | - Margarete Watzka
- Department of Microbiology and Ecosystem Science, University of Vienna, Vienna, Austria
| | - Hana Šantrůčková
- Department of Ecosystem Biology, University of South Bohemia, České Budějovice, Czech Republic
| | - Georg Guggenberger
- Institute of Soil Science, Leibniz Universität Hannover, Hannover, Germany.,VN Sukachev Institute of Forest, Siberian Branch of Russian Academy of Sciences, Krasnoyarsk, Russia
| | - Andreas Richter
- Department of Microbiology and Ecosystem Science, University of Vienna, Vienna, Austria.,Austrian Polar Research Institute, Vienna, Austria
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27
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Leffler AJ, Klein ES, Oberbauer SF, Welker JM. Coupled long-term summer warming and deeper snow alters species composition and stimulates gross primary productivity in tussock tundra. Oecologia 2016; 181:287-97. [PMID: 26747269 DOI: 10.1007/s00442-015-3543-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 12/25/2015] [Indexed: 11/26/2022]
Abstract
Climate change is expected to increase summer temperature and winter precipitation throughout the Arctic. The long-term implications of these changes for plant species composition, plant function, and ecosystem processes are difficult to predict. We report on the influence of enhanced snow depth and warmer summer temperature following 20 years of an ITEX experimental manipulation at Toolik Lake, Alaska. Winter snow depth was increased using snow fences and warming was accomplished during summer using passive open-top chambers. One of the most important consequences of these experimental treatments was an increase in active layer depth and rate of thaw, which has led to deeper drainage and lower soil moisture content. Vegetation concomitantly shifted from a relatively wet system with high cover of the sedge Eriophorum vaginatum to a drier system, dominated by deciduous shrubs including Betula nana and Salix pulchra. At the individual plant level, we observed higher leaf nitrogen concentration associated with warmer temperatures and increased snow in S. pulchra and B. nana, but high leaf nitrogen concentration did not lead to higher rates of net photosynthesis. At the ecosystem level, we observed higher GPP and NEE in response to summer warming. Our results suggest that deeper snow has a cascading set of biophysical consequences that include a deeper active layer that leads to altered species composition, greater leaf nitrogen concentration, and higher ecosystem-level carbon uptake.
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Affiliation(s)
- A Joshua Leffler
- Department of Biological Sciences, University of Alaska, Anchorage, Anchorage, AK, 99501, USA.
- Natural Resources Management, South Dakota State University, 1390 College Ave., Box 2140B, Brookings, SD, 57007, USA.
| | - Eric S Klein
- Department of Biological Sciences, University of Alaska, Anchorage, Anchorage, AK, 99501, USA
| | - Steven F Oberbauer
- Department of Biological Sciences, Florida International University, Miami, FL, 33199, USA
| | - Jeffrey M Welker
- Department of Biological Sciences, University of Alaska, Anchorage, Anchorage, AK, 99501, USA
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28
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Li Y, Sun D, Li D, Xu Z, Zhao C, Lin H, Liu Q. Effects of warming on ectomycorrhizal colonization and nitrogen nutrition of Picea asperata seedlings grown in two contrasting forest ecosystems. Sci Rep 2015; 5:17546. [PMID: 26655633 PMCID: PMC4674696 DOI: 10.1038/srep17546] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Accepted: 11/03/2015] [Indexed: 11/29/2022] Open
Abstract
Ectomycorrhiza (ECM) plays an important role in plant nitrogen (N) nutrition and regulates plant responded to climate warming. We conducted a field experiment in a natural forest and a plantation in the eastern Tibetan Plateau to estimate the warming effects of open-top chambers (OTC) on ECM and N nutrition of Picea asperata seedlings. Four-year warming significantly decreased ECM colonization, ECM fungal biomass, fine root vigor, and the N concentration of leaf, stem and coarse root, but significantly increased fine root N concentration and N content of leaf, stem, fine root and whole plant in natural forest. Contrarily, warming induced no obvious change in most of these parameters in plantation. Moreover, warming decreased rhizospheric soil inorganic N content in both forests. Our results showed that four-year warming was not beneficial for ECM colonization of P. asperata seedlings in the two forests, and the seedlings in natural forest were more sensitive and flexible to experimental warming than in plantation. The changes of ECM colonization and fine root biomass for effective N uptake would be good for plant growth and remit N leaching under future warming in natural forest.
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Affiliation(s)
- Yuejiao Li
- Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, P.O. Box 416, Chengdu 610041, P. R. China
- College of Life Sciences, Sichuan University, No.24 South Section 1, Yihuan Road, Chengdu 610065, P. R. China
- University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing 100049, P. R. China
| | - Didi Sun
- Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, P.O. Box 416, Chengdu 610041, P. R. China
- University of Chinese Academy of Sciences, No.19A Yuquan Road, Beijing 100049, P. R. China
| | - Dandan Li
- Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, P.O. Box 416, Chengdu 610041, P. R. China
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, P. R. China
| | - Zhenfeng Xu
- Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, P.O. Box 416, Chengdu 610041, P. R. China
- Institute of Forest Ecology, Sichuan Agricultural University, Chengdu 611130, P. R. China
| | - Chunzhang Zhao
- Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, P.O. Box 416, Chengdu 610041, P. R. China
| | - Honghui Lin
- College of Life Sciences, Sichuan University, No.24 South Section 1, Yihuan Road, Chengdu 610065, P. R. China
| | - Qing Liu
- Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, P.O. Box 416, Chengdu 610041, P. R. China
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29
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Lin X, Li J, Luo J, Wu X, Tian Y, Wang W. Precipitation Mediates the Response of Carbon Cycle to Rising Temperature in the Mid-to-High Latitudes of the Northern Hemisphere. PLoS One 2015; 10:e0132663. [PMID: 26172277 PMCID: PMC4501818 DOI: 10.1371/journal.pone.0132663] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Accepted: 06/18/2015] [Indexed: 11/24/2022] Open
Abstract
Over the past decades, rising air temperature has been accompanied by changes in precipitation. Despite relatively robust literature on the temperature sensitivity of carbon cycle at continental to global scales, less is known about the way this sensitivity is affected by precipitation. In this study we investigate how precipitation mediates the response of the carbon cycle to warming over the mid-to-high latitudes in the Northern Hemisphere (north of 30 °N). Based on atmospheric CO2 observations at Point Barrow (BRW) in Alaska, satellite-derived NDVI (a proxy of vegetation productivity), and temperature and precipitation data, we analyzed the responses of carbon cycle to temperature change in wet and dry years (with precipitation above or below the multiyear average). The results suggest that, over the past three decades, the net seasonal atmospheric CO2 changes at BRW were significantly correlated with temperature in spring and autumn, yet only weakly correlated with temperature and precipitation during the growing season. We further found that responses of the net CO2 changes to warming in spring and autumn vary with precipitation levels, with the absolute temperature sensitivity in wet years roughly twice that in dry years. The analyses of NDVI and climate data also identify higher sensitivity of vegetation growth to warming in wet years for the growing season, spring and summer. The different temperature sensitivities in wet versus dry years probably result from differences in soil moisture and/or nutrient availability, which may enhance (inhibit) the responsiveness of carbon assimilation and/or decomposition to warming under high (low) precipitation levels. The precipitation-mediated response of the terrestrial carbon cycle to warming reported here emphasizes the important role of precipitation in assessing the temporal variations of carbon budgets in the past as well as in the future. More efforts are required to reduce uncertainty in future precipitation projections, and to better represent the nonlinearity of carbon cycle responses to climate in current state-of-the-art land surface models.
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Affiliation(s)
- Xin Lin
- College of Water Sciences, Beijing Normal University, Beijing, China
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China
| | - Junsheng Li
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China
| | - Jianwu Luo
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China
| | - Xiaopu Wu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China
| | - Yu Tian
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China
| | - Wei Wang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, China
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30
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Wild B, Schnecker J, Knoltsch A, Takriti M, Mooshammer M, Gentsch N, Mikutta R, Alves RJE, Gittel A, Lashchinskiy N, Richter A. Microbial nitrogen dynamics in organic and mineral soil horizons along a latitudinal transect in western Siberia. GLOBAL BIOGEOCHEMICAL CYCLES 2015; 29:567-582. [PMID: 26693204 PMCID: PMC4676305 DOI: 10.1002/2015gb005084] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 04/09/2015] [Accepted: 04/01/2015] [Indexed: 05/22/2023]
Abstract
Soil N availability is constrained by the breakdown of N-containing polymers such as proteins to oligopeptides and amino acids that can be taken up by plants and microorganisms. Excess N is released from microbial cells as ammonium (N mineralization), which in turn can serve as substrate for nitrification. According to stoichiometric theory, N mineralization and nitrification are expected to increase in relation to protein depolymerization with decreasing N limitation, and thus from higher to lower latitudes and from topsoils to subsoils. To test these hypotheses, we compared gross rates of protein depolymerization, N mineralization and nitrification (determined using 15N pool dilution assays) in organic topsoil, mineral topsoil, and mineral subsoil of seven ecosystems along a latitudinal transect in western Siberia, from tundra (67°N) to steppe (54°N). The investigated ecosystems differed strongly in N transformation rates, with highest protein depolymerization and N mineralization rates in middle and southern taiga. All N transformation rates decreased with soil depth following the decrease in organic matter content. Related to protein depolymerization, N mineralization and nitrification were significantly higher in mineral than in organic horizons, supporting a decrease in microbial N limitation with depth. In contrast, we did not find indications for a decrease in microbial N limitation from arctic to temperate ecosystems along the transect. Our findings thus challenge the perception of ubiquitous N limitation at high latitudes, but suggest a transition from N to C limitation of microorganisms with soil depth, even in high-latitude systems such as tundra and boreal forest. KEY POINTS We compared soil N dynamics of seven ecosystems along a latitudinal transectShifts in N dynamics suggest a decrease in microbial N limitation with depthWe found no decrease in microbial N limitation from arctic to temperate zones.
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Affiliation(s)
- Birgit Wild
- Department of Microbiology and Ecosystem Science, University of Vienna Vienna, Austria ; Austrian Polar Research Institute Vienna, Austria ; Department of Earth Sciences, University of Gothenburg Gothenburg, Sweden
| | - Jörg Schnecker
- Department of Microbiology and Ecosystem Science, University of Vienna Vienna, Austria ; Austrian Polar Research Institute Vienna, Austria
| | - Anna Knoltsch
- Department of Microbiology and Ecosystem Science, University of Vienna Vienna, Austria ; Austrian Polar Research Institute Vienna, Austria
| | - Mounir Takriti
- Department of Microbiology and Ecosystem Science, University of Vienna Vienna, Austria ; Austrian Polar Research Institute Vienna, Austria
| | - Maria Mooshammer
- Department of Microbiology and Ecosystem Science, University of Vienna Vienna, Austria
| | - Norman Gentsch
- Institute of Soil Science, Leibniz Universität Hannover Hannover, Germany
| | - Robert Mikutta
- Institute of Soil Science, Leibniz Universität Hannover Hannover, Germany
| | - Ricardo J Eloy Alves
- Austrian Polar Research Institute Vienna, Austria ; Department of Ecogenomics and Systems Biology, University of Vienna Vienna, Austria
| | - Antje Gittel
- Department of Biology, Centre for Geobiology, University of Bergen Bergen, Norway ; Department of Bioscience, Center for Geomicrobiology Aarhus, Denmark
| | - Nikolay Lashchinskiy
- Central Siberian Botanical Garden, Siberian Branch of Russian Academy of Sciences Novosibirsk, Russia
| | - Andreas Richter
- Department of Microbiology and Ecosystem Science, University of Vienna Vienna, Austria ; Austrian Polar Research Institute Vienna, Austria
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31
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Morgado LN, Semenova TA, Welker JM, Walker MD, Smets E, Geml J. Summer temperature increase has distinct effects on the ectomycorrhizal fungal communities of moist tussock and dry tundra in Arctic Alaska. GLOBAL CHANGE BIOLOGY 2015; 21:959-72. [PMID: 25156129 PMCID: PMC4322476 DOI: 10.1111/gcb.12716] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Revised: 07/19/2014] [Accepted: 07/28/2014] [Indexed: 05/22/2023]
Abstract
Arctic regions are experiencing the greatest rates of climate warming on the planet and marked changes have already been observed in terrestrial arctic ecosystems. While most studies have focused on the effects of warming on arctic vegetation and nutrient cycling, little is known about how belowground communities, such as fungi root-associated, respond to warming. Here, we investigate how long-term summer warming affects ectomycorrhizal (ECM) fungal communities. We used Ion Torrent sequencing of the rDNA internal transcribed spacer 2 (ITS2) region to compare ECM fungal communities in plots with and without long-term experimental warming in both dry and moist tussock tundra. Cortinarius was the most OTU-rich genus in the moist tundra, while the most diverse genus in the dry tundra was Tomentella. On the diversity level, in the moist tundra we found significant differences in community composition, and a sharp decrease in the richness of ECM fungi due to warming. On the functional level, our results indicate that warming induces shifts in the extramatrical properties of the communities, where the species with medium-distance exploration type seem to be favored with potential implications for the mobilization of different nutrient pools in the soil. In the dry tundra, neither community richness nor community composition was significantly altered by warming, similar to what had been observed in ECM host plants. There was, however, a marginally significant increase in OTUs identified as ECM fungi with the medium-distance exploration type in the warmed plots. Linking our findings of decreasing richness with previous results of increasing ECM fungal biomass suggests that certain ECM species are favored by warming and may become more abundant, while many other species may go locally extinct due to direct or indirect effects of warming. Such compositional shifts in the community might affect nutrient cycling and soil organic C storage.
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Affiliation(s)
- Luis N Morgado
- Naturalis Biodiversity CenterP.O. Box 9517, Leiden, RA, 2300, The Netherlands
| | - Tatiana A Semenova
- Naturalis Biodiversity CenterP.O. Box 9517, Leiden, RA, 2300, The Netherlands
- Faculty of Science, Leiden UniversityP.O. Box 9502, Leiden, RA, 2300, The Netherlands
| | - Jeffrey M Welker
- Department of Biological Sciences, University of Alaska AnchorageAnchorage, USA
| | | | - Erik Smets
- Naturalis Biodiversity CenterP.O. Box 9517, Leiden, RA, 2300, The Netherlands
- Faculty of Science, Leiden UniversityP.O. Box 9502, Leiden, RA, 2300, The Netherlands
- Plant Conservation and Population Biology, KU LeuvenKasteelpark Arenberg 31, Box 2437, Leuven, 3001, Belgium
| | - József Geml
- Naturalis Biodiversity CenterP.O. Box 9517, Leiden, RA, 2300, The Netherlands
- Faculty of Science, Leiden UniversityP.O. Box 9502, Leiden, RA, 2300, The Netherlands
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Semenova TA, Morgado LN, Welker JM, Walker MD, Smets E, Geml J. Long‐term experimental warming alters community composition of ascomycetes in Alaskan moist and dry arctic tundra. Mol Ecol 2015; 24:424-37. [DOI: 10.1111/mec.13045] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Revised: 12/10/2014] [Accepted: 12/12/2014] [Indexed: 11/30/2022]
Affiliation(s)
- Tatiana A. Semenova
- Naturalis Biodiversity Center Darwinweg 2 P.O. Box 9517 2300 RA Leiden the Netherlands
- Faculty of Science Leiden University P.O. Box 9502 2300 RA Leiden the Netherlands
| | - Luis N. Morgado
- Naturalis Biodiversity Center Darwinweg 2 P.O. Box 9517 2300 RA Leiden the Netherlands
| | - Jeffrey M. Welker
- Department of Biological Sciences University of Alaska Anchorage Anchorage AL USA
| | | | - Erik Smets
- Naturalis Biodiversity Center Darwinweg 2 P.O. Box 9517 2300 RA Leiden the Netherlands
- Plant Conservation and Population Biology KU Leuven Kasteelpark Arenberg 31 Box 2437 3001 Leuven Belgium
| | - József Geml
- Naturalis Biodiversity Center Darwinweg 2 P.O. Box 9517 2300 RA Leiden the Netherlands
- Faculty of Science Leiden University P.O. Box 9502 2300 RA Leiden the Netherlands
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Allen RB, Hurst JM, Portier J, Richardson SJ. Elevation-dependent responses of tree mast seeding to climate change over 45 years. Ecol Evol 2014; 4:3525-37. [PMID: 25478145 PMCID: PMC4224528 DOI: 10.1002/ece3.1210] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Revised: 08/01/2014] [Accepted: 08/05/2014] [Indexed: 12/04/2022] Open
Abstract
We use seed count data from a New Zealand mono-specific mountain beech forest to test for decadal trends in seed production along an elevation gradient in relation to changes in climate. Seedfall was collected (1965 to 2009) from seed trays located on transect lines at fixed elevations along an elevation gradient (1020 to 1370 m). We counted the number of seeds in the catch of each tray, for each year, and determined the number of viable seeds. Climate variables were obtained from a nearby (<2 km) climate station (914-m elevation). Variables were the sum or mean of daily measurements, using periods within each year known to correlate with subsequent interannual variation in seed production. To determine trends in mean seed production, at each elevation, and climate variables, we used generalized least squares (GLS) regression. We demonstrate a trend of increasing total and viable seed production, particularly at higher elevations, which emerged from marked interannual variation. Significant changes in four seasonal climate variables had GLS regression coefficients consistent with predictions of increased seed production. These variables subsumed the effect of year in GLS regressions with a greater influence on seed production with increasing elevation. Regression models enforce a view that the sequence of climate variables was additive in their influence on seed production throughout a reproductive cycle spanning more than 2 years and including three summers. Models with the most support always included summer precipitation as the earliest variable in the sequence followed by summer maximum daily temperatures. We interpret this as reflecting precipitation driven increases in soil nutrient availability enhancing seed production at higher elevations rather than the direct effects of climate, stand development or rising atmospheric CO2 partial pressures. Greater sensitivity of tree seeding at higher elevations to changes in climate reveals how ecosystem responses to climate change will be spatially variable.
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Affiliation(s)
| | | | - Jeanne Portier
- Centre d'Etude de la Forêt, Université du Québec à Montréal C.P. 8888, Montréal, Québec, H3C 3P8, Canada
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Hiltbrunner E, Aerts R, Bühlmann T, Huss-Danell K, Magnusson B, Myrold DD, Reed SC, Sigurdsson BD, Körner C. Ecological consequences of the expansion of N₂-fixing plants in cold biomes. Oecologia 2014; 176:11-24. [PMID: 24938834 DOI: 10.1007/s00442-014-2991-x] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Accepted: 06/03/2014] [Indexed: 11/28/2022]
Abstract
Research in warm-climate biomes has shown that invasion by symbiotic dinitrogen (N2)-fixing plants can transform ecosystems in ways analogous to the transformations observed as a consequence of anthropogenic, atmospheric nitrogen (N) deposition: declines in biodiversity, soil acidification, and alterations to carbon and nutrient cycling, including increased N losses through nitrate leaching and emissions of the powerful greenhouse gas nitrous oxide (N2O). Here, we used literature review and case study approaches to assess the evidence for similar transformations in cold-climate ecosystems of the boreal, subarctic and upper montane-temperate life zones. Our assessment focuses on the plant genera Lupinus and Alnus, which have become invasive largely as a consequence of deliberate introductions and/or reduced land management. These cold biomes are commonly located in remote areas with low anthropogenic N inputs, and the environmental impacts of N2-fixer invasion appear to be as severe as those from anthropogenic N deposition in highly N polluted areas. Hence, inputs of N from N2 fixation can affect ecosystems as dramatically or even more strongly than N inputs from atmospheric deposition, and biomes in cold climates represent no exception with regard to the risk of being invaded by N2-fixing species. In particular, the cold biomes studied here show both a strong potential to be transformed by N2-fixing plants and a rapid subsequent saturation in the ecosystem's capacity to retain N. Therefore, analogous to increases in N deposition, N2-fixing plant invasions must be deemed significant threats to biodiversity and to environmental quality.
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Affiliation(s)
- Erika Hiltbrunner
- Department of Environmental Sciences, Institute of Botany, University of Basel, Schönbeinstrasse 6, 4056, Basel, Switzerland,
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