1
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Power CC, Normand S, von Arx G, Elberling B, Corcoran D, Krog AB, Bouvin NK, Treier UA, Westergaard-Nielsen A, Liu Y, Prendin AL. No effect of snow on shrub xylem traits: Insights from a snow-manipulation experiment on Disko Island, Greenland. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 916:169896. [PMID: 38185160 DOI: 10.1016/j.scitotenv.2024.169896] [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: 09/21/2023] [Revised: 12/18/2023] [Accepted: 01/02/2024] [Indexed: 01/09/2024]
Abstract
Widespread shrubification across the Arctic has been generally attributed to increasing air temperatures, but responses vary across species and sites. Wood structures related to the plant hydraulic architecture may respond to local environmental conditions and potentially impact shrub growth, but these relationships remain understudied. Using methods of dendroanatomy, we analysed shrub ring width (RW) and xylem anatomical traits of 80 individuals of Salix glauca L. and Betula nana L. at a snow manipulation experiment in Western Greenland. We assessed how their responses differed between treatments (increased versus ambient snow depth) and soil moisture regimes (wet and dry). Despite an increase in snow depth due to snow fences (28-39 %), neither RW nor anatomical traits in either species showed significant responses to this increase. In contrast, irrespective of the snow treatment, the xylem specific hydraulic conductivity (Ks) and earlywood vessel size (LA95) for the study period were larger in S. glauca (p < 0.1, p < 0.01) and B. nana (p < 0.01, p < 0.001) at the wet than the dry site, while both species had larger vessel groups at the dry than the wet site (p < 0.01). RW of B. nana was higher at the wet site (p < 0.01), but no differences were observed for S. glauca. Additionally, B. nana Ks and LA95 showed different trends over the study period, with decreases observed at the dry site (p < 0.001), while for other responses no difference was observed. Our results indicate that, taking into account ontogenetic and allometric trends, hydraulic related xylem traits of both species, along with B. nana growth, were influenced by soil moisture. These findings suggest that soil moisture regime, but not snow cover, may determine xylem responses to future climate change and thus add to the heterogeneity of Arctic shrub dynamics, though more long-term species- and site- specific studies are needed.
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Affiliation(s)
- Candice C Power
- Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, Denmark.
| | - Signe Normand
- Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, Denmark; SustainScapes - Center for Sustainable Landscapes under Global Change, Aarhus University, Denmark
| | - Georg von Arx
- Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Birmensdorf, Switzerland; Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland
| | - Bo Elberling
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Denmark; Center for Permafrost (CENPERM), Department of Geosciences and Natural Resource Management, University of Copenhagen, Denmark
| | - Derek Corcoran
- Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, Denmark; SustainScapes - Center for Sustainable Landscapes under Global Change, Aarhus University, Denmark
| | - Amanda B Krog
- Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, Denmark
| | | | - Urs Albert Treier
- Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, Denmark; SustainScapes - Center for Sustainable Landscapes under Global Change, Aarhus University, Denmark
| | - Andreas Westergaard-Nielsen
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Denmark; Center for Permafrost (CENPERM), Department of Geosciences and Natural Resource Management, University of Copenhagen, Denmark
| | - Yijing Liu
- Department of Geosciences and Natural Resource Management, University of Copenhagen, Denmark
| | - Angela L Prendin
- Ecoinformatics and Biodiversity, Department of Biology, Aarhus University, Denmark; Department of Land Environment Agriculture and Forestry (TeSAF), University of Padova, Legnaro, Italy
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2
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Hermesdorf L, Liu Y, Michelsen A, Westergaard-Nielsen A, Mortensen LH, Jepsen MS, Sigsgaard C, Elberling B. Long-term changes in the daytime growing season carbon dioxide exchange following increased temperature and snow cover in arctic tundra. GLOBAL CHANGE BIOLOGY 2024; 30:e17087. [PMID: 38273494 DOI: 10.1111/gcb.17087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 10/16/2023] [Accepted: 10/24/2023] [Indexed: 01/27/2024]
Abstract
Increasing temperatures and winter precipitation can influence the carbon (C) exchange rates in arctic ecosystems. Feedbacks can be both positive and negative, but the net effects are unclear and expected to vary strongly across the Arctic. There is a lack of understanding of the combined effects of increased summer warming and winter precipitation on the C balance in these ecosystems. Here we assess the short-term (1-3 years) and long-term (5-8 years) effects of increased snow depth (snow fences) (on average + 70 cm) and warming (open top chambers; 1-3°C increase) and the combination in a factorial design on all key components of the daytime carbon dioxide (CO2 ) fluxes in a wide-spread heath tundra ecosystem in West Greenland. The warming treatment increased ecosystem respiration (ER) on a short- and long-term basis, while gross ecosystem photosynthesis (GEP) was only increased in the long term. Despite the difference in the timing of responses of ER and GEP to the warming treatment, the net ecosystem exchange (NEE) of CO2 was unaffected in the short term and in the long term. Although the structural equation model (SEM) indicates a direct relationship between seasonal accumulated snow depth and ER and GEP, there were no significant effects of the snow addition treatment on ER or GEP measured over the summer period. The combination of warming and snow addition turned the plots into net daytime CO2 sources during the growing season. Interestingly, despite no significant changes in air temperature during the snow-free time during the experiment, control plots as well as warming plots revealed significantly higher ER and GEP in the long term compared to the short term. This was in line with the satellite-derived time-integrated normalized difference vegetation index of the study area, suggesting that more factors than air temperature are drivers for changes in arctic tundra ecosystems.
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Affiliation(s)
- Lena Hermesdorf
- Center for Permafrost (CENPERM), Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark
| | - Yijing Liu
- Center for Permafrost (CENPERM), Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark
| | - Anders Michelsen
- Center for Permafrost (CENPERM), Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Andreas Westergaard-Nielsen
- Center for Permafrost (CENPERM), Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark
| | - Louise Hindborg Mortensen
- Center for Permafrost (CENPERM), Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark
| | - Malte Skov Jepsen
- Center for Permafrost (CENPERM), Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark
- National Museum of Denmark, Environmental Archaeology and Materials Science, Kongens Lyngby, Denmark
| | - Charlotte Sigsgaard
- Center for Permafrost (CENPERM), Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark
| | - Bo Elberling
- Center for Permafrost (CENPERM), Department of Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark
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3
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Jia Z, Li P, Wu Y, Chang P, Deng M, Liang L, Yang S, Wang C, Wang B, Yang L, Wang X, Wang Z, Peng Z, Guo L, Ahirwal J, Liu W, Liu L. Deepened snow loosens temporal coupling between plant and microbial N utilization and induces ecosystem N losses. GLOBAL CHANGE BIOLOGY 2022; 28:4655-4667. [PMID: 35567539 DOI: 10.1111/gcb.16234] [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: 10/05/2021] [Accepted: 05/05/2022] [Indexed: 06/15/2023]
Abstract
Seasonal differences in plant and microbial nitrogen (N) acquisition are believed to be a major mechanism that maximizes ecosystem N retention. There is also a concern that climate change may interrupt the delicate balance in N allocation between plants and microbes. Yet, convincing experimental evidence is still lacking. Using a 15 N tracer, we assessed how deepened snow affects the temporal coupling between plant and microbial N utilization in a temperate Mongolian grassland. We found that microbial 15 N recovery peaked in winter, accounting for 22% of the total ecosystem 15 N recovery, and then rapidly declined during the spring thaw. By stimulating N loss via N2 O emission and leaching, deepened snow reduced the total ecosystem 15 N recovery by 42% during the spring thaw. As the growing season progresses, the 15 N released from microbial biomass was taken up by plants, and the competitive advantage for N shifted from microbes to plants. Plant 15 N recovery reached its peak in August, accounting for 17% of the total ecosystem 15 N recovery. The Granger causality test showed that the temporal dynamics of plant 15 N recovery can be predicted by microbial 15 N recovery under ambient snow but not under deepened snow. In addition, plant 15 N recovery in August was positively correlated with and best explained by microbial 15 N recovery in March. The lower microbial 15 N recovery under deepened snow in March reduced plant 15 N recovery by 73% in August. Together, our results provide direct evidence of seasonal differences in plant and microbial N utilization that are conducive to ecosystem N retention; however, deepened snow disrupted the temporal coupling between plant-microbial N use and turnover. These findings suggest that changes in snowfall patterns may significantly alter ecosystem N cycling and N-based greenhouse gas emissions under future climate change. We highlight the importance of better representing winter processes and their response to winter climate change in biogeochemical models when assessing N cycling under global change.
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Affiliation(s)
- Zhou Jia
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Ping Li
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yuntao Wu
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Pengfei Chang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Meifeng Deng
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Luyin Liang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Sen Yang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Chengzhang Wang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Bin Wang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Lu Yang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Xin Wang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Zhenhua Wang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- The Engineering Technology Research Center of Characteristic Medicinal Plants of Fujian, School of Life Sciences, Ningde Normal University, Ningde, Fujian, China
| | - Ziyang Peng
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Lulu Guo
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Jitendra Ahirwal
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Weixing Liu
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Lingli Liu
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
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4
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Shrubification along Pipeline Corridors in Permafrost Regions. FORESTS 2022. [DOI: 10.3390/f13071093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Pipeline corridors have been rapidly increasing in length and density because of the ever growing demand for crude oil and natural gas resources in hydrocarbon-rich permafrost regions. Pipeline engineering activities have significant implications for the permafrost environment in cold regions. Along these pipeline corridors, the shrubification in the right-of-way (ROW) has been extensively observed during vegetation recovery. However, the hydrothermal mechanisms of this ROW shrubification have seldom been studied and thus remain poorly understood. This paper reviews more than 112 articles mainly published from 2000 to 2022 and focuses on the hydrothermal mechanisms of shrubification associated with environmental changes induced by the rapidly degrading permafrost from pipeline construction and around the operating pipelines under a warming climate. First, the shrubification from pipeline construction and operation and the ensuing vegetation clearance are featured. Then, key permafrost-related ROW shrubification mechanisms (e.g., from the perspectives of warmer soil, soil moisture, soil type, soil nutrients, topography and landscapes, and snow cover) are discussed. Other key influencing factors on these hydrothermal and other mechanisms are hierarchically documented as well. In the end, future research priorities are identified and proposed. We call for prioritizing more systematic and in-depth investigations and surveys, laboratory testing, long-term field monitoring, and numerical modeling studies of the ROW shrubification along oil and gas pipelines in permafrost regions, such as in boreal and arctic zones, as well as in alpine and high-plateau regions. This review can improve our understanding of shrubification mechanisms under pipeline disturbances and climate changes and help to better manage the ecological environment along pipeline corridors in permafrost regions.
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5
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The Spatially Inhomogeneous Influence of Snow on the Radial Growth of Schrenk Spruce (Picea schrenkiana Fisch. et Mey.) in the Ili-Balkhash Basin, Central Asia. FORESTS 2022. [DOI: 10.3390/f13010044] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Snow has an important impact on forest ecosystems in mountainous areas. In this study, we developed 14 tree-ring-width chronologies of Schrenk spruce (Picea schrenkiana Fisch. et Mey.) for the Ili-Balkhash Basin (IBB), Central Asia. We analyzed the response of radial growth to temperature, precipitation and snow parameters. The results show that previous winter and current summer precipitation have an important influence on the radial growth of P. schrenkiana. Further, we find spatially inhomogeneous effects of snow on subsequent growing-season tree growth in IBB. The radial growth response of P. schrenkiana to snow shows a weak–strong–weak trend from west to east across the Ili-Balkhash Basin. This spatial difference is mainly related to precipitation, as snow has little effect on tree growth in regions that receive more precipitation. Thus, winter snow has an important influence on the radial growth of trees in regions that receive limited amounts of precipitation.
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6
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Yang G, Peng Y, Abbott BW, Biasi C, Wei B, Zhang D, Wang J, Yu J, Li F, Wang G, Kou D, Liu F, Yang Y. Phosphorus rather than nitrogen regulates ecosystem carbon dynamics after permafrost thaw. GLOBAL CHANGE BIOLOGY 2021; 27:5818-5830. [PMID: 34390614 DOI: 10.1111/gcb.15845] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 07/19/2021] [Accepted: 08/02/2021] [Indexed: 05/27/2023]
Abstract
Ecosystem carbon (C) dynamics after permafrost thaw depends on more than just climate change since soil nutrient status may also impact ecosystem C balance. It has been advocated that nitrogen (N) release upon permafrost thaw could promote plant growth and thus offset soil C loss. However, compared with the widely accepted C-N interactions, little is known about the potential role of soil phosphorus (P) availability. We combined 3-year field observations along a thaw sequence (constituted by four thaw stages, i.e., non-collapse and 5, 14, and 22 years since collapse) with an in-situ fertilization experiment (included N and P additions at the level of 10 g N m-2 year-1 and 10 g P m-2 year-1 ) to evaluate ecosystem C-nutrient interactions upon permafrost thaw. We found that changes in soil P availability rather than N availability played an important role in regulating gross primary productivity and net ecosystem productivity along the thaw sequence. The fertilization experiment confirmed that P addition had stronger effects on plant growth than N addition in this permafrost ecosystem. These two lines of evidence highlight the crucial role of soil P availability in altering the trajectory of permafrost C cycle under climate warming.
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Affiliation(s)
- Guibiao Yang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yunfeng Peng
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Benjamin W Abbott
- Department of Plant and Wildlife Sciences, Brigham Young University, Provo, Utah, USA
| | - Christina Biasi
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland
| | - Bin Wei
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Dianye Zhang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Jun Wang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Jianchun Yu
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Fei Li
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Guanqin Wang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Dan Kou
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- Department of Environmental and Biological Sciences, University of Eastern Finland, Kuopio, Finland
| | - Futing Liu
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Yuanhe Yang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
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7
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Pold G, Baillargeon N, Lepe A, Rastetter EB, Sistla SA. Warming effects on arctic tundra biogeochemistry are limited but habitat‐dependent: a meta‐analysis. Ecosphere 2021. [DOI: 10.1002/ecs2.3777] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Affiliation(s)
- Grace Pold
- Natural Resources Management & Environmental Sciences College of Agriculture, Food & Environmental Sciences California Polytechnic State University San Luis Obispo California USA
| | - Natalie Baillargeon
- Smith College Northampton Massachusetts USA
- Woodwell Climate Research Center Woods Hole Massachusetts USA
| | - Adan Lepe
- Amherst College Amherst Massachusetts USA
| | - Edward B. Rastetter
- Marine Biological Laboratories The Ecosystems Center Woods Hole Massachusetts USA
| | - Seeta A. Sistla
- Natural Resources Management & Environmental Sciences College of Agriculture, Food & Environmental Sciences California Polytechnic State University San Luis Obispo California USA
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8
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Kelsey KC, Pedersen SH, Leffler AJ, Sexton JO, Feng M, Welker JM. Winter snow and spring temperature have differential effects on vegetation phenology and productivity across Arctic plant communities. GLOBAL CHANGE BIOLOGY 2021; 27:1572-1586. [PMID: 33372357 DOI: 10.1111/gcb.15505] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 11/21/2020] [Accepted: 12/17/2020] [Indexed: 05/22/2023]
Abstract
Tundra dominates two-thirds of the unglaciated, terrestrial Arctic. Although this region has experienced rapid and widespread changes in vegetation phenology and productivity over the last several decades, the specific climatic drivers responsible for this change remain poorly understood. Here we quantified the effect of winter snowpack and early spring temperature conditions on growing season vegetation phenology (timing of the start, peak, and end of the growing season) and productivity of the dominant tundra vegetation communities of Arctic Alaska. We used daily remotely sensed normalized difference vegetation index (NDVI), and daily snowpack and temperature variables produced by SnowModel and MicroMet, coupled physically based snow and meteorological modeling tools, to (1) determine the most important snowpack and thermal controls on tundra vegetation phenology and productivity and (2) describe the direction of these relationships within each vegetation community. Our results show that soil temperature under the snowpack, snowmelt timing, and air temperature following snowmelt are the most important drivers of growing season timing and productivity among Arctic vegetation communities. Air temperature after snowmelt was the most important control on timing of season start and end, with warmer conditions contributing to earlier phenology in all vegetation communities. In contrast, the controls on the timing of peak season and productivity also included snowmelt timing and soil temperature under the snowpack, dictated in part by the snow insulating capacity. The results of this novel analysis suggest that while future warming effects on phenology may be consistent across communities of the tundra biome, warming may result in divergent, community-specific productivity responses if coupled with reduced snow insulating capacity lowers winter soil temperature and potential nutrient cycling in the soil.
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Affiliation(s)
- Katharine C Kelsey
- Department of Geography and Environmental Science, University of Colorado Denver, Denver, CO, USA
| | - Stine Højlund Pedersen
- Cooperative Institute for Research in the Atmosphere, Colorado State University, Ft. Collins, CO, USA
- Department of Biological Sciences, University of Alaska Anchorage, Anchorage, AK, USA
| | - A Joshua Leffler
- Department of Natural Resource Management, South Dakota State University, Brookings, SD, USA
| | | | - Min Feng
- terraPulse, Inc, Gaithersburg, MD, USA
| | - Jeffrey M Welker
- Department of Biological Sciences, University of Alaska Anchorage, Anchorage, AK, USA
- Ecology and Genetics Research Unit, University of Oulu, Oulu, Finland
- University of the Arctic-UArctic, Rovaniemi, Finland
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9
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Sorensen PO, Beller HR, Bill M, Bouskill NJ, Hubbard SS, Karaoz U, Polussa A, Steltzer H, Wang S, Williams KH, Wu Y, Brodie EL. The Snowmelt Niche Differentiates Three Microbial Life Strategies That Influence Soil Nitrogen Availability During and After Winter. Front Microbiol 2020; 11:871. [PMID: 32477299 PMCID: PMC7242569 DOI: 10.3389/fmicb.2020.00871] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 04/14/2020] [Indexed: 12/13/2022] Open
Abstract
Soil microbial biomass can reach its annual maximum pool size beneath the winter snowpack and is known to decline abruptly following snowmelt in seasonally snow-covered ecosystems. Observed differences in winter versus summer microbial taxonomic composition also suggests that phylogenetically conserved traits may permit winter- versus summer-adapted microorganisms to occupy distinct niches. In this study, we sought to identify archaea, bacteria, and fungi that are associated with the soil microbial bloom overwinter and the subsequent biomass collapse following snowmelt at a high-altitude watershed in central Colorado, United States. Archaea, bacteria, and fungi were categorized into three life strategies (Winter-Adapted, Snowmelt-Specialist, Spring-Adapted) based upon changes in abundance during winter, the snowmelt period, and after snowmelt in spring. We calculated indices of phylogenetic relatedness (archaea and bacteria) or assigned functional attributes (fungi) to organisms within life strategies to infer whether phylogenetically conserved traits differentiate Winter-Adapted, Snowmelt-Specialist, and Spring-Adapted groups. We observed that the soil microbial bloom was correlated in time with a pulse of snowmelt infiltration, which commenced 65 days prior to soils becoming snow-free. A pulse of nitrogen (N, as nitrate) occurred after snowmelt, along with a collapse in the microbial biomass pool size, and an increased abundance of nitrifying archaea and bacteria (e.g., Thaumarchaeota, Nitrospirae). Winter- and Spring-Adapted archaea and bacteria were phylogenetically clustered, suggesting that phylogenetically conserved traits allow Winter- and Spring-Adapted archaea and bacteria to occupy distinct niches. In contrast, Snowmelt-Specialist archaea and bacteria were phylogenetically overdispersed, suggesting that the key mechanism(s) of the microbial biomass crash are likely to be density-dependent (e.g., trophic interactions, competitive exclusion) and affect organisms across a broad phylogenetic spectrum. Saprotrophic fungi were the dominant functional group across fungal life strategies, however, ectomycorrhizal fungi experienced a large increase in abundance in spring. If well-coupled plant-mycorrhizal phenology currently buffers ecosystem N losses in spring, then changes in snowmelt timing may alter ecosystem N retention potential. Overall, we observed that snowmelt separates three distinct soil niches that are occupied by ecologically distinct groups of microorganisms. This ecological differentiation is of biogeochemical importance, particularly with respect to the mobilization of nitrogen during winter, before and after snowmelt.
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Affiliation(s)
- Patrick O. Sorensen
- Earth and Environmental Sciences, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Harry R. Beller
- Earth and Environmental Sciences, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Markus Bill
- Earth and Environmental Sciences, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Nicholas J. Bouskill
- Earth and Environmental Sciences, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Susan S. Hubbard
- Earth and Environmental Sciences, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Ulas Karaoz
- Earth and Environmental Sciences, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Alexander Polussa
- Earth and Environmental Sciences, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
- School of Forestry and Environmental Studies, Yale University, New Haven, CT, United States
| | - Heidi Steltzer
- Fort Lewis College, Durango, CO, United States
- Rocky Mountain Biological Laboratory, Gothic, CO, United States
| | - Shi Wang
- Earth and Environmental Sciences, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Kenneth H. Williams
- Earth and Environmental Sciences, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
- Rocky Mountain Biological Laboratory, Gothic, CO, United States
| | - Yuxin Wu
- Earth and Environmental Sciences, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Eoin L. Brodie
- Earth and Environmental Sciences, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
- Department of Environmental Science, Policy and Management, University of California, Berkeley, Berkeley, CA, United States
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10
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Li P, Sayer EJ, Jia Z, Liu W, Wu Y, Yang S, Wang C, Yang L, Chen D, Bai Y, Liu L. Deepened winter snow cover enhances net ecosystem exchange and stabilizes plant community composition and productivity in a temperate grassland. GLOBAL CHANGE BIOLOGY 2020; 26:3015-3027. [PMID: 32107822 DOI: 10.1111/gcb.15051] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 02/05/2020] [Indexed: 06/10/2023]
Abstract
Global warming has greatly altered winter snowfall patterns, and there is a trend towards increasing winter snow in semi-arid regions in China. Winter snowfall is an important source of water during early spring in these water-limited ecosystems, and it can also affect nutrient supply. However, we know little about how changes in winter snowfall will affect ecosystem productivity and plant community structure during the growing season. Here, we conducted a 5-year winter snow manipulation experiment in a temperate grassland in Inner Mongolia. We measured ecosystem carbon flux from 2014 to 2018 and plant biomass and species composition from 2015 to 2018. We found that soil moisture increased under deepened winter snow in early growing season, particularly in deeper soil layers. Deepened snow increased the net ecosystem exchange of CO2 (NEE) and reduced intra- and inter-annual variation in NEE. Deepened snow did not affect aboveground plant biomass (AGB) but significantly increased root biomass. This suggested that the enhanced NEE was allocated to the belowground, which improved water acquisition and thus contributed to greater stability in NEE in deep-snow plots. Interestingly, the AGB of grasses in the control plots declined over time, resulting in a shift towards a forb-dominated system. Similar declines in grass AGB were also observed at three other locations in the region over the same time frame and are attributed to 4 years of below-average precipitation during the growing season. By contrast, grass AGB was stabilized under deepened winter snow and plant community composition remained unchanged. Hence, our study demonstrates that increased winter snowfall may stabilize arid grassland systems by reducing resource competition, promoting coexistence between plant functional groups, which ultimately mitigates the impacts of chronic drought during the growing season.
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Affiliation(s)
- Ping Li
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Emma J Sayer
- Lancaster Environment Centre, Lancaster University, Lancaster, UK
| | - Zhou Jia
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Weixing Liu
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
| | - Yuntao Wu
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Sen Yang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Chengzhang Wang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Lu Yang
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Dima Chen
- College of Biological and Pharmaceutical Sciences, China Three Gorges University, Yichang, China
| | - Yongfei Bai
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Lingli Liu
- State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
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11
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Yan Y, Yan R, Wang X, Xu X, Xu D, Jin D, Chen J, Xin X. Grazing affects snow accumulation and subsequent spring soil water by removing vegetation in a temperate grassland. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 697:134189. [PMID: 31491640 DOI: 10.1016/j.scitotenv.2019.134189] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 07/17/2019] [Accepted: 08/28/2019] [Indexed: 06/10/2023]
Abstract
By altering plant and soil properties and microclimate environments, grazing has a profound influence on the structure and function of grassland ecosystems. However, few studies have addressed the potential grazing effects on snow accumulation and subsequent spring soil water after snow melting and soil thawing. In this study, vegetation properties, snow accumulation and soil water were measured in experimental plots subjected to 8 years of cattle grazing comprising six different grazing intensity treatments in a typical temperate grassland in eastern Eurasia. The results indicated that heavy grazing reduced the snow depth by 51% and the snow mass by 40%. Snow accumulation first rapidly increased but then remained relatively stable with increases in both the aboveground biomass and canopy height. An obvious inflection point occurred at approximately 200 g m-2 aboveground biomass and at a 12.5 cm canopy height. The obvious difference in soil water content between the heavily grazed and ungrazed treatments occurred mainly in the spring after snow melting and soil thawing. The spring soil water content (0-30 cm) reached 31.5% in the ungrazed treatment (G0), which was 1.7 times that in the heavily grazed treatment (G0.92). The soil water content increased exponentially with increasing vegetation properties (aboveground biomass, canopy height and canopy cover), and a similar trend occurred with increasing snow mass and snow depth. Our structural equation modeling showed that both vegetation properties and snow accumulation had significant positive effects on spring soil water. By removing vegetation, grazing at increased intensities had significant, indirect suppressive effects on snow accumulation and spring soil water. Therefore, to obtain increased amounts of snow accumulation and spring soil water, land managers should consider reducing the grazing intensity or leaving some plots ungrazed.
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Affiliation(s)
- Yuchun Yan
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Ruirui Yan
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
| | - Xu Wang
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Xingliang Xu
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy Sciences, 11A, Datun Road, Chaoyang District, Beijing 100101, China
| | - Dawei Xu
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Dongyan Jin
- Agricultural Information Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Jinqiang Chen
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Xiaoping Xin
- Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
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12
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Wallace CA, Baltzer JL. Tall Shrubs Mediate Abiotic Conditions and Plant Communities at the Taiga–Tundra Ecotone. Ecosystems 2019. [DOI: 10.1007/s10021-019-00435-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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13
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Wu X, Li X, Liu H, Ciais P, Li Y, Xu C, Babst F, Guo W, Hao B, Wang P, Huang Y, Liu S, Tian Y, He B, Zhang C. Uneven winter snow influence on tree growth across temperate China. GLOBAL CHANGE BIOLOGY 2019; 25:144-154. [PMID: 30295402 DOI: 10.1111/gcb.14464] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 08/29/2018] [Indexed: 06/08/2023]
Abstract
Winter snow is an important driver of tree growth in regions where growing-season precipitation is limited. However, observational evidence of this influence at larger spatial scales and across diverse bioclimatic regions is lacking. Here, we investigated the interannual effects of winter (here defined as previous October to current February) snow depth on tree growth across temperate China over the period of 1961-2015, using a regional network of tree ring records, in situ daily snow depth observations, and gridded climate data. We report uneven effects of winter snow depth on subsequent growing-season tree growth across temperate China. There shows little effect on tree growth in drier regions that we attribute mainly to limited snow accumulation during winter. By contrast, winter snow exerts important positive influence on tree growth in stands with high winter snow accumulation (e.g., in parts of cold arid regions). The magnitude of this effect depends on the proportion of winter snow to pre-growing-season (previous October to current April) precipitation. We further observed that tree growth in drier regions tends to be increasingly limited by warmer growing-season temperature and early growing-season water availability. No compensatory effect of winter snow on the intensifying drought limitation of tree growth was observed across temperate China. Our findings point toward an increase in drought vulnerability of temperate forests in a warming climate.
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Affiliation(s)
- Xiuchen Wu
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing, China
- Faculty of Geographical Science, Beijing Normal University, Beijing, China
| | - Xiaoyan Li
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing, China
- Faculty of Geographical Science, Beijing Normal University, Beijing, China
| | - Hongyan Liu
- College of Urban and Environmental Science, MOE Laboratory for Earth Surface Processes, Peking University, Beijing, China
| | - Philippe Ciais
- CEA-CNRS-UVSQ, UMR8212-Laboratoire des Sciences du Climat et de l'Environnement (LSCE), Gif-Sur-Yvette, France
| | - Yuanqiao Li
- Faculty of Geographical Science, Beijing Normal University, Beijing, China
| | - Chongyang Xu
- College of Urban and Environmental Science, MOE Laboratory for Earth Surface Processes, Peking University, Beijing, China
| | - Flurin Babst
- Dendro Sciences Group, Forest Dynamics Unit, Swiss Federal Research Institute WSL, Birmensdorf, Switzerland
- Department of Ecology, W. Szafer Institute of Botany, Polish Academy of Sciences, Krakow, Poland
- Laboratory of Tree-Ring Research, University of Arizona, Tucson, Arizona
| | - Weichao Guo
- College of Urban and Environmental Science, MOE Laboratory for Earth Surface Processes, Peking University, Beijing, China
| | - Bingyan Hao
- Faculty of Geographical Science, Beijing Normal University, Beijing, China
| | - Pei Wang
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing, China
- Faculty of Geographical Science, Beijing Normal University, Beijing, China
| | - Yongmei Huang
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing, China
- Faculty of Geographical Science, Beijing Normal University, Beijing, China
| | - Shaomin Liu
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing, China
- Faculty of Geographical Science, Beijing Normal University, Beijing, China
| | - Yuhong Tian
- State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing, China
- Faculty of Geographical Science, Beijing Normal University, Beijing, China
| | - Bin He
- College of Global Change and Earth System Science, Beijing Normal University, Beijing, China
| | - Cicheng Zhang
- Faculty of Geographical Science, Beijing Normal University, Beijing, China
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