Article
Multidisciplinary Sciences
Yanlan Liu, William J. Riley, Trevor F. Keenan, Zelalem A. Mekonnen, Jennifer A. Holm, Qing Zhu, Margaret S. Torn
Summary: This study shows that the expansion of Arctic shrubs is not controlled by environmental suitability, but rather determined by seed dispersal and fire. Better observations of seed recruitment and inclusion of seed dispersal and fire processes in land models are necessary for accurate predictions of shrub expansion and climate feedbacks.
NATURE COMMUNICATIONS
(2022)
Article
Environmental Sciences
Leon Nill, Inge Grunberg, Tobias Ullmann, Matthias Gessner, Julia Boike, Patrick Hostert
Summary: This study successfully estimated the fractional cover of shrubs and other surface components in the Arctic tundra using satellite observations and synthetic training data. The results showed an increase in shrub cover and a decline in herbaceous plant and lichen cover, indicating a replacement and homogenisation of Arctic vegetation communities. The proposed method provides new opportunities for quantitatively estimating the fractional cover of tundra vegetation and advancing our understanding of shrub expansion.
REMOTE SENSING OF ENVIRONMENT
(2022)
Article
Ecology
Jason A. Clark, Ken D. Tape, Jessica M. Young-Robertson
Summary: Vegetation water content is crucial for ecosystem water balance and plant physiology, especially in relation to drought resistance. This study utilized time-domain reflectometry to continuously measure shrub water content and established calibration equations for different shrub species. The findings revealed seasonal variations in stem water content, highlighting the dependence of shrubs on soil moisture availability.
ECOHYDROLOGY & HYDROBIOLOGY
(2022)
Article
Biodiversity Conservation
Yaping Chen, Feng S. Hu, Mark J. Lara
Summary: The study used high-resolution aerial and satellite imagery data to investigate the relationship between shrub-cover change in the Arctic tundra and key environmental drivers like climate change and fire disturbance. Results suggest that summer precipitation is the most important climatic driver for shrub expansion, and shrub expansion in the uplands is largely enhanced by wildfire.
GLOBAL CHANGE BIOLOGY
(2021)
Article
Ecology
T. Kiyo F. Campbell, Trevor C. Lantz, Robert H. Fraser, Danica Hogan
Summary: This study investigates the determinants of high Arctic vegetation change on Banks Island over the last three decades, finding significant increases in productivity in about 80% of the study area, attributed to biomass increases in both upland and lowland habitats. The analysis also shows that the magnitude of greening is moderated by terrain characteristics related to soil moisture, highlighting the need for further research on the impacts of more productive vegetation communities on Arctic processes.
Article
Soil Science
Laura Helene Rasmussen, Louise H. Mortensen, Per Ambus, Anders Michelsen, Bo Elberling
Summary: This study examined the fate of nitrogen released in the Arctic landscape, finding that season progression is the key factor influencing NO3- concentrations and N2O fluxes. Nitrification replaced denitrification as the main source of N2O during the growing season due to increased soil temperatures and decreased soil moisture. The loss of gaseous N from the slope in the first month of thaw was minimal, with NO3- immobilized or taken up by plants, reducing N2O emissions.
SOIL BIOLOGY & BIOCHEMISTRY
(2022)
Article
Environmental Sciences
Caren Ackley, Suzanne E. Tank, Kristine M. Haynes, Fereidoun Rezanezhad, Colin McCarter, William L. Quinton
Summary: The study reveals that low-severity wildfires have the potential to impact peat plateau-wetland complexes by accelerating snowmelt, increasing ground heat flux, altering subsurface thickness, and reducing preferential runoff pathways. The incorporation of ash and char into the peat matrix changes soil structure, promoting greater soil moisture retention and enhancing biogeochemical reactions, resulting in elevated concentrations of organic matter and mercury in pore water.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Plant Sciences
Lucrezia Unterholzner, Angela Luisa Prendin, Raffaella Dibona, Roberto Menardi, Valentino Casolo, Sara Gargiulo, Francesco Boscutti, Marco Carrer
Summary: With climate warming, the tundra ecotones are experiencing accelerated spring snowpack melting and extended growing seasons, which significantly affect vegetation. Winter precipitation has been recognized as a crucial factor for tundra shrub growth and physiology. However, we still have limited knowledge about the responses of long-lived plants to different snowpack durations, especially regarding the influence of intra-specific and year-to-year variability and multiple functional trait adjustments on long-term responses.
FRONTIERS IN PLANT SCIENCE
(2022)
Article
Environmental Sciences
Wenyi Xu, Bo Elberling, Per Lennart Ambus
Summary: Fire in combination with summer warming can increase microbial P pools, enhance soil N retention, and potentially increase N uptake by recovering plants. Additionally, fire may alter N uptake differently among dominant shrub species in the tundra ecosystem, potentially changing plant species composition in the longer term.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Environmental Sciences
Howard E. Epstein, Donald A. Walker, Gerald Frost, Martha K. Raynolds, Uma Bhatt, Ronald Daanen, Bruce Forbes, Jozsef Geml, Elina Kaarlejarvi, Olga Khitun, Artem Khomutov, Patrick Kuss, Marina Leibman, Georgy Matyshak, Nataliya Moskalenko, Pavel Orekhov, Vladimir E. Romanovsky, Ina Timling
Summary: Field sampling along the Eurasia Arctic Transect in northwestern Siberia showed that aboveground vegetation biomass, NDVI, and LAI all increased with the summer warmth index. Different soil types influenced the spatial patterns of these vegetation properties. Shrub biomass increased non-linearly with summer warmth index, while moss and lichen biomass responded differently to the increase in temperature.
ENVIRONMENTAL RESEARCH LETTERS
(2021)
Article
Biodiversity Conservation
Nathalie Isabelle Chardon, Jacob Nabe-Nielsen, Jakob Johan Assmann, Ida Bomholt Dyrholm Jacobsen, Maya Gueguen, Signe Normand, Sonja Wipf
Summary: The study aims to improve distribution and abundance models for woody shrubs in the Arctic and compares different validation approaches. The results show that temperature and precipitation are the best predictors for species distribution, while insolation and soil moisture are the best predictors for species abundance. Regardless of the validation approach used, the models performed poorly to moderately well, but including local scale biotic factors improved the abundance models' performance.
DIVERSITY AND DISTRIBUTIONS
(2022)
Article
Geosciences, Multidisciplinary
Florent Domine, Kevin Fourteau, Ghislain Picard, Georg Lackner, Denis Sarrazin, Mathilde Poirier
Summary: According to ground temperature observations and heat transfer simulations, Arctic shrubs cool permafrost in winter by acting as a thermal bridge through the snowpack. However, their overall thermal effect also depends on snow and shrub characteristics and terrain aspect. Including these thermal bridging processes into climate models may have an important impact on projected greenhouse gas emissions by permafrost.
Article
Ecology
Diane C. Huebner, Agata Buchwal, M. Syndonia Bret-Harte
Summary: Thermokarst disturbance in permafrost landscapes is likely to increase with climate warming, resulting in changes to topography, vegetation, and biogeochemical cycling. This study on shrub-thermokarst relationships in Alaska's North Slope found that thermokarst activity had strong successional effects on shrub growth, with shrubs in retrogressive thaw slumps (RTSs) showing wider growth rings compared to undisturbed areas. Climate effects on shrub growth varied across species and sites, but overall, a higher June temperature and increased September precipitation were associated with wider growth rings. This research highlights the importance of understanding the impacts of thermokarst activity on tundra shrubs and the potential contribution of retrogressive thaw slumps to tundra greening.
Article
Multidisciplinary Sciences
Adria Descals, David L. A. Gaveau, Aleixandre Verger, Douglas Sheil, Daisuke Naito, Josep Penuelas
Summary: Arctic fires can release large amounts of carbon from permafrost peatlands. Recent decades have seen an increase in temperature-related fire factors, which have a near-exponential relationship with annual burned area. With climactic warming, large fires in the Arctic are likely to occur before mid-century.
Article
Environmental Sciences
Yulin Zhou, Zhenxia Mu, Xing Wei
Summary: This study used the high-resolution Weather Research and Forecasting (WRF) model and data assimilation technology to construct the WRF-VIC atmospheric-hydrological coupling model for simulating snowmelt runoff in alpine areas, and achieved satisfactory simulation results.
FRESENIUS ENVIRONMENTAL BULLETIN
(2022)
