A5072360773- Climate change and permafrost
- Cryospheric studies and observations
- Geology and Paleoclimatology Research
- Tree-ring climate responses
- Peatlands and Wetlands Ecology
- Geological Studies and Exploration
- Polar Research and Ecology
- Arctic and Antarctic ice dynamics
- Indigenous Studies and Ecology
- Methane Hydrates and Related Phenomena
- Atmospheric and Environmental Gas Dynamics
- Scientific Research and Discoveries
- Rangeland and Wildlife Management
- Soil Geostatistics and Mapping
- Soil and Unsaturated Flow
- Tree Root and Stability Studies
- Energy, Environment, Agriculture Analysis
- Soil Carbon and Nitrogen Dynamics
- Science and Climate Studies
- Atmospheric chemistry and aerosols
- Lichen and fungal ecology
- Climate variability and models
- Winter Sports Injuries and Performance
- Rural development and sustainability
- Plant Water Relations and Carbon Dynamics
Dutch Research Council
2020-2024
Lund University
2016-2023
Senckenberg Biodiversity and Climate Research Centre
2023
Senckenberg Society for Nature Research
2023
University of Copenhagen
2012-2018
Vrije Universiteit Amsterdam
2014
Wageningen University & Research
2009-2012
Abstract Recent research using repeat photography, long-term ecological monitoring and dendrochronology has documented shrub expansion in arctic, high-latitude alpine tundra ecosystems. Here, we (1) synthesize these findings, (2) present a conceptual framework that identifies mechanisms constraints on increase, (3) explore causes, feedbacks implications of the increased cover ecosystems, (4) address potential lines investigation for future research. Satellite observations from around...
Abstract Climate change is expected to cause extensive vegetation changes in the Arctic: deciduous shrubs are already expanding, response climate warming. The results from transect studies suggest that increasing shrub cover will impact significantly on surface energy balance. However, little known about direct effects of permafrost thaw during summer. We experimentally quantified influence Betula nana a moist tundra site northeast Siberia with continuous permafrost. measured depth soil,...
Abstract. Soils in Arctic and boreal ecosystems store twice as much carbon the atmosphere, a portion of which may be released high-latitude soils warm. Some uncertainty timing magnitude permafrost–climate feedback stems from complex interactions between ecosystem properties soil thermal dynamics. Terrestrial fundamentally regulate response permafrost to climate change by influencing surface energy partitioning itself. Here we review how processes influence dynamics these linkages evolve...
Snow is an important driver of ecosystem processes in cold biomes. accumulation determines ground temperature, light conditions, and moisture availability during winter. It also affects the growing season’s start end, plant access to nutrients. Here, we review current knowledge snow cover’s role for vegetation, plant-animal interactions, permafrost microbial processes, biogeochemical cycling. We compare studies natural gradients with experimental manipulation assess time scale difference...
Arctic ecosystems are experiencing extreme climatic, biotic and physical disturbance events that can cause substantial loss of plant biomass productivity, sometimes at scales >1000 km 2 . Collectively known as browning events, these key contributors to the spatial temporal complexity greening vegetation dynamics. If we properly understand future terrestrial ecosystems, their feedbacks climate, understanding is essential. Here bring together in compare impacts rates recovery, likely...
Abstract. Deciduous shrubs are expected to rapidly expand in the Arctic during coming decades due climate warming. A transition towards more shrub-dominated tundra may have large implications for regional surface energy balance, permafrost stability and carbon storage capacity, with consequences global system. However, little information is available on natural long-term shrub growth response climatic variability. Our aim was determine factor time period that most important annual our...
Recently observed Arctic greening trends from normalized difference vegetation index (NDVI) data suggest that shrub growth is increasing in response to summer temperature. An increase cover expected decrease albedo and thus positively feed back climate warming. However, it unknown how NDVI are affected by inter-annual variations the climate. Here, we examine relationship between deciduous fractional cover, using field collected at a tundra site NE Siberia. Field showed increased decreased...
Abstract Many Arctic regions are currently experiencing substantial summer and winter climate changes. Litter decomposition is a fundamental component of ecosystem carbon nutrient cycles, with fungi being among the primary decomposers. To assess impacts seasonal climatic changes on litter fungal communities their functioning, Betula glandulosa leaf was surface‐incubated in two adjacent low sites contrasting soil moisture regimes: dry shrub heath wet sedge tundra at Disko Island, Greenland....
Abstract The majority of variation in six traits critical to the growth, survival and reproduction plant species is thought be organised along just two dimensions, corresponding strategies size resource acquisition. However, it unknown whether global trait relationships extend climatic extremes, if these interspecific are confounded by within species. We test cold extremes life on Earth using largest database tundra yet compiled. show that plants demonstrate remarkably similar economic...
Abstract Soils are warming as air temperatures rise across the Arctic and Boreal region concurrent with expansion of tall-statured shrubs trees in tundra. Changes vegetation structure function expected to alter soil thermal regimes, thereby modifying climate feedbacks related permafrost thaw carbon cycling. However, current understanding impacts on temperature is limited local or regional scales lacks generality necessary predict stability a pan-Arctic scale. Here we synthesize shallow...
The Arctic climate is projected to change during the coming century, with expected higher air temperatures and increased winter snowfall. These climatic changes might alter litter decomposition rates, which in turn could affect carbon (C) nitrogen (N) cycling rates tundra ecosystems. However, little known of seasonal effects on plant N dynamics, hampering predictions future arctic vegetation composition C balance. We tested snow addition (snow fences), warming (open top chambers), shrub...
Abstract Motivation The Tundra Trait Team (TTT) database includes field‐based measurements of key traits related to plant form and function at multiple sites across the tundra biome. This dataset can be used address theoretical questions about strategy trade‐offs, trait–environment relationships environmental filtering, trait variation spatial scales, validate satellite data, inform Earth system model parameters. Main types variable contained contains 91,970 18 traits. most frequently...
Abstract Aim Plant functional groups are widely used in community ecology and earth system modelling to describe trait variation within across plant communities. However, this approach rests on the assumption that explain a large proportion of among species. We test whether four commonly represent six ecologically important traits. Location Tundra biome. Time period Data collected between 1964 2016. Major taxa studied 295 tundra vascular Methods compiled database traits (plant height, leaf...
Summary Climate warming is faster in the Arctic than global average. Nutrient availability tundra soil expected to increase by climate through (i) accelerated nutrient mobilization surface layers, and (ii) increased thawing depths during growing season which increases accessibility of nutrients deeper layers. Both processes may initiate shifts vegetation composition. It important understand effects these two on plant functional types. We manipulated depth at a Northeast‐Siberian site...
Abstract Biogenic volatile organic compounds (BVOCs), which are mainly emitted by vegetation, may create either positive or negative climate forcing feedbacks. In the Subarctic, BVOC emissions highly responsive to temperature, but effects of climatic warming on have not been assessed in more extreme arctic ecosystems. The Arctic undergoes rapid change, with air temperatures increasing at twice rate global mean. Also, amount winter precipitation is projected increase large areas Arctic, and...
Significance Two defining features of climate change in the Arctic are rapid decline sea ice and “shrubification” tundra. While previous studies have inferred warming-related linkages between two, these been limited to a few locations. Our Pan-Arctic analysis shrub growth chronologies reveals two important insights. Tundra dynamics associated with throughout Arctic; however, while shrubs from most locations increased their growth, more than one-third showed evidence declining response...
Deeper winter snow is hypothesized to favor shrub growth and may partly explain the expansion observed in many parts of arctic during last decades, potentially triggering biophysical feedbacks including regional warming permafrost thawing. We experimentally tested effects depth on ecophysiology by measuring stem length hydrogen (δ2H), carbon (δ13C), nitrogen (δ15N) oxygen (δ18O) isotopic composition circumarctic evergreen dwarf Cassiope tetragona growing high-arctic Svalbard, Norway....