A5018369769- Climate change and permafrost
- Cryospheric studies and observations
- Atmospheric and Environmental Gas Dynamics
- Peatlands and Wetlands Ecology
- Methane Hydrates and Related Phenomena
- Geology and Paleoclimatology Research
- Plant Water Relations and Carbon Dynamics
- Climate variability and models
- Geological Studies and Exploration
- Soil Carbon and Nitrogen Dynamics
- Remote Sensing and LiDAR Applications
- Forest ecology and management
- Fire effects on ecosystems
- Remote Sensing in Agriculture
- Forest Management and Policy
- Indigenous Studies and Ecology
- Arctic and Antarctic ice dynamics
- Lichen and fungal ecology
- Marine and coastal ecosystems
- Climate Change Policy and Economics
- Hydrocarbon exploration and reservoir analysis
- Synthetic Aperture Radar (SAR) Applications and Techniques
- Hydrology and Watershed Management Studies
- Soil and Water Nutrient Dynamics
- Atmospheric chemistry and aerosols
Universität Hamburg
2019-2025
University of Liverpool
2024
Richard Wolf (Germany)
2022-2023
Institute of Soil Science
2021
Stockholm University
2013-2020
Bolin Centre for Climate Research
2013-2019
Sweco (Sweden)
2016
Max Planck Institute for Biogeochemistry
2006-2015
Max Planck Society
2008-2013
Friedrich Schiller University Jena
2004-2007
Carbon Cycle and Climate Change As climate change accelerates, it is important to know the likely impact of on carbon cycle (see Perspective by Reich ). Gross primary production (GPP) a measure amount CO 2 removed from atmosphere every year fuel photosynthesis. Beer et al. (p. 834 , published online 5 July) used combination observation calculation estimate that total GPP terrestrial plants around 122 billion tons per year; in comparison, burning fossil fuels emits about 7 annually....
Abstract Terrestrial ecosystems sequester 2.1 Pg of atmospheric carbon annually. A large amount the terrestrial sink is realized by forests. However, considerable uncertainties remain regarding fate this over both short and long timescales. Relevant data to address these are being collected at many sites around world, but syntheses still sparse. To facilitate future synthesis activities, we have assembled a comprehensive global database for forest ecosystems, which includes budget variables...
Significance Global food and biofuel production their vulnerability in a changing climate are of paramount societal importance. However, current global model predictions crop photosynthesis highly uncertain. Here we demonstrate that new space-based observations chlorophyll fluorescence, an emission intrinsically linked to plant biochemistry, enable accurate, global, time-resolved measurement photosynthesis, which is not possible from any other remote vegetation measurement. Our results show...
Half‐hourly measurements of the net exchanges carbon dioxide and water vapor between terrestrial ecosystems atmosphere provide estimates gross primary production (GPP) evapotranspiration (ET) at ecosystem level on daily to annual timescales. The ratio these quantities represents use efficiency. Its multiplication with mean daylight pressure deficit (VPD) leads a quantity which we call “inherent efficiency” (IWUE*). dependence IWUE* environmental conditions indicates possible adaptive...
The Budyko framework elegantly reduces the complex spatial patterns of actual evapotranspiration and runoff to a general function two variables: mean annual precipitation (MAP) net radiation. While methodology has first‐order skill, departures from globally averaged curve can be significant may usefully attributed additional controls such as vegetation type. This paper explores magnitude detected flux tower measurements ecosystem‐scale evapotranspiration, investigates their attribution site...
Abstract We present a new synthesis, based on suite of complementary approaches, the primary production and carbon sink in forests 25 member states European Union (EU‐25) during 1990–2005. Upscaled terrestrial observations model‐based approaches agree within 25% mean net (NPP) forests, i.e. 520±75 g C m −2 yr −1 over forest area 1.32 × 10 6 km 2 to 1.55 (EU‐25). New estimates long‐term (net biome production, NBP) EU‐25 amounts 75±20 . The ratio NBP NPP is 0.15±0.05. Estimates fate inputs via...
Abstract Aim To infer a forest carbon density map at 0.01° resolution from radar remote sensing product for the estimation of stocks in Northern Hemisphere boreal and temperate forests. Location The study area extends 30° N to 80° , covering three biomes – broadleaf mixed forests ( TBMF ), conifer TCF ) BFT over continents orth A merica, E urope sia). Methods This is based on recently available growing stock volume GSV retrieved synthetic aperture data. Forest biomass spatially explicit...
Abstract We estimated the long‐term carbon balance [net biome production (NBP)] of European (EU‐25) croplands and its component fluxes, over last two decades. Net primary (NPP) estimates, from different data sources ranged between 490 846 gC m −2 yr −1 , mostly reflect uncertainties in allocation, cropland area when using yield statistics. Inventories soil C change arable lands may be most reliable source information on NBP, but inventories lack full harmonized coverage EU‐25. From a...
Abstract Soil respiration represents the second largest CO 2 flux of terrestrial biosphere and amounts 10 times higher than current rate fossil‐fuel combustion. Thus, even a small change in soil could significantly intensify—or mitigate—current atmospheric increases , with potential feedbacks to climate change. Consequently, understand future dynamics earth system, it is mandatory precisely response changing environmental factors. Among those factors, temperature one clearest most certain...
The currently observed Arctic warming will increase permafrost degradation followed by mineralization of formerly frozen organic matter to carbon dioxide (CO2 ) and methane (CH4 ). Despite increasing awareness vulnerability, the potential long-term formation trace gases from thawing remains unclear. objective current study is quantify release matter. Therefore, Holocene Pleistocene deposits were sampled in Lena River Delta, Northeast Siberia. contained between 0.6% 12.4% carbon. CO2 CH4...
Abstract A significant portion of the large amount carbon (C) currently stored in soils permafrost region Northern Hemisphere has potential to be emitted as greenhouse gases CO 2 and CH 4 under a warmer climate. In this study we evaluated variability sensitivity C recent decades among land surface model simulations over between 1960 2009. The 15 all predict loss near‐surface (within 3 m) area region, but there are differences magnitude simulated rates models (0.2 58.8 × 10 km yr −1 )....
Abstract. The current version of JSBACH incorporates phenomena specific to high latitudes: freeze/thaw processes, coupling thermal and hydrological processes in a layered soil scheme, defining multilayer snow representation an insulating moss cover. Evaluations using comprehensive Arctic data sets show comparable results at the site, basin, continental circumarctic scales. Such comparisons highlight need include relevant high-latitude systems order capture dynamics, therefore realistically...
Abstract. The cycling of carbon (C) between the Earth surface and atmosphere is controlled by biological abiotic processes that regulate C storage in biogeochemical compartments release to atmosphere. This partitioning quantified using various forms C-use efficiency (CUE) – ratio remaining a system entering system. Biological CUE fraction taken up allocated biosynthesis. In soils sediments, depends also on processes, so term C-storage (CSE) can be used. Here we first review reconcile CSE...
Abstract It has been hypothesized that predecessors of today’s bryophytes significantly increased global chemical weathering in the Late Ordovician, thus reducing atmospheric CO 2 concentration and contributing to climate cooling an interval glaciations. Studies try quantify enhancement by non-vascular vegetation, however, are usually limited small areas low numbers species, which hampers extrapolating scale past climatic conditions. Here we present a spatially explicit modelling approach...
Abstract. Bryophyte and lichen cover on the forest floor at high latitudes exerts an insulating effect ground. In this way, decreases mean annual soil temperature can protect permafrost soil. Climate change, however, may change bryophyte cover, with effects state related carbon balance. It is, therefore, crucial to predict how will react environmental global scale. To date, current land surface models contain only empirical representations of which makes it impractical future function...
On local scale, the eddy covariance technique is suited to estimate gross primary production (GPP). Scaling up such observations regional and continental level, however, remains a challenge. Here, we show that there surprisingly robust stoichiometric relationship between vegetation CO 2 H O fluxes, mediated by vapor pressure deficit (VPD), across many different forest types. This used provide data‐driven of Europe's GPP from its water balance. Namely, watershed‐wide evapotranspiration (ET),...
Abstract. Water-use efficiency (WUE) has been recognized as an important characteristic of vegetation productivity in various natural scientific disciplines for decades, but only recently at the ecosystem level, where different ways exist to characterize water-use efficiency. Hence, objective this research was (a) systematically compare calculating (WUEe) from eddy-covariance measurements, (b) quantify diurnal, seasonal and interannual variability WUEe relation meteorological conditions, (c)...