A5089103506- Plant Water Relations and Carbon Dynamics
- Soil Carbon and Nitrogen Dynamics
- Tree-ring climate responses
- Isotope Analysis in Ecology
- Peatlands and Wetlands Ecology
- Plant responses to elevated CO2
- Geology and Paleoclimatology Research
- Soil and Water Nutrient Dynamics
- Plant and animal studies
- Climate change and permafrost
- Atmospheric and Environmental Gas Dynamics
- Ecology and Vegetation Dynamics Studies
- Microbial Community Ecology and Physiology
- Marine and coastal ecosystems
- Hydrology and Watershed Management Studies
- Soil erosion and sediment transport
- Groundwater and Isotope Geochemistry
- Species Distribution and Climate Change
- Plant Ecology and Soil Science
- Forest Ecology and Biodiversity Studies
- Plant nutrient uptake and metabolism
- Photosynthetic Processes and Mechanisms
- Fire effects on ecosystems
- Methane Hydrates and Related Phenomena
- Meta-analysis and systematic reviews
University of Idaho
2016-2024
Leibniz Centre for Agricultural Landscape Research
2010-2019
Lawrence Livermore National Laboratory
2015-2018
Swiss Federal Institute for Forest, Snow and Landscape Research
2018
Northern Research Station
2016-2017
United States Department of Agriculture
2017
Pacific Southwest Research Station
2017
Michigan Technological University
2017
Oregon State University
2008-2009
University of California, Berkeley
2005
Abstract. Stable isotope analysis is a powerful tool for assessing plant carbon and water relations their impact on biogeochemical processes at different scales. Our process-based understanding of stable signals, as well technological developments, has progressed significantly, opening new frontiers in ecological interdisciplinary research. This promoted the broad utilisation carbon, oxygen hydrogen applications to gain insight into cycling interaction with atmosphere pedosphere. Here, we...
The carbon (δ13C) and oxygen (δ18O) stable isotope composition is widely used to obtain information on the linkages between environmental drivers tree physiology over various time scales. tree-ring archive can especially be exploited reconstruct inter- intra-annual variation of both climate physiology. There is, however, a lack processes potentially affecting δ13C δ18O their way from assimilation in leaf ring. As consequence, aim this study was trace signals European beech (Fagus sylvatica...
Summary The oxygen stable isotope composition of plant organic matter (OM) (particularly wood and cellulose in the tree ring archive) is valuable studies plant–climate interaction, but there a lack information on transfer signal from leaf to heterotrophic tissues. We studied isotopic its enrichment above source water over diel courses five species covering broad range life forms. tracked water‐soluble OM further phloem‐transported OM. Observed evaporative was consistent with values predicted...
Abstract. Dissolved organic carbon (DOC) concentrations – mainly of terrestrial origin are increasing worldwide in inland waters. Heterotrophic bacteria the main consumers DOC and thus determine temporal dynamics availability for higher trophic levels. Our aim was to study bacterial (C) turnover with respect quantity chemical quality using both allochthonous autochthonous sources. We incubated a natural community C (13C-labeled beech leachate) increased pulses (intermittent occurrence matter...
In trees, the interplay between reduced carbon assimilation and inability to transport carbohydrates sites of demand under drought might be one mechanisms leading starvation. However, we largely lack knowledge on how effects new assimilate allocation differ species with different sensitivities these are modified by interspecific competition. We assessed fate (13) C labelled assimilates in above- belowground plant organs root/rhizosphere respired CO2 saplings drought-tolerant Norway maple...
Soil microbial communities play an important role in forest ecosystem functioning, but how climate change will affect the community composition and consequently bacterial functions is poorly understood. We assessed effects of reduced precipitation with aim simulating realistic future drought conditions for one growing season on its relation to soil properties management. manipulated beech conifer plots managed at different levels intensity three regions across Germany. The reduction...
Abstract Drought duration and intensity are expected to increase with global climate change. How changes in water availability temperature affect the combined plant–soil–microorganism response remains uncertain. We excavated soil monoliths from a beech ( Fagus sylvatica L.) forest, thus keeping understory plant–microbe communities intact, imposed an extreme event, consisting of drought and/or single heat‐pulse followed microbial community dynamics over time period 28 days. During treatment,...
Due to climate change, many lakes in Europe will be subject higher variability of hydrological characteristics their littoral zones. These different regimes might affect the use allochthonous and autochthonous carbon sources. We used sandy sediment microcosms examine effects (wet, desiccating, wet-desiccation cycles) on turnover. (13)C-labelled particulate organic was trace estimate uptake into bacterial biomass (via phospholipid fatty acids) respiration. Microbial community changes were...
Regulation of stomatal (gs) and mesophyll conductance (gm) is an efficient means for optimizing the relationship between water loss carbon uptake in plants. We assessed water-use efficiency (WUE)-based drought adaptation strategies with respect to different functional plant groups forest understory. Moreover we aimed at assessing mechanisms interactions CO2 mesophyll. The facts that increase WUE was observed only two species increased gm response moderate drought, over all five examined,...
Landscapes can be viewed as spatially heterogeneous areas encompassing terrestrial and aquatic domains. To date, most landscape carbon (C) fluxes have been estimated by accounting for ecosystems, while ecosystems largely neglected. However, a robust assessment of C on the scale requires estimation within between both components. Here, we compiled data from literature across air–water interface various We simulated emissions uptake five different scenarios which represent gradient increasing...
Molecular clocks drive oscillations in leaf photosynthesis, stomatal conductance, and other cell leaf-level processes over ∼24 h under controlled laboratory conditions. The influence of such circadian regulation whole-canopy fluxes remains uncertain; diurnal CO2 H2O vapor flux dynamics the field are currently interpreted as resulting almost exclusively from direct physiological responses to variations light, temperature environmental factors. We tested whether would affect plant canopy gas...
Across a landscape, aquatic-terrestrial interfaces within and between ecosystems are hotspots of organic matter (OM) mineralization. These characterized by sharp spatio-temporal changes in environmental conditions, which affect OM properties thus control mineralization other transformation processes. Consequently, the extent movement at across is crucial determining turnover carbon (C) cycling landscape scale. Here, we propose expanding current concepts aquatic terrestrial ecosystem sciences...
Abstract. Identifying the chemical mechanisms behind soil carbon bound in organo-mineral complexes is necessary to determine degree which organic stabilized belowground. Analysis of δ13C and δ15N isotopic signatures OM fractions along with mineral characteristics may yield important information about OM-mineral associations their processing history. We anlayzed from two matter (OM) proxies identify likely binding involved. analyzed hypothesized contain through complexes: (1) separated...
Abstract. Precipitation patterns across Central Europe are expected to change over the 21st century due climate change. This may reduce water availability during plant-growing season and hence affect performance vitality of forest ecosystems. We established a novel rainfall reduction experiment on nine sites in Germany investigate drought effects soil–forest–understory A realistic, but extreme annual with return period 40 years, which corresponds 2.5% percentile precipitation, was imposed....
In the future, periods of strongly increased temperature in concert with drought (heat waves) will have potentially detrimental effects on trees and forests Central Europe. Norway spruce might be at risk future climate However, Douglas-fir is often discussed as an alternative for heat sensitive spruce, because some provenances are considered to well adapted drier warmer conditions. this study, we identified physiological growth responses seedlings from two different atmospheric during a...
The carbon isotopic composition (delta(13)C) of recently assimilated plant is known to depend on water-stress, caused either by low soil moisture or atmospheric humidity. Air humidity has also been shown correlate with the delta(13)C respiration, which suggests indirectly that fixed photosynthates comprise a substantial component substrates consumed respiration. However, there are other reasons why delta(13)CO(2) efflux may change conditions, have not received as much attention. Using...