Benjamin StockerUniversität Bern | UniBe · Institute of Geography
Benjamin Stocker
Professor
About
155
Publications
133,757
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Introduction
I'm interested in how global environmental change affects vegetation productivity and the terrestrial carbon cycle. By developing new approaches to modelling the coupled carbon, nutrient, and water cycles, I'm trying to explain a range of generally observed phenomena.
personal website:
stineb.github.io
link to google scholar:
http://scholar.google.co.uk/citations?user=TX7egiYAAAAJ&hl=en
Additional affiliations
Education
September 2007 - October 2009
Publications
Publications (155)
Terrestrial primary productivity and carbon cycle impacts of droughts are commonly quantified using vapour pressure deficit (VPD) data and remotely sensed greenness, without accounting for soil moisture. However, soil moisture limitation is known to strongly affect plant physiology.
Here, we investigate light use efficiency, the ratio of gross prim...
Contents
Summary
507
I.
Introduction
507
II.
The return on investment approach
508
III.
CO 2 response spectrum
510
IV.
Discussion
516
Acknowledgements
518
References
518
Summary
Land ecosystems sequester on average about a quarter of anthropogenic CO 2 emissions. It has been proposed that nitrogen (N) availability will exert an increasingly...
Significance
Timing, extent, and impacts of preindustrial agricultural expansion are uncertain, yet crucial for understanding the role of humans in the Earth’s environmental history. The buildup of northern peatlands, initiated after ice-age conditions, was a major carbon sink and could have compensated large CO 2 emissions from land use, given tim...
Atmospheric concentrations of the three important greenhouse gases (GHGs) CO2, CH4 and N2O are mediated by processes in the terrestrial biosphere that are sensitive to climate and CO2. This leads to feedbacks between climate and land and has contributed to the sharp rise in atmospheric GHG concentrations since pre-industrial times. Here, we apply a...
Plants acclimate to temperature by adjusting their photosynthetic capacity over weeks to months. However, most evidence for photosynthetic acclimation derives from leaf-scale experiments. Here we address the scarcity of evidence for canopy-scale photosynthetic acclimation by examining the correlation between maximum photosynthetic rates (Amax,2,000...
Tropical forests dominate terrestrial photosynthesis, yet there are major contradictions in our understanding due to a lack of field studies, especially outside the tropical Americas. A recent field study indicated that West African forests have among the highest forests gross primary productivity (GPP) yet observed, contradicting models that rank...
Interactions between carbon (C) and nitrogen (N) cycles in terrestrial ecosystems are simulated in advanced vegetation models, yet methodologies vary widely, leading to divergent simulations of past land C balance trends. This underscores the need to reassess our understanding of ecosystem processes, given recent theoretical advancements and empiri...
Nutrient resorption from senescing leaves can significantly affect ecosystem nutrient cycling, making it an essential process to better understand long-term plant productivity under environmental change that affects the balance between nutrient availability and demand. Although it is known that nutrient resorption rates vary strongly between differ...
Global patterns of leaf nitrogen (N) and phosphorus (P) stoichiometry have been interpreted as reflecting phenotypic plasticity in response to the environment, or as an overriding effect of the distribution of species growing in their biogeochemical niches. Here, we balance these contrasting views. We compile a global dataset of 36,413 paired obser...
The aim of the study was to find out how new technologies can reduce the negative effects of climate change in Switzerland and make our society and economy more resilient. The experts have high hopes for the latest developments in artificial intelligence (AI) and satellite-based earth observations to overcome the various climate challenges. In comb...
Reducing uncertainty in carbon cycle projections relies on reliable representations of interactions between the carbon and nutrient cycles. Here, we build on a set of principles and hypotheses, funded in established theoretical understanding and supported by empirical evidence, to formulate and implement a dynamic model of carbon-nitrogen cycle (C-...
Plant water uptake from the soil is a crucial element of the global hydrological cycle and essential for vegetation drought resilience. Yet, knowledge of how the distribution of water uptake depth (WUD) varies across species, climates, and seasons is scarce relative to our knowledge of aboveground plant functions. With a global literature review, w...
Plants acclimate to temperature by adjusting their photosynthetic capacity over weeks to months. However, most evidence for photosynthetic acclimation derives from leaf-scale experiments. Here, we address the scarcity of evidence for canopy-scale photosynthetic acclimation by examining the correlation between maximum photosynthetic rates (Amax,2000...
Tropical forests dominate terrestrial photosynthesis, yet there are major contradictions in our understanding due to a lack of field studies, especially outside the tropical Americas. A recent field study indicated that West African forests have among the highest forests gross primary productivity (GPP) yet observed, contradicting models that rank...
Nutrient resorption from senescing leaves can significantly affect ecosystem nutrient cycling, making it an essential process to better understand long-term plant productivity under environmental change that affects the balance between nutrient availability and demand. Although it is known that nutrient resorption rates vary strongly between differ...
Accurate representation of plant water availability is crucial for climate modeling, due to its significant role in land-atmosphere interactions. Our study focuses on water storage dynamics and analyzes how soil moisture limitation is represented in Earth System Model (ESM) simulations of the Coupled Model Intercomparison Project phase 6 (CMIP6). W...
Tropical forests dominate terrestrial photosynthesis, yet there are major contradictions in our understanding due to a lack of field studies, especially outside the tropical Americas. A recent field study indicated that West African forests have among the highest forests gross primary productivity (GPP) yet observed, contradicting models that rank...
Understanding the role of groundwater in regulating photosynthesis is key in land-climate interactions. However, the impact of groundwater on terrestrial ecosystem productivity remains poorly understood. Here, we use satellite observations of solar-induced fluorescence as a proxy for photosynthesis, together with estimates of water table depth (WTD...
Theory predicts that rising CO2 increases global photosynthesis, a process known as CO2 fertilization, and that this is responsible for much of the current terrestrial carbon sink. The estimated magnitude of the historic CO2 fertilization, however, differs by an order of magnitude between long-term proxies, remote sensing-based estimates and terres...
Mechanistic vegetation models serve to estimate terrestrial carbon fluxes and climate impacts on ecosystems across diverse biotic and abiotic conditions. Systematically informing them with data is key for enhancing their predictive accuracy and estimate uncertainty. Here we present the Simulating Optimal FUNctioning {rsofun} R package, providing a...
While enhanced tree growth over the last decades has been reported in forests across the globe, it remains unclear whether it drives persistent biomass increases of forest stands, particularly in mature forests. Enhanced tree growth and stand‐level biomass are often linked with a simultaneous increase in density‐driven mortality and a reduction in...
Plant biomass production (BP), nitrogen uptake (Nup) and their ratio, and nitrogen use efficiency (NUE) must be quantified to understand how nitrogen (N) cycling constrains terrestrial carbon (C) uptake. But the controls of key plant processes determining Nup and NUE, including BP, C and N allocation, tissue C:N ratios and N resorption efficiency (...
Ecosystem manipulative experiments are a powerful tool to understand terrestrial ecosystem responses to global change because they measure real responses in real ecosystems and yield insights into causal relationships. However, their scope is limited in space and time due to cost and labour intensity. This makes generalising results from such exper...
Accurate predictions of environmental controls on ecosystem photosynthesis are essential for understanding the impacts of climate change and extreme events on the carbon cycle and the provisioning of ecosystem services. Using time-series measurements of ecosystem fluxes paired with measurements of meteorological variables from a network of globally...
Accounting for water limitation is key to determining vegetation sensitivity to drought. Quantifying water limitation effects on evapotranspiration (ET) is challenged by the heterogeneity of vegetation types, climate zones and vertically along the rooting zone.
Here, we train deep neural networks using flux measurements to study ET responses to pro...
Land carbon dynamics in temperate and boreal ecosystems are sensitive to environmental change. Accurately simulating gross primary productivity (GPP) and its seasonality is key for reliable carbon cycle projections. However, significant biases have been found in early spring GPP simulations of northern forests, where observations often suggest a la...
Climate change is shifting the growing seasons of plants, affecting species performance and biogeochemical cycles. Yet how the timing of autumn leaf senescence in Northern Hemisphere forests will change remains uncertain. Using satellite, ground, carbon flux, and experimental data, we show that early-season and late-season warming have opposite eff...
The resilience of biodiverse forests to climate change depends on an interplay of adaptive processes operating at multiple temporal and organizational scales. These include short-term acclimation of physiological processes like photosynthesis and respiration, mid-term changes in forest structure due to competition, and long-term changes in communit...
Ecosystem manipulative experiments are one of the most powerful tools to understand terrestrial ecosystem responses to global change because they measure real responses in real ecosystems. However, their scope is limited in space and time due to cost and labour intensity. This makes generalising results from such experiments difficult, which create...
The rooting-zone water-storage capacity—the amount of water accessible to plants—controls the sensitivity of land–atmosphere exchange of water and carbon during dry periods. How the rooting-zone water-storage capacity varies spatially is largely unknown and not directly observable. Here we estimate rooting-zone water-storage capacity globally from...
Wetlands have long been drained for human use, thereby strongly affecting greenhouse gas fluxes, flood control, nutrient cycling and biodiversity1,2. Nevertheless, the global extent of natural wetland loss remains remarkably uncertain³. Here, we reconstruct the spatial distribution and timing of wetland loss through conversion to seven human land u...
Leaf phenology is key for regulating total growing-season mass and energy fluxes. Long-term temporal trends towards earlier leaf unfolding are observed across Northern Hemisphere forests. Phenological dates also vary between years, whereby end-of-season (EOS) dates correlate positively with start-of-season (SOS) dates and negatively with growing-se...
Responses of the terrestrial biosphere to rapidly changing environmental conditions are a major source of uncertainty in climate projections. In an effort to reduce this uncertainty, a wide range of global change experiments have been conducted that mimic future conditions in terrestrial ecosystems, manipulating CO2, temperature, nutrient and water...
Supporting information for publication “When things get MESI: the Manipulation Experiments Synthesis Initiative – a coordinated effort to synthesize terrestrial global change experiments” by Van Sundert, Leuzinger et al. (2023).
While enhanced tree growth over the last decades has been reported in forests across the globe, it remains unclear whether it drives persistent biomass increases of the stands, particularly in mature forests. Enhanced tree growth and stand-level biomass are often linked with a simultaneous increase in density-driven mortality and a reduction in tre...
Using steady-state photosynthesis–intercellular CO2 concentration (A–Ci) response curves to obtain the maximum rates of ribulose-1,5-bisphosphate carboxylase oxygenase carboxylation (Vcmax) and electron transport (Jmax) is time-consuming and labour-intensive. Instead, the rapid A–Ci response (RACiR) technique provides a potential, high-efficiency m...
Plant biomass production (BP), nitrogen uptake (Nup) and their ratio, nitrogen use efficiency (NUE), must be quantified to understand how nitrogen (N) cycling constrains terrestrial carbon (C) uptake. But the controls of key plant processes determining Nup and NUE, including BP, C and N allocation, tissue C:N ratios and N resorption efficiency (NRE...
Gross primary production (GPP) by terrestrial ecosystems is a key quantity in the global carbon cycle. The instantaneous controls of leaf-level photosynthesis are well established, but there is still no consensus on the mechanisms by which canopy-level GPP depends on spatial and temporal variation in the environment. The standard model of photosynt...
The global carbon and water cycles are governed by the coupling of CO2 and water vapour exchanges through the leaves of terrestrial plants, controlled by plant adaptations to balance carbon gains and hydraulic risks. We introduce a trait-based optimality theory that unifies the treatment of stomatal responses and biochemical acclimation of plants t...
The current Chilean megadrought has led to acute water shortages in central Chile since 2010. Glaciers have provided vital fresh water to the region's rivers, but the quantity, timing and sustainability of that provision remain unclear. Here we combine in‐situ, remote sensing and climate reanalysis data to show that from 2010 to 2018 during the meg...
effects of experimental eCO2, warming, nutrient addition and/or water addition/removal on carbon and nutrient cycle related variables
We welcome contributions to the database on github.com/MESI-organization/mesi-db, or by email.
When data are used, please cite both the database doi as well as the accompanying manuscript:
Van Sundert, K., Leuzing...
Droughts affect terrestrial ecosystems directly and concurrently and can additionally induce lagged effects in subsequent seasons and years. Such legacy effects of drought on vegetation growth and state have been widely studied in tree ring records and satellite-based vegetation greenness, while legacies on ecosystem carbon fluxes are still poorly...
The advent of abundant Earth observation data enables the development of novel predictive methods for forecasting climate impacts on the state and health of terrestrial ecosystems. Here, we target the spatial and temporal variations of land surface reflectance and vegetation greenness, measuring the density of green vegetation and active foliage ar...
Understanding how leaf autumn phenology varies at different spatio-temporal scales is key to accurately predicting phenological changes under future climate. Recent projections and observations of autumn phenology in deciduous temperate and boreal forests appear conflicting. At the interannual scale, autumn senescence correlates positively with spr...
Droughts affect terrestrial ecosystems directly and concurrently, and can additionally induce lagged effects in subsequent seasons and years. Such legacy effects of drought on vegetation growth and state have been widely studied in tree-ring records and satellite-based vegetation greenness, while legacies on ecosystem carbon fluxes are still poorly...
Climate change is causing shifts in the growing seasons of plants1,2, affecting species performance and interactions3,4 as well as global carbon, water and nutrient cycles5,6. How the timing of autumn leaf senescence in extra-tropical forests will change remains unclear because of the complex seasonal interaction of climate warming, earlier and enh...
Future climate will be characterized by an increase in frequency and duration of drought and warming that exacerbates atmospheric evaporative demand. How trees acclimate to long-term soil moisture changes and whether these long-term changes alter trees' sensitivity to short-term (day to months) variations of vapor pressure deficit (VPD) and soil mo...
Leaf phenology is key for regulating total growing season mass and energy fluxes. Long-term temporal trends towards earlier leaf unfolding are observed across Northern Hemisphere forests. Phenological dates also vary between years, whereby end-of-season (EOS) dates correlate positively with start-of-season (SOS) dates and negatively with growing se...
Southeast Asia is a region known for active land‐use changes (LUC) over the past 60 years; yet, how trends in net CO2 uptake and release resulting from LUC activities (net LUC flux) have changed through past decades remains uncertain. The level of uncertainty in net LUC flux from process‐based models is so high that it cannot be concluded that newe...
Northern peatlands store 300–600 Pg C, of which approximately half are underlain by permafrost. Climate warming and, in some regions, soil drying from enhanced evaporation are progressively threatening this large carbon stock. Here, we assess future CO2 and CH4 fluxes from northern peatlands using five land surface models that explicitly include re...
The global terrestrial carbon sink is increasing1,2,3, offsetting roughly a third of anthropogenic CO2 released into the atmosphere each decade¹, and thus serving to slow⁴ the growth of atmospheric CO2. It has been suggested that a CO2-induced long-term increase in global photosynthesis, a process known as CO2 fertilization, is responsible for a la...
The uptake of carbon dioxide (CO2) from the atmosphere through photosynthesis is accompanied by an inevitable loss of water vapor through the stomata of leaves. The rate of leaf-level CO2 assimilation per unit stomatal conductance, i.e. intrinsic water-use efficiency (WUEi), is thus a key characteristic of terrestrial ecosystem functioning that is...
Using traditional photosynthesis-intercellular CO concentration ( A-C ) response (TACiR) curves to obtain the maximum rates of ribulose-1,5-bisphosphate carboxylase oxygenase carboxylation ( V ) and electron transport ( J ) is time-consuming and labor-intensive. Instead, the rapid A-C response (RACiR) technique provides a potential way with high ef...
The rooting zone water storage capacity (S 0) extends from the soil surface to the weathered bedrock (the Critical Zone) and determines land-atmosphere exchange during dry periods. Despite its importance to land-surface modeling, variations of S 0 across space are largely unknown as they cannot be observed directly. We developed a method to diagnos...
A poor understanding of the fraction of global plant biomass occurring belowground as roots limits our understanding of present and future ecosystem function and carbon pools. Here we create a database of root-mass fractions (RMFs), an index of plant below- versus aboveground biomass distributions, and generate quantitative, spatially explicit glob...
Global vegetation and land‐surface models embody interdisciplinary scientific understanding of the behaviour of plants and ecosystems, and are indispensable to project the impacts of environmental change on vegetation and the interactions between vegetation and climate. However, systematic errors and persistently large differences among carbon and...
Forest demographic processes-growth, recruitment and mortality are being altered by global change. The changing balance between growth and mortality strongly influences forest dynamics and the carbon balance. Elevated atmospheric carbon dioxide (eCO 2) has been reported to enhance photosynthesis and tree growth rates by increasing both light-use ef...
Terrestrial ecosystems remove about 30 per cent of the carbon dioxide (CO2) emitted by human activities each year¹, yet the persistence of this carbon sink depends partly on how plant biomass and soil organic carbon (SOC) stocks respond to future increases in atmospheric CO2 (refs. 2,3). Although plant biomass often increases in elevated CO2 (eCO2)...