Project PEAT (2022-2025): Measurement and modelling of peatland greenhouse gas fluxes

In this project we aim to understand the feedback from degrarded peatland ecosystems to the climate and quantify their capacity for mitigating climate change, by means of direct observations and modelling techniques. For this purpose we have established two eddy covariance stations in two degraded raised bogs in northwest Germany where we measure ecosystem greenhouse gas fluxes continuously with the eddy covariance technique and collect biometeorological measurements to seperate the biotic and abiotic drivers of gas fluxes.

To address our objectives we emply a mixture of in-situ observations, data analysis, and modeling approaches to address three main objectives:

1) Quantify ecosytem carbon fluxes and budgets

2) Identify driving mechanisms of greenhouse gas and water fluxes in response to climate, land-use, and vegetation type

3) Model the interdependency of gas and water fluxes with climatology, ecophysiology, and phenology under extreme climatic conditions (i.e., drought, heatwaves)

The eddy covariance station in Amtsvenn-Hündfelder Moor (DE-Amv) was established in collaboration with the Biological Station Zwillbrock in September 2022 and the second station in Oppenwehe Moor was established in collaboration with the Minden-Lübbecke district in July 2023. Both stations are sites of strong collaboration within the Institute of Landscape Ecology of University of Münster, and provide a diverse range of teaching and research opportunities. DE-Amv is an ICOS candiate site.

Amtsvenn-Hündfelder Moor (DE-Amv) eddy covariance station
© Nicolas Behrens
Oppenweher Moor eddy covariance station
© Mana Gharun

Project ACCLIM (2024-2027): Ecosystem acclimation to escalating atmospheric and soil dryness

Atmospheric and soil dryness have a strong influence on the exchange of greenhouse gases between terrestrial ecosystems and the atmosphere. With climate change, the frequency and intensity of extreme dryness that limits ecosystem ecophysiological functioning are increasing. However, the cascading effect on the ecosystems, the memory from past events, and the level of ecosystem acclimation to increased dryness are not clear. This project aims to quantify and understand the effect of more frequent and more intense atmospheric and soil dryness on the carbon uptake of natural ecosystems (e.g., forests, grasslands, peatlands) based on ecosystem-level gas flux observations. The primary focus will be on testing statistical methods for quantifying ecosystem memory and acclimation and discovering the underlying causal networks in ecosystem-atmosphere exchange processes.

Project CERES (2024-2027): Impacts of air pollution and climate extremes on the resilience of European forests

Global change drivers such as air pollution (nitrogen, sulfur), but also extreme events in air temperature, precipitation, soil and atmospheric dryness have direct effects on the functioning of forests and might reduce or even offset the effectiveness of nature-​based solutions in the future. Defining effective mitigation strategies needs to consider resilience, i.e., resistance and recovery, of forests to air pollution and extreme events. This requires a mechanistic understanding of tree ecophysiological processes that drive forest CO2 uptake and evaporative cooling, and directly affect the capacity of forests for mitigating climate change. In CERES, we aim to improve the mechanistic understanding of how changes in tree ecophysiology in response to air pollution and climate extremes drive the forest ecosystem's capacity to sequester C and its evaporative cooling. Our hypothesis is that spatio-​temporal variations in atmospheric N and S deposition interact with climate drivers (positively or negatively depending on their magnitude) to change trends in resistance, recovery, and resilience of forests in response to extreme events.

This project is hosted at ETH Zürich.


Project EMBER-SIM (2024-2025): Simulating fire spread across forest and grassland ecosystems

Due to climate change the intensity and frequency of bushfires are increasing globally. Modeling bushfire spread is a multifaceted approach that involves public safety, resource management, conservation, and environmental protection. It provides valuable insights for decision-makers, emergency responders, and communities to better prepare for and respond to wildfires. In EMBER-SIM we aim to develop an interactive web-based fire spread simulation tool, suited for forest and grassland ecosystems.

This project is a collaboration with the Institute of Geoinformatics of the University of Münster

© Mana Gharun

Project COCO (2021-2024): COS and below-​canopy CO2 fluxes of two Swiss forests

Achieving “nature-​based” solutions, proposed in the Paris Agreement, needs a comprehensive understanding of consequences of climate change on forest carbon budgets. This requires the existence and availability of long-​term, high-​quality data on ecosystem functions, such as net ecosystem exchange (NEE), which can be partitioned into ecosystem CO2 uptake (GPP) and respiratory losses (Reco), crucial to understand the mechanisms underlying forest responses and assess their potential for sustained C sequestration. Thus, detection of flux (un)certainty is crucial, and is best done by additional constraints, e.g. by below-​canopy flux measurements, advection estimates as well as carbonyl sulphide (COS) fluxes. In COCO aims are to 1) independently validate gross primary production estimates with COS fluxes, 2) to constrain ecosystem respiration estimates using below-​canopy fluxes, 3) to quantify advection of CO2, and 4) to identify long-​term trends and short-​term responses of CO2 fluxes to climate extremes.

This project is hosted at ETH Zürich.

© Matthias Paintner

Project FEVER (2019-2023): Forest vulnerability to extreme and repeated climatic stress

The frequency and severity of heat events are increasing across Europe: by the end of the 21st century, countries in central Europe will experience the same number of hot days as are currently experienced in southern Europe. The uncertainty of how forest trees react to increased temperatures and heat stress is also related to the fact that ecophysiological reactions vary across species, sites and regions, biome types, and prevailing climatic conditions, which makes their realization in land-​atmosphere models challenging. To improve the understanding of forest-​climate interactions, a multi-​scale approach is needed, that is able to investigate the ecosystem as a whole, to be able to predict the degree to which the forest ecosystem is susceptible to adverse climatic stress impacts. The project FEVER linked physiological leaf, tree, and root processes with the ecosystem-​level fluxes of water vapor, to understand the contribution of vegetation, and the direction in which forest-​climate interactions will be affected by future changes in climate.

© Shekhar et al. 2024 STOTEN