Research activities

The understanding of the functional basis of how organisms interact with each other and with their environment is a key research objective of our department. Trait approaches are used to characterize functional community structure, to quantify the effects of organisms on ecosystem functioning, and for the parameterization of models on species distribution and ecosystem carbon and water balance. A particularly strong research focus lies on the impact of global change factors such as increasing drought and land use change on biodiversity and ecosystem processes. Using field and laboratory experiments and modeling approaches, we study mainly terrestrial ecosystems with a focus on Mediterranean systems, but also including tropical ecosystems mainly in South America, and temperate and alpine ecosystems.

Head of the department: Stephan HÄTTENSCHWILER

Key words

Biogeochemical cycles | Climate change | Community structure | Functional diversity | Functional traits | Global change | Mechanistic modelling | Mediterranean ecosystems | Plant-soil interactions | Soil ecology | Terrestrial ecosystems | Water relations

New publication :

• Joly F.-X., Scherer-Lorenzen M., Hättenschwiler S. 2023. Resolving the intricate role of climate in litter decomposition. Nature Ecology & Evolution, DOI: s41559-022-01948-z
  
  

Abstract

With approximately 60 Pg of carbon (C) released as CO₂ annually, the decomposition of dead organic matter feeds the major terrestrial global CO₂ flux to the atmosphere. Macroclimate control over this critical C flux facilitates the parametrization of the C cycle in Earth system models, and the understanding of climate change effects on the global C balance. Yet, the long-standing paradigm of climate control was recently challenged by the so far underestimated environmental heterogeneity at local scales, questioning the conceptual framework of thousands of decomposition studies and accuracy of current predictive models. Using three complementary decomposition experiments at European scale, we showed that macroclimate and litter characteristics largely control plant litter decomposition, reaffirming the role of macroclimate as integrative decomposition driver through direct environmental control and by influencing co-evolving local plant and decomposer communities. Neglecting this latter indirect effect, commonly used standard litter types overrated micro-environmental control and failed to predict local decomposition of plot-specific litter. Our data help clarify a key question on the regulation of the global C cycle by identifying the relative role of control factors over decomposition and the scales at which they matter, and by highlighting sources of confusion in the literature.

Link to the full article

                           News release (CNRS-INEE webpage)