Identifying early warning signals of catastrophic shifts in ecosystems

With the current global change, it is becoming increasingly important for us to be able to anticipate shifts in ecological communities. Shifts are often responsible for large, long-lasting changes and can result in dramatic ecological and economic consequences. Are there early warning signs that an ecosystem is loosing resilience?

Generic indicators, that can be quantified on the temporal and spatial dynamics of ecosystems, have been identified in the literature. In addition, for terrestrial ecosystems, it has been hypothesized that vegetation patchiness could be used as a signature of imminent transitions in ecosystems. Using both field data and modelling approaches,I investigate when and where these indicators can be quantified and when their predictions in terms of ecosystem degradation are reliable, with a current focus on arid ecosystems.

Arid and semi-arid ecosystems, which cover about 40% of the Earth’s terrestrial surface, are expected to be among the ecosystems most sensitive to environmental changes. There are growing concerns that climatic changes may lead to increased desertification, impacting approximately 25% of the world’s population. I am developing models of the vegetation dynamics in arid ecosystems aiming at better understanding the functioning of arid ecosystems and their response to changes in external conditions, such as grazing pressure or climate change.

CASCADE

Learn more about the European project CASCADE (2011-2017)

spatialwarnings

R-package on spatial early warning signals (lead by A. Génin)

Some publications:

Kéfi et al. 2024. PNAS

Génin, A. et al. 2020. Biological Conservation.

Génin, A.et al. 2018. Methods in Ecology and Evolution.

Kéfi, S. and P. Couteron. 2018. Ecological indicators.

Berdugo, M. et al.2017. Nature in Ecology and Evolution.

Schneider, F.D. and S. Kéfi. 2016. Theoretical Ecology.

Kéfi, S. et al. 2014. PLoS ONE.

Kéfi, S.et al. 2013. Oikos.

Kéfi, S. et al. 2011. Ecology Letters.

Kéfi, S. et al. 2007. Theoretical Population Biology.

Kéfi, S. et al. 2007. Nature.