Abteilung Aquatische Ökologie

Observations of biodiversity change and tipping points from space

Using remote-sensing we are able to make inferences about global average trends of change within local ecosystems. This approach allows us to investigate whether trends that we observe in well-studied systems locally are indeed representative of global changes, or are biased due to their location and human choices of study sites.

 In a first project in collaboration with Luis Gilarranz, Vasilis Dakos, Rosi Siber and Daniel Odermatt, we are using satellite images to understand changes in phytoplankton communities (abundance and composition) in lakes in Switzerland and around the world. What is the influence of environmental change and perturbation on productivity and community composition? Do we observe tipping points in lakes and if so, how common are they across the globe?

 In a second project, we hope to use remotely sensed land-use change observations to understand whether or not biodiversity is declining locally on average across the globe. Land-use change is one of the major causes of biodiversity change. Using satellite hyper-spectral imagery we one can study the transitions between land cover classes. We are comparing species occurrence records from biodiversity databases with processed remote sensing imagery to determine the extent to which biodiversity change is predictable based on land-use conversion. In this way, we aim to provide a first pass at a global answer to the hotly debated question: "Is local biodiversity increasing or decreasing?"