Project 7

Determination of critical thresholds for lake ecosystem resilience from long-term HFM data.  

 Based in: Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany.

Objectives: long-term changes are often of a non-linear nature, surpassing critical thresholds and leaving systems in a different state, often with temperature as a main forcing for a cascade of abrupt environmental changes. We know little about the temporal scales we need to consider for detecting change in resilience and how extreme events contribute to long-term trends and variability in ecosystem functionality. This PhD will use high frequency measurement (HFM) data to study the effects of episodic events on algal mass and lake metabolism as a proxy of ecosystem functionality, using the Metabolic Theory of Ecology as a universal concept. The PhD will test how general anthropogenic pressure acts to erode ecosystem resilience and brings the system closer to a critical transition. High taxonomic resolution long-term data will allow us to study the role of episodic events in the context of known long-term trends (30+ years) and short term recovery, and link overlapping effects of climate and other anthropogenic induced responses to overall ecosystem functionality. The overall objective is to quantify critical thresholds of the amplitude and frequency of episodic events affecting algal development and test whether generally available proxies can be used to capture human interferences with lake ecosystem functionality and resilience.

This student will be primarily based in Berlin at the Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Germany, supervised by Prof. Rita Adrian, and will be co-supervised by and spend study time with Prof. Bas Ibelings, University of Geneva. The PhD will be a double degree awarded by the Free University of Berlin and University of Geneva.