Fachbereich Geowissenschaften

Coupled Modelling of Vegetation-Hydrology Dynamics

How does the development of vegetation patterns depend on hydrological patterns and to which extent are these controlled by the vegetation patterns?

PhD Researcher: Maximiliane Herberich
Supervisors: Katja Tielbörger (University of Tübingen), Sebastian Gayler (University of Hohenheim), Madhur Anand (University of Guelph)

Water and vegetation dynamics are strongly interrelated: water availability affects biomass production, vegetation distribution and the type of vegetation, which in turn influences the infiltration capacity, evapotranspiration and runoff. Understanding this interrelation is needed to develop tools for a more sustainable use of water resources and management of natural ecosystems.

In recent decades, dynamic vegetation models have emerged as a powerful tool for quantifying ecosystem dynamics in response to hydrological processes. The major difficulty of coupling vegetation and hydrology dynamics is to depict the complexity and spatiotemporal variability of natural ecosystems. Existing vegetation-hydrology models tried to capture the essential dynamics of ecosystems by modelling few key plant species or subjective plant functional types. However, this simplification restricts the models to predefined trait combination and trade-offs.

We will use a novel and highly flexible, spatially-explicit, individual based approach that models abundance and spatial distribution of functional traits instead of pre-defined species (i.e. fixed trait combinations) as a function of the topographical and hydrological conditions, as well as of biotic interactions. An important innovation of this approach is that there are no a priori defined trade-offs among traits which would limit the combinations of traits that are 'allowed'. The specific traits and trait combinations establishing under different hydrological regimes then reflect the best adaptation to the specific hydrological regime, i.e. trait combinations yielding the highest reproductive output will be selected for.

Publications

  • Herberich, M., Gayler, S., Anand, M., Tielbörger, K. (2017): Hydrological Niche Segregation of Plant Functional Traits in an Individual-based Model. Ecological Modelling, 356, 14-24, doi: 10.1016/j.ecolmodel.2017.04.002