Eco-hydrology and biodiversity

Abstract

One of the branches of eco-hydrological research deals with relationships of hydrology and biodiversity, especially the relation between hydrology and the occurrence of individual plant species and plant communities. Every plant has specific demands on its environment, such as temperature, light and the availability of water, oxygen and nutrients. These demands are called the ‘environmental site conditions’ of species. Because of differences in site conditions between plant species, species have an indicator value for the state of the environment. Indicator values can be used to assess which species are to be expected on certain soil types and under which hydrological conditions, but also which species will appear or disappear after certain measures have been taken at a site. They are, therefore, often used in environmental-impact studies and ecological engineering projects. In this chapter we will discus the problems encountered by researchers who study the demands that plant species make on their environment. We shall argue why ecohydrologists often use indicator values of plant species for site factors related to water management (e.g. moisture regime, nutrient richness, acidity) and demonstrate how these indicator values can be applied successfully to the eco-hydrological modeling of biodiversity. We will introduce a novel model that predicts the occurrence probabilities of vegetation types with the aid of indicator values