Integrated nature conservation valuation (INCV): A new biotic area-assessment method based on habitats and species occurrences and derivation of hydroecologic vulnerability

Groundwater depletion through drinking water abstraction, irrigation or climate change generally has a negative impact on terrestrial groundwater-dependent ecosystems. Towards the concept of ecologically sustainable groundwater abstraction management, a method is needed to uniformly evaluate different areas on the basis of biotic value. Biotic value represents the natural value of a habitat for protected species conservation (nature value). Established and currently indispensable methods of landscape planning generally evaluate habitat function via the habitats, whereby the inventory of animal species is largely ignored. Thus, there is a crucial need for additional species-based animal and ecology data to be methodologically standardised, quantified and incorporated into planning practice. Initial faunistic assessment methods already have been developed and applied in practice, but are generally limited to single groups of species, such as birds and bird breeding areas. In this paper, we present a new method that, in addition to the established habitat type module, incorporates a species module to enable multiple plant or animal species besides birds to be included in biotic area assessment. The use of this approach allows for standardized comparison of changing biotic area values over time, or among, for example, European Natura 2000 areas. By considering groundwater dependency and groundwater impact, special attention can be paid to derivation of the hydroecological vulnerability. This method makes it possible to calculate further vulnerabilities by considering other environmental threat factors. We test this method in the case study of the drinking water catchment area of the city of Karlsruhe.