Of Birds and Bees: Biodiversity and the Colonization of Ecosystems

Biodiversity is an important aspect of Earth’s ecosystems, and is closely related to the provision of essential goods and services for human society. In this chapter, we discuss concepts and causes of biological diversity and, based on the socioecological interaction model, the relationship between human society and biodiversity. Furthermore, we present two empirical studies relating an energy-based pressure indicator to species richness numbers. This indicator, the human appropriation of net primary production (HANPP), can be linked to one of the major theories explaining biodiversity, the species-energy hypothesis, as well as to socioecological processes such as the consumption of biomass. Both studies are located in Austria. The first focuses on a transect covering cultural landscapes in the East of Austria and investigates several autotrophic and heterotrophic taxonomical groups. The second compares spatial patterns of avian diversity and HANPP for the whole Austrian territory. Both studies find clear evidence of a positive relationship between energy availability and species richness numbers, supporting the species-energy hypothesis. Moreover, these results suggest the suitability of applying an energy-related pressure indicator such as the HANPP to biodiversity.