ABSTRACT
Biodiversity is vital to the health of the planet and its people. It secures our food supply, provides a source of medicine and new technologies, and helps regulate our climate. According to the Secretariat of the Convention on Biological Diversity, “A major challenge for the twenty-first century will be making the conservation and sustainable use of biodiversity a compelling basis for development policies, business decisions, and consumer desires” (2000). But biodiversity is particularly affected by global change (cf. Li and Reynolds 1994; Dramstad et al. 1996; Forman 1997; Gustafson and Gardner 1996). For this reason, it is essential that indicators of biodiversity be integrated 150in sustainability monitoring systems. Data derived from such systems should then be made available to local administrations, policy and decision makers, as well as stakeholders to aid them in decision-making processes. However, it is difficult to determine which indicators are suitable to assess the effects of global changes on spatiotemporal biodiversity, as only limited quantifiable data on biological diversity are available (Honnay et al. 2003; Dierssen 2006). This makes it nearly impossible to meaningfully compare different space levels as well as different time periods. Numerous attempts have been made to develop and establish monitoring systems at ecosystem and regional scales (Olsen et al. 1999; Hoffmann-Kroll et al. 2003). Some systems have been up and running for a few decades, such as the British Countryside Survey (Haines-Young et al. 2003). However, available data still do not stretch back over a sufficiently long time span. In addition, there is still no formal definition of what is an adequate measure of biodiversity (Yoccoz et al. 2001; Büchs 2003; Dudley et al. 2005).
