FOR816/2 Biodiversity and Sustainable Management of a Megadiverse Mountain Ecosystem in South Ecuador
Speaker of the research unit:
Project description: Everywhere, local biodiversity is threatened directly by an encroachment and intensification of land use and indirectly by the local effects of the global climate change which together result in alarming rates of species extinction (e.g. Sala et al. 2000, Thuiller 2007). Globally, Martens et al. (2003) stressed that one species goes extinct nearly every 20 minutes and that 12.5% of all plant species can be rated as severely threatened. They assumed that global economic losses due to the loss of biological resources and degradation of ecosystems may add up to an order of 50 billion EUR per year. The majority of these consequences affect tropical countries where biodiversity and its ecosystem services are highest, but where environmental management and conservation efforts are still overrun by the basic needs of a dramatically increasing population. Not only species disappear before their discovery and description, but also natural ecosystems, which are converted intoanthropogenic ecosystems of limited permanence and sustainability. The implied shifts in ecosystem services have direct and indirect monetary aspects. Direct effects can be valuated from the striven economic output achieved with the conversion, but the concomitant losses of ecosystem services (Millenium ecosystem assessment 2005) are difficult to estimate. In most cases these losses can not be quantified because a direct comparison of the original and the follow-up anthropogenic ecosystem is not possible. An exception to this situation is the research area of the RU816 in South Ecuador (Fig. 1), where the natural tropical mountain rain forest on the orographically right side of the narrow Rio San Francisco valley verges several variants of an anthropogenic replacement system on the other side of the river: (i) Active pastures, (ii) overweeded and abandoned pastures, and (iii) plantations of exotic trees. On an area basis abandoned pastures by far dominate (Göttlicher et al. 2009). At distances of less than 1 km natural and anthropogenic systems can be compared at various altitudes, and ecosystem services can be extrapolated from the comparison. The research area belongs to the five hottest hotspots of biodiversity, not only with respect to the abundance of vascular (Barthlott et al. 2007) and cryptogamic plants (Gradstein 2008) but also to many other, though not all groups of organisms. An unrivalled volume of research has been already performed since 1997, concentrated on a comparatively small core area of 11 km2 and an extended satellite area of about 100 km2, the results of which have been presented in three books and 239 publications1. Until 2007, priority of research was put on the functioning of the natural tropical mountain rain forest ecosystem and its supporting ecosystem services. These studies were complemented by two long-term experiments, a fertilization experiment (NUMEX) and an experiment on the ecological effects of a sustainable forest management. In spite of considerable progress in data evaluation and understanding of that ecosystem, ultimate answers, e.g. to the burning question of the role of biodiversity for the stability and resilience of the ecosystem require further investigation. Facing the challenge to understand ecosystem functioning in a biodiversity hotspot of the south Ecuadorian Andes and to find sustainable land use management strategies, which can buffer the impacts of local and global environmental change, a new program “Biodiversity and Sustainable Management of a Megadiverse Mountain Ecosystem in South Ecuador“ was launched in 2007. In the first phase of the new Research Unit (RU 816), more emphasis has been put on the anthropogenic systems where several ecological experiments have been jointly implemented: Reforestation, repastorization, fertilization and also a fire experiment. Due to the long-term nature of such experiments our understanding of these anthropogenic ecosystems shows already general contours but is not yet comprehensive enough for an assessment of the ecosystem services.