Between deforestation and climate impact: the Bariri Flux tower site in the primary montane rainforest of Central Sulawesi, Indonesia

Continent, is on the one hand particularly exposed to the irregularities of global circulation patterns (Walker Circulation, Hadley Cell) like ENSO due to its location in Western Equatorial Pacific. On the other hand it is characterized by a highly heterogeneous mixture of mountainous islands and ocean surface which in some parts amplify and in some parts inhibit the impact of global circulation. Our analysis of remote sensing data has shown (Erasmi et al., 2009) that the montane rainforests of Sulawesi are particularly resilient to the drought anomalies caused even by strongest ENSO-warm events (El Nino), but its future sensitivity to the changing frequency and extent of climatic variability is unknown. The current trends in land use change indicate that these mountainous rain forests might soon become the only remaining tropical rain Tropical rain forests in Indonesia are challenged by land use and climate changes Tropical forest ecosystems play an important role in the interaction between climate and biosphere. They are vulnerable to external forcing, especially along their boundaries (in transient zones between land use types) and, when affected, may exercise important controls on the global Earth system. Recent reports showed alarming data on net loss in tropical forest areas (FAO, 2000). A particular rapid decrease of tropical forests is observed in South-East Asian countries, where areas covered by forest decreased from 53.9% in 1990 to 48.6% in 2000 (UN, 2005). In many regions including Indonesia such changes are connected with a rapidly growing human population and nonsustainable land-use practices for food and timber production. Weber et al, 2007 estimated the average rate of anthropogenic deforestation on Sulawesi of about 0.6% yr for the period of 1971-2001. Additionally to anthropogenic deforestation some losses of forests can be also caused by natural factors, e.g. climate change, extreme weather events including El Nino Southern Oscillation (ENSO) caused droughts. Deforestation of tropical rain forest areas results in changes of energy, H2Oand CO2-budgets of the land surface, and as a consequence, in changes of local and regional climate (Lawton et al., 2001). The Lore Lindu National Park (LLNP) in Sulawesi plays an essential role in conservation of endemic flora and fauna. Therefore, deforestation, either natural or anthropogenic, results in serious threats for remaining rainforest ecosystems and in loss of biodiversity. Indonesia, the so called Maritime Panferov, O., Ibrom, I., Kreilein, H., Oltchev, A., Rauf, A., June, T., Gravenhorst G. and A. Knohl