Tropical Rainforests and Agroforests Under Global Change

not only for land use systems that depend on the regular supply of rain or irrigation water but also for the future development of natural rainforests as drought stress has been shown to a?ect tree growth and species composition in old-growth forests (Wright 1991, Walsh and Newbery 1999, Engelbrecht et al. 2007). A drought experiment conducted in a cacao agroforestry plantation showed that this plantation was surprisingly resilient to an induced drought of more than a year (Schwendenmann et al. 2009). However, droughts can have a strong impact on household incomes from agriculture, they strongly a?ect the vulnerability to poverty and thus have to be analyzed as important exogenous shocks to households, forcing them to adjust their behaviour and develop strategies to cope with these problems. The stability of rainforest margins is a critical factor in the protection of tropical rainforests (Tscharntke et al. 2007). At present, however, rainf- est margins in many parts of the tropics are far from stable, both in soc- economic and in ecological terms. For example, protected areas may attract, rather than repel, human settlement, which may be due to international donor investment in national conservation programs (Wittemeyer et al. 2008). An alternative hypothesis is that protected areas might be compromised if leakage takes place, that is, if impacts that would take place inside the restricted area are displaced to a nearby, undisturbed area (Ewers and Rodrigues 2008).

Tropical rainforests are disappearing due to agricultural intensification and climate change, causing irreversible losses in biodiversity and associated ecosystem functioning. Ecosystem properties and human well-being are profoundly influenced by environmental change, which is often not considered during land use intensification. Understanding these processes needs an integrated scientific approach linking ecological, economic and social perspectives at different scales, from the household and village level to landscapes and regions. The chapters in this book cover a broad range of topical research areas, from sustainable agroforestry management, climate change effects on rainforests and agroforests to integrated concepts of land use in tropical landscapes.