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Today, much of the widespread concern about the loss of tropical forests stems from increased public awareness about their importance as a major repository of biodiversity. Yet reliable scientific knowledge about the nature and extent of biodiversity loss from forest disturbance is still quite limited.
CIFOR research in this area includes studies to determine the impacts of disturbances such as logging, non-timber forest product extraction and forest fragmentation on in situ conservation of biodiversity. A goal is to acquire generalisable data from representative ecoregional research sites that can be used to generate and test spatial and process models.
In a wide-ranging project, researchers from India, Thailand, Indonesia and Malaysia have been working under the auspices of CIFOR and the International Plant Genetic Resources Institute (IPGRI) to investigate how human activities affect the genetic resources of forests. The work is multidisciplinary, involving research components on genetic resources, reproduction ecology of the species studied and socioeconomic aspects of communities in and around the forest sites.
In Malaysia, for example, it was found that although the impacts of logging were evident in all species sampled, the loss of genetic diversity did not exceed 24 percent. Similarly, the impact of harvesting wood for timber and fuel in Thailand was significant only at very high harvesting intensities. A study in Central Kalimantan demonstrated a significant increase in species inbreeding after logging results that will be investigated further in a dipterocarp species.
In 1998, with the recruitment of Danish International Development Agency associate expert Dr. John Poulsen, CIFOR launched a new initiative under this project in Indias Western Ghats. The study, which entails extensive interviewing of local tribal and non-tribal people, will assess landscape-scale impacts of non-timber forest product extraction on the regions flora and fauna, including birds, butterflies, small mammals, trees and herbs.
Other work in India done as part of this project revealed that poorer households are most heavily dependent on the collection of NTFPs, and with many NTFPS entering the market there is a tendency toward unsustainable harvesting, even among indigenous communities that traditionally have relied on these products for their livelihoods. Consequently, the regeneration of some important plant species has been almost completely absent in some areas, thereby eroding the genetic diversity of these species.
In Central Kalimantan, CIFOR scientists are studying the impacts of logging on the diversity of birds and small mammals, as well as on vegetation structure. Initial results from the comparison of biodiversity in logged versus unlogged sites have indicated that selective logging has less significant impacts on species richness and diversity. Patterns of bird community structure, species composition and relative abundance were adversely affected by both logging activity and landscape factors (as gauged by topographic position and wetness).
Meanwhile, biodiversity baseline data from integrated surveys in Indonesia, Thailand, the Western Amazon basin and Cameroon are providing insights into the response of biodiversity and carbon sequestration along gradients of land-use intensity. New, generic indicators of these response patterns have been identified through the use of Plant Functional Types (PFTs), which reflect plant adaptation to changing physical environments. A multidisciplinary study conducted in lowland Sumatra, Indonesia, has established potentially useful linkages between vegetation structure, key groups of plant and animal species, PFTs and soil nutrient availability.
Finally, in Costa Rica, CIFOR researchers and their collaborators are studying impacts of fragmentation on genetic diversity. The studies are being done in an area of 22 riverine fragments of landscape that was cleared, mainly for cattle ranching. The research is designed to determine whether the fragmentation adversely affects the work of insect pollinators and possible consequences on the genetic diversity of four important tree species.