ABSTRACT
Human impact on forests and tree resources may take two different forms. From an ecological conservation perspective attention is mostly focused on negative human impacts resulting in degradation in the form of loss of biodiversity and ecosystem services. This negative human impact is related to human overexploitation and to decreased production potential. Alternatively, from a socio-economic development perspective, attention is also given to human agency in enriching natural resources through a process of domestication resulting in resource enrichment. For understanding the relations between these different types of human impacts it is useful to consider the process of domestication in more detail. In a narrow sense, domestication is considered as a biological process involving changes in morphological and genetic make-up of selected crop, tree or animal species in order to increase its productivity (Simons and Leakey, 2004). In a wider sense, it is considered as also involving an ecological process in the form of homogenization of production conditions: ecosystems are adjusted to the human domain by increasing the production of human-valued natural resources. And in an even more inclusive interpretation, domestication is conceived of as also including an acculturalization process involving the adaptation of species to human-controlled production conditions (Wiersum, 1997a; Simons and Leakey, 2004), including the implementation of conscious human practices for the conservation and stimulation of the provisioning of valuable natural resources. As a result of the multidimensional nature of domestication, there are different opinions about the relation between domestication and degradation in forest ecosystems. It can be argued that domestication as a process of tree improvement involves a loss in genetic diversity and that it results in monospecific tree plantations of genetically selected trees (Simons and Leakey, 2004). From this point of view, domestication of forest resources is often considered as reflecting negative human impacts on the forest ecological structure and functioning, and hence as a degradation process. However, increasingly attention is given to domestication as a process of increasing production in biodiverse agroforestry systems (Simons and Leakey, 2004), and it is argued that domestication involves a process of human agency in enriching forest resources and improving livelihood conditions. Several authors (Michon and De Foresta, 1997; Wiersum, 1997a) have indicated that the process of forest domestication does not involve a simple process of creating monocultural plantations, but rather a multi-trajectory pathway involving various stages ranging from forest conservation to forest modification and forest transformation. From this perspective, domestication of forest resources is considered as reflecting human agency in adapting forests to human environments.
