Implications of Wood Collecting Activities on Invertebrates Diversity of Conservation Areas

Biomass, in the form of deadwood can be described as the end product of series of physiological processes that lead to the deterioration of a piece of wood or the entire tree (Kaarik, 1974; Franklin et al., 1987). The rate at which this occurs depend on the exposure of the tree to various physical and physiological stresses (Savory, 1954; Bader et al, 1987; Jansson & Jansson, 1995). Once dead, the tree or part thereof can be harvested and used as a source of energy, mostly for cooking or heating in the household. While these are common uses of deadwood, what is also apparent is that deadwood supports ecological systems that are crucial for the maintenance of various components of biodiversity (Graham, 1925; Gosz et al., 1972; Ausmus, 1977; Harmon et al., 1993). As a result natural processes and systems of deadwood production which are often well preserved and maintained within the conserved environment (Graham, 1925; Raphael & Morrison, 1987; Harmon et al., 1993) requires that deadwood be regarded as critical part of biodiversity management (Harmon et al., 1993; Bergeron, 2000; Andrzej, 2002; Hagar, 2007). In the past years, the management of deadwood within conservation areas has solely been based on observations that 1) deadwood provides habitat for different species of birds, bats and mammals (Brandlmaier et al., 2004), 2) deadwood serves as a source of food for various organisms (Raphael & White, 1984; Harmon et al., 1993) including the less visible invertebrates, fungi and lichens and that 3) deadwood has a potential of supplementing soil organic nutrient (Hart, 1999) and thus promoting soil fertility. As with the case of standing dead trees (Andrzej, 2002), which are used by different vertebrates, such as birds for nesting sites (Johnston & Odum, 1956; Du Plessis, 1995), fallen dead trees are used by small mammals (Rhoades, 1986), reptiles and various species of invertebrates as mating sites, shelter or sources of food (Hirth, 1959; Harmon 1982). All these observations, combined have increased the value of deadwood as playing a key role in sustaining the efficiency and productivity of the ecological systems within conservation areas. Unfortunately in most parts of the world deadwood still remain the main source of energy and is in great demand for domestic fuel. This is the main cause for concern among conservation agencies (Anderson & Fishwick, 1984; Wall & Reid, 1993; Abbot & Mace, 1999) as it poses a threat to biodiversity that is housed within deadwood (Kavin, 2001). Of considerable importance is that among certain societies dead wood is not only used for energy alone but has some cultural link (Furness, 1979). An example is the Xhosa, Vhenda