The effect of forest fragmentation is a growing concern among ecologists and forest managers. Habitat fragmentation is often defined as a process in which "a large tract of habitat is transformed into a number of smaller patches of smaller total area, isolated from each other by a different habitat matrix." of the original” (Wilcove et al., 1986). . The exact definition of fragmentation differs between studies and commentators, but characteristics such as size of largest fragment, total perimeter area, average fragment size, number of fragments, and average distance between fragments have been been considered as aspects of fragmentation. The definition of habitat fragmentation above implies four effects of the fragmentation process on habitat patterns: (a) reduction in the amount of habitat, (b) increase in the number of habitat patches, ( c) decrease in habitat patch size, and (d) increase in patch isolation. These four effects form the basis of most quantitative measures of habitat fragmentation (Fahrig, 2003). Because fragmentation is generally accompanied by habitat loss, it is difficult to analyze the effects of these two processes (Wilcove et al. 1986). Many people use the term "fragmentation" loosely to refer to the two processes together. Habitat fragmentation is generally thought to have a significant negative effect on biodiversity and is therefore widely considered an aspect of habitat degradation (Haila, 2002). This conclusion, however, is generally only valid for conceptualizations of fragmentation that are inseparable from habitat loss. Empirical studies to date suggest that habitat loss has significant and consistent negative effects on biodiversity. Habitat fragmentation per se has much weaker effects on biodiversity that are at least as weak...... middle of paper ...... interpreted as intensifying the effects of habitat loss at low levels of habitat. One aspect of the issue of fragmentation, and the one that has been most widely discussed and addressed in the models, is the extent to which the configuration of the landscape allows for movement. The issue of connectivity in general and corridors in particular is therefore part of the issue of fragmentation. Ultimately, complex landscapes give rise to complex interactions and it will take clever manipulative experiments to unravel the often confusing effects of boundary quantity, boundary quality, matrix. habitat, patch size and patch isolation on different species. This separation is crucial for conservation purposes, given that habitat fragmentation and loss are among the most important causes of species declines worldwide (Haila et al., 1994; Murcia, 1995; Didham et al ., 1996;, 1997).