Spatial Heterogeneity Patterns — a Comparison Between Gorges and Ridges in the Upper Part of an Evergreen Lower Montane Forest

In the RBSF, as in many tropical mountain regions, the topography consists of a complex system of crests, ridges, steep slopes, valleys and gorges. These different physical features have an influence on the vegetation composition, stand structure and further processes, which also change with increasing elevation (Lieberman et al. 1996; see Part III 1 in this volume) as well as at the same elevation in line with the topography along a horizontal gradient (Takyu et al. 2002; Tanner 1977). ‘The topography, including the elevation, is a major physical factor, which affects the composition, growth, and distribution of tropical forests’ (cf. Basnet 1992). Climate parameters such as wind speed and light condition or transpiration (see Chapter 16 in this volume) may be different at ridges and gorges. Because of erosion of soils, soil contents are expected to accumulate on lower slopes and in valleys and gorges (Kubota et al. 2004). Therefore, the hypothesis for the study was that changes in abiotic parameters alter the vegetation structure and composition along the vertical gradient as well as along the horizontal gradient formed by the topographical structure in the lower part of the RBSF (see Chapter 10.3 in this volume).