Controlling spatial structure of forested landscapes: a case study towards landscape management

Abstract

This paper presents an overview of the landscape management design process and focuses on changes in forest landscape dynamics as a result of different harvesting patterns and initial landscape structure. A case study involved two different forest landscapes, one quite fragmented and the other little fragmented, with both covering the same total area and having similar forest age class distributions. The effects of four different harvesting patterns (scatter, negative edge distribution, edge progressive and nuclei progressive) and two different initial forest landscape structures on landscape fragmentation were explored using a GIS-based landscape management model (LANDMAN). The model suggested that future landscape patterns vary greatly according to initial landscape structure as well as to the four harvesting patterns. The scatter harvesting pattern created fragmented landscapes, while the nuclei progressive pattern significantly reduced fragmentation, regardless of initial spatial structure. Likewise, the negative edge distribution and edge progressive harvesting patterns tended also to reduce fragmentation. The model indicated that for a given harvesting pattern, fragmentation was generally reduced in the initially fragmented forest, whereas the clustered forest became fragmented initially, but later recovered. In conclusion, the case study demonstrated that geographically prescribed harvesting patterns, in combination with indicators of forest performance and landscape fragmentation, provide an opportunity to design management for the creation of alternative forest landscapes of significantly different spatial structure. The prerequisites for on-the-ground forest landscape management are a quantitative description of the forest landscape, a computer model, geographically-prescribed harvest interventions, an understanding of spatial forest dynamics, and a GIS-based management design process.