An analysis of deforestation: Metrics used to describe pattern change

Cartographic modeling was used to examine the influence of deforestation on landscape pattern metrics. Progressive deforestation resulted in an increa se in the spatial heterogeneity, fragmentation, and edge characteristics of a landscape while connectivity attributes varied with deforestation stage. Pattern changes in heterogeneity and edge characteristics were curvilinear , with metrics changing direction at the half-way point of deforestation. T he progressive loss of forest enhanced edge length, interspersion, and conv exity. There was an exponential decline in interior forest and mean patch s ize, while patch density and interpatch distance increased. The variability displayed by several pattern metrics reflect the unpredictability in patch disappearance. The relative contribution of each metric for discriminating between contigu ous and fragmented landscape conditions was ranked using discriminant analy sis. The results suggested that the mastery of landscape analysis can be di rectly Linked to the choice of the pattern metric. Percent forest interior, contiguity, and convexity were highly significant (P<0.001). Forest loss w as also significantly reflected by mean patch size, number of patches, mean patch density, and interpatch distance. Metrics that contributed Little to discrimination displayed unpredictable behavior or exhibited high variabil ity about their mean values. This paper develops an approach for monitoring the influence of deforestati on on the landscape, and examines how pattern-related habitat components ar e affected by deforestation. The ability to quantify pattern change resulti ng from deforestation has direct implications to resource management and wi ldlife habitat assessment. Descriptions of pattern change accompanying defo restation provide a critical component of habitat analyses. (C) 1999 Elsevi er Science B.V. All rights reserved.