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 increase 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. The progressive loss of forest enhanced edge length, interspersion, and convexity. There was an exponential decline in interior forest and mean patch size, 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 contiguous and fragmented landscape conditions was ranked using discriminant analysis. The results suggested that the mastery of landscape analysis can be directly Linked to the choice of the pattern metric. Percent forest interior, contiguity, and convexity were highly significant (P<0.001). Forest loss was 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 variability about their mean values. This paper develops an approach for monitoring the influence of deforestation on the landscape, and examines how pattern-related habitat components are affected by deforestation. The ability to quantify pattern change resulting from deforestation has direct implications to resource management and wildlife habitat assessment. Descriptions of pattern change accompanying deforestation provide a critical component of habitat analyses. (C) 1999 Elsevier Science B.V. All rights reserved.