Global-Scale Patterns of Forest Fragmentation

This data set is a grid map of forest fragmentation based on 1-km resolution land cover maps for the globe cover (Loveland and Belward 1997; Loveland et al. 1991, 2000; Olsen and Watts 1982). Measurements in analysis windows from 81 km 2 (9 x 9 pixels, small scale) to 59,049 km 2 (243 x 243 pixels, large scale) were used to characterize the fragmentation around each forested pixel. Six categories of fragmentation (interior, perforated, edge, transitional, patch, and undetermined) are identified from the amount of forest and its occurrence as adjacent forest pixels. Interior forest exists only at relatively small scales; at larger scales, forests are dominated by edge and patch conditions.

At the smallest scale, there were significant differences in fragmentation among continents; within continents, there were significant differences among individual forest types. Tropical rain forest fragmentation was most severe in North America and least severe in Europe and Asia. Forest types with a high percentage of perforated conditions were mainly in North America (five types) and Europe and Asia (four types), in both temperate and subtropical regions. Transitional and patch conditions were most common in 11 forest types, of which only a few would be considered as naturally patchy (e.g., dry woodland). The five forest types with the highest percentage of interior conditions were in North America; in decreasing order, they were cool rain forest, coniferous, conifer boreal, cool mixed, and cool broadleaf.

References:

Loveland, T. R. and A. S. Belward. 1997. The IGBP-DIS Global 1 km Land Cover Data Set, DISCover First Results. International Journal of Remote Sensing 18: 3289-3295.

Loveland, T. R., J. W. Merchant, D. O. Ohlen, and J. F. Brown. 1991. Development of a Land-Cover Characteristics Database for the Conterminous U.S. Photogrammetric Engineering and Remote Sensing 57: 1453-1463.

Loveland, T. R., B. C. Reed, J. F. Brown, D. O. Ohlen, Z. Zhu, L. Yang, and J. W. Merchant. 2000. Development of a Global Land Cover Characteristics Database and IGBP DISCover from 1-km AVHRR Data. International Journal of Remote Sensing, 21(6/7): 1303-1330.

Olsen, J. S. and J. A. Watts. 1982. Major World Ecosystems Complex Map. Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA.