CHANGE IN SPATIAL CHARACTERISTICS OF FOREST OPENINGS IN THE KLAMATH MOUNTAINS OF NORTHWESTERN CALIFORNIA, USA

被引:66
作者
SKINNER, CN
机构
[1] U.S.D.A. Forest Service, Pacific Southwest Research Station, Silviculture Laboratory, Redding, 96001, CA
关键词
CALIFORNIA; FOREST OPENINGS; KLAMATH MOUNTAINS; SPATIAL ATTRIBUTES; LANDSCAPE CHANGE; LANDSCAPE ECOLOGY;
D O I
10.1007/BF00129256
中图分类号
Q14 [生态学(生物生态学)];
学科分类号
071012 ; 0713 ;
摘要
Change in the spatial characteristics of forest openings was investigated in three forested watersheds in northwestern Siskiyou County, California totalling approximately 24,600 hectares. Watersheds with minimal human disturbance were chosen for study. However, fire suppression has been pervasive throughout. Characteristics of forest openings (area, perimeter, distance between neighboring openings) were measured on aerial photographs taken 41 years apart. An index of regional form was determined for the landscape. Shape complexity for each opening was calculated using two indices based upon fractals. Significant differences were found using the Kolmogorov-Smirnov two-sample test between the perimeters, areas, distance from sample point to nearest opening, and distance between neighboring openings. The perimeters and areas became smaller, and the distances from the sample point to the nearest opening and between neighboring openings became greater over the 41 years between aerial photo sets. The estimated area occupied by openings decreased from 25.8% to 15.6% of the study area. No significant difference was found in the shape of the openings except as the shape indices were influenced by changes in size of the openings.
引用
收藏
页码:219 / 228
页数:10
相关论文
共 36 条
  • [1] Agee J.K., Fire history along an elevational gradient in the Siskiyou Mountains, Oregon, Northwest Science, 65, pp. 188-199, (1991)
  • [2] Atzet T., Martin R., Natural disturbance regimes in the Klamath Province, Proceedings of the Symposium on Biodiversity of Northwestern California, pp. 40-48, (1992)
  • [3] Atzet T., Wheeler D.L., Historical and ecological perspectives on fire activity in the Klamath geological province of the Rogue River and Siskiyou National Forests, (1982)
  • [4] Austin R.F., Measuring and comparing two-dimensional shapes, Spatial Statistics and Models, pp. 293-312, (1984)
  • [5] Baker W.L., Landscape ecology and nature reserve design in the Boundary Waters Canoe Area, Minnesota, Ecology, 70, pp. 23-25, (1989)
  • [6] Bingham B.B., Sawyer J.O., Distinctive features and definitions of young, mature and old-growth Douglas-fir/hardwood forests, Wildlife and Vegetation of Unmanaged Douglas-fir Forests, pp. 362-377, (1991)
  • [7] Davis J.C., Statistics and data analysis in geology, (1986)
  • [8] De Cola L., Fractal analysis of a classified landsat scene, Photogrammetric Engineering and Remote Sensing, 55, pp. 601-610, (1989)
  • [9] Edmonds R.L., Western coniferous forests: how forest management has changed them, Biology Digest, 5, pp. 12-23, (1979)
  • [10] Forman R.T.T., Godron M., Landscape ecology, (1986)