首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到5条相似文献,搜索用时 0 毫秒
1.
Temporal change in forest fragmentation at multiple scales   总被引:1,自引:0,他引:1  
Previous studies of temporal changes in fragmentation have focused almost exclusively on patch and edge statistics, which might not detect changes in the spatial scale at which forest occurs in or dominates the landscape. We used temporal land-cover data for the Chesapeake Bay region and the state of New Jersey to compare patch-based and area–density scaling measures of fragmentation for detecting changes in the spatial scale of forest that may result from forest loss. For the patch-based analysis, we examined changes in the cumulative distribution of patch sizes. For area–density scaling, we used moving windows to examine changes in dominant forest. We defined dominant forest as a forest parcel (pixel) surrounded by a neighborhood in which forest occupied the majority of pixels. We used >50% and ≥60% as thresholds to define majority. Moving window sizes ranged from 2.25 to 5,314.41 hectares (ha). Patch size cumulative distributions changed very little over time, providing no indication that forest loss was changing the spatial scale of forest. Area–density scaling showed that dominant forest was sensitive to forest loss, and the sensitivity increased nonlinearly as the spatial scale increased. The ratio of dominant forest loss to forest loss increased nonlinearly from 1.4 to 1.8 at the smallest spatial scale to 8.3 to 11.5 at the largest spatial scale. The nonlinear relationship between dominant forest loss and forest loss in these regions suggests that continued forest loss will cause abrupt transitions in the scale at which forest dominates the landscape. In comparison to the Chesapeake Bay region, dominant forest loss in New Jersey was less sensitive to forest loss, which may be attributable the protected status of the New Jersey Pine Barrens.  相似文献   

2.
Landscape Ecology - Several initiatives seek to increase the pace and scale of dry forest restoration and fuels reduction to enhance forest resilience to wildfire and other stressors while...  相似文献   

3.
Land-use/land-cover change is the most important factor in causing biodiversity loss. The Mediterranean region has been affected by antropic disturbance for thousands of years, and is, nowadays, one of the most significantly altered hotspots in the world. However, in the last years a significant increase in forest cover has been measured. These new patterns are independent from planned conservation strategies and appear to have a substantial impact on landscapes and biodiversity. We used three land-use/land-cover maps (from 1960 to 2000) covering the Italian peninsula to analyze the pattern of land-use/land-cover change. We measured an increase in forests, especially in mountains, an increase in artificial areas, especially in coastal zones, and a decrease in pastures. Intensively cultivated areas showed a limited decrease while extensively cultivated ones showed a marked decrease. In the same period mammal and bird species followed a similar pattern, with forest birds, ungulates and carnivores increasing, and typically Mediterranean species decreasing. We suggest that our results may provide important information, which could be useful for conservation planning in the entire Mediterranean hotspot. We suggest that an increasing conservation effort should be made to protect the Mediterranean-type forests and scrublands, as well as traditional agricultural practices. Moreover, future conservation efforts should consider the broad socio-political and ecological processes that are most likely to occur across the whole hotspot, especially along coastal areas, and the network of protected areas should be functionally integrated in a conservation strategy that includes the human-dominated landscape.  相似文献   

4.
5.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号