Elevational pattern of forest fragmentation and its influential factors in Helan Mountain
Forest fragmentation pattern impacts the overall pattern,mass,and energy flow of forest ecosystems,which urgently needs to be monitored and evaluated. However,limited by the availability of forest distribution data,research on fine-scale analysis of forest fragmentation pattern is still lacking. In this study,Helan Mountain was taken as the study area,and its accurate forest distribution data was extracted using high-resolution remote sensing data. The forest fragmentation pattern in the eastern and western slopes was depicted using landscape indexes,and its response to the environmental variables along the elevational gradient was explored based on generalized linear regression and logistic regression. The results demonstrate that:(1 )The degree of forest fragmentation first decreases and then increases with increasing elevation. Besides,the degree of forest fragmentation on the eastern slope is higher than that on the western slope. (2 )The elevational distribution characteristics of forest fragmentation show a unimodal relationship with the topographic and climatic environmental gradients. (3 )Natural and human factors jointly shape the forest fragmentation pattern in Helan Mountain. Among them,climatic factors and their interaction with topographic and human activity factors play a leading role. (4)Climate conditions during the growing season control the upper and lower limits of tree distribution. The critical climatic thresholds for the upper limit of tree distribution are growing season length=222 days and mean temperature of summer=10. 9 ℃on the eastern and western slopes respectively,while the critical climatic thresholds for the lower limit of tree distribution are precipitation of summer=177 mm and precipitation of summer=243 mm respectively. These findings help to reveal the characteristics of forest fragmentation pattern in temperate semi-arid and arid mountainous areas under the complex influence of natural and human factors,can provide support for the protection and management of forest resources,and can also provide certain references for other related studies.
万方数据
维普
