落叶松毛虫对大兴安岭呼中林区森林的景观长期影响模拟

Long-term effects of Dendrolimus superans Bulter disturbance on forest landscape in Huzhong Forest Bureau of Great Xing'an Mountains:A simulation study

应用空间直观景观模型(LANDIS)模拟了落叶松毛虫对呼中林区森林景观的长期影响,利用统计软件APACK计算了落叶松毛虫、代表性树种的分布面积以及反映物种分布格局的聚集度指数和森林斑块的平均面积,模拟了300年(1990—2290年)内有无落叶松毛虫干扰预案下大兴安岭呼中林区森林景观的动态变化.结果表明:研究区落叶松毛虫的分布面积呈先增加后降低的趋势;在落叶松毛虫干扰预案下,落叶松在模拟前150年的分布面积、平均斑块面积均低于无干扰预案,聚集度指数在前190年低于无干扰预案;干扰预案下白桦的分布面积和平均斑块面积百分比均高于无干扰预案,聚集度指数只在模拟的80～190年高于无干扰预案;樟子松的分布面积、聚集度指数和平均斑块面积在干扰预案下略低于无干扰预案.落叶松毛虫在一定程度上导致森林景观的破碎化.

A spatially explicit landscape model LANDIS was applied to simulate the long-term effects of Dendrolimus superans Bulter disturbance on the forest landscape in Huzhong Forest Bureau of Great Xing＇an Mountains. The statistical software pakage APACK was used to calculate the distribution area of D. superans and representative tree species,the aggregation index reflecting the spatial pattern,and the average area of forest patchs. The dynamics of forest landscape in the study region was simulated under two scenarios,i.e.,with and without D. superans disturbance for 300 years （from 1990 to 2290）. In the region,the distribution area of D. superans showed a trend of increased first and decreased then. Under D. superans disturbance scenario,the distribution area and the average patch size of Larix gmelinii in 0-150 years and the aggregation index of L. gmelinii in 0-190 years,the distribution area and the average patch size of Betula platyphylla and its aggregation index in 80-190 years,as well as the distribution area,average patch size,and aggregation index of Pinus sylvestris var. mongolica were lower or slightly lower than those under no disturbance scenario. D. superans disturbance led to the fragmentation of forest landscape to some extent.