基于NDVI的不同火烧强度下大兴安岭林火迹地森林景观恢复

Forest landscape restoration assessment based on NDVI under different burn intensity in the burned blank of Daxinganling Mountains

利用LANDSATTM影像,通过分类、提取森林景观类型及NDVI值,在较大尺度上探讨了火烧区火烧强度与森林景观格局、功能恢复的关系。结果表明,火烧区森林总体恢复情况较好。恢复状况与火烧强度具有明显的相关性。火烧强度越高,恢复状况越差。重度火烧区的针叶林景观所占比重低且生长状况较差;沼泽面积高于未火烧对照区,这一现象应引起足够重视,特别是在全球变化气温升高的背景下,应防止寒温带针叶林的退化以及林地沼泽化。在三种主要森林类型(针叶林、阔叶林、针阔叶混交林)中,针阔叶混交林是生长状况最好的。

Integrating the forest landscape types and NDVI from LANDSAT TM image of 2000 with burn intensity map,the relationship between forest landscape restoration and burn intensity was discussed.The results showed that the restoration of whole burned blank was remarkable.The degree of restoration negatively correlated with fire intensity,which meant that the more severely it was burned,the worse the restoration was.The conifers in the severely burned area occupied less area with low growth rate.The area proportion of swamp in the burned area was much more than that in the contrast area,which should be paid more attention to.Under the influence of global warming,the conifers degradation and increase swamp must be prevented.Mixed forest grew best among three forest types,which meant the vegetation succession in the burned blank was transforming from initial stage to middle stage.