Effects of catastrophic wind disturbance on formation of forest patch mosaic structure on the western and southern slopes of Changbai Mountain

Abstract

In the cold temperate zone of the western and southern slopes of the Changbai Mountain, Betula ermanii Cham. forest, Picea jezoensis (Siebold & Zucc.) Carrière forest, and mixed forests of B. ermanii and P. jezoensis are heterogeneously distributed in a mosaic of patches, and the reason for this formation is still unclear. In August 1986, a typhoon disturbed the forests on the western and southern slopes of Changbai Mountain, forming a large number of forest gaps. After more than 30 years of vegetation succession, vegetation patches in wind-stricken areas are obvious. To reveal the effects of catastrophic wind on the patch mosaic structure of these forests, a study was carried out in the cold temperate wind-stricken areas of the western and southern slopes of Changbai Mountain. Vegetation differences were classified according to the degree of vegetation damage by the catastrophic wind and the status of vegetation restoration was investigated, as well as the soil fertility was determined. The results show that the degree of forest damage caused by the catastrophic wind is not homogeneous, and there are significant differences in community composition and structure in the wind-stricken areas. After 30 years of restoration, some of the differences in damaged forests have been enhanced. The heterogeneity of vegetation in wind-stricken areas is due to both the difference in the degree of catastrophic wind damage and the differences in the succession of the damaged vegetation. There is a strong correlation between vegetation and soil fertility, and the variation in soil fertility strengthens the heterogeneity of vegetation in wind-stricken areas. Therefore, it can be inferred that several catastrophic wind disasters may occur in the history, which resulted in succession from shrub and herb to B. ermanii forest and then from B. ermanii forest to P. jezoensis forest on the western and southern slopes. This pattern of disturbance and succession formed the patch mosaic distribution pattern of the forests on Changbai Mountain.