A Comparative Study Of Plant Species Diversity Between The Northern Boundary And The Core Distribution Area Of The Broad-leaved Korean Pine Forest

Pinus koraiensis forest,as zonal vegetation and succession top vegetation,has been seriously cut down in recent decades,and the large area of original broad-leaved Korean pine forest has become a large area of secondary forest.In this study,shengshan National Nature Reserve and Liangshui National Nature Reserve were selected as the north boundary of broadleaf Korean pine forest distribution.The diversity of plant species in the two reserves was analyzed based on ? and ? diversity.The effects of disturbance on plant species diversity were discussed.And the changes of plant species diversity in birch forest,Larch forest,mixed forest and Korean pine forest during early,middle and late succession.The main results are as follows:(1)Based on the survey of the sample plots of the two reserves,there were 169 species of plants belonging to 116 genera and 55 families in the Liangshui Reserve.176 species belonging to 111 genera and 49 families were recorded in shengshan National Nature Reserve.Species composition and distribution showed that shengshan contained more species.There were 9 species of coldwater dominance,including 4 species of woody plants and 5 species of herbaceous plants.There are 7 dominant families in Shengshan,including 3 woody plants and 4 herbaceous plants.The number of species in single family and single genus was more in liangshui than shengshan,and the distribution of plants in liangshui was more dispersed.Rare and endangered plants liangshui 15 species and Shengshan contains 10 species.(2)Shannon Wiener index and Margalef index were higher than that of cool water under different latitudes.In the vertical structure of the community,herb layer was consistent with the overall trend,while tree layer and shrub layer were contrary to the overall trend.The Jaccard index and Sorenson index in Shengshan and Liangshui were all less than 0.5,and the Cody index was higher than 90.The species similarity between the two reserves was very low.(3)By comparing the disturbed and undisturbed plots in Shengshan and Liangshui nature Reserve,we found that Shannon Wiener index,richness index,Pielou index and dominance index were all smaller after disturbance than without disturbance,and the richness index of Shengshan Nature Reserve significantly decreased after disturbance.The Jaccard index,Sorenson index and Cody index were all less than 0.5and 88 respectively,indicating a significant difference in species composition.(4)? diversity in shengshan and Liangshui nature reserve was always greater than that in Shengshan nature reserve during the succession stages of Birch forest and Larch forest.The diversity of ? in Shengshan was greater than that in liangshui in the late stage of Larch forest.Compared with other forest types,the similarity index of Korean pine forest in Shengshan decreased gradually.