| Climate change,atmospheric nitrogen deposition and human factors are seriously threatening the maintenance of species diversity.In the ecosystem,plant species diversity is a small unit,but it represents the core function required by the system and the distribution characteristics of community species.Through the methods of field sampling,indoor identification and integration,this paper investigates the composition and distribution of vegetation in typical sample plots of Fenglin Nature Reserve;adopt ?Diversity ? Diversity calculate the diversity of plant species in the sample plot,grasp the changing trend of diversity;The tree carbon pool of the sample plot was calculated by using the allometric growth equation method,and then the relationship between species diversity and tree carbon pool was analyzed,so as to provide a theoretical basis for further study on the species protection value of the reserve;At the same time,the rare and endangered plant species in the reserve are analyzed and evaluated.The following results are obtained:(1)A total of 54 families,101 genera and 135 species of vascular plants grow in the survey plot,13 species belonging to 6 families,7 genera and ferns;1 family,4 genera and5 species of gymnosperms;There are 117 species of angiosperms belonging to 90 genera and 47 families;There are 25 species in a single genus and family,including 103 species in 79 genera of 40 families of dicotyledons and 13 species in 11 genera of 6 families of monocotyledons.There is one relatively family:Rosaceae,two species of middle families:Compositae and Betulaceae;25 small families,and 23 monotypic families.Most of the protected areas are small families and monotypic families.In addition to common families and genera,we should pay attention to rare families,genera and species in the process of protection.(2)Nine rare and endangered plants are covered by typical plots in the nature reserve,and they are all listed as national class II protection.Vulnerable plants include Korean pine,Manchurian ash and Phellodendron amurense;Low risk plants: beichonglou,dog jujube,kiwi fruit,Schisandra chinensis.Most trees can be used as timber and ornamental trees,and the sample plots are rich in medicinal,edible and nectar plants.(3)With the succession of time,the trend of plant species diversity in the community is parabolic.Changes of plant species diversity at different levels in different stages of succession: the trend of arbor and shrub layer is also parabolic,and the number of herbs continue to increase.After the disturbance in the protected area,the tree species in the coniferous and broad-leaved mixed forest decreased the fastest,and the overall trend of circuitous fluctuation appeared.Results of vegetation diversity in each forest type: the peak value of species diversity in tree layer was pushed back from natural succession of coniferous and broad-leaved mixed forest to spruce-fir and Korean pine forest;The species diversity of herbaceous layer was seriously disturbed,and the succession track changed from satisfying the richness theory in the natural succession process to a new track,and the herbaceous layer showed a circuitous change trend.It delayed the peak time of species diversity in the disturbance community.(4)Trees can store a large amount of carbon pools,of which the trunk is the main storage location.The distribution of carbon storage in the whole tree after natural succession and disturbance is consistent,that is,stem > root > branch > leaf.There is a positive correlation between species diversity and tree carbon storage in both cases.The investigation of vegetation composition,species diversity and carbon storage in nature reserve is the basis of forest ecosystem value.No matter natural succession or community disturbance,the vegetation distribution,plant species diversity and carbon storage in mixed forest stage are unique.Therefore,the value of mixed forest in ecological services should be paid more attention in nature reserve protection and ecosystem value consideration. |
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