Spatial Distribution Of Sprouting Plants And Influence Factors In Jianfenling 60 Hm~2 Dynamic Plot

Clone is one of the most common characteristics of plants,especially for woody plants.Besides the seed reproduction,clone provides an alternative and important way for plants to reproduce next generation.In this study,based on the literature review and statistical analyses,the plants distribution and environmental conditions in a 60 hm~2plot were investigated to clarify the species composition,individual number,and key influence factors of the clone plants.Relationships between clone plants and species diversity at the community level were also examined.The main results are showed as follows:(1)There are 439 676 stems in the plot,including 391 686 individuals,29 103 sprout stems and 18 887 branch stems,which belong to 62 families,155 genera and 290 species.The total individuals of clone plants are 33 919,accounting for 7.7%of total individuals in the plot.These clone plants belong to 260 species,142 genera and 58 families,accounting for 93.5%,91.6%and 89.7%of the total species,genus,families in the whole plot,respectively.Clones plants are then classified as sprouts and branches.As much as 248 species in the plot have sprouts,which belong to 56 families and 135 genera,accounting for 90.3%,87.1%and 85.5%of the total species,genus,families in the whole plot,respectively.There are 237species having branches in the plot,belonging to 55 families and 132 genera,accounting for88.7%,85.2%and 81.7%of the total species,genus,families in the whole plot,respectively.In the whole plot,Psychotria of Rubiaceae,Neolitsea and Crypotcarya of Lauraceae have relatively high proportion of clone plants.Psychotria rubra(2423),Cryptocarya chinensis(2317),Neolitsea ovatifolia(1724),Lasianthus trichophlebus(1556)and Ardivire virens(1477)have relatively high number of clone stems.L.trichophlebus(25.17%)has the greatest clone rate,followed by N.ovatifolia(23.10%),P.rubra(16.02%),C.chinensis(13.78%)and A.virens(13.65%).Except of C.chinensis and Castanopsis jianfenglingensis,the number of clone stems has no significant influence on the calculation of importance values.(2)Spatial distribution of clone plants is influenced by both the neighbor effects and environmental factors.When the neighbor distance is between 3 and 10 m,neighbor species diversity and abundance have significant competition effects on the clone plants,and this effect is a non-random process.Among soil water content,soil density,soil p H value,elevation,slope and convex,only elevation has significant correlation with the proportion of branches and sprouts at the quadrat level(P<0.001).As shown in the spatial distribution map of clone plants,there are more branch plants along the ridge but less in the gully area.Therefore,elevation is an important factor determine the number and spatial distribution of clone plants.(3)At the 20 m×20 m quadrat level,the proportion of clone species varied between1.89%-66.1%with an average value of 12.13%,which is significantly and positively correlated with species richness,Shannon-Wiener,Simpson,and Pielou diversity indices(P<0.001).The proportion of clone stems varied between 4.56%-35.48%and the average value is 18.12%,which is also significantly and positively correlated with species richness,Shannon-Wiener and Simpson diversity indices(P<0.001),but significantly and negatively correlated with Pielou evenness index(P<0.001).Therefore,clone plants occupy important niches in the tropical mountain rain forests.It is the outcome of competition from neighbor species and adaption to the environmental conditions.The existence of clone plants has important effects on the diversity of community.