Plant Community Diversity And Spatial Distribution Pattern Of Dominant Species In Cenwanglaoshan Natural Reserve

The Cenwanglaoshan Nature Reserve,located in the southern subtropical zone,is an ideal place for ecological research for its rich vegetation,strong native forests and obvious vertical distribution.Five lhm2 sample plots at different altitude gradients were established in Cenwanglaoshan natural reserve according to the operation guide of center for tropical forest science(CTFS).The analysis is based on the five plots,showing the species diversity,the influence of terrain factors on species distribution and the size structure and population distribution pattern of dominant populations.The main results are as follows:1?It was concluded that there are a total of 389 species of plants of 147 genera and 52 families in 5 sample plots in terms of species diversity,considered a species-rich region.The Simpson index,Shannon-Wiener index and Pielou evenness index were applied for analysis,and the result 1 shows that:the species diversity decreases with the rise of the elevation gradients.The level of community species diversity of different diameter is small diameter>middle diameter>large diameter in terms of the number of species,while it is large diameter>middle diameter>small diameter in terms of species evenness level.The species area curve shows that the minimumsampling area gradually increases with the decreasing altitude.2?The CCA analysis of terrain factors on species distribution shows that:The elevation factor is the most significant.Convexity has little effect on species distribution.The influence of slope orientation on species distribution decreases as the elevation gradient increases.Although the slope has a significant relationship with the species distribution,it has not found that there is a pattern of synergistic changes with elevation gradients or other terrain factors.The result shows that the influence of slope is not all that relevant to the three terrain factors that researched in this paper,but the effect that other factors exert on the distribution of species.Species respond differently to various terrain factors at different stages of diameter.3?Studies of dominant species indicate that most of the dominant species have similar diameter-scale structures,which is callled the growing population.Only in sample plot D and E are the pioneer species of the community,showing a tendency of decline.Ripley's K function was used for the analysis of the distribution patterns of dominant species in different plots.The results show that most of the dominant species are generally clustered distributions;some species are randomly distributed on a small scale,and the degree of aggregation increases as the scale increases.From all kinds of dominant population correlation between the species,the species habitat preference has great impact on interspecific association:Species with the same habitat preference are positively correlated,while the others with different habitat preferences are negatively correlated.Also,there will be no correlation due to interspecific competition at a small scale.