| The specie diversity of forest community is important to the structural stability and functional diversity of the forest ecological system. Researching the diversity and spatial distribution patterns of the forest species is of great significance in the further understanding of forest biodiversity maintenance, coexistence mechanisms between species and the sustainable management of the forest. In this paper, a 4 hm2 fixed monitoring plot of the Picea secondary forest in Guandi Mountain is as the research platform. We investigate the vegetations, locate and mornitoring the understory shrubs. As follows, we analysis the species composition, structure and species diversity of the shrubs. Spatial distribution patterns in different scales of the secondary Picea forest are researched. In this study, The pair correlation function, the univariate O-ring statistic of the point pattern analysis was used to analyze spatial distribution of tree species in each community, while bivariate O-ring statistic was used to analyze spatial associations of different species in each community. This research is intended to reveal the species diversity and maintain the mechanism of the secondary Picea forest. The results show that:(1) There are 25 shrub species in the plot. They are belong to 10 families,18 genera,25 species.The most family is Rosaceae;The most genus is Lonicera. The number of the all shrubs is 362,a total of 15208 branches.(2)In the plot, there are 4 dominant species with the important value> 10.They are Lonicera chrysantha Turcz, Corylus mandshurica Maxim, Rosa davurica Pall and Cotoneaster acutifolius. For the shrubs of the forest, the Simpson index D is 0.84, the Shannon Wiener index H is 2.13, the Pielou evenness index D is 0.66.All these indexes are higher than the herbs and arbors.(3)Through drawing the specie-area curve, the minimum plot area (1600 m2) is determined.(4)In this plot, the 25 shrub species are divided into three distinct layers.0-1m is a forest layer, 1-2m is a layer and 2-3m is another layer. The vertical stratification of the forest is obvious.(5)Through analyzing the spatial distribution patterns of the 8 main shrubs(≤50m), we find that Lonicera hispida Pall. ex Roem. et are of aggregate distribution in all research scales.The other 7 shrubs are of aggregate distribution in small research scales,but in the larger scale, Rosa davurica Pall., Corylus mandshurica Maxim. et, Lonicera szechuanica Batal.and Spiraea pubescens Turcz. are of randomly distribution, Cotoneaster acutifolius, Lonicera chrysantha Turcz. ex and Rosa davurica Pall. are of uniform distribution.(6)The correlation analysis of the 4 dominant species shows that positive correlations among different species are found in smaller scales. And the negative correlations of the different species are found in larger scales(larger than their positive correlation dimension range). |
