Study on Plant Diversity of Mountain Areas of Yangmeikeng and Chiao, Shenzhen, China

In this study, Yangmeikeng mountain area with a long-term natural restoration status (communities 1, 2, and 3) and Chiao mountain area with an artificially disturbed status (communities 4 and 5) in Shenzhen in China were subjected to plant community composition and diversity statistical analysis on the basis of the following indices: plant height;density;tree layer DBH;coverage;number of family, genus, and species;calculated diversity indices;richness;similarity coefficients of family, genus and species;and species evenness. The diversity levels of each index in each community were compared, and the relationships of family, genus, and species in the communities with one another were determined. The integrated diversity levels in the two areas were also analyzed. Results showed that the composition status of three communities, especially communities 2 and 3, which were located at high elevation, in Yangmeikeng with the long-term natural restoration status was better. The diversity values were also evidently higher. The vegetation composition in Yangmeikeng was also greater than that in Chiao. The integration status of numerous diversity indices, such as evenness and richness, was higher than that of the latter. These data could be used as a basis for arguments regarding the status of natural and artificial forest biodiversities. Many species in the community in artificial forests were shrubs and herbs. The richness and proportion of tree species were distinctly low. Thus, shrubs and herbs were the main components of the artificial interference community. The number and richness of the tree species in natural or long-term natural restoration forests were higher than those of the former. The family diversity Df of the three communities in Yangmeikeng was slightly lower than that of the two communities in Chiao. By contrast, the genus diversity Dg, family richness, and genus richness in Yangmeikeng were higher than those in Chiao. In terms of α-diversity and similarity coefficient, family, genus, and species were not directly related to one another. Therefore, species, genus, and family composition should be combined with their diversity status in the statistical and biodiversity analysis of a community. Synthetic diversity indices should be further analyzed to evaluate the diversity status of a community objectively.

Studies on Ecological Monitoring of Plant Community and Plant Diversity in Shenzhen, Southern China

From Jan. 2013 to Nov. 2018, we carried out the investigation on vegetation studies in the ecological monitoring programs, Shenzhen and totally researched 170 plant communities of mountain areas etc., few areas of street regions and parks etc., for communities’ structural characteristics and plant diversity. We comparatively analyzed natural forests, semi-natural forest and artificial forest composition and structural characters and family, genus and species diversity level and the main affected factors. We also researched and analyzed these communities’ structural characteristics and pant diversity, comparatively analyzed natural forests, semi-natural forest and artificial forest composition and structural characters and family, genus and species diversity level, the main affected factors;researched and analyzed the relationship between plant community structure characteristics with the absorbing ability to PM2.5 pollutants. The result showed that the structure and plant diversity of natural forest were obviously better than artificial disturbed forest or artificial forest, the semi-natural forest was the middle level of the forests, In the indices of height, DBH, coverage and crow width etc. of tree layer, natural forests and semi-natural forests were obvious higher than that of artificial disturbed forest or artificial forest;in some forests of artificial disturbed forest or artificial forest, though their richness indices of family and genus were a slightly higher, but this contribution was majorly due to herb layer plants, and some shrub layer plants. Analyzing three kinds of communities, the number of tree layer species of natural forest was the largest, and their every α-diversity index value was the highest;these characteristics values of semi-natural forest were second, artificial disturbed forests or artificial forests were the lowest;in shrub layer, and herb layer, few α-diversity indices of artificial disturbed forest or artificial forest were a slightly higher than that of some natural forests, but the integral values of the diversity indices of natural forest and semi-natural forest were obviously higher than the former. The research showed that in the artificial disturbed forest or artificial forest, because there have some little scale clearing areas, so some pioneer plant species could enter the community and formed a temporarily increase of species diversity, however, these species major were some shrub and herb plants;but tree layer possessed obviously more, even surpassed several ten times biomass than shrub and herb layers. Therefore, the respects of maintain ecosystem stability and other ecological efficient have major and dominated position and so on;and then this community can be natural recovery and succession, those forementioned new entire plants shall withdraw from the community and are replaced by the original plants of the community;but this process has already caused the ecological efficient loss and ecosystem unstable. Above research results are better evidence and theory reference to the argument problems on that are natural forest and natural restoration forest biodiversity higher? or is artificial forest biodiversity higher? and or is more artificial disturbed forest higher? Our researches showed that used random investigation method set quadrats, and combined typical investigation method, the structural indices in the all layer of community and all diversity indices of tree, shrub and herb layers and the integral values were similar, same or usually these indices in the community which set 600 m2, 800 m2 total quatrat area were higher (α-diversity) than that of more than 3000 m2, 4000 m2 or 7000 m2, even more than 17,000 m2 total quadrat area of communities. These lots of researches further proved that according to minimum area method for vegetation survey, in subtropical region, using random investigation method combined with typical investigation set 400 m2 or 400 m2 - 500 m2 total quad