Study On The Speices Biodiversity Of Plantation Communities In Semi-arid Region On Losea Plateaus

Semi-arid Loess Plateau ecological construction in semi-arid Loess Plateau is to improve the ecological environment of the important elements. In China, since returning farmland to forest, plantation area has reached 466.667 million hm2. To a large extent, it improved the Loess semi-arid area of the ecological environment, but also has brought great benefits for local farmers. With the increase in plantation area, the study of the plantation community of species diversity is very necessary. The improvement of species diversity of Plantation Community , can effectively reduce the incidence of forest diseases and insect pests, but can also increase the plantation ecosystem stability. Through the study of plantation community of species diversity on the Loess semi-arid area, it will provide reasonable technical measures for Loess semi-arid zones of ecological construction of plantation and the sustainable development of plantations.In this paper, species composition of plantation community, species diversity within the community, between communities of different species diversity and community life of the species diversity index Multiple comparisons were analyzed in Toqiaogou valley of the Fangshan county in Shanxi Province, the study results show that:(1)To analysis the community species composition, there are 39 species plant under Platycladus Orientalis plantation, belonging to 33 genera of 16 families. There are 54 specise plant under R.pseudoacacia plantation, belonging to 42 genera of 21 families. There are 43 specise plant under Ulmus pumila plantation, belonging to 35 genera of 18 families. There are 53 specise plant under Larix principis-rupprechti and mixed community, belonging to 40 genera of 22 families. Composite, Leguminosae and legumes are the advantage species.(2)To analysis the Community Drive-class structure, Platycladus Orientalis community and Larix principis-rupprechti are growth-oriented structure; R.pseudoacacia communities and Ulmus pumila communities are stable structure. With the vertical structure analysised, all community-level structure is relatively simple and divide into the tree layer, the shrub layer, the herb layer.(3)Species diversity within the community for the comparative analysis showed that: Platycladus Orientalis, R.pseudoacacia, Ulmus pumila, Larix principis-rupprechti and mixed, species-rich communities index S trend basically the same, that is, herb layer> shrub layer> tree layer . SW diversity index of the trend, tree layer of Platycladus Orientalis and herb layer > shrub layer; R.pseudoacacia, tree layer and shrub layer > herb layer; Ulmus pumila, the trend of tree layer and herb layer is consistent. of trends consistent with the shrub layer in the tree layer and herb layer On the contrary; Larix principis-rupprechti and mixed community, herb layer and shrub layer > tree layer. Diversity index SP and evenness index Jsw ,tree layer> shrub layer and herb layer.(4)Different life-form diversity index analysis showed that: species richness S index shows, the herb layer> shrub layer> tree layer. S index of herb layer of Community shows, Larix principis-rupprechti > R.pseudoacacia > Ulmus pumila > Platycladus Orientalis. SW index shows, the herb layer> tree layer> shrub layer. SP index shows, shrub layer> tree layer> herb layer. Jsw index shows. shrub layer> herb layer> tree layer.(5) Through the different types of species diversity of different communities of multiple comparative analysis of results showed that: tree layer, Platycladus Orientalis > Larix principis-rupprechti > Ulmus pumila > R.pseudoacacia. Shrub layer, Ulmus pumila > Larix principis-rupprechti > R.pseudoacacia>Platycladus Orientalis. Herb layer, Larix principis-rupprechti > R.pseudoacacia > Ulmus pumila > Platycladus Orientalis. From the overall analysis, S index and the index between the SP, SW index and the index between Jsw, SW index and the index between the SP There was a significant difference, S index and the index between SW, S index and the index between Jsw, Jsw index SP between the index and no difference was not significant.