Comparison: Carbon Sequestration Benefits Of Different Forest Types In Main District Of Chongqing City

With the economic and social development, the greenhouse effect and climate warming further exacerbated, and its associated problems-forest carbon sinks has been paid to more and more attention. The carbon sequestration of urban forest can mitigate the deterioration of the environment, and thus plays a vital role in the creation of the urban environment. Although there are many domestic and international researches on carbon sinks, but those on the application of carbon sequestration in urban green space planning are few. Similar studies have been done in Guangdong and other places, but only for different types of forest, with no detailed study of the urban forest in different community types and the individual carbon sequestration capacity differences of common species.This article put a study on the urban forest in the built-up areas of Chongqing, and based on the basic principles of ecology. With the measuring instrument of plant growth, and through the extraction of relevant information and analysis of information, we make a survey on the characteristics of trees in urban area of Chongqing city such as species composition and volume of tree growth, and make a comparison between different tree species and different communities to find their ability differences on carbon sequestration. Based on the analysis, we choose the main carbon sinks-effective species and forest types with strong carbon sequestration capacity, at the same time, make a study on the artificial configuration technology of carbon sequestration forest and put forward the specific configuration pattern on the construction of the plant communities in Chongqing City. Finally, evaluation ability differences of carbon sequestration through the plant growth factors and provide a theoretical reference on the construction of low-carbon city of Chongqing. The results are as follows:1. In the urban area of Chongqing City the common tree species increased biomass and carbon sequestration capacity in decreasing order is Ginkgo biloba L, Cinnanomum camphora (L.) Presl.,Ficus microcarpa L. f., Ficus virens Ait. var. sublanceolata (Miq.) Corner, Cinnanomum japonicum (Diels) Sieb., Osmanthus fragrans Lour., Populus x canadensis Moench, Koelreuteria bipinnata Franch., Pinus massoniana Lamb. Ficus biomass of the annual increase Ginkgo biloba L 18.58 m3, Cinnanomum camphora (L.) Presl.10.84 m3, Ficus microcarpa L. f.8.21 m3; Ficus fixed annual CO2 were 9.29kg,5.42kg,4.11kg.2. In the urban area of Chongqing City the major forest types in decreasing order of increased biomass is mixed coniferous> coniferous mixed forest> deciduous forest> Pinus massoniana Lamb. forest> shrub woodland. Annual growth conifer biomass maximum mixed coniferous 16.57t, shrub woodland minimum 5.0t.3. In the urban area of Chongqing City, among the major forest types of carbon sequestration, the net carbon sequestration per unit area of each forest type in decreasing order is mixed coniferous> coniferous mixed forest> deciduous forest> Pinus massoniana Lamb, forest> shrub woodland. Conifer is the best plant on economic benefits of carbon sequestration, shrub woodland is the plant which has the poorest efficiency of carbon sequestration; Forest Park is the best type of urban green space with the highest carbon sequestration.4. The main city of Chongqing urban green space is less than the overall capacity of natural forests in carbon sequestration, urban green space is about natural forest carbon sequestration capacity of 2/3. The carbon sequestration capacity of urban green space in decreasing order is:Forest Park> Road Green> City Park> Campus Green.