| With the impact of human activities on the natural environment, biological invasion triggered a series of ecological and economic problems and played an important role in global environmental change, which has aroused widespread concern around the world. Solidago canadensis, a long-lived rhizomatous perennial herb originating from North America, which has ever been introduced all over the world as an ornamental plant, now has been invaded into Europe, Oceania, America, as well as parts of Asia. Previous studies about S. canadensis mainly focused on the harm and the prevention, allelopathy and its mechanism, physiological and ecological characteristics, chemical composition, and invasion of prognosis, but little on the quantitative study of its invasion. With in-depth study of biological invasion, especially since the 1990s, mathematical models, quantitative experiments, and bio-technology research tools have been introduced into this area, people's understanding of biological invasion has been greatly improved. At present, use of GIS technology to simulate the spatial distribution patterns of alien invasive species is an important research tools. More and more studies have used GIS and statistical analysis methods to identify the relationship between the alien species richness and spatial heterogeneity. However, there are less studies on a single species occurrence area at home and abroad. Therefore, this dissertation aimed at the current invasion of S. canadensis in Zhejiang, through the province survey based on towns, and obtained S. canadensis occurrence area data at county level. On this basis, S. canadensis spatial distribution pattern was built with the application of GIS software, and applied statistical analysis to find out the relationship between human activities and S. canadensis invasion area. The results provided a theoretical basis for the prevention and control of S. canadensis.Using Zhejiang county (city, district) level administrative divisions in 2005 for the research unit, and 34 regions was selected as the sampling data. The occurrence area of S. canadensis and related human activities factors (including geographic location, land-use conditions, economic factors, demographic factors and distribution factors) as the research objects. The geographic information systems (GIS) and the traditional statistical analysis methods (correlation analysis, principal component analysis and regression analysis) were applied to reveal the occurrence area and relative area of S. canadensis spatial distribution pattern at county, and explore the relationship between distribution pattern and the indicators of human activity. The results indicate that there is a significant spatial heterogeneity of S. canadensis areal distribution in the study area. Imports and intensity of agricultural activities are major factors in S. canadensis occurrence area, while length of highways accounts for the variance in relative area of S. canadensis..Using Zhejiang county (city, district) level administrative divisions in 2005-2007 for the research unit and selected the province's 69 districts. The occurrence area of S. canadensis was concerned as the research objects, and exploratory spatial data analysis was applied to reveal the S. canadensis occurrence area spatial distribution pattern at county in 2005-2007, and analysis the distribution pattern's spatial correlation. The results showed that the S. canadensis occurrence area in Zhejiang Province had both significant global spatial autocorrelation and local spatial autocorrelation, and had obvious spatial concentration feature, namely that the high S. canadensis occurrence area tended to focus on areas of high, and low together with the lower area of S. canadensis occurrence area.Using Zhejiang county (city, district) level administrative divisions in 2006 for the research unit and selected the province's 69 districts. The occurrence area of S. canadensis and related human activities factors (including land-use types and population factors) were concerned as the research objects. The Geographic Information Systems (GIS) and Simultaneous Autoregressive Model were applied to reveal the relative area of S. canadensis spatial distribution pattern at county, and explore the relationship between the distribution pattern and human activities. The results showed that relative area of S. canadensis in Zhejiang Province had a significant spatial autocorrelation. Relative area of S. canadensis and farmland, transportation population, water, settlements and mining sites showed a significant positive correlation, and population density show a significant negative correlation. |
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