A Study On Community Ecology Of Alien Weeds In Jinhua Suburban

Invasive plants have been receiving increasing attention for their impact on social system, and ecosystem. Prediction of the invasive potentials of alien species is of importance in invasion ecology. Some "hot topics" of contemporary plant invasion ecology has emerged, such as the invasiveness of plants and the invisibility of habitats. However, there is still a lack of generalization regarding these invasion impacts.Based on the current theory of invasion ecology, the dissertation, was carried out surveys of community plots in Jinhua suburban, Zhejiang province, mainly focusing on the following subjects: â‘  to get the background data of the alien weeds in Jinhua suburban; â‘¡ to reveal the ecological relations (including niche) among the alien weeds and the dominate native weeds, the species diversity in the invaded habitats; â‘¢ to analyze the relationship among the plant traits, the environmental variables and invasiveness (i.e. ecological important values) by using the method of Canonical Correspondence Analysis, in order to find a a new method for the study of plant invasion ecology. The major conclusions are summarized as follows:1. The species of alien weeds in the suburban of Jinhua during spring, earlier summer and autumn were surveyed with the square plot method in different habitats. Based on our investigation, together with the previous researches, 76 exotic weed species, belonging to 54 genera and 24 families, were recorded from the suburban of Jinhua, among them, Compositae (species / genera = 21/17), Gramineae (7/5), Leguminosae (7/5), Amaranthaceae (7/2), Euphorbiaceae (4/2), Convolvulaceae (4/2) are the dominant families. In these alien weeds, Oenothera laciniata is an alien weed new to the centre of Zhejing Province, and Lactuca serriola new to eastern China. 1) Compared with the flora geographic elements of Mount Bei in Jinhua, higher tropical proportion was found in alien weed, and special attention should be paid to species with Tropical Asia & Tropical America disjuncted distribution pattern; 2) Totally about 81% of the alien weeds originate from America (59%) and Europe (22%), so appropriate measures to control the introduction of these origin plants are essential.2. Based on the ecological important value of 21 alien weeds and 29 native companion weeds, their niche breadth and overlap were calculated. The application of the methods The...