许昌市郊区入侵种加拿大蓬的生态分布与危害评价

为了查清外来入侵植物加拿大蓬(Conyza canadensis)在许昌市郊区的生态分布与危害状况,采用野外调查、室内分析、建立风险评价体系等方法对许昌市郊区的加拿大蓬进行研究。结果显示,加拿大蓬广泛分布于路边、荒地、垃圾堆、农田边、建筑用地等各种生境,密度在18～110株/m2,排序为:果园>荒地>垃圾堆>苗圃>路边>城镇住宅区附近;盖度在10%～90%,排序为:果园>荒地>苗圃>垃圾堆>路边>城镇住宅区附近;平均株高134cm,最高株高达275cm;秋季是加拿大蓬危害最严重的季节,在果园、荒地、垃圾堆等生境易形成大面积的单优群落。据建立的外来入侵植物危害风险评价指标分析,其危害风险指数为9.55,危害等级为一级,严重威胁着许昌市农业生产和生态环境。因此,加拿大蓬对生物多样性和社会经济的影响应引起重视,需加强防控。

Ecological Distribution and Risk Evaluation of an Alien Plant,Conyza canadensis in Xuchang Suburbs

In order to identify the ecological distribution and damage conditions of the alien plant Conyza canadensis in Xuchang suburbs,the field investigation,laboratory analysis and creation of a risk evaluation system are used to study the plant.The results show that Conyza canadensis is widely distributed in the place of no agricultural plants and other bare ground such as the roadside,wasteland,garbage dumps,agricultural side,construction sites,etc,where the density range is 18-110 plants/m2,sequenced as:orchard>wasteland>garbage dumps>nursery>roadside>residential area of town;the coverage range is 10%-90%,and the sequence is:orchard>wasteland>nursery>garbage dumps>roadside>residential area of town;the average plant height is 134 cm,and the highest one is 275 cm;autumn is the most serious season when Conyza canadensis harmed,and in some places such as orchard,wasteland and garbage dumps,etc,it is easy to form a single large area of priority community.According to the analysis of the established damage evaluation index of alien plants,the harm rank of Conyza canadensis is first-level(the hazard risk index R=9.55),showing that it brings serious harm to Xuchang's agricultural production and ecological environment,and it also has some adverse effects on the biodiversity and the social economy.Therefore,prevention and control of Conyza canadensis need to be strengthened.