不同生境条件下紫茎泽兰实生幼苗的生存特性比较

Survival traits of Crofton weed (Eupatorium adenophorum) seedlings in different habitats

外来植物紫茎泽兰(Eupatorium adenophorum)入侵我国西南地区并造成了严重的生态灾难,了解其幼苗的生存特性,有助于预防和治理其危害。本研究于2005年8月到2006年8月通过盆栽实验和样方调查,研究了不同光照和水分条件下紫茎泽兰幼苗的生长、生存状况和开花比例。结果表明:(1)紫茎泽兰从种子萌发到1年后形成幼苗并开花结果的概率为1.16×10-13-2.43×10-11;(2)湿润偏阴生境利于紫茎泽兰的种子萌发和幼苗存活,其萌发出现率和存活率都达到最高,分别为13.93%和79.50%;(3)在水分充足的情况下,增加光照有利于紫茎泽兰生长;(4)出土1年后的紫茎泽兰有3.92-5.05%的植株开花结果,产生的种子密度为23,000-52,000inds./m2。虽然紫茎泽兰种子个体成功生存的概率很小,但种子产量大增加了该物种成功定居的机会,特别是湿润偏阴环境能够促进幼苗的定居。

Crofton weed （Eupatorium adenophorum） is a highly invasive species. To provide information for controlling or preventing its spread and invasion, we examined recruitment, survival and flowering characteristics of Crofton weed seedlings through container and field experiments in different habitats between Aug. 2005 and Aug. 2006. The results showed that the probability of a seed developing into a mature plant was only 1.16×10^-13 to 2,43×10^-11 The highest emergence rate （13.93%） and seedling survival rate （79.50%） in the first 10 weeks after seed planting occurred in shady and wet habitats, indicating that these two habitats are favorable for seedling emergence and survival. In addition, seedlings grew better in sunny habitat than in shady habitat when soil water was sufficient. One year after emergence, 3.92% to 5.05% of seedlings flowered. Density of seeds produced by these flowering individuals ranged from 23,000-52,000 ind/m^2. Although survival rate of individual Crofton weed was low, enormous seed production ensured the successful colonization and development of sustainable populations, especially in humid and shady habitat.