湿地外来植物再力花入侵风险研究初报

Preliminary Study on the Invasion Risk of Thalia dealbata as an Alien Species in Wetlands

系统地描述了湿地外来植物再力花(Thaliadealbata)的生物学特点;提出再力花适生区域的气候特征指标为:日平均气温稳定通过≥10℃的天数大于180d;最冷月(1月)月平均气温高于-5℃;年极端最低气温不低于-15℃。再力花在中国的适生范围为沈阳以北、沈阳—北京—太原—成都—丽江一线以东所围区域。再力花入侵风险主要表现在3方面:①再力花侵占力强,能在地上和地下高密度占领生境,从而影响其他生物生长,降低群落物种多样性;②繁殖速度快,再力花自然生长一年的个体繁殖达到7～12倍,既可通过根茎营养繁殖,又可以种子繁殖;③植株根除难度大,再力花为挺水植物,通常生长于水深60cm及以下水域,营养繁殖体根茎生长在水下淤泥之中,人工根除过程中,根茎的片断残留仍然可以作为繁殖体长出新的植株,并且快速繁殖,扩大其生长面积。在适生区种植再力花,容易形成再力花的单一优势种群,降低区域物种多样性,破坏生态系统的稳定性,并大面积侵占水域和河道。再力花的入侵风险程度极高,属于"不可引入"物种。最后,提出了再力花引种的风险管理建议。

The biological characteristics of Thalia dealbata,an alien plant,in wetlands were described through morphological observation.The climatic standards to identify the potential distribution areas were defined as follows：the number of days in which daily average air temperature was stably higher than（or equals） 10 ℃ was larger than 180 days;the average monthly air temperature in the coldest month（January） was higher than-5 ℃;the extremely lowest annual temperature was not lower than-15 ℃.According to the meteorological data and climatic characteristics,warm temperate humid region,warm temperate semi-humid region,warm temperate semi-arid region,north subtropical humid region,mid subtropical humid region,south subtropical humid region,edge tropical humid region,mid tropical humid region,equatorial tropical region and plateau subtropical region were identified as the potential distribution areas of T.dealbata in China.The invasive risks of T.dealbata were displayed in three aspects.First,T.dealbata is highly aggressive that it occupies the habitat in high density both ground and underground,which may affect other species and leads to a drop in community species diversity.Second,it has an extremely high reproductive speed,which may grow 7-12 times each year,due to its vegetative propagation and seed propagation.Third,the difficulties in wedding and the residue of its tissues also contribute to its rapid reproduction.The assessment of invasion risk of T.dealbata indicated that T.dealbata had a very high risk of invasion,which meant that T.dealbata was extremely dangerous and a forbidden species to be introduced.Some suggestions on biological risk management were given.To control plant introduction and establish and update the database of the information of harmful plants were proposed on the basis of the growth habit of T.dealbata.