中国农业生态系统外来种入侵及其管理现状

农业生态系统极易遭受外来生物入侵。作者根据文献资料和多年工作观察统计出入侵我国农业生态系统的外来生物共计92科175属239种, 其中植物155种, 动物55种, 微生物29种, 植物多为有意引入后逸生, 而动物和微生物则主要是无意引入。外来入侵种发生数量呈现从南到北、从东到西逐渐减少的趋势。这些入侵种中, 来源于美洲的最多(占45.04%), 其次是欧洲(22.90%); 菜地(包括温室大棚)和果园入侵种最多, 分别达64.85%和66.53%, 而半年期的秋熟旱地和夏熟旱地分别占34.31%和23.85%。其中17种外来杂草、10种害虫、7种病原菌为恶性有害生物, 应作为防除的重点目标。目前农业生态系统外来入侵物种的控制以化学防治为主, 但由于长期施用化学农药, 在侵入我国农田的入侵种中, 已有51种在世界不同地区演化出抗药性生物型, 因而需重视生物防治、农业和生态防治以及检疫等的综合应用。今后外来种对农业生态系统的入侵格局、机制和趋势, 入侵途径以及生物入侵和抗药性生物型对农业生态系统中有害生物群落演替的影响、转基因作物导致的生物入侵等问题值得关注。

Invasive alien species in Chinese agricultural ecosystems and their management

Agricultural ecosystems are vulnerable to biological invasions. There are a total of 239 invasive alien species in a variety of agricultural ecosystems in China. Among them, 155 species are plants, 55 are animals and 29 are microbes. The number of invasive alien species decreases from south to north, and from east to west in China. Invasive alien plant species are generally introduced intentionally, while animals and microbes are mainly unintentionally introduced. Among these invaders, 45.04% have a geographical origin in the Americas, 22.90% in Europe, and 16.41% in Asia. Of these species, 64.85% and 66.53% occur in vegetable gardens (including greenhouses) and orchards, respectively, while 34.31%, 23.85% and 6.28% occur in summer-harvested crop dry land, autumn-harvested crop dry land and paddy field, respectively. Among these 239 invaders, 17 plant species, 10 animals and 7 microbes are noxious pests which, we feel, deserve closer management attention. Currently, chemical control is the principal approach to managing these species in agricultural ecosystems. However, long-term application of pesticides has led to pesticide resistance in some invasive species, with 51 of the 239 invasive alien species reported as exhibiting pesticide-resistant populations worldwide. Therefore, more attention should be paid to management which integrates biological control, ecological measures, agronomic means and quarantine. We suggest that research into the following issues would be fruitful: patterns and mechanisms of and trends in biological invasions in agricultural ecosystems, origin sources and invasion pathways, influences of biological invasions and pesticide resistance on successions of pest communities, and biological invasions caused by transgenic crops.