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氮肥和种植密度对紫茎泽兰生长和竞争的影响

田耀华1,2,3;冯玉龙1;刘潮4   

  1. 1中国科学院西双版纳热带植物园昆明分部, 昆明 650223;2云南省热带作物科学研究所, 云南景洪 666100;3中国科学院研究生院, 北京 100039;4曲靖师范学院, 云南曲靖 655000
  • 收稿日期:2008-07-08 修回日期:1900-01-01 出版日期:2009-04-10 发布日期:2009-04-10

Effects of nitrogen fertilization and planting density on Ageratina adenophora growth and its competitive traits.

TIAN Yao-hua1,2,3;FENG Yu-long1;LIU Chao4   

  1. 1Kunming Division, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming 650223, China;2Yunnan Institute of Tropical Crops, Jinghong 666100, Yunnan, China;3Graduate University, Chinese Academy of Sciences, Beijing 100049, China;4Qujing Normal College, Qujing 655000, Yunnan, China
  • Received:2008-07-08 Revised:1900-01-01 Online:2009-04-10 Published:2009-04-10

摘要: 紫茎泽兰(Ageratina adenophora)是我国西南热带亚热带地区危害最严重的外来入侵植物之一。本研究在野外设置不同氮肥供给水平和种植密度下的紫茎泽兰、拔毒散(Sida szechuensis)、伏生臂形草(Brachiaria decumbens)和非洲狗尾草(Setaria anceps)的单种和紫茎泽兰与其他3种植物混种的人工群落,从植被-土壤相互作用的角度分析紫茎泽兰的入侵机制。结果表明:单种时4种受试植物均表现了对氮营养的响应,随氮肥水平的升高,根冠比降低,比叶面积升高;通过比较总生物量增幅,氮响应能力非洲狗尾草>伏生臂形草>紫茎泽兰>拔毒散。混种时受试植物与紫茎泽兰的生物量比和株高也表明非洲狗尾草的竞争能力>伏生臂形草>紫茎泽兰>拔毒散;与拔毒散混种的紫茎泽兰以及与 紫茎泽兰混种的伏生臂形草和非洲狗尾草的种内竞争随种植密度的增大而增大,导致种间竞争能力下降,在高种植密度下对混种物种的抑制作用减弱。紫茎泽兰在氮响应能力、竞争能力和表型可塑性方面均强于本地种,可能与其入侵机制有关;牧草的氮响应能力和竞争能力强于紫茎泽兰,其中非洲狗尾草又强于伏生臂形草,可能更适宜于入侵地的替代控制。

关键词: 异丙甲草胺, 金都尔, 过氧化氢酶, 手性农药, 土壤微生物

Abstract: Ageratina adenophora, a noxious perennial forb, has invaded a large ar ea of open habitats and grasslands in tropical and subtropical areas of southwes tern China. To study the invasion mechanism of A. adenophora from the viewpo int of vegetation-soil interaction, a field experiment was conducted with the m onocultures of A. adenophora, Sida szechuensis, Brachiaria decumbens, and Se taria anceps, and the mixed cultures (50%/50%) of A. adenophora and other th ree species under three levels of nitrogen fertilization and planting density. T he results showed that the monocultures of four test species exhibited considera ble nitrogen-acclimation ability. With the increase of nitrogen fertilization l evel, their root/crown ratio decreased, while specific leaf area increased. The increment of biomass growth with nitrogen fertilization level was S. anceps>B. decumbens>A. adenophora>S. szechuensis. In mixed cultures, the same trends existed. Under medium planting density, A. adenophora had the greatest adver se effects on S. szechuensis; while under low planting density and high nitr ogen fertilization level, S. anceps and B. decumbens suppressed A. ade nophora. These results revealed that the intraspecific competition of the domi nant species in mixed cultures increased with planting density, resulting in the decrease of interspecific competition and the decreased inhibitory effects of A. adenophora on the mixed species under high planting density. In summary, A. adenophora inhibited the growth of other species via increasing soil fertility to promote itself. The positive feedback between A. ade-nophora and soil env ironment was related to its invasiveness, ensuring its competitive dominance in community. In addition, S. anceps could be more suitable to replacement control.

Key words: Metolachlor, S-Metolachlor (Dual Gold), Chiral pesticide, Catalase activity, Soil microorganisms