紫茎泽兰入侵对生物多样性及土壤养分的影响

研究了不同强度紫茎泽兰入侵(重度入侵,HI;中度入侵,MI;轻度入侵,LI;未入侵,CK)对入侵地生物多样性及土壤养分的影响.结果表明,紫茎泽兰改变了土壤结构并且降低了入侵地生物多样性,土壤容重和pH随紫茎泽兰入侵强度的增加表现为降低趋势,土壤含水量、电导率和总孔隙度表现为增加趋势,除了土壤全磷以外,土壤其他养分和微生物量也呈相应的增加趋势,均表现为HI＞MI＞LI＞CK,表明了紫茎泽兰入侵显著提高了土壤养分和微生物量,其中土壤有效养分对于茎泽兰入侵较为敏感;在紫茎泽兰入侵条件下土壤养分和微生物量呈现出季节同步变化规律,具体表现为冬季＞秋季＞夏季＞春季,表明紫茎泽兰入侵对土壤养分及微生物量的影响与其生长节律有关.相关性分析结果表明,紫茎泽兰入侵条件下生物多样性和土壤养分与微生物量呈显著的相关性,它们作为相互作用和影响的有机整体表现出统一性和同步性.

Effects of invasive plant Eupatorium adenophorum on soil nutrients and biological diversity

Study the effects of invasion of Eupatorium adenophorum on the biological diversity and soil nutrients (high invasion, HI; moderate invasion, MI; light invasion, LI; no invasion, CK). The results showed that E. adenophorum changed the soil structure and reduced the biological diversity. Soil bulk density and pH value decreased and soil moisture content,conductivity and total porosity increased with the increasing invasion of E. adenophorum, soil nutrients and microbial biomass except total phosphorus showed increasing trend which showed HI>MI>LI>CK and turned out that E. adenophorum invasion significantly improved the soil nutrients and microbial biomass, and the soil available nutrients were sensitive to E. adenophorum invasion. Moreover, soil nutrients and microbial biomass followed the seasons change pattern with winter>autumn>summer>spring, and it was suggested that the effects of the invasion of E. adenophorum was related to the growth rhythm of E. adenophorum. Correlation analysis showed that the indexes of biological diversity were significantly related to soil nutrients and microbial biomass, and they interacted and influenced each other as an organic whole which showed the uniformity and synchronicity.