不同海拔梯度下干热河谷植被恢复对土壤线虫群落的影响OA

[Objective]Vegetation restoration is one of the most effective approaches to improve the ecological environment of the dry-hot valley of the Jinsha River,Yunnan Province.Exploring the changes in composition and structure of soil nematode communities under artificial and natural vegetation restoration can provide a theoretical basis for the reasonable management of the forest ecosystem in this region.[Method]In dry-hot valley of the Jinsha River,Leucaena leucocephala plantation and natural shrub-grass with Phyllanthus emblica and mixed Terminalia franchetii+Pistacia weinmannifolia were selected at low(1 150-1 200 m),middle(1 350-1 400 m)and high(1 550-1 600 m)altitudes.The effects of the vegetation restoration approach under different altitudes on the functional structure of nematode communities were analyzed by using ecological indices,c-p life history,and nutritional structure indices.[Result]1)A total of 17 genera of bacterivores were captured,accounting for 37.3%of the total number,and omnivores-predators belonging to 21 genera,accounted for 53.2%.Also,Aporcelaimus,Acrobeles,and Microdorylaimus were the dominant genera.2)Nematode trophic taxa were dominated by omnivores-predators and bacterivores,while plant-parasites and fungivores had relatively low proportions.However,the taxa were biased towards K-strategies.3)The responses of nematode abundance,trophic taxa,and life history strategies to vegetation restoration varied across different altitudes.As the altitude increased,the diversity and stability of the nematode community under T.franchetii+P.weinmannifolia mixed shrub-grass increased gradually,while that under P.emblica shrub-grass showed the opposite trend.However,the L.leucocephala plantation showed the lowest"V"pattern with the middle altitude.Meanwhile,L.leucocephala plantation at the low altitude increased the metabolic footprints of bacterivores and omnivores-predators,implying that the food web was relatively complex and stable.4)Soil nitrate nitrogen,available phosphorus,and moisture were the main driving factors of nematode community changes in artificial and natural vegetation restoration.[Conclusion]We recommend taking L.leucocephala as the main plantation at the low altitude area in the process of vegetation restoration and actively protect the pure and mixed natural shrub-grass at the middle and high altitudes to promote the ecological restoration of degraded soil in the dry-hot valley of the Jinsha River.