青藏高原高寒草甸灌丛化对圆穗蓼昆虫植食作用的影响  

Effect of shrub encroachment on insect herbivory of Polygonum macrophyllum in alpine meadow of Qinghai-Xizang Plateau

作　　者：谭晓丹 张鹏[2] 朱思睿 刘向 周淑荣 刘木 Xiaodan Tan;Peng Zhang;Sirui Zhu;Xiang Liu;Shurong Zhou;Mu Liu(Key Laboratory of Genetics and Germplasm Innovation of Tropical Special Forest Trees and Ornamental Plants of Ministry of Education,College of Forestry,Hainan University,Haikou 570100;State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems,College of Ecology,Lanzhou University,Lanzhou 730000)

机构地区：[1]海南大学热带农林学院热带特种林木与观赏植物遗传与种质创新教育部重点实验室,海口570100 [2]兰州大学生态学院草种创新与草地农业生态系统全国重点实验室,兰州730000

出　　处：《生物多样性》2024年第1期85-93,共9页Biodiversity Science

基　　金：国家自然科学基金(32371611,32201291)。

摘　　要：灌丛化在青藏高原高寒草甸普遍存在,其发生的可能原因包括全球变暖、CO_(2)浓度增加、过度放牧和人类活动等。灌丛化对草地生态系统有正负两方面的影响,且该影响的方向和强度依赖于环境条件。虽然已有诸多研究探讨了灌丛化对草地生态系统的影响,但其对昆虫植食作用的影响格局和机制仍不清楚。本研究以青藏高原高寒草甸常见物种圆穗蓼(Polygonum macrophyllum)为研究对象,通过比较不同盖度(0、50%、100%)的金露梅(Potentilla fruticosa)灌丛下圆穗蓼的昆虫植食作用,探究了灌丛化对昆虫植食作用的影响,以及这种影响如何随气候和土壤条件变化而变化。结果表明:(1)圆穗蓼昆虫植食作用随灌丛盖度增加而增强;(2)灌丛化对圆穗蓼昆虫植食作用的影响在年均温低、土壤有效磷含量低、土壤碳含量和氮含量高的情况下更显著。本研究揭示了灌丛化对青藏高原高寒草甸生态系统中圆穗蓼昆虫植食作用的影响,并进一步揭示这种影响具有环境依赖性。这一结论为探究灌丛化对草地昆虫植食作用的影响提供了证据,对于认识和科学管理青藏高原灌丛化草地具有重要的现实意义。Aims:Shrub encroachment is ubiquitous in the alpine meadows of Qinghai-Xizang Plateau,caused by global warming,increased carbon dioxide concentration,overgrazing,and human activities.Shrub encroachment has both positive and negative effects on grassland ecosystems,and the direction and intensity of these effects depend on environmental factors.Although the effect of shrub encroachment on grassland ecosystem has been demonstrated in many studies,the pattern and mechanism of these effects on insect herbivory are still unclear.In this study,Polygonum macrophyllum,a common species in alpine meadows on the Qinghai-Xizang Plateau,was used to explore the effect of shrub encroachment on insect herbivory of and how the effect changed with climatic and soil factors by comparing the insect herbivory of P.macrophyllum under different Potentilla fruticosa coverages.Methods:In this study,ten blocks were selected from four sampling sites in the eastern part of the Qinghai-Xizang Plateau alpine meadow,and three 0.5 m×0.5 m quadrats with 0,50%,100%P.fruticosa coverage were selected in each block by visual inspection.Soil samples were collected in four additional quadrats near the quadrat of each sample.In addition,we obtained the annual mean temperature,average annual precipitation,and altitude data for each sampling site.Results:(1)The insect herbivory of P.macrophyllum increased with the increase of shrub coverage.(2)The effect of shrub encroachment on the insect herbivory of P.macrophyllum was more significant in regions with low mean annual temperature,soil available phosphorus content and high soil carbon and nitrogen content.Conclusion:This study revealed the effect of shrub encroachment on insect herbivory of P.macrophyllum in the alpine meadow ecosystem on the Qinghai-Xizang Plateau,and further found that this effect was environmentally dependent.This conclusion provides evidence for exploring the effect of shrub encroachment on insect herbivory,and has important practical significance for scientific management of shrub-

关 键 词：灌丛化 昆虫植食作用 避难所效应 屏障效应 土壤资源可利用性 沃岛效应 生长-分化平衡 

分 类 号：S812[农业科学—草业科学]