中国农业科学 ›› 2016, Vol. 49 ›› Issue (9): 1826-1834.doi: 10.3864/j.issn.0578-1752.2016.09.019

• 研究简报 • 上一篇    

放牧强度对高寒草地不同类群土壤动物的群落结构和多样性的影响

武 崎,吴鹏飞,王 群,文勇立,高艳美,张荣芝,龙 伟   

  1. 西南民族大学生命科学与技术学院,成都 610041
  • 收稿日期:2015-11-10 出版日期:2016-05-01 发布日期:2016-05-01
  • 通讯作者: 吴鹏飞,E-mail:wupf@swun.cn
  • 作者简介:武崎,E-mail:1152094089@qq.com
  • 基金资助:
    国家自然科学基金(41371270、40801092)、中央高校优秀团队及重大孵化项目(2014NZYTD01)、四川省教育厅创新团队(14TD0049)、西南民族大学研究生创新型科研项目(CX2015SZ071)

Effects of Grazing Intensity on the Community Structure and Diversity of Different Soil Fauna in Alpine Meadow

WU Qi, WU Peng-fei, WANG Qun, WEN Yong-li, GAO Yan-mei, ZHANG Rong-zhi, LONG Wei   

  1. College of Life Sciences and Technologies, Southwest University for Nationalities, Chengdu 610041
  • Received:2015-11-10 Online:2016-05-01 Published:2016-05-01

摘要: 【目的】明确放牧强度对高寒草地生态系统中不同类群土壤动物群落结构和多样性的影响。【方法】2014年9月在川西北红原县的西南民族大学“青藏高原生态保护与畜牧业高科技研究示范基地”内选取轻度放牧(light grazing,LG,15 sheep/hm2)、中度放牧(medium grazing,MG,22 sheep/hm2)、重度放牧(heavy grazing,HG,36 sheep/hm2)及无放牧(对照)(no grazing,NG) 4个样地。使用Vortis便携式吸虫器采集地表小型节肢动物;用环刀采集0—5、5—10和10—15 cm层土样,每层采2份,分别用干漏斗法(Tullgren)和湿漏斗法(Baermann)分别分离土壤节肢动物和土壤线虫。【结果】主成分(PCA)分析结果表明,无放牧处理与其他放牧处理样地间的3类土壤动物群落结构均存在明显差异,说明放牧对土壤动物群落结构具有显著影响;而土壤线虫群落结构在3种放牧强度之间的差异最明显,其次是地表节肢动物,土壤节肢动物群落结构在3中放牧强度间的差异相对最小。3种放牧强度样地中的土壤节肢动物及土壤线虫的群落密度均显著高于无放牧处理样地(P<0.01),而地表节肢动物群落密度则以轻度放牧样地最低。地表节肢动物的类群数随放牧强度增加而增加,但不同放强度间无显著差异(P>0.05);Shannon多样性指数和Pielou均匀度指数均随放牧强度的增加呈先下降后增加的变化趋势,且以无放牧处理最高,中度放牧处理最低,不同放牧强度间具有显著差异(P<0.05)。土壤节肢动物的类群数和Shannon多样性指数均呈先增加后下降的变化趋势,且均是中度放牧强度样地的多样性显著高于其他放牧强度样地(P<0.05);而Pielou 均匀度指数无明显变化趋势(P>0.05)。土壤线虫的类群数以轻度放牧最高,Shannon多样性指数则是随放牧强度增加而下降,Pielou均匀度指数呈先下降后增加的趋势,以中度放牧最低,无放牧处理最高;单因素方差分析结果表明土壤线虫的多样性指数在各放牧处理间均有显著差异(P<0.05)。多元回归分析结果表明地表和土壤节肢动物的密度和多样性指数与土壤化学性质呈显著相关(P<0.05或P<0.01),土壤线虫群落密度和多样性指数与土壤化学性质和放牧强度呈显著相关(P<0.01)。【结论】不同类群土壤动物对放牧强度的响应不同,重度放牧有利于地表节肢动物,中度放牧利于土壤节肢动物,轻度放牧利于土壤线虫。因此在评价放牧对草地生态系统的影响时选取合适的土壤动物类群非常关键。

关键词: 放牧强度, 高寒草地, 地表节肢动物, 土壤节肢动物, 土壤线虫

Abstract: 【Objective】The objective of this study is to reveal the effects of grazing intensity on the community structure and diversity of different soil fauna in alpine meadow ecosystems.【Method】The investigations were conducted on the soil faunal communities and soil environment of alpine meadows under different grazing intensities (light grazing, LG, 15 sheep/hm2; medium grazing, MG, 22 sheep/hm2; heavy grazing, HG, 36 sheep/hm2; no grazing, NG) in September 2014 in Hongyuan county, northwest Sichuan. Epigeic arthropods were investigated using Vortis sinensis with sampling area 0.2 m2 and preserved in 75% alcohol. The soil cores were used to collect soil samples from 0-5, 5-10 and 10-15 cm layers. Two soil samples were collected from each layer. The Tullgren and Baermann methods were used to extract soil arthropods and soil nematodes, respectively, from soil samples. 【Result】 The principal component analysis (PCA) results showed that the community structure of the three kinds of soil fauna in no grazing treatment differed from those of grazing treatments, indicating that the community structure of soil fauna can be affected by grazing. Community structure of soil nematodes in the three grazing treatments were differed clearly from each other, the similar phenomenon was also found for epigeic and soil arthropods. The community densities of soil arthropods and nematodes in grazing treatments were greater than those in no grazing treatment (P<0.01). The minimum values of community density of epigeic arthropods were recorded in the light grazing treatment and the maximum values of community group number were observed in the heavy grazing treatment (P>0.05). Shannon index and Pielou index fluctuated among the treatments, and the maximum values of Shannon index and Pielou index were observed in the no grazing treatment, the minimum values in the light treatment (P<0.05). The Shannon index and group number of soil arthropods increased then reduced with increasing grazing intensity, and the values of Shannon index and group number were greater in light grazing treatments than in other grazing treatments (P<0.01), but Pielou index changed with no significance (P>0.05). The maximum values of soil nematode community group number were observed in the light grazing treatment, Shannon index of soil nematodes significantly reduced with increasing grazing intension with the maximum values observed in the no grazing treatment; Pielou index were lower before increase, and the maximum values of Pielou index were observed in the no grazing treatment. One-Way ANOVA results showed that diversity indexes of soil nematodes differed significantly between the four grazing treatments (P<0.05). The densities and Shannon index of epigeic and soil arthropods were significantly correlated to some soil chemical properties (P<0.05 or P<0.01), but the density and Shannon index of soil nematodes were significantly correlated to some soil chemical properties and grazing intensity. 【Conclusion】The results suggested that different groups of soil fauna respond differently to grazing intensity; The heavy, medium and light grazing benefit, respectively, the epigeic arthropods, soil arthropods and soil nematodes, indicating that selecting an appropriate kind of soil fauna is very important to evaluate the effects of grazing intensity on grassland ecosystems.

Key words: grazing intensity, alpine grassland, epigeic arthropods, soil arthropods, soil nematode