摘要
为从污染程度的角度探索土壤线虫多样性与群落稳定性的关系,以重金属铜和锌为扰动因子,设置不同程度的胁迫水平,通过恒温培养试验对比高生物多样性的自然林地和低生物多样性的农田土壤线虫群落对重金属胁迫的响应。结果表明:自然林地土壤线虫数量随Cu和Zn的添加浓度升高而降低;农田土壤线虫总数呈现低浓度扰动条件下降低,中、高浓度又反弹的现象。占绝对优势的食细菌线虫数量变化规律与线虫总数相近;自然林地中捕食杂食性线虫仅在添加高浓度Zn处理有所减少,而在农田土壤中,中、高浓度Cu,以及低浓度Zn处理均呈现出显著的抑制效应。重金属梯度对自然林地线虫多样性无显著影响,但是降低了农田线虫的香农指数,提高了优势度。总体上,Cu和Zn扰动对自然林地线虫的影响主要表现在数量上,对农田线虫的影响更多体现在群落结构、多样性和生态指数上。就污染程度以及生物群落结构的角度而言,高多样性的自然林地线虫群落对Cu和Zn污染的抵抗力更强。
【Objective】The relationship between biodiversity and community stability is a fundamental component of soil ecology.To explore effects of pollution on the relationship between soil nematode diversity and community stability,comparisons were made of nematode communities in woodlands vs.those in farmlands that were simulated to be contaminated with copper(Cu)or zinc(Zn)varying in concentration.【Methods】Cu or Zn was added to fresh soil samples,which were convert to final concentrations of the minerals in dry soil equivalent to 0,100,400,and 800 mg·kg–1.For each treatment had three replicates,a total of 42 subsamples(14 treatments×3 replicates)were prepared.The soil samples were incubated at 25°C for 23 days before nematodes were collected using the cotton-wool filter method.Comparisons were made in nematode community structure(abundance,diversity and functional indices)between soils different in pollution gradient and between habitats.【Results】A total of fifty-two taxa of nematodes,belonging to four main trophic groups,were identified,48 taxa in the woodland soil and 32 in the farmland soil.Bacterivores dominated both the woodland and farmland samples.Herbivores were the second most dominant trophic group in the woodland soil,but bottomed in the farmland soil.Nematode abundance in the woodland soil decreased with rising Cu and/or Zn concentrations.In the farmland soil,however,nematode abundance was lower when Cu and/or Zn concentrations were low and higher when they were medium or high.Bacterivores and the total of nematodes in a similar trend.In the woodland soil,omnivore-carnivore abundance decreased when soil Zn was the highest or low in concentration,and when soil Cu was medium and high in concentration.In the natural woodland soil,the gradient of heavy metal concentration had no significant effect on diversity of nematodes,but in the farmland soil,it reduced Shannon–Wiener(H’)index and increased nematode dominance(λ).High concentration of Cu significantly affected structure index(SI)of the nematodes in the farmland soil.In the woodland soil,basic index(BI)was reduced when soil Zn was low in concentration and increased when it was high.SI was also significantly reduced when soil Zn was high in concentration.In the farmland soil,the effect of soil Zn on nematode functional indices varied displaying a wavy trend.Principal component analysis(PCA)shows that in the woodland soil,nematode communities were similar to those in the control soil in all the treatments,except for treatments medium in Cu and/or Zn concentration and high in Zn concentration.In the farmland soil,as affected by treatments,nematode communities differed from those in the control soil.【Conclusion】The soil nematode community in the woodland or farmland soil responds differently to the gradient of Cu and/or Zn contamination.In the woodland soil,the response is embodied mainly in overall abundance of nematodes,while in the farmland soil,it is in community structure,diversity,and ecological indices.The nematode community in the natural woodland soil is high in diversity and more able to tolerate Cu and Zn pollution than that in the farmland soil,which is relatively simple in the soil food web.
作者
李钰飞
李吉进
许俊香
刘本生
乔玉辉
孙钦平
LI Yufei;LI Jijin;XU Junxiang;LIU Bensheng;QIAO Yuhui;SUN Qinping(Institute of Plant Nutrition and Resources,Beijing Academy of Agriculture and Forestry Sciences,Beijing 100097,China;Beijing Key Laboratory for Biodiversity and Organic Farming,College of Resources and Environmental Science,China Agricultural University,Beijing 100193,China)
出处
《土壤学报》
CAS
CSCD
北大核心
2020年第6期1492-1503,共12页
Acta Pedologica Sinica
基金
北京市农林科学院科技创新能力建设专项(KJCX20180708)
奶牛产业技术体系北京市创新团队项目(BAIC06-2019)
北京市生物多样性与有机农业重点实验室开放课题(BOF201906)资助。
