森林土壤螨类群落结构及多样性对气候变化的响应

发布时间：2018-07-08 14:52

本文选题：甲螨 + 中期门螨　；参考：《西南民族大学》2016年硕士论文

【摘要】：土壤螨类是陆地态系统的重要分解者,对C、N等物质循环起重要调控作用,因此螨类对气候变化的响应可以影响生态系统的结构和功能。但目前关于土壤螨类对气候变化的响应机制并不清楚。2013年12月利用土柱移植法将贡嘎山东坡海拔3200 m的土柱分别移植到2800 m、2400 m、2000 m和1600 m处实现自然增温,并对移植土柱采取控制降水和凋落物(CT1)和不控制降水和凋落物(CT2)两种处理分别研究温度增加其他条件不变、以及温度、降水和植被等环境条件都变情况下土壤螨类的响应。2014年12月分别对5个海拔梯度的CT1、CT2两组移植土柱和各海拔对照林地(CK)(代表长期适应的稳定结果)的土壤螨类群落及环境因子进行了调查,主要研究结果如下。不同处理对土壤理化性质影响不同。CT1组中仅土壤pH随温度增加而显著下降;CT2组中的土壤有机质、全氮、有效磷、有效钾和全钾含量均随温度增加而显著上升,土壤pH变化趋势不同,表现为在移植梯度2400 m显著高于其他梯度,而其他移植梯度间无显著差异;CK组各海拔梯度中土壤pH、有机质、全磷、全钾和有效氮变化趋势不同且存在显著差异。表明气候植被等因素综合作用对土壤理化性质影响较强,而单一温度变化对土壤理化性质影响较弱。不同处理组土壤螨类群落组成类群存在差异。盖头甲螨属(Tectocepheus)是3种处理组的共同优势类群,赤螨科(Erythacidae)是CT1和CT2组的优势类群,CT1、CT2和CK分别有特有类群13、3和42属。总类群数和总个体数大小顺序为CK(107属1755只)CT1(63属1026只)CT2(26属476只)。主成分分析(PCA)结果表明CT1组梯度3200 m、2800 m、2400 m、2000 m和1600 m间土壤螨类群落结构差异明显;CT2组中海拔3200 m的土壤螨类群落结构与2800 m和2400 m比较相似,与移植梯度2000 m和1600 m的差异较大;CK组海拔3200 m、2800 m、2000 m和1600 m间的土壤螨类群落结构差异明显,而海拔2400 m与2800 m、2000 m间群落结构相似。观测结果表明气候变化能够影响土壤螨类群落组成结构,并受温度变化幅度、凋落物和降水等环境因子的影响。随温度增加,CT1和CT2组土壤螨类群落密度均呈显著增加,但CK组密度变化趋势不同,表现为从2800 m至1600 m间逐渐下降,但仍显著高于3200 m。三组处理土壤螨类的类群数和Shannon-Wiener均随温度增加而显著增加。三组间的群落密度、类群数和Shannon-Wiener指数均表现为CKCT1CT2(P0.01),均匀度和优势度指数无明显变化趋势。密度和多样性指数的变化表明气候变暖能显著增加土壤螨类群落密度和多样性,温度增加对土壤动物的影响比温度、降水及凋落物等综合作用更明显。不同螨类对气候变化的响应也不同。CK组各梯度间的中气门螨类群落结构和多样性差异最大,甲螨差异最小;CT1组各移植梯度间甲螨群落结构和多样性变化最大,中气门螨类变化最弱;CT2组的中气门螨类群落结构和多样性变化最大,前气门螨类变化最弱。中气门螨类的MI指数表明温度升高还可以增加捕食性K-选择螨类数量。不同螨类受环境影响也不同,在3种处理中均是甲螨受环境影响最强,表明甲螨对土壤环境变化最敏感,可作为气候变化的指示生物。多元回归分析结果表明,不同处理组螨类所受的环境影响因子不同。CT1组各移植梯度中土壤螨类群落受土壤pH、有效钾和温度影响显著;CT2组土壤螨类群落受pH、全氮、有效钾和全钾影响显著;CK组土壤螨类群落受pH值、土壤全氮、全钾、空气湿度和土壤温度影响显著。土壤螨类与环境因子关系表明单一温度变化或温度、降水量、植被等变化综合作用可以通过改变土壤化学性质对土壤螨类群落产生影响。以上研究结果表明增温及其与降水植被等综合作用可以改变森林土壤螨类群落组成、提高群落多样性及密度,促进生态系统的物质循环,因此气候变化将对土壤生态系统的结构和功能产生较大影响。
[Abstract]:Soil mite is an important decomposer of the terrestrial system, which plays an important role in regulating the circulation of C and N. Therefore, the response mechanism of mite to climate change can affect the structure and function of the ecosystem. However, the response mechanism of soil mite to climate change is not clear at present in December by using soil column transplantation in Shandong slope of Gongga 3. 200 m soil columns were transplanted to 2800 m, 2400 m, 2000 m and 1600 m to achieve natural temperature increase, and two treatments of controlled precipitation and litter (CT1) and no control of precipitation and litter (CT2) were used to study the other conditions of temperature increase, as well as temperature, precipitation, vegetation and other environmental conditions. The soil mite communities and environmental factors of 5 altitudinal CT1, CT2 two groups and altitudinal control woodland (CK) were investigated in December of.2014. The main results were as follows. The effects of different treatments on soil physical and chemical properties in different.CT1 groups were significantly increased with the increase of temperature in the soil. The soil organic matter, total nitrogen, available P, available K and total K in the CT2 group increased significantly with the increase of temperature, and the change trend of soil pH was different, which showed that the 2400 m in the transplant gradient was significantly higher than the other gradient, but there was no significant difference between the other gradients, and the soil pH, organic matter, total phosphorus, total potassium and available nitrogen in the CK group were pH. The change trend is different and there are significant differences. It shows that the influence of climatic vegetation and other factors on soil physical and chemical properties is stronger, but single temperature change has a weak influence on soil physical and chemical properties. There are differences in soil mites community composition in different treatment groups. Tectocepheus is the common dominant group of 3 treatment groups, red mite. Family (Erythacidae) is the dominant group in CT1 and CT2 groups, CT1, CT2 and CK have specific groups 13,3 and 42 genera respectively. The total and total number of groups are CK (107 genera 1755) CT1 (63 genera 1026) CT2 (26 genera 476). Principal component analysis (PCA) results show that CT1 group gradient 3200, 2800, 2400, 2000, and 1600 soil mites structure differences Obviously, the soil mite community structure of 3200 m in the CT2 group was similar to that of 2800 m and 2400 m. The soil mite community structure in the CK group was 3200 m, 2800 m, 2000 m and 1600 m, while the altitude 2400 m and 2800 and 2000 community structure were similar. The observation results showed climate change. The density of soil mite communities in CT1 and CT2 groups increased significantly with the increase of temperature, but the trend of density variation in the CK group was different from 2800 m to 1600 m, but it was still significantly higher than that of 3200 M. three groups. The number and Shannon-Wiener of the soil mites increased significantly with the increase of temperature. The community density, the group number and the Shannon-Wiener index of the three groups were all CKCT1CT2 (P0.01), and the evenness and dominance index had no obvious change trend. Diversity, the effect of temperature increase on Soil animals was more obvious than temperature, precipitation and litter. The response of different mites to climate change was different in the.CK group, and the diversity of mite community was the largest, and the difference of mite was the smallest. The structure and diversity of mite community in the CT1 group were the most. The change of mites was the weakest, and the structure and diversity of mite community in the CT2 group had the greatest change, and the change of the front mite was the weakest. The MI index of mite mites showed that the increase in temperature could also increase the number of predatory K- selection mites. The different mite was also affected by the environment, and the 3 treatments were all the most affected by the environment. It shows that mite is most sensitive to soil environmental changes and can be used as a indicator of climate change. The results of multiple regression analysis show that the soil mite communities in different.CT1 groups are affected by soil pH, effective potassium and temperature, and the soil mite community in group CT2 is affected by pH, total nitrogen and effective potassium. The effect of soil mite community in CK group was significantly affected by pH value, total nitrogen, total potassium, air humidity and soil temperature. The relationship between soil mites and environmental factors indicates that the effects of change or temperature, precipitation and vegetation on soil mite community can be influenced by the change of soil chemical properties. The results show that the combined effect of increasing temperature and its vegetation can change the composition of mite community in the forest soil, improve the community diversity and density, and promote the material circulation of the ecosystem, so the climate change will have a great influence on the structure and function of the soil ecosystem.
【学位授予单位】：西南民族大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：S714.3

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