旱涝事件对皖北地区农田土壤动物的影响机理
发布时间：2018-07-21 17:26
【摘要】：皖北地区是大面积的平原区,拥有90%以上的栽培作物,属于典型的农田土壤生态系统。由于其受南北气候双重影响,旱涝事件频发,广发,严重影响了农田土壤生态系统的生产能力和稳定性。土壤线虫是农田土壤生态系统的重要组成部分,在维持生态系统生物多样性及营养元素循环过程中发挥重要作用,是研究未来气候变化情景下地下生态系统结构、功能变化的重要指示性生物。因此,旱涝事件对农田土壤动物的影响机理是急需了解的核心问题。本研究基于历史资料分析了皖北地区旱涝灾害发生的原因,并结合SPI指数,分析了皖北地区53年来旱涝事件的时空演变规律。通过设置不同的干旱和淹水情景模拟旱涝事件,研究在不同旱涝情景下的农田土壤动物群落演变特征。研究得出了以下结论:皖北地区由于降水变幅大且蒸发量大、水资源较少以及社会经济薄弱,造成了该地区的旱涝灾害频发;在时间尺度水平,皖北地区的旱涝事情呈现旱涝交替的特点,在夏季偏旱,在其他季节都偏涝。在空间尺度水平,亳州、淮北宿州皆是旱涝事件的易发区,旱涝事件在不同季节有着不同的区域特点。在干旱处理下鉴定出18科32属土壤线虫,其中食细菌线虫13属,植物寄生线虫10属,食真菌线虫4属,杂食-捕食线虫5属;其中Eucephalobus和Helicotylenchus是干旱情景下的优势属。在种群水平,土壤线虫的数量和属数有所降低,并且随着干旱时间的增加呈明显下降趋势;在营养类群水平,食细菌线虫和杂食/捕食性线虫有所减少,而食真菌线虫和植物寄生线虫有所增加;在群落多样性水平,土壤线虫多样性有所降低。在不同淹水处理下鉴定出18科32属土壤线虫,其中食细菌线虫13属,植物寄生线虫10属,食真菌线虫4属,杂食-捕食线虫5属。在种群水平,土壤线虫的数量和属数有所降低,并且随着淹水时间的增加呈明显下降趋势;在营养类群水平,食细菌线虫所占百分比基本上变化不大,保持在40%以上,食真菌线虫所占百分比变化也不是很大,植物寄生线虫所占百分比增加明显;在群落多样性水平,土壤线虫多样性有所降低,结合NCR值可以看出在淹水情景下,食细菌线虫在土壤分解通道上保持了绝对的优势。
[Abstract]:Northern Anhui is a large plain area with more than 90% of cultivated crops, which belongs to the typical farmland soil ecosystem. Due to the influence of the north and south climate, the frequent and widespread drought and flood events have seriously affected the productivity and stability of the farmland soil ecosystem. Soil nematode is an important component of farmland soil ecosystem, which plays an important role in maintaining ecosystem biodiversity and nutrient cycling. It is also used to study the structure of underground ecosystem in future climate change scenarios. An important indicator of functional change. Therefore, the influence mechanism of drought and flood events on farmland soil animals is the core problem that needs to be understood. Based on the historical data, this study analyzed the causes of drought and flood disasters in northern Anhui, and analyzed the temporal and spatial evolution of drought and flood events in the past 53 years in northern Anhui with SPI index. By setting up different drought and flood scenarios to simulate the drought and flood events, the evolution characteristics of soil fauna communities in farmland under different drought and flood scenarios were studied. The conclusions are as follows: the drought and waterlogging disasters occur frequently in the north of Anhui Province due to the large variation of precipitation, large evaporation, less water resources and weak social economy; at the time scale level, the drought and flood disasters occur frequently in this area. The drought and waterlogging in northern Anhui show the characteristics of alternate drought and flood, which are partial to drought in summer and waterlogging in other seasons. At the spatial scale level Bozhou and Huai Bei Suzhou are prone areas of drought and flood events and drought and flood events have different regional characteristics in different seasons. Under drought treatment, soil nematodes belonging to 32 genera belonging to 18 families were identified, including 13 genera of bacterial nematodes, 10 genera of plant parasitic nematodes, 4 genera of fungal nematodes, 5 genera of omnivorous and predatory nematodes, among which Eucephalobus and Helicotylenchus were the dominant genera in drought scenarios. At the population level, the number and genera of soil nematode decreased, and with the increase of drought time, the number of bacterial nematode and omnivorous / predatory nematode decreased. But the edible fungi nematodes and plant parasitic nematodes increased, and the soil nematode diversity decreased at the community diversity level. Soil nematodes belonging to 32 genera of 18 families were identified under different flooding treatments, including 13 genera of bacteriophagous nematodes, 10 genera of plant parasitic nematodes, 4 genera of fungal nematodes and 5 genera of omnivorous and predatory nematodes. At the population level, the number and genus of soil nematode decreased, and with the increase of flooding time, the percentage of bacterial nematodes decreased significantly, and the percentage of bacterial nematodes remained above 40%. The percentage of fungal nematodes did not change significantly, but the percentage of plant parasitic nematodes increased significantly, and the diversity of soil nematodes decreased at the community diversity level. Bacteriophagous nematodes maintain an absolute advantage in soil decomposition pathways.
【学位授予单位】：东华大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：S154.5;S42
[Abstract]:Northern Anhui is a large plain area with more than 90% of cultivated crops, which belongs to the typical farmland soil ecosystem. Due to the influence of the north and south climate, the frequent and widespread drought and flood events have seriously affected the productivity and stability of the farmland soil ecosystem. Soil nematode is an important component of farmland soil ecosystem, which plays an important role in maintaining ecosystem biodiversity and nutrient cycling. It is also used to study the structure of underground ecosystem in future climate change scenarios. An important indicator of functional change. Therefore, the influence mechanism of drought and flood events on farmland soil animals is the core problem that needs to be understood. Based on the historical data, this study analyzed the causes of drought and flood disasters in northern Anhui, and analyzed the temporal and spatial evolution of drought and flood events in the past 53 years in northern Anhui with SPI index. By setting up different drought and flood scenarios to simulate the drought and flood events, the evolution characteristics of soil fauna communities in farmland under different drought and flood scenarios were studied. The conclusions are as follows: the drought and waterlogging disasters occur frequently in the north of Anhui Province due to the large variation of precipitation, large evaporation, less water resources and weak social economy; at the time scale level, the drought and flood disasters occur frequently in this area. The drought and waterlogging in northern Anhui show the characteristics of alternate drought and flood, which are partial to drought in summer and waterlogging in other seasons. At the spatial scale level Bozhou and Huai Bei Suzhou are prone areas of drought and flood events and drought and flood events have different regional characteristics in different seasons. Under drought treatment, soil nematodes belonging to 32 genera belonging to 18 families were identified, including 13 genera of bacterial nematodes, 10 genera of plant parasitic nematodes, 4 genera of fungal nematodes, 5 genera of omnivorous and predatory nematodes, among which Eucephalobus and Helicotylenchus were the dominant genera in drought scenarios. At the population level, the number and genera of soil nematode decreased, and with the increase of drought time, the number of bacterial nematode and omnivorous / predatory nematode decreased. But the edible fungi nematodes and plant parasitic nematodes increased, and the soil nematode diversity decreased at the community diversity level. Soil nematodes belonging to 32 genera of 18 families were identified under different flooding treatments, including 13 genera of bacteriophagous nematodes, 10 genera of plant parasitic nematodes, 4 genera of fungal nematodes and 5 genera of omnivorous and predatory nematodes. At the population level, the number and genus of soil nematode decreased, and with the increase of flooding time, the percentage of bacterial nematodes decreased significantly, and the percentage of bacterial nematodes remained above 40%. The percentage of fungal nematodes did not change significantly, but the percentage of plant parasitic nematodes increased significantly, and the diversity of soil nematodes decreased at the community diversity level. Bacteriophagous nematodes maintain an absolute advantage in soil decomposition pathways.
【学位授予单位】：东华大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：S154.5;S42
【参考文献】
相关期刊论文 前10条
1 杨志勇;袁U，
本文编号：2136251
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