【摘要】：皖北地區(qū)是大面積的平原區(qū),擁有90%以上的栽培作物,屬于典型的農(nóng)田土壤生態(tài)系統(tǒng)。由于其受南北氣候雙重影響,旱澇事件頻發(fā),廣發(fā),嚴重影響了農(nóng)田土壤生態(tài)系統(tǒng)的生產(chǎn)能力和穩(wěn)定性。土壤線蟲是農(nóng)田土壤生態(tài)系統(tǒng)的重要組成部分,在維持生態(tài)系統(tǒng)生物多樣性及營養(yǎng)元素循環(huán)過程中發(fā)揮重要作用,是研究未來氣候變化情景下地下生態(tài)系統(tǒng)結(jié)構(gòu)、功能變化的重要指示性生物。因此,旱澇事件對農(nóng)田土壤動物的影響機理是急需了解的核心問題。本研究基于歷史資料分析了皖北地區(qū)旱澇災害發(fā)生的原因,并結(jié)合SPI指數(shù),分析了皖北地區(qū)53年來旱澇事件的時空演變規(guī)律。通過設(shè)置不同的干旱和淹水情景模擬旱澇事件,研究在不同旱澇情景下的農(nóng)田土壤動物群落演變特征。研究得出了以下結(jié)論:皖北地區(qū)由于降水變幅大且蒸發(fā)量大、水資源較少以及社會經(jīng)濟薄弱,造成了該地區(qū)的旱澇災害頻發(fā);在時間尺度水平,皖北地區(qū)的旱澇事情呈現(xiàn)旱澇交替的特點,在夏季偏旱,在其他季節(jié)都偏澇。在空間尺度水平,亳州、淮北宿州皆是旱澇事件的易發(fā)區(qū),旱澇事件在不同季節(jié)有著不同的區(qū)域特點。在干旱處理下鑒定出18科32屬土壤線蟲,其中食細菌線蟲13屬,植物寄生線蟲10屬,食真菌線蟲4屬,雜食-捕食線蟲5屬;其中Eucephalobus和Helicotylenchus是干旱情景下的優(yōu)勢屬。在種群水平,土壤線蟲的數(shù)量和屬數(shù)有所降低,并且隨著干旱時間的增加呈明顯下降趨勢;在營養(yǎng)類群水平,食細菌線蟲和雜食/捕食性線蟲有所減少,而食真菌線蟲和植物寄生線蟲有所增加;在群落多樣性水平,土壤線蟲多樣性有所降低。在不同淹水處理下鑒定出18科32屬土壤線蟲,其中食細菌線蟲13屬,植物寄生線蟲10屬,食真菌線蟲4屬,雜食-捕食線蟲5屬。在種群水平,土壤線蟲的數(shù)量和屬數(shù)有所降低,并且隨著淹水時間的增加呈明顯下降趨勢;在營養(yǎng)類群水平,食細菌線蟲所占百分比基本上變化不大,保持在40%以上,食真菌線蟲所占百分比變化也不是很大,植物寄生線蟲所占百分比增加明顯;在群落多樣性水平,土壤線蟲多樣性有所降低,結(jié)合NCR值可以看出在淹水情景下,食細菌線蟲在土壤分解通道上保持了絕對的優(yōu)勢。
[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.
【學位授予單位】：東華大學
【學位級別】：碩士
【學位授予年份】：2016
【分類號】：S154.5;S42

【參考文獻】

相關(guān)期刊論文 前10條

1 楊志勇;袁U，

本文編號：2136251