青藏高原东部高寒草甸土壤线虫群落对施肥的响应研究

发布时间：2018-03-13 04:15

本文选题：高寒草甸　切入点：线虫群落　出处：《兰州大学》2017年硕士论文　论文类型：学位论文

【摘要】：本文主要以青藏高原东部高寒草甸地区土壤线虫为对象,研究了线虫群落对施氮肥(5g·m-2,10g·m-2,15g·m-2)、施磷肥(2g·m-2,4g·m-2,8g·m-2)、氮磷混合施肥(氮肥固定为10g·m-2,磷肥为2g·m-2,4g·m-2,8g·m-2)的响应,旨在揭示青藏高原高寒草甸土壤线虫群落在人为干扰后,线虫对施氮肥、磷肥、氮磷混合肥的响应和对土壤食物网结构和功能变化的指示作用,为该生态系统的健康持续管理提供依据。研究结果表明:(1)氮磷混合施肥显著增加了土壤线虫的数量,添加氮肥和磷肥对线虫数量没有显著性的影响。施氮肥减少了植物寄生线虫的数量,增加了食真菌线虫的数量,施磷肥增加了食细菌线虫的数量。(2)施氮肥与氮磷混合施肥对土壤线虫的多样性与成熟度指数没有显著影响,施磷肥对线虫多样性、成熟度指数的影响存在年际变化。(3)添加少量氮肥、施磷肥和添加大量氮磷混合肥条件下土壤食物网更复杂,更趋向于稳定状态,食物网由退化状态逐渐变为结构化状态,分解途径主要以真菌为主。施氮肥10g·m-2,磷肥4g·m-2条件下,线虫在代谢过程中对碳的利用率最高,对低营养级有调节功能。线虫群落与区系组成的变化能够通过改变土壤食物网的结构和养分分解途径影响土壤生态系统的功能。(4)不同线虫的体积大小对土壤养分的响应不同,线虫体积加权平均值能够为土壤生态系统线虫群落对环境干扰的响应提供一个衡量的指标。
[Abstract]:In this paper, the responses of nematode communities to nitrogen fertilizer 5g 路m ~ (-2) ~ (10) g 路m ~ (-2) ~ (-1) ~ (15) g 路m ~ (-2) ~ (-1), N ~ (2 +) ~ (2) ~ (-1) ~ (-1) ~ (-1) ~ (-1) ~ (-1) ~ (-1) ~ (-1) ~ (-1) ~ (-1) ~ (-1) ~ (-1) ~ (-1) ~ (-1) ~ (-1) ~ (-1) in the alpine meadow area of Qinghai-Xizang Plateau were studied. The responses of nematode communities to nitrogen fertilizer application were studied. In order to reveal the response of nematode communities in alpine meadow soil to nitrogen fertilizer, phosphorus fertilizer, nitrogen and phosphorus mixed fertilizer, and to indicate the change of structure and function of soil food web, the response of nematode community to nitrogen fertilizer, phosphorus fertilizer, nitrogen and phosphorus mixed fertilizer and soil nematode community in alpine meadow were revealed. The results showed that nitrogen and phosphorus mixed fertilization significantly increased the number of soil nematodes. The addition of nitrogen fertilizer and phosphorus fertilizer had no significant effect on the number of nematodes. Applying nitrogen fertilizer reduced the number of plant parasitic nematodes and increased the number of fungal nematodes. Application of phosphorus fertilizer increased the number of bacterial nematodes. (2) nitrogen fertilizer and nitrogen and phosphorus mixed fertilization had no significant effect on the diversity and maturity index of soil nematodes, but phosphorus fertilizer had no significant effect on the diversity of nematodes. The effect of maturity index is interannual variation. (3) adding a small amount of nitrogen fertilizer, the soil food web is more complex and more stable under the condition of applying phosphorus fertilizer and adding a large amount of nitrogen and phosphorus mixed fertilizer, and the food web gradually changes from degraded state to structured state. Under the conditions of 10 g 路m ~ (-2) N fertilizer and 4 g 路m ~ (-2) phosphate fertilizer, nematodes had the highest carbon utilization rate during metabolism. The change of nematode community and floristic composition can affect the function of soil ecosystem by changing the structure of soil food web and nutrient decomposition pathway. The weighted average of nematodes volume can provide an index to measure the response of nematode communities to environmental disturbance in soil ecosystem.
【学位授予单位】：兰州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S812.2

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