| 牦牛粪分解及对土壤理化性质、微生物生物量和酶活性的影响 | |
| Alternative Title | YAK DUNG DECOMPOSITION AND ITS EFFECTS ON SOIL PHYSICOCHEMICAL CHARACTERISTICS, MICROBIAL BIOMASS AND ENZYME ACTIVITIES |
| 张志阳 | |
| Subtype | 硕士 |
| Thesis Advisor | 张世挺 |
| 2019-05-05 | |
| Degree Grantor | 兰州大学 |
| Place of Conferral | 兰州 |
| Degree Name | 硕士 |
| Degree Discipline | 生态学 |
| Keyword | 高寒草甸，牦牛粪分解，溶解性碳，溶解性氮，微生物生物量，酶活性 |
| Abstract | 牦牛是青藏高原地区主要畜种，世界上94%以上的牦牛生活在我国青藏高原，约有1330万头。放牧期间，大量的粪便直接沉积在草地表面，成为分解者物质和能量的重要来源以及养分归还草地的主要途径。因此，研究牦牛粪沉积及其分解对理解青藏高原高寒草地生态系统功能，尤其是能量与物质循环，具有重要意义。2017年7月至10月，在兰州大学高寒草甸与湿地生态系统定位研究站（合作站），使用人工模拟牛粪沉积的方法，研究了牦牛粪分解及其对土壤理化性质，微生物生物量和酶活性的影响。主要研究结果如下：（1）经过3个月的分解，牦牛粪质量损失了55.4％，牦牛粪中溶解性有机碳（DOC）和溶解性有机氮（DON）的含量分别减少了83.2％和88.4％。（2）牦牛粪添加增加了土壤含水量、土壤DOC和DON含量，降低了土壤pH值。（3）牦牛粪添加增加了土壤微生物生物量碳（MBC），生物量氮（MBN）和微生物呼吸（SMR），降低了MBC/MBN比值。（4）土壤含水量与微生物生物量之间不存在显著的相关性，而与微生物呼吸成正相关；pH与微生物生物量及微生物呼吸成负相关；DOC和DON与微生物生物量及微生物呼吸成正相关。（5）牦牛粪添加增加了C-循环（β-1,4-葡糖苷酶，β-1,4-木糖苷酶，多酚氧化酶和过氧化物酶）和N-循环（脲酶）相关的酶活性。（6）微生物生物量碳（MBC）和生物量氮（MBN）均与C、N-循环的酶之间存在显著的正相关；土壤微生物呼吸（SMR）与C-循环的酶之间不存在显著的相关性，而与N-循环的酶之间存在极显著的正相关。上述结果表明，牦牛粪沉积增加了土壤养分供应，促进了土壤微生物的生长和活性。因此，牦牛粪沉积加快了高寒草地生态系统的养分循环，对青藏高原高寒生态系统健康的维持具有积极的作用。 |
| Other Abstract | Yak grazing is a prevalent phenomenon in Qinghai-Tibetan plateau, where there are more than 13.3 million domestic yak, a large proportion of dung directly deposit on the surface of the pasture and become an important source of material and energy for the decomposer. Yak dung is considered as a main way to return nutrients to the grassland. Therefore, the study on yak dung deposition and its decomposition is of great importance for understanding ecosystem function of alpine grasslands in the Qinghai-Tibet Plateau, especially material and energy cycling. Using artificially simulated dung deposition, we investigated the decomposition of yak dung and its effects on soil physicochemical characteristics, microbial biomass and enzyme activities from July to October 2017. The experiment was conducted at the Alpine Meadow and Wetland Ecosystem Research Station of Lanzhou University (Hezuo research station). The main findings were as follows:(1) During the whole experiment, the percent mass loss was 55.4%, and the content of dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) decreased by 83.2% and 88.4%, respectively.(2) Yak dung addition increased the soil water content and soil dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) concentration, but decreased soil pH.(3) Yak dung addition increased soil microbial biomass carbon (MBC), microbial biomass nitrogen (MBN) and microbial respiration (SMR), and decreased the ratio of MBC/MBN.(4) Soil water content did not correlate with soil microbial biomass, while positively correlated with soil microbial respiration; soil pH negatively correlated with soil microbial biomass and soil microbial respiration respectively; Both DOC and DON positively correlated with soil microbial biomass and soil microbial respiration, respectively.(5) Yak dung addition increased enzyme activities which were related with C-cycling and N-cycling, for example, β-1, 4-glucosidase, β-1, 4-xylosidase, Polyphenol oxidase, Peroxidase and Urease.(6) There was a significant positive relationship between both microbial biomass carbon (MBC) and microbial biomass nitrogen (MBN) positively correlated with C and N- cycling enzymes; Microbial respiration (SMR) did not correlated with C- cycling enzymes, while positively correlated with N- cycling enzyme.In conclusion, the yak dung deposition increased the supply of soil nutrients and promoted the growth and activity of soil microorganisms. Therefore, yak dung deposition accelerates the nutrient cycling of the alpine grassland ecosystem and facilitate the maintenance of the alpine ecosystem in the Qinghai-Tibet Plateau. |
| Pages | 45 |
| URL | 查看原文 |
| Language | 中文 |
| Document Type | 学位论文 |
| Identifier | https://ir.lzu.edu.cn/handle/262010/342001 |
| Collection | 生命科学学院 |
| Affiliation | 生命科学学院 |
| First Author Affilication | School of Life Sciences |
| Recommended Citation GB/T 7714 | 张志阳. 牦牛粪分解及对土壤理化性质、微生物生物量和酶活性的影响[D]. 兰州. 兰州大学,2019. |
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