放牧强度对高寒草甸群落碳氮磷化学计量特征的影响

发布时间：2018-06-27 02:53

本文选题：放牧强度 + 高寒草甸　；参考：《草业科学》2017年03期

【摘要】：植被生态化学计量特征是高寒草甸生态系统稳定性的基础,但其对放牧管理的响应仍不清楚。为此,以2011年在青海海北高寒矮嵩草(Kobresia humilis)草甸建立的不同放牧强度试验地为研究对象,于2014年植物生长季的5月-9月,通过测定禁牧(对照,CK)、轻度放牧(light grazing,LG)、中度放牧(moderate grazing,MG)和重度放牧(heavy grazing,HG)样地的地上植被生产力和植被群落结构及群落叶片碳(carbon,C)、氮(nitrogen,N)、磷(phosphorus,P)含量,研究放牧强度对高寒草甸群落生态化学计量的影响。结果表明,MG能显著提高地上生物量和优良牧草禾草类植物的生物量比例,C含量的变异均在MG处理下最大,此结果支持了中度干扰理论;重牧能显著提高群落叶片的N含量(P0.05);放牧管理对叶片P含量的影响无明显规律;禁牧有利于系统N和P的周转。本研究结果显示,适度的放牧强度有利于高寒草甸生产力的提高,而禁牧可能通过改变群落优势种增强系统的N、P循环强度。
[Abstract]:The ecological stoichiometric characteristics of vegetation is the basis for the stability of alpine meadow ecosystem, but its response to grazing management is still unclear. Therefore, the experiment land of different grazing intensities established in 2011 in the meadow of Kobresia humilis in Haibei Qinghai Province was used as the research object, and the plant growth season was May-September of 2014. The aboveground vegetation productivity, vegetation community structure and the contents of carbon (C C), nitrogen (N), phosphorus (P) in leaves of forbidden grazing (CK), light grazing (LG), moderate grazing (moderate grazing MG) and heavy grazing (heavy grazing HG) were measured. The effects of grazing intensity on ecological stoichiometry of alpine meadow community were studied. The results showed that the variation of C content in aboveground biomass and fine forage grasses was the largest under MG treatment, which supported the theory of moderate interference. Heavy grazing could significantly increase the N content of leaves (P0.05); grazing management had no obvious effect on P content of leaves; forbidding grazing was beneficial to the turnover of N and P. The results showed that the moderate grazing intensity was beneficial to the productivity of alpine meadow, while forbidding grazing might enhance the NNP cycle intensity of the system by changing the dominant species of the community.
【作者单位】：中国科学院西北高原生物研究所;中国科学院高原生物适应与进化重点实验室;青海大学环境工程学院;中国科学院大学;
【基金】：国家自然基金项目(31300385、31270523) 青海省国际科技合作项目(2015-HZ-804)
【分类号】：S812

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