季节性放牧对黄河源区高寒草甸植被耗水量及水分利用效率的影响

发布时间：2018-04-16 04:00

本文选题：高寒草甸 + 季节性放牧　；参考：《冰川冻土》2017年01期

【摘要】：研究季节性放牧对植被耗水量、水分利用效率的影响,是探索如何提高高寒草甸水源涵养能力的重要内容之一。以青藏高原三江源高寒草甸季节性放牧样地与自然放牧样地为研究对象,分析了季节性放牧和自然放牧条件下高寒草甸植被耗水量、水分盈亏量、水分利用效率(WUE)的动态变化及其与环境因素的关系。结果表明:在植被生长季(5-9月),季节性放牧样地和自然放牧样地植被耗水量在5月开始增加,7月达最高,分别为160.94 mm和145.96 mm,季节性放牧样地植被总耗水量(395.52 mm)比自然放牧样地(348.14 mm)高13.61%。生长季平均来看,季节性放牧样地和自然放牧样地5-9月水分正盈余,分别为13.58 mm和70.96 mm,但在植物生长旺季(8月)略有亏缺。季节性放牧样地和自然放牧样地植被耗水量均与降水量呈弱的正相关关系。季节性放牧样地植被地上净初级生产量(ANPP)、地下净初级生产量(BNPP)和总的净初级生产量(NPP)比自然放牧样地分别高32.54 g·m~(-2)、5.96 g·m~(-2)、38.50 g·m~(-2),季节性放牧样地ANPP的水分利用效率(WUE)比自然放牧样地高53.85%,而BNPP、NPP的WUE比自然放牧样地分别低13.06%和9.97%。这表明,季节性放牧可提高植被生产量和耗水量,但对高寒草甸WUE的影响因放牧方式不同导致地上、地下生物量分配格局不同而有所差异。
[Abstract]:Study on seasonal grazing on vegetation water consumption, influence of water use efficiency, is one of the important contents to explore how to improve the water conservation ability. Alpine meadow on the Tibetan Plateau alpine meadow in Sanjiang source of seasonal grazing land and natural grazing land as the research object, analyzes the seasonal grazing and natural grazing alpine meadow vegetation water consumption, water budget, water use efficiency (WUE) and the relationship between the changes of environmental factors. The results showed that during the growth season of vegetation (5-9 months), seasonal grazing land and natural grazing land vegetation water consumption in May began to increase and reached the highest in July, 160.94 mm and 145.96 mm respectively. Seasonal grazing land vegetation, the total water consumption (395.52 mm) than the natural grazing land (348.14 mm) high 13.61%. growth season average, seasonal grazing land and natural grazing land 5-9 month water is surplus, respectively 13.5 8 mm and 70.96 mm, but in the growing season of plants (August). A slight deficit seasonal grazing land and natural grazing land vegetation water consumption showed a weak positive correlation with precipitation. The seasonal grazing land vegetation aboveground net primary production (ANPP), belowground net primary production (BNPP) and total net primary production (NPP) than the natural grazing plots were higher 32.54 G - m~ (-2), 5.96 G - m~ (-2), 38.50 G - m~ (-2), seasonal grazing land water use efficiency of ANPP (WUE) is 53.85% higher than that of natural grazing land and BNPP, NPP WUE were lower than the natural grazing plots 13.06% and 9.97%. which showed that seasonal grazing can improve vegetation production and water consumption, but the effect on WUE by grazing in alpine meadow in different ways to the ground, underground biomass allocation patterns vary.

【作者单位】：中国科学院西北高原生物研究所;中国科学院大学;中国科学院高原生物适应与进化重点实验室;
【基金】：国家重点研发计划项目(2016YFC0501802) 中国科学院战略性先导科技专项(XDB03030502) 青海省自然科学基金项目(2016-ZJ-943Q)资助
【分类号】：S812

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