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作 者 ：马银山,杜国祯,张世挺*

期 刊 ：生态学报 2010年 30卷 2期 页码：279~287

关键词：施肥；刈割；地上生物量；补偿生长；冷地早熟禾；

Keywords:fertilization, clipping, aboveground biomass, compensation growth, Poa crymophila,

摘 要 ：以青藏高原东部高寒草甸常见牧草冷地早熟禾（Poa crymophila）为研究对象,比较研究了肥力和不同刈割处理对植物生长和生物量补偿的影响。实验采用随机设计，肥力分为施肥和不施肥，刈割处理为刈割时间、刈割频度和刈割强度3因子组合。结果表明：不刈割情况下，施肥显著促进冷地早熟禾的生长，而在刈割情况下，施肥对植物的生长没有明显的促进作用甚至有负作用。不施肥，刈割可促进冷地早熟禾地上生物量的增加并发生超补偿，但补偿程度因刈割强度、刈割频度和刈割时间而异；施肥时，刈割没有或很少促进植株发生超补偿。超补偿发生时，资源贫瘠的条件可能是必需的。冷地早熟禾发生超补偿可能是以损耗地下部分的资源为代价的，刈割刺激分蘖的增加对超补偿的发生也有一定的贡献。

Abstract:A study was conducted with Poa crymophila, a common grass of alpine meadows of the eastern Tibetan Plateau, to examine the effects of fertilization and clipping on compensatory growth. A factorial field experiment was conducted with seventy-eight 1.3×0.8 m plots subjected to 24 treatment combinations (2 fertilization×2 first clipping time×3 clipping frequency×2 clipping intensity), with one unclipping control treatment. Our results showed that fertilization tended to promote growth of Poa crymophila only in the absence of clipping. Clipping led to increased aboveground biomass and over-compensation in the absence of fertilization，but the degree of compensation depended on intensity, frequency and time of clipping. It may be that a poor resource supply is necessary for over-compensatory growth to occur. We considered two mechanisms as explanations for over-compensatory growth of Poa crymophila: the consumption of underground resources and an increase in the numbers of tillers.

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