刈割强度对伊犁绢蒿叶功能性状及构件的影响

以新疆荒漠草地典型植物种伊犁绢蒿(Seriphidiumt ransiliense)为研究对象,通过生长季内多次采样方法(每30d采样一次),比较不同刈割强度比叶面积、叶干物质含量的变化及相互关系,以及对茎叶比和地下生物量变化的影响,以揭示伊犁绢蒿叶片对刈割胁迫的最佳响应机制,为建立模型估算单位面积生物生产力提供理论依据,并试图得出一个既可合理利用又利于种群更新的刈割强度阈值。结果表明,比叶面积和叶干物质含量在刈割后初期各刈割强度间存在显著性差异(P<0.05),个别达极显著差异(P<0.01),恢复一段时间后,各刈割强度间差异不显著;适度的刈割强度可增大伊犁绢蒿SLA与LDMC之间的相关性;除对照(CK)外,C2处理处于较高水平,说明适度刈割有助于伊犁绢蒿生殖枝的产生及生长,C2这种刈割强度在实际生产利用上占绝对优势;伊犁绢蒿根系干重随着刈割强度增大而增加。

Influence on Leaf Function Traits and Modules of Mowing Intensity in Seriphidum transiliense

We investigated the typical plant-Seriphidiumt ransiliense in Xinjiang desert grassland with interval 30 days sampling in 2009.To understand the distribution and the best repose mechanism of its leaves in mowing intensities,we designed four different mowing intensities and analyzed the effect of treatments to SLA,LDMC,their correlation,stem-leaf ratio and underground biomass.The results showed that SLA and LDMC under different mowing intensity had significant difference(P<0.05) or extreme significant difference(P<0.01) after mowing early days.Meanwhile,different four treatments had a slight difference after a long period of time.The correlation coefficient between SLD and LDMC increased under proper mowing intensity.Stem/leaf ratio showed higher level of C2 but CK,which showed Seriphidum transiliense could produce new procreation twigs under a proper mowing intensity.Root dry matter increased along with mowing intensities.So C2 was a relative proper treatment for production.Whether a certain mowing intensity threshold could reasonably use grassland and renew population was verified.The research provided basic theories to guide practical production and theoretical basis for model building of unit leaf area productivity.