季节放牧下内蒙古温带草原羊草根茎叶功能性状的权衡

发布时间：2018-03-17 21:00

  本文选题：软性状　切入点：气体交换　出处：《植物学报》2017年03期 　论文类型：期刊论文

【摘要】：放牧是草地主要利用方式之一,不同季节放牧通过影响草地功能性状间的权衡从而影响牧后再生及补偿性生长。通过测定内蒙古温带草原优势种羊草(Leymus chinensis)的株高、节间距和分蘖数等软性状及气体交换、抗氧化酶系统和根茎叶渗透调节物质的含量等硬性状,分析了不同季节放牧处理下羊草功能性状的变化及其权衡关系。结果表明,3年短期放牧处理下,类连续放牧(T1)比春季放牧样地(T2)羊草表现出更强的避牧性与耐牧性。类连续放牧与春季放牧样地羊草软性状及光合特性表现出一致性,6月放牧干扰降低了羊草的净光合速率(P_n),8月放牧干扰通过增加电子传递速率(ETR)及光系统Ⅱ(PSⅡ)分配于光化学反应(P)的比值等增大P_n。但春季放牧样地羊草株高较高,且光合产物较多分配于叶片,导致大量有机物质被啃食,不利于牧草再生。而类连续放牧羊草将较多的有机物质分配于根茎,有利于牧草根系吸水及牧后再生。因此,3年短期放牧处理下,类连续放牧更有利于牧草再生及草原的可持续利用。
[Abstract]:Grazing is one of the main ways of grassland utilization. Grazing in different seasons affects regeneration and compensatory growth after grazing by affecting the trade-offs between functional traits of grassland. The plant height of Leymus chinensis, a dominant cultivator in temperate grassland of Inner Mongolia, was determined. Soft characters, such as pitch of nodes and number of tillers, gas exchange, antioxidant enzyme system and content of osmotic regulator in rhizome and leaf, etc. The changes of functional traits of Leymus chinensis under different season grazing treatments and their trade-offs were analyzed. Compared with spring grazing plots, Leymus chinensis showed stronger grazing avoidance and tolerance. The soft characters and photosynthetic characteristics of Leymus chinensis were consistent with those of spring grazing land. In June, grazing disturbance decreased the grazing ability of Leymus chinensis. In August, the ratio of grazing disturbance to photochemical reaction (P) was increased by increasing electron transfer rate (ETR) and photochemical reaction (PS 鈪，

本文编号：1626450