植物学报 ›› 2017, Vol. 52 ›› Issue (3): 307-321.DOI: 10.11983/CBB16109

• 研究报告 • 上一篇    下一篇

季节放牧下内蒙古温带草原羊草根茎叶功能性状的权衡

潘琰1, 龚吉蕊1,*(), 宝音陶格涛2, 罗亲普1, 翟占伟1, 徐沙1, 王忆慧1, 刘敏1, 杨丽丽1   

  1. 1北京师范大学地理科学学部资源学院, 北京师范大学地理科学学部地表过程与资源生态国家重点实验室, 北京 100875
    2内蒙古大学生命科学学院, 呼和浩特 010021
  • 收稿日期:2016-05-12 接受日期:2016-10-16 出版日期:2017-05-01 发布日期:2017-05-27
  • 通讯作者: 龚吉蕊
  • 作者简介:

    # 共同第一作者

  • 基金资助:
    国家自然科学基金(No.41571048)、国家重点基础研究发展计划(No.2014CB138803)和国家重点研发计划(No.2016YFC0500- 502)

Effect of Seasonal Grazing on Trade-off Among Plant Functional Traits in Root, Stem and Leaf of Leymus chinensis in the Temperate Grassland of Inner Mongolia, China

Yan Pan1, Jirui Gong1*, Taogetao Baoyin2, Qinpu Luo1, Zhanwei Zhai1, Sha Xu1, Yihui Wang1, Min Liu1, Lili Yang1   

  1. 1State Key Laboratory of Earth Surface Processes and Resource Ecology, College of Resources Science & Technology, Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China
    2College of Life Sciences, Inner Mongolia University, Hohhot 010021, China
  • Received:2016-05-12 Accepted:2016-10-16 Online:2017-05-01 Published:2017-05-27
  • Contact: Gong Jirui
  • About author:

    # Co-first authors

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(Pn), 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Pn。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 represents the main way for utilization of grassland, and different seasonal grazing affects compensatory growth and regrowth by affecting the trade-off among plant functional traits. To understand the trade-off and variation among the ‘soft’ and ‘hard’ traits under different seasonal grazing, we measured soft traits such as plant height, internode length, and tillers and hard traits such as photosynthetic capacity, antioxidant system and substance contents of osmotic adjustment in root, stem and leaf of Leymus chinensis. Compared with spring grazing, under continuous grazing, L. chinensis adopts stronger avoidance and tolerance strategies. The soft traits and some hard traits, such as photosynthetic capacity, chlorophyII fluorescence characteristics and energy partition show the same trend: net photosynthetic rate decreasing in June and increasing in August. However, the plants have higher photosynthetic product in leaf under spring grazing, which is harmful for regrowth, with vast organic matter contents eaten after grazing. However, under continuous grazing, L. chinensis allocates more to stem and root, which is conducive to uptake water from soil and regrow by using the remaining organic matter. Thus, under three-year grazing, continuous grazing is better for regrowth of L. chinensis and sustainable for grassland.