植物生态学报 ›› 2014, Vol. 38 ›› Issue (8): 878-887.DOI: 10.3724/SP.J.1258.2014.00082

• 研究论文 • 上一篇    下一篇

不同载畜率下瓣蕊唐松草的生长和繁殖对策

乔丽青1,2, 田大栓2, 万宏伟2, 宝音陶格涛1,*(), 潘庆民2,*()   

  1. 1内蒙古大学生命科学学院, 呼和浩特 010021
    2中国科学院植物研究所植被与环境变化国家重点实验室, 北京 100093
  • 收稿日期:2014-04-15 接受日期:2014-05-22 出版日期:2014-08-01 发布日期:2014-08-18
  • 通讯作者: 宝音陶格涛,潘庆民
  • 作者简介:bytgtnm@126.com
    * E-mail: pqm@ibcas.ac.cn;
  • 基金资助:
    国家科技支撑计划(2011BAC07B01);中国科学院知识创新工程方向项目(KSCX2-EW-Z-5)

Growth and reproductive strategies of Thalictrum petaloideum under different stocking rates

QIAO Li-Qing1,2, TIAN Da-Shuan2, WAN Hong-Wei2, BAOYIN Taogetao1,*(), PAN Qing-Min2,*()   

  1. 1College of Life Science, Inner Mongolia University, Hohhot 010021, China
    2State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
  • Received:2014-04-15 Accepted:2014-05-22 Online:2014-08-01 Published:2014-08-18
  • Contact: BAOYIN Taogetao,PAN Qing-Min

摘要:

放牧是内蒙古草原最主要的利用方式, 而草原植物在不同放牧压力下的生长和繁殖策略是它们与有蹄类动物长期协同进化的结果。为了了解瓣蕊唐松草(Thalictrum petaloideum)的生长和繁殖策略如何响应载畜率的变化, 作者依托中国科学院内蒙古草原站的大型放牧实验平台, 从种群、个体和器官三个组织水平上研究了该物种对放牧强度的响应。结果表明: 1)在种群水平上, 随着载畜率的增加, 瓣蕊唐松草减少了生殖株丛数或不进行有性生殖生长。该实验条件下, 载畜率每hm 2 7.5只羊(夏季)是瓣蕊唐松草不再进行生殖生长的阈值; 2)在个体水平上, 随着载畜率的增加, 瓣蕊唐松草降低了株高和个体生物量, 减少了生殖枝、花朵和种子等生殖器官的数量。随着载畜率的增加, 瓣蕊唐松草生殖分配的调节从依赖于植株个体大小向不依赖于植株个体大小转变。3)在器官水平上, 随着载畜率的增加, 瓣蕊唐松草减少了生殖枝的花朵负荷, 提高了单粒质量。籽粒数量和籽粒质量之间的权衡是瓣蕊唐松草应对放牧干扰的重要机制。

关键词: 放牧, 多年生杂类草, 种群, 生殖分配, 典型草原

Abstract:

Aims Grazing is one of the major measures for grassland management in Nei Mongol steppe. The growth and reproductive strategies of grassland plants are developed under their long-term co-evolution with ungulates in grassland ecosystems. This study was conducted to understand how Thalictrum petaloideum would change its growth and reproductive strategies with increasing stocking rate.
Methods By using a grazing experiment in a typical steppe ecosystem initiated by the Nei Mongol Grassland Ecosystem Research Station in 2006, we examined the responses of T. petaloideum to stocking rates at population, individual and organ levels during the 2012 and 2013 growing seasons.
Important findings With increasing stocking rate, the number of reproductive individuals decreased and the reproductive process ceased in T. petaloideum at the population level. The threshold for ceasing the reproductive process was at a stocking rate of 7.5 sheep per hm 2. The plant height, plant biomass and the numbers of reproductive branches, flowers and seeds all decreased with increasing stocking rate at an individual level. Two shifts were detected for the reproductive allometric relationships with increases in stocking rate. With the increase of stocking rates, T. petaloideum reduced the number of flowers per reproductive branch decreased but the individual seed weight increased with increasing stocking rate at the organ level. A trade-off between the number of seed and the weight of seed was found, which might be an important mechanism in T. petaloideum responding to grazing disturbance.

Key words: grazing, perennial forbs, population, reproductive allocation, typical steppe