植物生态学报 ›› 2022, Vol. 46 ›› Issue (9): 1018-1026.DOI: 10.17521/cjpe.2022.0134

所属专题: 青藏高原植物生态学:种群生态学

• 研究论文 • 上一篇    下一篇

放牧方式影响高寒草地矮生嵩草种子大小与数量的关系

董全民1,2(), 赵新全2,3, 刘玉祯1, 冯斌1, 俞旸1, 杨晓霞1, 张春平1, 曹铨1, 刘文亭1,*()   

  1. 1青海大学畜牧兽医科学院, 青海省畜牧兽医科学院, 青海省高寒草地适应性管理重点实验室, 西宁 810016
    2青海大学省部共建三江源生态与高原农牧业国家重点实验室, 西宁 810016
    3中国科学院西北高原生物研究所, 西宁 810008
  • 收稿日期:2022-04-11 接受日期:2022-07-22 出版日期:2022-09-20 发布日期:2022-10-19
  • 通讯作者: 董全民,赵新全,刘玉祯,冯斌,俞旸,杨晓霞,张春平,曹铨,刘文亭
  • 作者简介: (qhdxlwt@163.com)
  • 基金资助:
    青海省科技基础条件平台项目(2020-ZJ-T07);国家自然科学基金(U20A2007);国家自然科学基金(32160340)

Effects of different herbivore assemblage on relationship between Kobresia humilis seed size and seed number in an alpine grassland

DONG Quan-Min1,2(), ZHAO Xin-Quan2,3, LIU Yu-Zhen1, FENG Bin1, YU Yang1, YANG Xiao-Xia1, ZHANG Chun-Ping1, CAO Quan1, LIU Wen-Ting1,*()   

  1. 1Academy of Animal Science and Veterinary Medicine, Qinghai University, Qinghai Academy of Animal Science and Veterinary Medicine, Qinghai Provincial Key Laboratory of Adaptive Management on Alpine Grassland, Xining 810016, China
    2State Key Laboratory of Plateau Ecology and Agriculture in the Three River Head Waters Region, Qinghai University, Xining 810016, China
    3Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810008, China
  • Received:2022-04-11 Accepted:2022-07-22 Online:2022-09-20 Published:2022-10-19
  • Contact: DONG Quan-Min,ZHAO Xin-Quan,LIU Yu-Zhen,FENG Bin,YU Yang,YANG Xiao-Xia,ZHANG Chun-Ping,CAO Quan,LIU Wen-Ting
  • About author: (qhdxlwt@163.com)
  • Supported by:
    Qinghai Science and Technology Basic Condition Platform(2020-ZJ-T07);National Natural Science Foundation of China(U20A2007);National Natural Science Foundation of China(32160340)

摘要:

种子大小和种子数量变异是植物适合度研究的核心问题, 探究不同大型草食动物对嵩草(Kobresia spp.)草地优势种种子大小与数量的影响, 有助于了解其繁殖策略和种群更新机制。该研究依托青藏高原高寒草地-家畜系统适应性管理技术平台, 对不放牧(对照)、牦牛单牧、藏羊单牧、牦牛藏羊1:2混牧、牦牛藏羊1:4混牧、牦牛藏羊1:6混牧6个放牧处理下矮生嵩草(K. humilis)的种子大小和数量特征, 种子大小和数量与生殖性状的关系, 种子大小和数量的权衡关系进行研究。结果显示: 1)放牧处理增加矮生嵩草种子大小15%以上, 增加种子数量30%以上; 除了牦牛藏羊1:2混牧处理, 其他放牧处理与对照相比种子大小变异系数降低15%以上, 种子数量变异系数降低25%以上。2) Pearson相关分析结果显示, 放牧处理下矮生嵩草种子数量、种子大小与生殖相关性状均呈正相关关系。3)放牧处理增加了矮生嵩草种子大小与数量的权衡, 单条生殖枝质量是影响种子大小与数量权衡的重要性状。研究表明, 即使是中度放牧, 家畜依旧是矮生嵩草资源获取的限制性因子; 长期的放牧改变了矮生嵩草性状间的潜在联系和权衡关系, 稳定了种子大小和种子数量特征, 并通过提高种子大小和种子数量的方式优化繁殖策略, 提高了子代的竞争力和适合度。

关键词: 高寒草地, 矮生嵩草, 中度放牧, 放牧方式, 种子大小, 种子数量

Abstract:

Aims Seed size and number variation is the core issue in the study of plant fitness. Exploring the grazing effects of different large herbivore assemblage on the relationship between seed size and number of dominant species in Kobresia grasslands, is helpful to understand the reproductive strategy and population regeneration mechanism.

Methods This research was conducted on the technical platform of adaptive management of alpine grassland- livestock system on the Qingzang Plateau. There were six grazing treatments: no grazing (control), single yak grazing, single Xizang sheep grazing, yak:Xizang sheep grazing ratios of 1:2, 1:4 and 1:6. And we analyzed the reproductive characteristics of K. humilis, the relationship between seed size, seed number and its tradeoff.

Important findings The results showed that: 1) Grazing treatment increased the seed size and seed number of K. humilis by more than 15% and 30%, respectively. The variation coefficient of seed size decreased by at least 15% under other grazing treatments except for yak:Xizang grazing ratio of 1:2. While the variation coefficient of seed number decreased by more than 25%. 2) Pearson correlation analysis showed that there were positive correlation between seed size, seed number and reproductive traits under grazing treatments. 3) Grazing treatments increased the tradeoff between seed size and seed number which was largely affected by the mass of single reproductive branch. The results suggest that even at moderate grazing, livestocks are still the limiting factors for the acquisition of resources. Long-term grazing changes the potential relationship and tradeoff among the traits of K. humilis, stabilizes the features of seed size and seed number. The reproductive strategy of K. humilis is optimized by increasing seed size and seed number, which improves the near-ground competitiveness and fitness of offsprings.

Key words: alpine grassland, Kobresia humilis, moderate grazing, herbivore grazing assemblage, seed size, seed number