植物生态学报 ›› 2022, Vol. 46 ›› Issue (预发表): 0-0.DOI: 10.17521/cjpe.2022.0017

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放牧家畜类型对内蒙古典型草原植物多样性和群落结构的影响

王姝文 李文怀 李艳龙 严慧 李永宏   

  1. 内蒙古大学
  • 收稿日期:2022-01-11 修回日期:2022-02-25 出版日期:2022-08-11 发布日期:2022-06-09
  • 通讯作者: 李文怀

Effects of different livestock species on plant species diversity and community structure in a typical steppe of Inner Mongolia

WANG Shu-Wen, LI Wen-Huai*, LI Yan-Long, YAN Hui, LI Yong-Hong   

  1. 1. Inner Mongolia University
    2. 生态与环境学院
  • Received:2022-01-11 Revised:2022-02-25 Online:2022-08-11 Published:2022-06-09

摘要: 放牧家畜是调控草原植物多样性的重要因素之一, 探究不同家畜类型及其采食行为下植物多样性的响应, 有助于全面理解草原植物多样性维持机制。该研究以内蒙古大学野外实验基地放牧控制实验为平台(包括对照、牛、山羊、绵羊放牧4个处理), 系统地研究了中等放牧强度下不同家畜类型及其选择性采食和聚集性采食行为对植物多样性(α、β和γ多样性)和群落结构的影响。结果表明: (1)中等放牧强度的牛、山羊、绵羊均在一定程度上提高了植物α、β和γ多样性。其中, 牛对植物多样性的提升作用最大且具有显著性。(2) 3种家畜放牧与对照相比均使群落结构发生显著改变, 但绵羊选择性采食导致下层优势物种糙隐子草(Cleistogenes squarrosa)的相对生物量显著降低, 使绵羊放牧与牛或山羊放牧群落结构的变化趋势相反。(3) 3种家畜选择性采食和聚集性采食行为不同。其中, 牛和山羊放牧使上层优势种羊草(Leymus chinensis)和大针茅(Stipa grandis)、下层优势种糙隐子草地上生物量显著降低, 而绵羊放牧仅使糙隐子草地上生物量显著降低。此外, 牛的采食空间聚集性显著低于山羊和绵羊。(4)植物多样性随上层或下层优势种地上生物量增加而显著降低或呈下降趋势, 表明放牧家畜能够通过抑制优势种生物量从而提高植物多样性。(5)植物多样性随家畜采食空间聚集程度增加而显著降低或表现出下降趋势, 说明较低的空间聚集性有利于植物多样性的维持。综上所述, 保护草原植物多样性不仅要选择适宜的放牧强度, 还应考虑不同家畜类型的影响。

关键词: 植物多样性, 物种组成, 选择性采食, 聚集性采食, 家畜轨迹定位

Abstract: Aims Livestock grazing is one of the most important factors that affect grassland plant diversity. However, the information on the effects of different livestock species and their behaviors on grassland plant diversity and community composition are less available. A better understanding of how changes in plant diversity and community composition are affected by various livestock is essential to the management and preservation of grassland biodiversity. Methods Based on a grazing experiment with four treatments (control, cattle, goat, sheep) in a typical steppe of the Inner Mongolia grassland, we examined the effects of different livestock species and their behaviors (selectivity and aggregation) on plant diversity (i.e., α, β and γ diversity) and community composition. Important findings Our results showed that: (1) cattle, goat, and sheep grazing all increased plant α, β, and γ diversity at moderate grazing intensity, and the increase was largest and significant under cattle grazing. (2) Three livestock species all changed community structure, and sheep grazing resulted a contrary community structure to cattle and goat due to its lower relative abundance of Cleistogenes squarrosa. (3) Cattle and goat grazing significantly reduced the aboveground biomass of upper dominant species Leymus chinensis and Stipa grandis, and lower dominant species Cleistogenes squarrosa, while sheep grazing only decreased Cleistogenes squarrosa biomass. Cattle grazing also had a lower spatial aggregation than that of goat and sheep. (4) Plant diversity decreased with increasing aboveground biomass of either upper or lower dominant species, indicating livestock could promote plant species diversity by limiting aboveground biomass of dominant species. (5) Plant diversity decreased with the increase of livestock grazing spatial aggregation, indicating lower aggregation of livestock could benefit maintenance of plant species diversity. Overall, our study suggests that both the effect of grazing intensity and grazing animal types on plant diversity should be considered in the development of grazing management regime for better conservation and sustainable use of the grassland resources.

Key words: plant diversity, species composition, selective foraging, spatial aggregation, livestock tracking