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中国沙漠 ›› 2013, Vol. 33 ›› Issue (2): 501-507.DOI: 10.7522/j.issn.1000-694X.2013.00068

• 中国地理学会沙漠分会2012年学术研讨会论文选 • 上一篇    下一篇

沙质草地放牧和封育下物种丰富度和生物量关系的季节变化

左小安, 赵学勇, 张铜会, 王少昆, 罗亚勇, 周 欣   

  1. 中国科学院寒区旱区环境与工程研究所 奈曼沙漠化研究站, 甘肃 兰州 730000
  • 收稿日期:2012-11-17 修回日期:2012-12-21 出版日期:2013-03-20 发布日期:2012-12-21

Seasonal Changes of the Relationship between Species Richness and Community Biomass in Grassland under Grazing and Exclosure in Horqin Sandy Land, Northern China

ZUO Xiao-an, ZHAO Xue-yong, ZHANG Tong-hui, WANG Shao-kun, LUO Ya-yong, ZHOU Xin   

  1. Naiman Desertification Research Station, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Science, Lanzhou 730000, China
  • Received:2012-11-17 Revised:2012-12-21 Online:2013-03-20 Published:2012-12-21

摘要:

研究了科尔沁沙质草地放牧和封育下植被盖度、密度、丰富度与地上生物量关系的季节变化。结果表明:放牧和封育草地4月的植被盖度、丰富度和生物量均低于生长旺季8月,而4月植物密度要高于8月;封育草地生长季盖度高于放牧草地,6月和8月生物量高于放牧草地, 4月和6月植物密度则低于放牧草地。封育草地8月物种丰富度与生物量呈极显著的负线性关系(p<0.01);放牧草地植物密度与生物量4月表现出极显著的正线性关系(p<0.01)、8月为极显著的负线性关系(p<0.01)。放牧草地优势植物糙隐子草4月的密度和生物量呈极显著的正线性关系(p<0.01)、8月为极显著的负线性关系(p<0.01);黄蒿和狗尾草8月的密度和生物量均呈极显著的负线性关系(p<0.01);猪毛菜4月和6月的密度和生物量呈极显著的正线性关系(p<0.01)。封育草地达乌里胡枝子、猪毛菜8月的植物密度和生物量呈极显著的正线性关系(p<0.01)。持续放牧和季节变化及其二者的交互作用对植被盖度、密度和生物量均有重要的影响(p<0.05);放牧通过影响草地生长季中的优势植物密度变化和生物量积累,引起了草地植物密度和生物量关系的季节变化,也导致生长季物种丰富度和生物量无显著关系;封育草地植物的竞争导致了物种丰富度和生物量关系的季节变化。

关键词: 沙质草地, 密度, 生长季, 生产力, 物种丰富度, 线性关系

Abstract:

This study carried out an analysis of seasonal changes in relationships between vegetation cover, plant density, species richness and above-ground biomass in grassland under grazing and exclosure in Horqin Sandy Land. Results showed that in grassland being grazed and fenced, vegetation cover, richness and biomass were lower in April than those in August, while plant density showed a reverse trend. Vegetation cover over the season was higher in fenced grassland than that in grazed grassland; biomass in June and August was higher in fenced grassland than that in grazed grassland, while plant density in April and June and was lower in fenced grassland than that in grazed grassland. In fenced grassland, the relationship between species richness and biomass was significantly negative in August (p<0.01); in grazed grassland, the relationship between plant density and biomass was significantly positive in the April (p<0.01) and was significantly negative in August (p<0.01). The relationship between plant density and total biomass for dominant species varied with seasonal changes under grazing and exclosure. In grassland under grazing, the relationship between plant density of Cleistogenes squarrosa and biomass was significantly positive in April (p<0.01) and was significantly negative in August (p<0.01); the relationship between plant density of Artemisia scoparia or Setaria viridis and biomass was significantly negative in August (p<0.01); the relationship between plant density of Salsola collina and biomass was significantly positive in April and June (p<0.01). In fenced grassland, the relationship between plant density of Lesredeza davurica or Salsola collina and biomass was significantly positive in August (p<0.01). These results suggest that long-term grazing, seasonal changes and their interaction significantly influence vegetation cover, plant density and biomass in grassland (p<0.05). Long-term grazing also affects the seasonal changes of plant density and biomass of dominant species, which further affects the seasonal relationship between plant density and biomass in grassland. Species competition in fenced grassland results in the seasonal changes of relationship between species richness and biomass.

Key words: sandy grassland, density, growing season, productivity, species richness, linear relation

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