植物生态学报 ›› 2012, Vol. 36 ›› Issue (2): 126-135.DOI: 10.3724/SP.J.1258.2012.00126

• 研究论文 • 上一篇    下一篇

古尔班通古特沙漠南缘草本层对积雪变化的响应

范连连1,2,3, 马健1, 吴林峰1, 徐贵青1, 李彦1, 唐立松1,*()   

  1. 1中国科学院新疆生态与地理研究所, 荒漠与绿洲生态国家重点实验室, 乌鲁木齐 830011
    2中国科学院研究生院, 北京 100049
    3中国科学院阜康荒漠生态系统研究站, 新疆阜康 831500
  • 收稿日期:2011-08-22 接受日期:2011-10-29 出版日期:2012-08-22 发布日期:2012-02-22
  • 通讯作者: 唐立松
  • 作者简介:* E-mail: tangls@ms.xjb.ac.cn

Response of the herbaceous layer to snow variability at the south margin of the Gurbantonggut Desert of China

FAN Lian-Lian1,2,3, MA Jian1, WU Lin-Feng1, XU Gui-Qing1, LI Yan1, TANG Li-Song1,*()   

  1. 1State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, ürümqi 830011, China
    2Graduate University of Chinese Academy of Sciences, Beijing 100049, China
    3Fukang Station of Desert Ecology, Chinese Academy of Sciences, Fukang, Xinjiang 831500, China
  • Received:2011-08-22 Accepted:2011-10-29 Online:2012-08-22 Published:2012-02-22
  • Contact: TANG Li-Song

摘要:

草本层是古尔班通古特沙漠植物群落下层层片的构建者, 冬季积雪提供了其生长发育所需要的主要水分, 积雪的增加或减少对草本植物数量和生物量会产生显著的影响。该研究利用人工增减积雪的方法, 在古尔班通古特沙漠南缘设置了5个不同厚度的积雪处理: 0积雪、50%积雪、100%积雪、150%积雪和200%积雪, 其中100%积雪为自然积雪。采用1 m × 1 m的样方, 对草本层片的物种数、盖度、密度、高度进行了调查, 还采用收获法测定了草本层片的地上生物量和优势种小花荆芥(Nepeta micrantha)的单株地上生物量。对研究区内13个科29种草本植物的研究表明: 1)单位面积出土幼苗数量跟积雪厚度呈显著正相关关系, 草本层片的盖度、密度对积雪的变化响应显著, 随着积雪增加, 草本层片的密度和盖度呈递增趋势, 而草本层片的平均高度呈递减趋势, 但不同积雪处理间的物种数和总地上生物量没有显著差异; 2)积雪厚度与优势种的株高和地上生物量呈显著负相关关系, 积雪的增加导致优势种的单株生物量和株高显著降低; 3)积雪厚度的变化主要影响了草本层片植物种子萌发的数量, 但对物种数量没有显著影响。这表明: 虽然积雪是草本植物的主要水分来源之一, 但荒漠植物群落的草本植物对积雪的变化具有很强的缓冲能力, 即使积雪很少, 草本层片的物种构成也不会发生显著变化, 草本层片的净初级生产力也保持相对稳定。

关键词: 生物量, 古尔班通古特沙漠, 草本层, 积雪量, 物种多样性

Abstract:

Aims The herbaceous layer is an important component of the plant community of China’s Gurbantonggut Desert, and it primarily depends on early spring snow-melt water for germination and development. However, few studies have shown how the herbaceous layer responds to variability of precipitation. Generally, snow thickness changes in accordance to variability of precipitation. Therefore, our objective was to determine how snow thickness affects the ecological and physiological traits of the herbaceous layer in a typical arid zone.
Methods We used five treatments of snow thickness (0, 50%, 100%, 150% and 200%), and natural snow thickness (100%) was the control. We investigated species number, coverage, density and height of plants in 1 m × 1 m quadrats and used the harvest method to measure aboveground biomass of both the herbaceous layer and the dominant species (Nepeta micrantha).
Important findings Seedling density of the herbaceous layer was positively correlated with the amount of snow, but average height was negatively correlated with it. Also, total aboveground biomass and number of species showed no significant differences among treatments. Plant height and aboveground biomass of the individual dominants were negatively correlated with the amount of snow. For other species in the layer, the average height was also negatively correlated with the snow thickness. The number of seeds germinating and the abundance of herbaceous plants increased with the amount of snow, but species richness was not influenced by snow thickness. Our results suggested that although melted snow is the main water source for herbaceous plants, they have developed a strong buffering capacity against variation in the snow thickness. Therefore, species diversity and net primary productivity of the herbaceous layer can be stable even under strong variation of snow accumulation.

Key words: biomass, Gurbantonggut Desert, herbaceous layer, snow thickness, species diversity