中国沙漠 ›› 2018, Vol. 38 ›› Issue (3): 524-534.DOI: 10.7522/j.issn.1000-694X.2017.00016

• 生物与土壤 • 上一篇    下一篇

浑善达克沙地榆树(Ulmus pumila)种群结构和动态特征

张志永1,2, 杨晓晖2, 张晓2, 刘艳书2, 时忠杰2   

  1. 1. 中国林业科学研究院 林业科技信息研究所, 北京 100091;
    2. 中国林业科学研究院 荒漠化研究所, 北京 100091
  • 收稿日期:2017-03-01 修回日期:2017-03-23 出版日期:2018-05-20 发布日期:2018-11-06
  • 通讯作者: 时忠杰(
  • 作者简介:张志永(1986-),男,山东寿光人,博士,主要从事恢复生态学和生态管理方面的研究。
  • 基金资助:

Structure and Dynamic Characteristics of Ulmus pumila Population in the Otindag Sandy Land

Zhang Zhiyong1,2, Yang Xiaohui2, Zhang Xiao2, Liu Yanshu2, Shi Zhongjie2   

  1. 1. Research Institute of Forestry Policy and Information, Chinese Academy of Forestry, Beijing 100091, China;
    2. Institute of Desertification Studies, Chinese Academy of Forestry, Beijing 100091, China
  • Received:2017-03-01 Revised:2017-03-23 Online:2018-05-20 Published:2018-11-06

摘要: 榆树(Ulmus pumila)疏林是一种以榆树为优势种的疏林草地类型,榆树的存在对于维持区域生态稳定性具有重要意义。采用空间代替时间的方法,通过编制静态生命表,绘制存活、死亡率和消失率曲线,同时应用生存函数、积累死亡率函数、死亡密度函数和危险率函数分析了浑善达克沙地榆树的种群结构和发展动态。结果表明:在4个区域中,榆树的种群密度、胸径、树高、冠幅具有一定的差异性,东部区域的种群密度最大,胸径、树高、冠幅最小。榆树种群的年龄结构呈现2个峰值,存在断层问题。榆树种群整体呈现前期锐减、中期稳定、后期衰退的动态特征。前期数量锐减可能是自然灾害、土地沙化、牲畜啃食以及人为破坏等干扰活动综合作用的结果,后期衰退可能是榆树个体间对水分、光照、养分等生存因子相互竞争的结果。本研究区域存在数量较多的榆树幼苗,在合理的经营管理措施下,榆树可以实现种群的自主更新。该过程可能需要至少30 a的时间,需要长期稳定的政策支持。

关键词: 榆树(Ulmus pumila), 年龄结构, 静态生命表, 存活曲线, 种群更新

Abstract: Ulmus pumila-dominated savanna, playing a great role in maintaining the region's ecological stability, is an important savanna type where U. pumila is a dominant species. In this paper, the structure and dynamics of U. pumila population were analyzed by the spatial series substituting for time series method. The static life tables and the curves of survival, mortality and loss rate for the population were calculated, respectively. In addition, the survival analysis were performed, including the survival, cumulative mortality, death density and risk rate. The results show that population density, diameter at breast height, height and crown diameter of U. pumila had a certain difference in four regions:There were the biggest population density and least values of the diameter at breast height, height and crown in the eastern region among the different regions. The ages of population were shown two peaks with a characteristics of sharp-dropping in the seedling, stability in juveniles, and slow-declining in the adults, suggesting an obvious declining of population. The sharp-dropping in seedling might be a result of comprehensive factors, such as natural disaster, land desertification, grazing, as well as man-made destruction. The declining in adults may be caused by the strong competition for moisture, light and nutrient among the trees. There was a number of seedlings in the study area, which suggests the U. pumila population will be regenerated under the reasonable managements. However, at least 30 years will be required to restore the U. pumila-dominated savanna ecosystem.

Key words: Ulmus pumila, age structure, life table, survival curve, population regeneration