中国沙漠 ›› 2017, Vol. 37 ›› Issue (6): 1127-1134.DOI: 10.7522/j.issn.1000-694X.2017.00059

• 生物与土壤 • 上一篇    下一篇

基于V_Hegyi竞争指数的绿洲边缘人工固沙植被梭梭(Haloxylon ammodendron)的种群竞争

郑颖1,2, 赵文智1, 张格非1   

  1. 1. 中国科学院西北生态环境资源研究院 中国生态系统研究网络临泽内陆河流域研究站/中国科学院内陆河流域生态水文重点实验室, 甘肃 兰州 730000;
    2. 中国科学院大学, 北京 100049
  • 收稿日期:2017-04-26 修回日期:2017-06-14 出版日期:2017-11-20 发布日期:2017-11-20
  • 通讯作者: 赵文智(
  • 作者简介:郑颖(1989-),女,甘肃酒泉人,博士研究生,研究方向为干旱区恢复生态学。
  • 基金资助:

Spatial Analysis of Competition in Haloxylon ammodendron Community Based on the V_Hegyi index in an Oasis-desert Ecotone

Zheng Ying1,2, Zhao Wenzhi1, Zhang Gefei1   

  1. 1. Linze Inland River Basin Research Station/Key Laboratory of Inland River Basin Ecohydrology, Northwest Institute of Eco-Environment and Resources, Lanzhou 730000, China;
    2. University of Chinese Academy of Science, Beijing 100049, China
  • Received:2017-04-26 Revised:2017-06-14 Online:2017-11-20 Published:2017-11-20

摘要: 种群动态与种内竞争是植物生态学经典研究核心,特别是对于植被组成相对简单的荒漠,对种内竞争机制的研究有助于深入理解荒漠植被的稳定机制与自组织过程。以河西走廊绿洲边缘最主要的人工固沙植物梭梭(Haloxylon ammodendron)为对象,采用空间代替时间的方法,研究梭梭种群的演变过程及种群竞争强度随建植年龄的变化。选择5个(5~10、10~20、20~30、30~40、>40 a)生长阶段的受人为干扰较小的梭梭种群样地,分别设置5个50 m×60 m样方。选用V_Hegyi竞争指数分析梭梭种群的种内竞争在时间维度上的变化规律。结果表明:研究区梭梭人工林从定植到生长20 a左右,梭梭林密度减小了60%左右,生长30~40 a左右的梭梭样地出现大量的更新幼苗,导致密度增加,由于梭梭幼苗和部分成年树的死亡,密度再次下降;梭梭基径越大,竞争指数越小,不同径级梭梭竞争指数大小依次为幼苗、幼年树和成年树;梭梭种群竞争强度由大到小依次为30~40、5~10、>40、20~30、10~20 a。

关键词: 竞争, 梭梭(Haloxylon ammodendron), 空间分析, V_Hegyi竞争指数

Abstract: Competition is a major factor structuring plant communities. Plants contend with limiting resources and space under abiotic and biotic stress. The competition effect of plant populations is of significance in population dynamics of desert vegetation. Our objective is to explore the population dynamics of Haloxylon ammodendron and relative intensity of competition with the population growth in the Linze oasis fringe area in the middle of Hexi Corridor. The goal is to provide helpful information related to understanding the mechanisms and interactions influencing adaptation and succession of artificial sand-fixation desert vegetation. H. ammodendron is a commonly-used sand-fixing species in the desert area of northwestern China; it has been abundantly planted in areas where annual precipitation is about 120 mm in the Hexi Corridor since the 1970s. H. ammodendron in five stages of development (5-10-year,10-20-year,20-30-year,30-40-year,>40-year) were analyzed. Five 0.3-hm2 (50 m×60 m) permanent plots were established in each of five developmental stages, H. ammodendron was classified as seedlings, juvenile and mature trees, all individuals were measured and stem-mapped, to gain insights into population dynamics over a course of succession driven by resource competition. One-way ANOVA was used to describe the variation among seedlings, juvenile and mature trees, and the variation among different developmental stages. We then used the tool create thiessen polygons in GIS to create voronoi of H. ammodendron in five developmental stages, On the basis of voronoi, defining the competition unit. Finally, we used a competition index which is called V_Hegyi index put forward by Tang Mengping to evaluate the relative intensity of competition with the population growth of H. ammodendron. The results show: (1) The population density of H. ammodendron revealed a reduction in 10-20-year, and a small increase with a large number of seedlings appeared in 30-40-year, but for the low survival rate of seedlings, the density declined at a later stage. (2) In the same developmental stage, there were significant differences in the relative intensity of competition of seedlings, juvenile and mature trees. The bigger the diameter at basal, the smaller the V_Hegyi index is. The V_Hegyi index of seedlings is the biggest, juvenile trees followed, the V_Hegyi index of mature trees is the smallest. (3)The relative intensity of competition of H. ammodendron in 30-40-year stage is the greatest, the order of the other four stages was 5-10-year, >40-year, 20-30-year and 10-20-year stage. The results showed that the variation of relative intensity of competition of H. ammodendron was influenced mainly by variations of the source of water, varies with population growth. In conclusion, population competition should be considered during breaking wind and fixing sands in the arid desert area where annual precipitation is less than 120 mm.

Key words: competition, Haloxylon ammodendron plantation, spatial analysis, V_Hegyi Index