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林业科学 ›› 2013, Vol. 49 ›› Issue (12): 1-9.doi: 10.11707/j.1001-7488.20131201

• 论文与研究报告 • 上一篇    下一篇

腾格里沙漠南缘唐古特白刺无性系种群分株年龄结构及其动态

周资行1, 焦健1, 李毅1, 李永兵2, 张世虎2   

  1. 1. 甘肃农业大学林学院 兰州 730070;
    2. 甘肃省民勤县林业局 武威 733300
  • 收稿日期:2012-03-30 修回日期:2013-10-15 出版日期:2013-12-25 发布日期:2014-01-01
  • 通讯作者: 焦健
  • 基金资助:

    国家科技部(农转资金)项目(2009GB2G100375);农业科技成果转化资金计划甘肃省科技厅项目(0805XCNA063)。

Ramet Age Structure and Its Dynamics of Nitraria tangutorum Clonal Populations in the Southern Margin Area of Tengger Desert

Zhou Zihang1, Jiao Jian1, Li Yi1, Li Yongbing2, Zhang Shihu2   

  1. 1. College of Forestry, Gansu Agricultural University Lanzhou 730070;
    2. Minqin Forestry Bureau of Gansu Province Wuwei 733300
  • Received:2012-03-30 Revised:2013-10-15 Online:2013-12-25 Published:2014-01-01

摘要:

对腾格里沙漠南缘景泰点、古浪点和民勤点及对照点兰州天然分布的唐古特白刺无性系种群分株年龄结构及其动态进行分析。结果表明:4地唐古特白刺年龄结构均呈增长型;由南向北随着水分梯度递减,各地唐古特白刺无性系种群中龄分株比重增大,呈现出幼龄居群向成年居群过渡的趋势;静态生命表均显示唐古特白刺无性系种群幼龄分株随着年龄增加,生活力和环境适应能力增强,期望寿命逐渐增大,Ⅴ龄级后分株期望寿命逐渐减小,Ⅲ和Ⅳ龄级死亡率和亏损率明显增大;存活曲线均趋于Deevey-Ⅲ型;兰州点唐古特白刺种群繁育旺盛,导致空间制约强烈,使得幼龄死亡率较高;景泰点和古浪点中龄分株死亡率低;民勤点各龄级死亡率均较大,Ⅵ龄级分株数反常增加;4地唐古特白刺无性系种群分株生存分析整体较为一致,均显示出随龄级增大,生存率单调递减,相应的累积死亡率逐渐上升;由于竞争激烈,兰州点的累积死亡率和危险率较高,而民勤点则在长期的恶劣条件下形成适应环境的种群更新策略,死亡率和危险率均较小;谱分析表明,唐古特白刺分株年龄结构和动态变化受整个生命周期中生物学特性的影响较为明显,总波序末的周期振幅A4能够反映出种群具有一定的环境适应力和抗干扰能力;动态指数表明,由南向北唐古特白刺无性系种群增长潜力逐渐降低:兰州南山(1.27%)>景泰白墩子(0.37%)>古浪马路滩(0.35%)>民勤勤峰农场(0.24%),腾格里沙漠南缘3地,特别是民勤勤峰农场,唐古特白刺无性系种群分株的增长潜力有限,需要加强抚育保护,增进种群持续发展。

关键词: 唐古特白刺, 无性系种群, 分株, 年龄结构, 动态指数, 静态生命表, 生存分析, 谱分析, 腾格里沙漠南缘

Abstract:

This paper studied the age structure and dynamic change of Nitraria tangutorun clonal ramet populations which naturally distribute at Jingtai, Gulang and Minqin in the southern margin area of Tengger Desert, as well as Lanzhou served as a control. The results showed as follows: The age structures of the four plots all belonged to progressive type. Along with the moisture gradient descending from south to north, the proportion of middle-aged ramets increased. There was a transition tendency from youth to adulthood. In the 4 plots, the static life tables all showed that youth ramet vitality and adaptability enhanced, life expectancy increased with age until Ⅴ age class, after which the life expectancy decreased gradually. The qx and Kx obviously increased in Ⅲ and Ⅳ age class. The ramet population survival curves in the 4 plots all approached to Deevey type Ⅲ. The population bred exuberantly on the south hill in Lanzhou City, leading to severe space constraint and high infant mortality. The middle-aged ramets had low mortality at Baidunzi of Jingtai County and Malutan of Gulang County. Compared with other plots, the N. tangutorum clonal population at Qinfeng farm of Minqin County had higher mortality in all age classes, however, the ramet number in the age class Ⅵ increased unusually. The ramet survival analysis results were consistent in the 4 plots. The S(t) monotonically decreased and F(t) gradually increased with the age increasing. The F(t) and λ(t) of the populations on south hill in Lanzhou City were higher due to fierce competition, but were relatively lower at Qinfeng farm of Minqin County, probably as the population updated strategy to adapt harsh environment. The spectral analysis results showed that, the ramet age structure and dynamic change were mainly influenced by the biological characteristics in life cycle. The harmonic amplitude A4 indicated the populations had to certain degree environment adaptability and anti-interference ability. Dynamic index Vpi″ showed that growth potential of the ramet populations gradually declined from south to north with the order of: South hill in Lanzhou City (1.27%)>Baidunzi of Jingtai County (0.37%)>Malutan of Gulang County (0.35%)>Qinfeng farm of Minqin County(0.24%). The population growth potential in the desert southern margin, especially Qinfeng farm of Minqin county, was limited. The N. tangutorum population should be protected by proper tending practices to enhance sustainable development.

Key words: Nitraria tangutorum clonal, population, ramet, age structure, dynamic index, static life table, survival analysis, spectral analysis, southern margin area of Tengger Desert

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