甘肃省民勤连古城自然保护区沙木蓼种群的结构与动态

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 甘肃省民勤连古城自然保护区沙木蓼种群的结构与动态 DOI: 10.5846/stxb201409281913 作者: 作者单位: 甘肃省荒漠化与风沙灾害防治国家重点实验室,甘肃民勤荒漠草地生态系统国家野外科学观测研究站,甘肃省荒漠化与风沙灾害防治国家重点实验室,甘肃省连古城国家级自然保护区管理局,甘肃省荒漠化与风沙灾害防治国家重点实验室,甘肃省荒漠化与风沙灾害防治国家重点实验室,甘肃省荒漠化与风沙灾害防治国家重点实验室 作者简介: 通讯作者: 中图分类号: 基金项目: 甘肃省创新群体资助项目（145RJIA335）；甘肃省创新团队资助项目（1207TTCA002） Structure and dynamics of Atraphaxis bracteata populations in Minqin Liangucheng Nature Reserve, Gansu Author: Affiliation: State Key Laboratory of Desertification and Aeolian Sand Disaster Combating,Wuwei,Gansu,Gansu Minqin National Field Observation and Research Station on Ecosystem of Desertification Rangeland,Minqin,Gansu,State Key Laboratory of Desertification and Aeolian Sand Disaster Combating,Wuwei,Gansu,,,State Key Laboratory of Desertification and Aeolian Sand Disaster Combating,Wuwei,Gansu,State Key Laboratory of Desertification and Aeolian Sand Disaster Combating,Wuwei,Gansu Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:根据甘肃省民勤连古城自然保护区沙木蓼种群的生境和植被差异，分别选择低山剥蚀残丘覆沙地（生境Ⅰ）和山前倾斜洪积扇沙地，有小型风积沙丘（生境Ⅱ）和无风积沙丘（生境Ⅲ）3种生境类型样地，对其种群的发育状况、年龄结构、静态生命曲线与分布格局进行了研究，揭示沙木蓼种群动态规律并评价其在构建荒漠植被方面的价值，为科学合理地管护和持续利用沙木蓼种质资源提供科学依据。研究结果表明，1）沙木蓼苗龄级、幼龄级、成熟龄级和老龄级种群密度大小顺序为生境Ⅲ > 生境Ⅰ > 生境Ⅱ，而3种生境中同龄级种群在株高、冠幅、新梢生长量方面差异不显著；2）苗龄级种群在3种生境下都占据了较大的优势地位，对沙木蓼种群的更新具有积极作用。生境Ⅰ和Ⅲ的幼龄级和成熟龄级的年龄结构为连续增长型，老龄级为独立的增长型，种群具有较大的发展空间。而生境Ⅱ的幼龄级和成熟龄级种群的年龄结构为连续的稳定型，老龄级种群为稳定型，种群结构比较稳定。3）种群lx，dx和qx曲线在苗龄级、幼龄级和成熟龄级阶段具有相同的变化趋势，其中苗龄级种群向幼龄级种群转变过程中均呈下降趋势，幼龄级和成熟级种群发育过程中基本保持平稳，但在老龄级种群阶段3种曲线变化趋势的差异性较大，其中生境Ⅰ和Ⅲ种群产生重叠，沙木蓼种群的死亡高峰主要发生在苗龄级和老龄级阶段，具有前期增长，中期稳定，后期衰退的一般规律。4）沙木蓼苗龄级、幼龄级和成熟级种群的分布格局均为聚集分布，而老龄级种群为随机分布。以上分析表明，3种生境下沙木蓼种群更新能力旺盛，种群结构趋于合理，生境差异（风沙流活动）只对土壤种子库、种子萌发和幼苗保存具有显著影响，对其它龄级种群发育没有显著影响，在荒漠植被演变中表现出较强的适应能力和优越性，因此沙木蓼在荒漠植被恢复和重建中具有重要的利用价值。 Abstract:The Minqin Liangucheng Nature Reserve has different types of habitats and vegetations of Atraphaxis bracteata populations. In this study, three types of habitats, i.e., the low denuded hills covered by gravel (habitat I), tilted alluvial fans with small aeolian sand dunes (habitat Ⅱ), and tilted alluvial fans without aeolian sand dunes (habitat Ⅲ), were selected to compare the development status, age structure, static life curve, and distribution pattern of A. bracteata populations at this reserve to reveal their succession dynamics, assess their ecological value, and provide the scientific knowledge for their rational management and sustainable usage. We found that (1) the population densities of young, mature, and old seedlings of A. bracteata were the highest at habitat I, followed by those at habitats Ⅱ and Ⅲ. However, there were no significant differences in the average height, average crown width, and new shoot growth among the same age groups at the three population habitats. (2) The seedlings of all ages dominated position at the three habitats and played a vital role on the propagation of A. bracteata. The age structures of young and mature populations at habitats I and Ⅲ showed continuous growth curves, but that of the old population showed a single growth curve, suggesting that A. bracteata populations at these habitats were developing. The age structures of young and mature populations at habitat Ⅱ showed continuous stable growth curves, but that of old population showed a single stable curve, indicating that A. bracteata populations at this habitat were stable. (3) The lx, dx, and qx curves of seedlings and young and mature populations at the three habitats showed similar change trends. These curves showed decreasing trends from seedling age stage to young age stage, and then stabilized in the young and mature age stages, whereas the curves of old age grade were significantly different, and the populations overlapped between habitats Ⅲ and I. This suggested that seedlings and older A. bracteata populations showed peak mortality, and there was a general pattern of growth at the earlier stage, which stabilized at the middle stage and then decreased at the later stage. (4) The distribution patterns of seedlings and young and mature populations were clump, whereas those for old populations were Poisson. The results indicated that the A. bracteata populations at the three habitats propagated vigorously and showed relatively optimal structure. The environmental difference among the three habitats only had significant impacts on soil seed bank, seed germination, and seedling preservation, but not on population development. These findings suggested that A. bracteata has strong adaptability and dominance in desert areas and can be restored and reconstructed. 参考文献 相似文献 引证文献