广西大石围天坑群草本植物多样性及其生态位变化规律

Abstract

PDF HTML阅读 XML下载 导出引用 引用提醒 广西大石围天坑群草本植物多样性及其生态位变化规律 DOI: 10.5846/stxb202204251137 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金（31960047）；珍稀濒危动植物生态与环境保护教育部重点实验室研究基金（ERESEP2019Z04）；广西重点研发计划项目（桂科AB21220057）；广西漓江流域景观资源保育与可持续利用重点实验室研究基金（LRCSU21Z0101） Diversity and niche characteristics of herbaceous plants in Dashiwei Tiankeng Group, Guangxi Author: Affiliation: 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:研究不同发育时期天坑草本植物的多样性，能更好的理解草本层对天坑环境变化的响应机制。以广西大石围天坑群中不同发育时期天坑（初期、中期和后期）为研究对象，采用空间代替时间的方法，分析不同发育时期天坑草本植物多样性和生态位变化规律。结果表明：（1）广西大石围天坑群调查样地共记录到草本植物34科71属98种，以鳞毛蕨科、荨麻科、凤尾蕨科、菊科和禾本科为主。（2）后期天坑草本植物的Pielou's指数和Shannon-Wiener指数均显著高于初期天坑（P<0.05），表明随着天坑发育到后期，草本层物种数逐渐增多，物种分布更为均匀。（3）随着天坑的发育，草本层喜阴植物重要值下降，喜阳、半阴植物重要值上升，喜阳植物逐渐取代喜阴植物在群落中占据优势地位，草本层将经历喜阴植物-喜阴、半阴植物-喜阳植物的三个生态型转变过程。（4）各发育时期优势草本生态位相似性比例和生态位重叠平均值均<0.5，表明天坑不同发育时期对草本植物的生态位影响较小，各时期草本层总体呈现生态分化明显、种间竞争较弱的特点。（5）各发育时期优势草本生态位重叠值大、相对高度差小的种对数中，不同生态习性的种对数占比不同，中期天坑种对数远高于初期和后期天坑，表明不同发育时期中不同生态习性的草本对光能的竞争程度存在差异，中期天坑草本植物对光能竞争最为激烈。综上所述，广西大石围天坑群各发育时期草本层生态分化明显、群落结构稳定，后期天坑草本多样性最为丰富。 Abstract:Studying the diversity and niche characteristics of herbaceous plants in different developmental stages of Tiankeng can better understand the response mechanism of the herbaceous layer to the environmental changes and provide an important scientific basis for the protection of ecological environment and biodiversity resources in Tiankeng. In this study, the herbaceous in different developmental stages of Tiankeng (the earlier stage, middle stage, and later stage) were selected as the objects. We used the method of space instead of time to establish 168 herbaceous quadrates in Dashiwei Tiankeng Group, Guangxi and carried out investigations. Shannon-Wiener index, Simpson index, Pielou's index and Patrick index were used to evaluate the herb diversity at different developmental stages of the Tiankeng. The ecological niche characteristics (niche width and niche overlap) of main species in the herb layer of the different developmental stages of Tiankeng were calculated. The results showed that:(1) a total of 98 species of herbaceous plants belonging to 71 genera and 34 families were recorded in Dashiwei Tiankeng Group, Guangxi. The principal families were Dryopteridaceae, Urticaceae, Pteridaceae, Asteraceae and Poaceae. (2) Pielou's index and Shannon-Wienner index of herbs in the later development stage of Tiankeng were significantly higher than those in the earlier development stage of Tiankeng (P<0.05), indicating that with the Tiankeng developed to the later stage, the number of species in the herb layer increased and the species distribution pattern was steady. (3) With the development of Tiankeng, the importance value of sciophiles in herb layer decreased, while the importance value of heliophiles and semishade increased and the dominance was prevalent in heliophiles than sciophiles. The herb layer would go through three ecotype transition processes of sciophiles-sciophiles and semishade-heliophiles. (4) The average value of niche similarity and niche overlap of dominant herbs at each developmental stage of Tiankeng were lower than 0.5, indicating that different developmental stages of Tiankeng had a slight impact on the niche of herbs. The herbaceous layer had obviously ecological differentiation and weakly inter-specific competition. (5) In the species pairs of dominant herbs large niche overlap and small relative height at each development stage, the species pairs of different ecological habits accounted for different proportions. The species pairs of the middle development stage of Tiankeng was much higher than that of earlier and later development stages of Tiankeng. The results showed that herbaceous plants with different ecological habits at different development stages had different competition degrees for light energy. The herbs in the middle development stage of Tiankeng had the fierce competition for light. In a word, the herb layer of Dashiwei Tiankeng Group in Guangxi was obviously differentiated, the community structure was relatively stable, and the species diversity of the later development stage of Tiankeng in herb layer was rich. 参考文献 相似文献 引证文献