Page 49 - 《广西植物》2025年第6期
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6 期 杨旭霏等: 桂西南喀斯特季节性雨林东京桐群落物种多样性的时序动态 1 0 3 5
( 1. College of Tourism and Landscape Architectureꎬ Guilin University of Technologyꎬ Guilin 541006ꎬ Guangxiꎬ Chinaꎻ 2. Guangxi Key Laboratory
of Plant Conservation and Restoration Ecology in Karst Terrainꎬ Guangxi Institute of Botanyꎬ Guangxi Zhuang Autonomous Region and
Chinese Academy of Sciencesꎬ Guilin 541006ꎬ Guangxiꎬ Chinaꎻ 3. Nonggang Karst Ecosystem Observation
and Research Station of Guangxiꎬ Chongzuo 532499ꎬ Guangxiꎬ China )
Abstract: Deutzianthus tonkinensisꎬ classified as a national secondary key protected wild plant in Chinaꎬ serves as the
foundational species in communities that constitute one of the primary rare vegetation types within the northern tropical
karst seasonal rainforests. These communities harbor rich biodiversity and numerous endemic speciesꎬ possessing
significant ecological and economic values. Howeverꎬ the temporal dynamics of species diversity within these
communities and their underlying driving factors remain poorly understood. To investigate the temporal dynamics and
identify the driving factors of species diversity in D. tonkinensis communitiesꎬ this study conducted three cycles of
2
periodic re ̄surveys within a 1 hm long ̄term monitoring plot in Nonggangꎬ Guangxi Zhuang Autonomous Region. The
objective was to analyze the changes in species diversity from 2012 to 2022 and to explore the impacts of topographic
factors on these dynamics. The results were as follows: (1) The importance values of dominant species remained
stable. Concurrentlyꎬ there was an increase in the basal area at breast heightꎬ indicating the growth of these
species. Howeverꎬ species abundance declinedꎬ suggesting a shift in the population structure within the community. (2)
A total of 18 rare and occasional species withdrew from the communityꎬ resulting in a 14% reduction in species
richness. Additionallyꎬ the Shannon ̄Wiener indexꎬ a measure of species diversityꎬ declined significantly (P<0.05)ꎬ
indicating a loss of biodiversity within the community. (3) The number of quadrats that significantly contributed to β ̄
diversityꎬ which reflects the variation in species composition among different locations within the communityꎬ decreased
by 2%. Furthermoreꎬ the temporal β ̄diversity index declined in 80% of the quadratsꎬ indicating that species loss
significantly exceeded species gains within the plot. This suggests a trend of homogenization in species composition over
time. (4) Elevation had a significant impact on species loss within the plot (P< 0.05). This finding highlights the
importance of topographic factorsꎬ particularly elevationꎬ in shaping the species diversity dynamics within the
community. In conclusionꎬ while the overall community structure of Deutzianthus tonkinensis remained stable over the
past ten yearsꎬ significant changes were observed in both α ̄diversity and β ̄diversity. The loss of rare and occasional
species drove these diversity changesꎬ indicating a potential threat to the biodiversity of the community. Among the
topographic factorsꎬ elevation emerged as a significant influence on species diversity changes. These research findings are
crucial for enhancing our understanding of biodiversity dynamics and their driving mechanisms in karst seasonal
rainforestsꎬ which are essential for conservation efforts and sustainable management strategies.
Key words: Deutzianthus tonkinensisꎬ β ̄diversityꎬ temporal dynamicsꎬ B ̄C plotꎬ Nonggang National Nature Reserve
生物多样性持续减少已成为全世界所面临的 落的 α 多样性一般随着演替的过程(即时间变化)
挑战(罗茂芳等ꎬ2023)ꎮ 为实现« 昆明-蒙特利尔 而增加(Li et al.ꎬ 2021)ꎮ 但是最近研究认为ꎬ森
全球生物多样性框架» 提出的遏制并扭转生物多 林 α 多样性的时序动态存在阶段性ꎬ演替早期 α
样性减少趋势的目标ꎬ监测并识别不同生态系统 多样性通常因种群扩散与定居而逐渐增加( 李其
生物多样性变化的主要驱动因素是关键( 马克平ꎬ 斌等ꎬ2022)ꎻ演替后期阶段ꎬ因种间竞争逐渐加
2023ꎻ张丽荣等ꎬ2023)ꎮ 森林作为陆地最重要的 剧ꎬ竞争力较弱的物种可能会被淘汰( Shen et al.ꎬ
物种基因库ꎬ热带森林保存了陆地超过 50%的已 2013)ꎬ从而导致 α 多样性的下降ꎮ 因此ꎬ森林 α
发现物种( Wright et al.ꎬ 2021)ꎬ理解其生物多样 多样性的时序动态可能会随着森林类型的差异及
性的动态变化及其驱动因素至关重要ꎮ 然而ꎬ不 环境因素的不同而呈现出各异的变化趋势ꎬ但目
同森林生物多样性的动态特征及其驱动因素目前 前仍未得到充分探索ꎬ尤其在异质性且生物多样
没有一致的研究结论ꎮ 性极高的喀斯特森林ꎮ 此外ꎬ以往研究大都采用
群落 α 多样性的时序动态一直是生物多样性 空间代替时间的方法ꎬ基于固定样地长期监测的
的研究重点( 陈瑶琪等ꎬ2024)ꎮ 以往研究认为群 研究结果相对较少( Zhou et al.ꎬ 2021ꎻWei et al.ꎬ

