Page 95 - 《广西植物》2023年第3期
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3 期               余林兰等: 神木天坑不同小生境木本植物叶功能性状的差异与关联                                            4 9 5

                 Abstract: In order to further explore the survival strategy of woody plants in tiankeng habitat. This study selected woody
                 plants in different microhabitats (bottomꎬ waist and edge of Shenmu Tiankeng) as the objects. Shenmu Tiankeng is a
                 typical karst tiankeng in Dashiwei Tiankeng Group in Guangxiꎬ and there is a well ̄preserved underground forest that is
                 easily accessible. Ten leaf functional traits (leaf thicknessꎬ leaf tissue densityꎬ leaf areaꎬ etc.) were selectedꎬ and
                 single ̄factor analysis of variance and correlation analysis were conducted to investigate the relationship between leaf
                 functional traits in different microhabitats. The results were as follows: (1) Among the 10 leaf functional traits of woody
                 plants in Shenmu Tiankengꎬ the variable coefficient for leaf area (113.9%) was highestꎬ while leaf carbon content was
                 relatively stable (10.5%). (2) Ten leaf functional traits were almost no significant differences (P>0.05) for woody
                 lianas in three different microhabitats. The leaf tissue density for trees was significantly higher at the edge and waist
                 compared to the bottom (P<0.05)ꎬ while the leaf potassium contents for trees and shrubs at the bottom were higher than
                 that at the edge (P<0.05). (3) There were some differences in the correlation of leaf functional traits in different
                 microhabitats. Leaf thickness was extremely significantly positively correlated with leaf area (P<0.01) at the edge of
                 Tiankeng. The results of principal component analysis suggested that leaf tissue density ( - 0. 833)ꎬ leaf potassium
                 content (0.782)ꎬ and leaf dry matter content (-0.647) were the critical indicators for leaf functional traits of woody
                 plants in different microhabitats of Shenmu Tiankeng. In conclusionꎬ there is a general correlation between leaf functional
                 traitsꎬ and this study demonstrate that different growth types of woody plants can adapt to the three microhabitats of
                 tiankeng via the trade ̄off of leaf functional traits. This study is expected to provide theoretical guidance for understanding
                 the adaptation mechanism of plants to special habitats and the protection of tiankeng vegetation.
                 Key words: leaf functional traitsꎬ woody plantsꎬ tiankengꎬ trait differenceꎬ correlation




                植物功能性状能在一定程度上反映植物对气                            等ꎬ2019)ꎮ 天坑全名喀斯特天坑(karst tiankeng)ꎬ
            候与环境变化的适应和响应ꎬ是生态学的研究热                              是指一种大型陷坑状负地形( 朱学稳等ꎬ2003)ꎬ具
            点(杨浩和罗亚晨ꎬ2015)ꎮ 植物功能性状是指植                          有独特的生态环境和生物多样性等综合属性( 朱
            物个体水平上可测量的任何形态、生理或物候特                              学稳和陈伟海ꎬ2006)ꎬ是乡土植物区系“ 避难所”
            征ꎬ通过对生长、繁殖和生存的影响ꎬ间接影响其                             (Su et al.ꎬ 2017)ꎮ 近年来ꎬ对天坑的科学考察更
            适合度( Violle et al.ꎬ 2007)ꎮ 叶片是植物进行光                加频繁ꎬ众多学者对天坑的演化及植被生态系统
            合作用与蒸腾作用的主要场所ꎬ是对环境胁迫响                              进行了深入研究( 蒲高忠等ꎬ2021)ꎮ 天坑底部到

            应的敏感器官( 龚春梅等ꎬ2011ꎻLi et al.ꎬ 2017)ꎮ                顶部边缘ꎬ物种呈现圈层分布的特点ꎬ小生境差异
            叶功能性状能够反映植物养分变化以及植物对生                              大(黄林娟等ꎬ2021)ꎬ底部能获得更多的水分及养
            存环境的适应策略( 胡耀升等ꎬ2014)ꎮ 对不同生                         分ꎬ土 壤 有 机 质、 全 氮 以 及 钙 含 量 高 ( Pu et al.ꎬ
            境的植物叶功能性状进行深入研究ꎬ有助于揭示                              2019)ꎬ天坑群落成层现象明显ꎬ乔木层优势种、灌
            植物在不同生境的生长策略及资源分配模式ꎬ为                              木层优势种分布均匀(于燕妹等ꎬ2021)ꎮ 然而ꎬ作
            预测全球变暖变化下植物叶功能性状的响应机制                              为喀斯特的特殊生境ꎬ对天坑森林开展的叶功能

            提供科学依据(何芸雨等ꎬ2019)ꎮ                                 性状研究较少ꎬ仅有学者针对单一科植物在退化
                 喀斯特生态系统可以解释为受喀斯特环境制                           天坑 不 同 坡 位 的 功 能 性 状 进 行 研 究 ( 冯 洁 等ꎬ
            约的生态系统ꎬ其内涵包括喀斯特环境对生命的                              2021)ꎬ对天坑不同小生境叶功能性状之间的关系

            影响 以 及 生 命 对 喀 斯 特 环 境 的 反 作 用 ( Yuanꎬ             却鲜见报道ꎮ 鉴于此ꎬ本研究以神木天坑不同小
            2001)ꎮ 近年来ꎬ在喀斯特地区开展了一系列关于                          生境(底部、坑腰和边缘)木本植物为对象ꎬ选取环
            叶功能性状变异及其适应策略的研究ꎮ 钟巧连等                             境中相对稳定的结构型性状ꎬ即叶厚度、叶组织密
            (2018)研究表明木本植物采取较小的比叶面积ꎬ                           度、叶面积、比叶面积、叶干物质含量、叶碳含量、
            较大的叶组织密度等来适应干旱贫瘠的生境ꎮ 贵                             叶氮含量、叶磷含量、叶钾含量和叶氮磷比 10 个
            州的喀斯特高原峡谷优势种也采取类似的叶功能                              叶功能性状指标进行测量ꎬ采用单因素方差分析、
            性状策略在高温、缺水和少土的生境生存( 程雯                             相关性分析及主成分分析等方法ꎬ拟探讨以下问
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