Page 170 - 《广西植物》2023年第3期
P. 170

5 7 0                                  广  西  植  物                                         43 卷
                                        1             1ꎬ2ꎬ3             1ꎬ2ꎬ3               1ꎬ2
                         MAO Yanjiao ꎬ XIAO Zibo          ꎬ DENG Wei        ꎬ ZHANG Chao ꎬ
                                                             2ꎬ3        1ꎬ2∗
                                             TANG Xiaoxin ꎬ JIN Yi
                ( 1. School of Life Sciencesꎬ Guizhou Normal Universityꎬ Guiyang 550025ꎬ Chinaꎻ 2. Key Laboratory of National Forestry and Grassland
              Administration on Biodiversity Conservation in Karst Mountainous Areas of Southwestern Chinaꎬ Guizhou Normal Universityꎬ Guiyang 550025ꎬ
                 Chinaꎻ 3. Key Laboratory of Plant Physiology and Developmental Regulationꎬ Guizhou Normal Universityꎬ Guiyang 550025ꎬ China )

                 Abstract: In order to understand of the drivers of the ratio of deciduous broad ̄leaved plants (DBL) to evergreen broad ̄
                 leaved plants (EBL) and the diversities of each leaf habit group in the karst forestsꎬ with 43 secondary karst forest
                 sample plots in Puding County of Guizhou Province as study objectsꎬ we adopted statistical methods such as the
                 generalized linear regression modelꎬ model selection and the multiple regression extension of the Mantel testꎬ and we
                 examined the effects of geographical distanceꎬ environment ( including topography and bedrock type)ꎬ and human
                 activities on the proportion of DBL and EBL as well as their phylogenetic alpha and beta diversities. The results were as
                 follows: (1) The DBL and EBL in puding were about equal in overall richness and abundanceꎬ but large differences
                 existed among sample plotsꎻ the phylogenetic alpha diversity(i.e.ꎬ SES. MPD) of DBL and EBL was not differentꎬ
                 whereas the phylogenetic beta diversity( i. e.ꎬ SES. betaMPD) of DBL between sample plots was smaller than EBL
                 plants. (2) The richness ratio and relative abundance of DBL shifted with bedrock typeꎬ and displayed as the marlstone
                 forests comprised higher richness ratio and relative abundance of DBL compared with limestone forests. In additionꎬ the
                 richness ratio of DBL also increased as human activities intensified. (3) The phylogenetic alpha diversity of DBL
                 increased with the intensified human activitiesꎬ whereas the phylogenetic alpha diversity of EBL was not influenced by
                 the environmental factors and human activitiesꎬ which might partly be due to the conserved resource utilization strategies
                 of EBL that blunt their claim for the resources released by human disturbance. The phylogenetic beta diversities of DBL
                 and EBLꎬ howeverꎬ were shaped by different sets of factorsꎬ the former increased with the change of bedrock type and
                 the intensity of human activitiesꎬ the latter increased with geographical distance. The findings imply that the ratio of DBL
                 to EBL in the secondary karst forests of Puding are mainly driven by environment conditions and human activitiesꎬ based
                 on which the phylogenetic diversities of DBL are regulated by niche processes such as habitat filtering mediated by
                 topography and bedrock typeꎬ whereas EBL are shaped by spatial processes such as dispersal limitation mediated by
                 geographical distance. This study sheds light on the biodiversity maintenance mechanisms of karst forestsꎬ and provides
                 theoretical support for the management of karst forests.
                 Key words: topographyꎬ human activitiesꎬ bedrock typeꎬ community assemblyꎬ tree layerꎬ leaf habit



                在我国亚热带西南地区的喀斯特地貌上ꎬ广                            (Fang et al.ꎬ 2016)ꎮ 同时ꎬ长期的人类活动干扰
            泛生长着一类非地带性森林ꎬ被称为喀斯特森林                              对西南地区喀斯特森林物种组成产生了重要影响
            (屠玉鳞ꎬ1989ꎻ周游游等ꎬ2003)ꎬ主要分布在贵                        (姚长 宏 等ꎬ 2001ꎻ 刘 长 成 等ꎬ 2021ꎻ 贺 忠 权 等ꎬ
            州、广西及云南等地区(吴征镒ꎬ1980)ꎮ 典型的喀                         2021)ꎮ 喀斯特森林受到干扰较多(郭柯等ꎬ2011)

            斯特森林通常为常绿落叶阔叶混交林( 朱守谦ꎬ                             且植被演替慢(李婷婷等ꎬ2021) 等ꎬ可能有利于落
            1997ꎻ兰斯安等ꎬ2016)ꎬ林内含有较大比例的落叶                        叶阔叶植物在喀斯特森林内持久生存ꎮ 但是ꎬ目

            阔叶植物ꎮ                                              前尚不清楚地形、基岩类型和人类活动干扰等因
                 喀斯特地貌上的地形( 郑鸾和龙翠玲ꎬ2020)                       素ꎬ如何共同影响喀斯特森林内落叶和常绿阔叶
            和基岩类型( Cottleꎬ 2004ꎻ 张喜ꎬ2007ꎻ Li et al.ꎬ           木本被子植物所占比例ꎮ
            2022)等环境因子复杂多样ꎬ通过光照、土壤和水                               Bews(1927) 和 Axelrod(1966) 从被子植物起
            分等ꎬ调控着喀斯特森林内的植物组成ꎮ 研究表                             源演化推定ꎬ常绿性状较落叶性状古老ꎮ 近期针
            明ꎬ与常绿阔叶植物相比ꎬ落叶阔叶植物更喜好高                             对我国亚热带常绿阔叶林内落叶和常绿阔叶木本
            光照( Jin et al.ꎬ 2018) 和 肥 沃 土 壤 等 环 境 条 件          被子植物谱系多样性差异的研究结论( 车俭等ꎬ
   165   166   167   168   169   170   171   172   173   174   175