Page 47 - 《广西植物》2024年第10期
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10 期      王雅楠等: 喀斯特石山老龄林檵木根际和非根际土壤微生物群落及酶活性的旱、雨季节变化                                       1 8 4 9

              (1. Key Laboratory of Rare and Endangered Animal and Plant Ecology and Environmental Protectionꎬ Ministry of Educationꎬ Guilin 541006ꎬ
                Guangxiꎬ Chinaꎻ 2 Key Laboratory of Landscape Resource Conservation and Sustainable Utilization in the Lijiang River Basin of Guangxiꎬ
                     Guilin 541006ꎬ Guangxiꎬ Chinaꎻ 3. Key Dynamics Laboratoryꎬ Ministry of Natural Resourcesꎬ Institute of Karst Geologyꎬ
                                    Chinese Academy of Geological Sciencesꎬ Guilin 541006ꎬ Guangxiꎬ China )

                 Abstract: To understand the seasonal changes and influencing factors of soil biological activity in karst areasꎬ we
                 investigated the changes in rhizosphere and non ̄rhizosphere soil microbial communities and enzyme activity of the
                 Loropetalum chinense community in the aged forest stage of karst areasꎬ as well as their relationships with environmental
                 factors. The results were as follows: (1) During the rainy seasonꎬ the pH valueꎬ organic matterꎬ total carbonꎬ total
                 nitrogenꎬ total potassiumꎬ total phosphorus contentsꎬ and alkaline phosphataseꎬ catalaseꎬ and urease activities of
                 rhizosphere soil were lower than those of non ̄rhizosphere soilꎬ indicating that nutrient leaching in rhizosphere soil was
                 more severe and affected the activity of related enzymes. In contrastꎬ the changes in dry season were nutrient enrichment
                 strategies adopted by rhizosphere soil for healthy plant growth. (2) The diversities of fungi in rhizosphere and non ̄
                 rhizosphere soils were both significantly higher in the dry season than in the rainy seasonꎻ the bacterial diversity of non ̄
                 rhizosphere soil was significantly higher in the rainy season than in the dry seasonꎬ but the seasonal differences in
                 bacterial diversity of rhizosphere soil were not significant. Regardless of the dry and rainy seasonsꎬ the dominant fungal
                 phyla in rhizosphere and non ̄rhizosphere soils were Ascomycotaꎬ Mortierellomycotaꎬ and Basidiomycotaꎬ while the
                 dominant bacterial phyla were Actinobacteriotaꎬ Proteobacteriaꎬ and Acidobacteriota. The seasonal changes had
                 significant differences in the structure of microbial communities in rhizosphere and non ̄rhizosphere soils. (3) The
                 dominant factors of rhizosphere and non ̄rhizosphere soil microbial communities varied in different seasons. During the
                 rainy seasonꎬ the rhizosphere soil exhibited pHꎬ catalase and alkaline phosphatase activitiesꎬ while non ̄rhizosphere soil
                 exhibited catalaseꎬ alkaline phosphataseꎬ cellulase activitiesꎬ and total potassium contentꎻ during the dry seasonꎬ the
                 rhizosphere soil exhibited catalase activity and soil water contentꎬ while non ̄rhizosphere soil exhibited cellulase and
                 sucrase activity. In additionꎬ soil enzyme activity was significantly correlated with carbonꎬ nitrogenꎬ phosphorusꎬ
                 potassiumꎬ and soil water content. (4) Compared to bacteriaꎬ fungal functions in rhizosphere and non ̄rhizosphere soils
                 were more sensitive to seasonal changes. In summaryꎬ the adaptive strategies adopted for microbial communities and
                 enzyme activities in rhizosphere and non ̄rhizosphere soils during the rainy and dry seasons are significantly different. The
                 research results provide theoretical references for vegetation restoration and soil succession in karst areas.
                 Key words: karstꎬ Loropetalum chinense communityꎬ aging forestꎬ dry and rainy seasonsꎬ rhizosphere soilꎬ soil
                 enzymesꎬ soil microorganisms



                根际是连接植物-土壤-微生物之间相互作用                           系统一旦遭受破坏ꎬ将会面临植被易退化、难修复
            的最重要区域ꎬ也是物质和能量循环的场所ꎬ与非                             等严重石漠化生态问题ꎮ Wang 等(2023) 研究表
            根际土壤间差异性明显(Xia et al.ꎬ 2022)ꎮ 根际土                  明ꎬ喀斯特石漠化演变是多种因素综合作用的结
            壤酶和微生物群落对环境变化十分敏感ꎬ能更快地                             果ꎬ与气候变化关系的探究目前主要集中在宏观层
            响应旱、雨季节变化导致的土壤变化(Thakur et al.ꎬ                    面ꎬ若细化到林、草、微生物、动物、土壤养分对月
            2019)ꎮ 旱、雨季变化使得地表土壤一直经历干、湿                         份、季节气候因子的响应研究ꎬ则将有助于人们在
            循环作用ꎬ不仅通过改变土壤水分直接影响土壤酶                             微观层面上对石漠化演变和气候作用机制更深入
            活性和土壤微生物群落(Yang et al.ꎬ 2021)ꎬ还通过                  了解ꎮ 目前ꎬ国内外已有学者对季节变化下喀斯特
            影响植物群落和其他土壤理化性质对土壤酶活性                              生态系统的调控进行研究ꎮ 霍灿灿等(2022) 研究
            和微生物群落产生间接影响(Lu et al.ꎬ 2019)ꎮ 广                   发现广西喀斯特区生长的山核桃叶片生理特性随
            西是我国典型喀斯特地貌代表之一ꎬ属热带、亚热                             季节变化存在显著差异ꎬ随着不同环境因子变化表
            带季风气候ꎬ旱、雨季降水差异极大ꎮ 喀斯特地区                            现出不同的适应机制ꎻWu 等(2020) 研究表明极端
            土层浅薄ꎬ土壤富钙且储水力差ꎬ对气候变化响应                             气候事件会显著降低喀斯特洼地土壤中的碳氮储
            敏感且承受力弱(陈燕丽等ꎬ2022)ꎬ其脆弱的生态                          量ꎻLeitner 等(2020)研究表明全球气候变化下对中
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