内蒙古灌丛化草原小叶锦鸡儿的种群特征及其土壤影响因子  

Population characteristics of Caragana microphylla and the influencing soil factors in shrub-encroached grassland of Inner Mongolia,China

作　　者：文艺瑶 朱江 王欢 张梦迪 鲁顺保[1] 郑淑霞[2] WEN Yiyao;ZHU Jiang;WANG Huan;ZHANG Mengdi;LU Shunbao;ZHENG Shuxia(College of Life Sciences,Jiangxi Normal University,Nanchang 330022,China;State Key Laboratory of Vegetation and Environmental Change,Institute of Botany,Chinese Academy of Sciences,Beijing 100093,China;School of Ecology and Environment,Inner Mongolia University,Hohhot 010021,China;College of Life Sciences,Shandong Agricultural University,Tai'an 271018,Shandong,China;College of Grassland,Resources and Environment,Inner Mongolia Agricultural University,Hohhot 010018,China)

机构地区：[1]江西师范大学生命科学学院,南昌330022 [2]中国科学院植物研究所植被与环境变化国家重点实验室,北京100093 [3]内蒙古大学生态与环境学院,呼和浩特010021 [4]山东农业大学生命科学学院,山东泰安271018 [5]内蒙古农业大学草原与资源环境学院,呼和浩特010018

出　　处：《应用生态学报》2024年第6期1525-1533,共9页Chinese Journal of Applied Ecology

基　　金：国家重点研发计划项目(2023YFF1305301);国家自然科学基金项目(32371779)资助。

摘　　要：本文对内蒙古锡林郭勒草原不同灌丛化阶段(轻度、中度、重度)下小叶锦鸡儿的种群特征及其土壤影响因子进行研究。结果表明:在草原轻度-中度-重度灌丛化的发展过程中,小叶锦鸡儿的密度和高度逐渐增加,两阶段密度和高度分别增长196.0%、34.5%和25.4%、17.6%。小叶锦鸡儿的冠幅、基径、每丛分蘖数和地上生产力均呈先减少后增加的趋势,地上生物量向叶片的分配比例减少。小叶锦鸡儿在中度灌丛化阶段与草本植物之间的竞争最为强烈,其通过减少横向生长如冠幅、基径和每丛分蘖数,增加密度和高度以获取竞争优势。在不同灌丛化阶段小叶锦鸡儿所受到的土壤限制因子明显不同。在轻度灌丛化阶段,土壤因子对小叶锦鸡儿生长的限制作用较小;在中度灌丛化阶段,深层(20~50 cm)土壤水分和土壤pH是限制小叶锦鸡儿密度的关键因素;在重度灌丛化阶段,深层土壤水分和pH限制小叶锦鸡儿纵向生长的主要因素,浅层(0~20 cm)土壤水分和养分是限制灌从横向扩张的主要因素。We studied the population characteristics of Caragana microphylla and related soil factors across diffe-rent stages of shrub encroachment(i.e.,light,moderate,and severe)on the Xilingol Grassland of Inner Mongolia.The results showed that the density and height of C.microphylla gradually increased during the process of grassland shrub-encroachment from light to moderate to severe.The density and height were increased by 196.0% and 34.5% from light to moderate stage of shrub encroachment,and were increased by 25.4% and 17.6% from moderate to severe stage.Crown size,basal diameter,tiller number per clump,and aboveground productivity of C.microphylla tented to decrease first and then increase,while the proportion of aboveground biomass allocation to leaves decreased across the stages of shrub encroachment.The competition between C.microphylla and herbaceous species was strongest in the moderate encroachment stage.C.microphylla reduced its lateral growth(such as crown size,basal diameter,and tiller number per clump)and increased density and height to get competitive advantage.Limi-ting soil factors for C.microphylla varied significantly at different stages of shrub encroachment.In the light encroachment stage,soil factors had little effect on the growth of C.microphylla.In the moderate encroachment stage,soil moisture in the deep layer(20-50 cm)and soil pH were the key factors limiting shrub density.In the severe encroachment stage,soil moisture in the deep layer and pH limited the vertical growth of C.microphylla,while soil moisture of shallow layer(0-20 cm)and nutrients were the limiting factors for the lateral expansion of shrubs.

关 键 词：灌丛化 种群特征 小叶锦鸡儿 土壤理化性质 内蒙古草原 

分 类 号：S812[农业科学—草业科学]