水分对湿地生态系统不同植被类型土壤种子库的影响  

Soil Seed Bank Heterogeneity Caused by Water Variance in Wetlands with Different Vegetation Communities

作　　者：陈超 夏凡 阚海明 庞卓[1] 王庆海[1] CHEN Chao;XIA Fan;KAN Hai-ming;PANG Zhuo;WANG Qing-hai(Beijing Research and Development Center for Grass and Environment,Beijing Academy of Agriculture and Forestry Sciences,Beijing 100097,P.R.China;College of Environmental Science and Engineering,Central South University of Forestry and Technology,Changsha 410004,P.R.China)

机构地区：[1]北京市农林科学院草业与环境研究发展中心,北京100097 [2]中南林业科技大学环境科学与工程学院,长沙410004

出　　处：《水生态学杂志》2023年第4期70-76,共7页Journal of Hydroecology

基　　金：北京市农林科学院科技创新能力建设专项(KJCX20200301、KJCX20230305、KJCX20190404、KJCX201612120016)。

摘　　要：探讨退化河流湿地生态系统不同植被类型土壤种子库对水分变化的响应机制,了解植物群落的演替规律和退化驱动力,可为进一步了解生态系统的退化过程及生态恢复提供参数依据。通过水分控制试验(干旱、湿润和积水),在妫水河流域自然湿地生态系统5种不同植被类型的表层土样上开展土壤种子库的萌发试验。结果表明,不同的植被类型对于水分变化的响应模式明显不同。根据其植被特征可分为3类:(1)对于以中旱生植物为主的林下杂类草群落,随着水分的增加其植物种类和数量明显增多。相比较干旱处理,积水处理组植物种类和数量增加的幅度分别为43.8%和249.5%,其中湿生植物明显增多;多样性指数的分析也表明积水处理组其多样性较干旱处理组更高。(2)对于湿生/水生的欧地笋杂类草、芦苇杂类草和芦苇优势种群落,其表现为湿润处理时单位面积物种数和植物密度最低,而干旱和积水处理皆高于湿润处理;多样性水平则呈现随水分增加而降低的趋势。(3)水生的香蒲优势种群落则呈现和林下杂类草群落相反的结果,随水分增加其植物种类明显下降、多样性水平显著降低,但植物数量随水分的增加而呈增加趋势、最大增幅为137.6%。在植物群落组成和相似度方面,5种植被类型皆有其特定的优势植物及结构组成,并和其他植被类型有较高或较低的相似性,并呈现出对于不同水分条件的适应特异性。水分因子在植物群落的发生和演替中起重要作用,是湿地生态系统植被类群演替的重要外在环境因素。In this study,water control experiments(drought,normal and flooded)were conducted to ex-plore succession of the soil seed bank of different vegetation communities and the driving forces in a de-graded river wetland ecosystem,aiming to provide a basis for protecting and restoring the ecology of de-graded wetlands.The natural wetlands of the Guishui River basin,an important ecological corridor of Bei-jing,was selected for study.The vegetation community was characterized and five types of vegetation were identified.The top soil layer from each of the five types of vegetation was sampled and germination experiments of the soil seed bank were conducted.Three water treatments(drought,normal and flooded)were set,with five repetitions of each treatment,and species were identified and plants were counted peri-odically during the four-month experiment.The five vegetation communities(miscellaneous plants domi-nated by mesophytes and xerophytes;gipsywort+miscellaneous plants,reed+miscellaneous plants,reed dominated,and aquatic cattail dominated)were divided into three categories based on community charac-teristics,and responses among the five different vegetation communities to variation in water availability were significantly different.The results were summarized as follows:(1)For the miscellaneous plant com-munity,dominated by mesophytes and xerophytes under an artificial forest,plant species and quantity in-creased significantly with increased water.Compared with the drought treatment,plant species increased by 43.8%and quantity increased by 249.5%in the flooded treatment.The species and quantity of hydric plants such as sedge(Cyperus spp.)increased significantly,and the diversity indices of the vegetation community in the flooded treatment were higher than that of the drought treatment.(2)For the hydric and aquatic plant communities(gipsywort+miscellaneous plants community,reed+miscellaneous plants,and reed dominated)the number and density of plants were lowest in the normal treatment,but the diversi-ty of the plant com

关 键 词：湿地 植被类型 种子库 水分 妫水河 

分 类 号：S91[农业科学—水产科学]