民勤绿洲盐碱化退耕地植被自然演替及土壤水分垂直变化研究  

Natural Vegetation Succession and Soil Water Change in Fallow Salinization Cropland in Minqin Oasis,Gansu Province

作　　者：何芳兰[1] 李治元[1] 赵明[1] 尉秋实[1] 郭树江[1] 王多泽[1] 

机构地区：[1]甘肃省治沙研究所甘肃民勤荒漠草地生态系统国家野外科学观测研究站,甘肃武威733000

出　　处：《中国沙漠》2010年第6期1374-1380,共7页Journal of Desert Research

基　　金：国家"十一五"科技支撑计划项目(2007BAD46B00);甘肃省重大科技专项(0702NKDH030)资助

摘　　要：采用时空互代的方法,对民勤绿洲盐碱化退耕地21个样地105个样方的自然恢复植被以及土壤水分进行调查,并对各植被群落特征和土壤水分垂直变化进行统计分析。结果表明,退耕后50a的植被演替过程中,调查样方内共出现植物22种,分属于11科21属;退耕地植被自然恢复的过程大致经历了田旋花、独行菜、骆驼蒿、苏枸杞和盐爪爪5种群落类型的演替;在整个演替过程中,植被恢复大体分为迅速恢复期(1～2a)、初始更替期(3～8a)、高级更替期(9～28a)和缓慢恢复期(29a以后)4个阶段,同时,Margalef指数、Simpson指数和Shannon-wiener指数均呈现出波动式减小的变化趋势,Monk指数、Pielou指数和Alatalo指数则呈现出波动式增大的变化趋势。此外,不同时间退耕地土壤水分垂直变化差异显著,随着退耕时间的不断延长,土壤水分整体经历了先急剧减小后缓慢递增的变化趋势;根据其含水率大小大致分为3组:土壤含水率较低者(20世纪70年代、1978年和1999年退耕),大部分土壤含水率低于10%;土壤含水率较高者(20世纪50年代、60年代和2004年退耕),土壤含水率绝大部分大于10%;土壤含水率最高者(2007年退耕),土壤含水率大部分大于20%。Survey on natural vegetation and soil water of fallow salinization croplands in Minqin oasis,Gansu Province has been conducted by sampling in105 quadrates of 21 sample plots.The natural vegetation succession and soil water change were studied by the method of space series replacing time series.In the 50 years of natural vegetation succession since cropland being fallow there appeared 22 plant species,belonging to 21 genera of 11 families.The community generally experienced a succession of Convolvulus arvensis community to Lepidium apetalum community to Peganum nigellastrum community to Lycium ruthenicum community and to Kalidium foliatumcommunity.The succession process can be divided into four stages：the speedy restoration stage（1-2 years）,primary alternating stage（3-8 years）,high-level alternating stage（9-28 years）and slow restoration stage（after 29 years）.Along with the vegetation succession,the Margalef index,Simpson index,and Shannon-wiener index decreased and the Monk index,Pielou index,and Alatalo index increased except for some secondary fluctuating.Simultaneously,soil water content experienced sharp decrease at first and a slow increase afterwards.The soil water content is lower than 10%in croplands being fallow in 1970s,1978 and 1999;is within 10%-20%in croplands being fallow in 1950s,1960s and 2004;and is higher than 20%in croplands being fallow in 2007.

关 键 词：植被特征 自然恢复 物种多样性 土壤水分 退耕地 民勤绿洲 

分 类 号：Q948.15[生物学—植物学]