检索规则说明:AND代表“并且”;OR代表“或者”;NOT代表“不包含”;(注意必须大写,运算符两边需空一格)
检 索 范 例 :范例一: (K=图书馆学 OR K=情报学) AND A=范并思 范例二:J=计算机应用与软件 AND (U=C++ OR U=Basic) NOT M=Visual
作 者:郭砺[1]
机构地区:[1]内蒙古大学生命科学学院,呼和浩特010021
出 处:《内蒙古大学学报(自然科学版)》2004年第6期658-662,共5页Journal of Inner Mongolia University:Natural Science Edition
摘 要:对内蒙古土默特平原(40~41°N,109~112°E)由于生境变化引起的草原沙蜥(Phryno-cephalusfrontalis)种群特征的变化作了研究.在植被盖度<10%的沙地生境,草原沙蜥密度较高,当沙地种植柠条(Caraganakorshinskii)7~8年后,植被盖度变为>40%且食物较以前丰富充足,其密度下降,低年龄组死亡率增高是种群衰退的主要原因.营养生态位宽度指数增大,但沙蜥对鞘翅类昆虫的取食频次有所减少.The effects of habitat changes on pasture lizard (Phrynocephalus frontalis) population were studied from 1989~1992 and from 2000~2001 in Tumote plain(40~41°N,109~112°E),NeiMongol.In the sandy habitat,the density of P.frontalis was higher when the vegetation coverdegree was <10%,whereas the density of P.frontalis population declined gradually when Caragana korshinskii was planted at the habitat 7~8 years later,the vegetation coverdegree rose to >40% and the diet became more abundant for pasture lizard.The higher mortality of the 2-year old group was the main reason for degeneration of lizard population.When the width of the trophic niche enlarged,the eating frequency of pasture lizard to insects Coleoptera decreased obviously.
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在链接到云南高校图书馆文献保障联盟下载...
云南高校图书馆联盟文献共享服务平台 版权所有©
您的IP:216.73.216.15