中文摘要：

本文以宁夏白芨滩国家级自然保护区两种典型的边缘类型：荒漠草原-人工固沙柠条林（边缘类型Ⅰ）和荒漠草原-固定半固定沙地（边缘类型Ⅱ）作为研究对象，以距离梯度（25米）的形式设置样点，主要采用巴氏罐诱法探讨边缘效应对其地表甲虫群落多样性的影响。本研究共采集到地表甲虫标本6760头，分属于19科68种，其中样地Ⅰ采集到2045头，样地Ⅱ采集到4715头。统计发现，拟步甲科昆虫占样地Ⅰ的70.46%、样地Ⅱ的81.91%，是该地区地表甲虫中的绝对优势类群。边缘类型Ⅰ中，边缘生境地表甲虫的物种数、优势度指数以及丰富度指数均高于相邻生境内部核心区域，而其均匀度指数和多样性指数则低于人工固沙柠条林核心生境。边缘类型Ⅱ中，边缘生境地表甲虫的物种数、丰富度指数以及多样性指数均高于相邻生境的内部核心区域。边缘效应强度分析表明，边缘类型Ⅰ的EH’ =0.9958，EC=1.1391，呈负的边缘效应，但负效应很弱，边缘类型Ⅱ的EH’ =1.1394，EC=0.5994，呈正的边缘效应，这一结果与边缘地带的环境复杂性和生境异质性有关。

英文摘要：

Two typical edge types of the Ningxia Baijitan National Nature Reserve were studied： desert steppe-artificial （for sand-fixation） Caragana korshinskii forest edge （edge type I ） and desert steppe-fixed semi-fixed sandy edge （edge type II ）. Sample points were in the form of a distance gradient over 25 meters, and beetles were collected, mainly with pitfall traps, to explore the impact of the edge effect on community diversity. A total of 6 760 beetles, comprising 68 species from 19 families were collected; 2 045 beetles from plot I and 4 715 from plot I1. Tenebrionidae comprised 70.46% of all specimens captured in plot I and 81.91% in plot H , Tenebrionidae are considered to be the absolutely dominant group in this region. In edge type I, species number, dominance （C） and richness （D） of ground-dwelling beetles living in the marginal area were higher than for those living in core areas of adjacent habitats, but evenness （J） and diversity （H＇） of ground-dwelling beetles living in the marginal area were both lower than for those living in the core area of the artificial sand-fixation C. korshinskii forest. In edge type H , species number, richness （D） and diversity （H＇） of ground-dwelling beetles living in the marginal area were higher than for those living in the core area of adjacent habitats. Strength analysis of the edge effect showed that in edge type I , E,, = 0. 9958, Ec = 1. 1391, which indicates a weak negative edge effect. In edge type II , EH, = 1. 1394, Ec = 0. 5994, which indicates a positive edge effect. These results relate to the complexity of the environment and habitat heterogeneity in marginal areas.