不同土地利用方式对河北坝上步甲物种多样性的影响

Influence of land uses on species diversity of carabid beetles(Coleopeta,Carabidae) in Bashang region,Hebei,Northern China

为了探讨土地利用方式对步甲物种多样性的影响及其与环境因子的关系,于2009年5-10月利用巴氏罐法,对河北坝上塞北管理区内的灌草丛、马铃薯地、苜蓿地、围封草地、中度放牧草地和重度放牧草地6种生境的步甲进行了系统调查。结果表明:(1)共捕获步甲标本10804号,计10属18种,其中强足通缘步甲Pterostichus fortipes、侧步甲Carabus latreillei和双斑猛步甲Cymindis binotata占优势,个体数分别占总数的67.5%,7.53%和7.06%。(2)苜蓿地中的步甲密度、物种丰富度、Margalef丰富度指数、Shannon-Wiener多样性指数和均匀度指数均较高,其他样地较低。(3)聚类分析结果显示,不同生境的步甲群落相似性与受干扰强度和土地利用方式一致。(4)步甲主要在6-9月活动,高峰期为7-8月。各物种在不同土地利用方式生境内的季节变化趋势与不同生境植被生长季节相关,步甲个体数量随着植物生物量的增加而增加。强足通缘步甲Pterostichus fortipes高峰期大多出现在植物生长旺盛的7月,仅围封草地内的高峰出现在8月;双斑猛步甲Cymindis binotata的高峰期出现在8-9月。(5)典范对应分析表明,土壤含水量、土壤温度、植物盖度、植物生物量及植株高度是影响步甲群落组成的重要环境因子。结论认为,不同土地利用方式对环境的干扰影响了步甲赖以生存的生境,进而影响了其物种的组成和数量分布格局。

To study the species diversity pattern of carabids and its relation with environment factors in different ways of land use,systematic investigation of carabid beetles were conducted from May to October in 2009 by pitfall traps in Saibei Administrative Region,Hebei Province,Northern China.Carabid beetles caught from six habitats of different land uses,i.e.,shrub-meadow,potato land,clover field,enclosed meadow,moderately grazed meadow and heavily grazed meadow,were identified and analyzed.The results showed that a total of 10 804 carabid beetles were collected,belonging to 10 genera and 18 species.Among all collected specimens,Pterostichus fortipes,Cymindis binotata and Carabus latreillei accounted for 67.5%,7.53% and 7.06% of total specimens,respectively.The highest density of carabids was found in clover field,followed by potato field,and the lowest density in heavily grazed meadow.As to clover field,there was almost no disturbance,and the species richness,Margalef richness index,Shannon-Wiener diversity index and the evenness index of carabids were higher in clover field than other ones.The result of clustering analysis showed that the similarity of beetle community in different habitats accords with interference strength and land use patterns.Beetles seasonal activities were mainly from June to September,and peaked in July and August.Various species in different land use patterns have different seasonal trends.The number of carabid individuals increased with the plant biomass.Pterostichus fortipes mostly reached a peak in July when plants grow in luxuriance,except that the peak within the enclosed meadow appeared in August; Cymindis binotata peaked in 8-9 months.Canonical corresponding analysis indicated that the soil moisture,soil temperature,plant cover,plant biomass and plant height were important environmental factors in carabid community composed.The results suggest that the disturbance of different land uses influenced the environments where carabid beetles survived,and then influenced the species composition and quantity distribution pattern.