干旱区景观异质性对地表甲虫多样性的影响

The influence of landscape heterogeneity on diversity of ground beetles in arid regions

以古河道、绿洲农田和沙漠区3种景观条件下的11个生境为实验对象,采用陷阱技术,监测景观异质性条件下不同生境地表甲虫多样性动态分布。在整个监测期内11个生境中共采集地表甲虫1262头,地表甲虫隶属15科,其中拟步甲科Tenebrionidae、步甲科Carabida和象甲科Curculionidae为该地区的优势类群,分别占地表甲虫个体总量的58.72%、20.6%和8.72%;古河道和沙漠区物种丰富度大于绿洲区,但绿洲区有机农田防护林(L2)多样性指数在11个生境中最大,不同生态界面之间的多样性指数没有显著性差异,但小生境内存在差异性。群落排序表明:拟步甲喜好干旱、地表有一定凋落物的小生境;步甲则偏好有机质比较高、土壤湿度大的绿洲农业区。绿洲农业区域拟步甲类群数量相对沙漠区域下降近20倍,古河道区域该类甲虫数量下降近8倍。土地开垦导致景观破碎化和微环境变化是物种多样性丧失的重要因子。在干旱区管理中,土地开垦区域选择、残留地和动物通道的设置及环境友好农业生产建设,是保护地表甲虫的重要途径。

The impact of landscape heterogeneity on the ground beetle diversity was evaluated in the dry river beds, oasis agricultural area and the desert landscape under the condition of 11 habitat . A total of 1262 ground beetle samples were collected in 11 habitats by using pitfall traps during the monitoring time. Results indicated that all beetles belonged to 15 families, and Tenebrionidae was the dominant species in the area, accounting for 58.72% of the total number of individuals, following Carabidae （20.6%） and Curculionidae （8.72%）. Species richness in the dry river beds and the desert was greater than that in the oasis agricultural area, and the diversity index of forest belts in the oasis area was highest among the 11 habitats. There were not significant differences among the landscape interfaces, and significant differences among 11 habitats. The individuals of Tenebrionidae preferred the dry habitats with litter cover while those of Carabidae favored the wet habitats with rich organic matter by the CCA ordination. Individuals of Tenebrionidae in desert with trivial disturbance, and 8 times agricultural area reduced 20 times more compared to those in more than those in dry river beds with moderate interference.Beetle diversity decrease imply that it is important for protecting the ground beetles to choose reclamation area, protect remnant habitat and build the channels of animals.