坝上地区不同海拔农田和恢复半自然生境下尺蛾多样性

为研究生境恢复及地形变化导致的景观异质性对退化景观中生物多样性的影响,于2006和2007年对河北坝上3个不同海拔村庄的农田生境与恢复中的禁牧草地或再造林等半自然生境的尺蛾群落采用灯诱法进行取样调查,比较不同生境的尺蛾多样性.结果表明:两种生境类型间物种数和个体数存在显著差异、不同海拔村庄物种数也存在显著差异,但不同海拔村庄间个体数差异不显著,不同海拔村庄间以及各村庄内农田和半自然生境稀疏标准化物种数和Fisherα指数无显著差异;非度量多维标度法(NMDS)显示不同海拔的不同生境下尺蛾群落结构显著不同.地形变化导致的景观异质性对坝上地区尺蛾群落组成及多样性影响显著,而无论是恢复中的草地、再造林等半自然生境还是农田生境均是维持尺蛾多样性的重要生境.注重不同地形条件下农田生境和半自然生境景观镶嵌体的保护对维持尺蛾群落γ多样性具有重要意义,但生境恢复能否促进尺蛾群落多样性恢复尚需长期监测.

Diversity of geometrid moth (Lepidoptera: Geometridae) in cropland and reforested semi-natural habitats at different altitudes of Bashang Plateau, Hebei Province of China

In order to understand the effects of landscape heterogeneity induced by habitat restoration and landform change on the biodiversity in degraded landscapes, an investigation by using light trap was conducted on the geometrid moth (Lepidoptera: Geometridae) diversity in the cropland and reforested semi-natural habitats in three villages at different altitudes of Bashang Plateau in 2006 and 2007. There existed significant differences in the species richness and individual number of geometrid moth between cropland and reforested semi-natural habitats and in the species richness of geometrid moth between the villages at different altitudes, but no significant differences in the individual number of geometrid moth between the villages at different altitudes and in the standardized sparseness index and Fisher' s alpha index between the villages and between the cropland and reforested semi-natural habitats within each village. The non-metric multi-dimensional scaling (NMDS) indicated that the community structure of geometrid moth in different habitats and at different altitudes differed significantly. This study indicated that the landscape heterogeneity induced by land-form change had significant effects on the community structure and diversity of geometrid moth on Bashang Plateau, and, both cropland and reforested semi-natural habitats were the important habits for geometrid moth. It was suggested that to protect the landscape mosaics containing cropland and reforested semi-natural habitats across the varied landform of Bashang Plateau would have significances in the conservation of high gamma-diversity of geometrid moth, but whether the reforestation and creation of semi-natural habitats could improve the biodiversity of geometrid moth should be monitored in long term.