山西省兽类一新记录

通过分子实验证实了采集于山西省芦芽山国家级自然保护区的一只雌性鼩鼱(头骨不完整)标本为苔原鼩鼱,为山西省兽类一新纪录。该分布点是苔原鼩鼱在全球最南分布点,黄河是苔原鼩鼱向南扩展的一道屏障。标本保存于四川省林业科学研究院动物标本室。     

基于Cyt b基因全序列鼩鼱属分子系统学分析——我国东北地区鼩鼱属物种的系统发生地位

利用mtD NA的Cyt b基因全序列对39个鼩鼱属物种的系统分化进行分析,其中包括我国东北地区具有的9个鼩鼱属物种。计算了遗传距离和构建了系统进化树。分子系统学分析支持鼩鼱属应该分为主要分布于古北区的亚属和主要分布于新北区的亚属。Sorex亚属包括分布在古北区的鼩鼱属物种和分布在全北区的苔原鼩鼱和姬鼩鼱,以及分布在新北区的北极鼩鼱。Otisorex亚属包括分布在新北区的鼩鼱属物种和分布在古北区的堪察加鼩鼱和弗兰格尔鼩鼱。特氏鼩鼱-索绪尔鼩鼱类群高度特化,支持其与Otisorex亚属具有更近的系统进化关系。本文探讨了我国东北地区具有的9个鼩鼱属物种的系统分化和分类学问题,进而明确了其在鼩鼱属的系统发生地位。支持姬鼩鼱为全北区物种。扁颅鼩鼱在系统发生地位上较为特化。支持栗齿鼩鼱属于XY_1Y_2性染色体复杂种组。大鼩鼱是东北分布的鼩鼱属物种中最特化的一个物种。我国东北分布和日本北海道分布的细鼩鼱属于不同亚种。     

Distribution of small mammals in a silvoarable agroforestry system in Northern England

The importance of agroforestry systems in temperate regions in providing habitat for small mammals has not been investigated. Numbers and densities of small mammals were assessed by live trapping in a complex farming landscape including mature hedgerows, arable fields, areas of trees planted at forestry density (2,500 trees ha–1) and trees in an agroforestry configuration (178 trees ha^–1) consisting of rows of trees separated by arable alleys. Over a 2 -year period, 1680 animals were captured; 69% were Apodemus sylvaticus L., 20% Sorex araneus L. and 10% Clethrionomys glareolus Schreber. Small numbers of Mus domesticus Rutty, Sorex minutus L., and Neomys fodiens Pennant were also caught. The density of captures of A. sylvaticus and S. araneus varied little over the whole farming landscape in contrast to C. glareolus which had a greater density of captures in mature hedgerows. However, for the small mammals collectively, away from hedgerows, the highest density of captures was found in the agroforestry tree rows (15.5 per 100 trap nights) and the least in open arable crop (4.3), with both arable alleys and forestry density trees having intermediate values (9.1 and 9.2 respectively).Densities of captures of A. sylvaticus were greater in the tree rows and arable alleys than in the forestry area and the adjacent open arable crop, whereas for S. araneus they were greater in the habitats with trees. It is clear that the range of habitats in an agroforestry system is valuable for small mammal conservation.     

Small mammals in agricultural landscapes: Opposing responses to farming practices and landscape complexity

Organic farming often counteracts the decline of various taxa owing to agricultural intensification, but little is known about the relative importance of local management and landscape context for small mammals. We examined the abundance, species richness and diversity of small mammal communities in 22 organically and conventionally managed winter wheat fields pairwise located along a gradient of landscape structural complexity (41–94% arable land). Complex landscapes significantly increased small mammal abundance and (with marginal significance) species richness and diversity, but only in conventional fields, whereas organic farming increased small mammals in simple landscapes. These results indicate the importance of landscape complexity for small mammal populations in an intensified agriculture. Analyses at multiple spatial scales (100 m, 250 m, 500 m radii around focal fields), showed opposing responses of the three most abundant species to landscape complexity. Apodemus agrarius PALLAS abundance increased with increasing landscape complexity at a spatial scale of 100 m, whereas Microtus arvalis PALLAS and Sorex araneus L. abundances decreased with increasing landscape complexity at spatial scales of 100 m and 500 m, respectively, suggesting species-specific ecological needs as well as functional spatial scales for conservation management. In conclusion, agri-environmental measures for small mammals such as organic farming are most effective in simple landscapes, while complex landscapes presumably function as source habitats and can compensate for local agricultural intensification in conventional fields.