贺兰山石鸡越冬期栖息地的选择

Winter Habitat Selection of Alectoris chukar potanini in Helan Mountains,China

于2004年11月-2005年1月期间,采用样带法对贺兰山区石鸡的栖息地选择进行研究。共测定了74个利用样方,结果表明:贺兰山石鸡(Alectoris chukar potanini)对植被类型具有选择性(χ2=453.17,df=3,P≤0.001),喜欢利用山地草原带,避免选择山地疏林草原带、山地针叶林带、亚高山灌丛和草甸带;对优势乔木的利用有选择性(χ2=195.76,df=6,P≤0.001),喜欢利用无树的栖息地,随机利用灰榆优势的栖息地,避免选择山杨、杜松、油松、青海云杉占优势和混合型的栖息地;对坡向(χ2=85.12,df=2,P≤0.001)选择性利用,喜欢位于阳坡的栖息地,避免利用阴坡的栖息地,对半阴和半阳坡随机利用;对坡位也具有选择性(χ2=44.93,df=2,P≤0.001),偏好下坡位,避免上坡位,对中坡位随机利用。并对利用样方和任意样方进行比较,石鸡的利用样方以乔木密度低、灌木密度低、草本覆盖度高、坡度小、雪覆盖浅、低海拔为主要特征。逐步判别分析表明,乔木密度、草本覆盖度、灌木密度和雪深具有重要作用。由这4个变量构成的方程在对利用样方和任意样方进行区分时,正确判别率可以达到94.9%。

A survey was conducted to study the habitat selection of chukar （Alectoris chukar potanini ） by transect-sampling method in Helan Mountains during November 2004 and January 2005. Seventy-four sample plots used by chukars were located and measured. The chi-square goodness-of-fit test indicates a significant difference between availability and usage of vegetation types. Chukars prefer montane grassland, and avoid other vegetation types （montane steppe, montane conifer, subalpine shrubland and meadowland） in Helan Mountains. There is also a markedly difference in dominant tree between availability and utilization. Chukars prefer habitats with no tree, and avoid habitats with Populus davidiana, Juniperus rigida, Pinus tabulaeformis, Picea crassifolia as dominant tree species or with mixed trees. Chukars use habitats dominated by Ulmus glaucescens in proportion to its availability. An obvious difference was also found between availability and usage of slope direction. Chukars show a strong preference for sunny slope and avoid shady slope. Chukars randomly utilize half sunny and shady slope. Slope position used by chukars exhibits a significant difference between availability and utilization. Chukars prefer lower slope, avoid upper slope, and select middle slope in proportion to its availability. Compared with random plots, the used plots are characterized by fewer trees, fewer shrubs, higher herbage coverage, steeper slope, shallower snow cover and lower ahitude. Tree density, herbage coverage, shrub density, and snow depth are identified to discriminate the used plots and random plots for chukars. Overall classification success of the model reaches 94.9%.