贺兰山区马鹿对冬季生境的选择性

Winter Habitat Selection by Red Deer (Cervus elaphus alxaicus) in Helan Mountain,China

20 0 3年 11— 12月 ,在贺兰山采用样带法对马鹿阿拉善亚种的生境选择性做了研究。在选定的 2 5条样带上一共测定了 87个利用样方以及 5 0个任意样方的 14种生态因子 (植被类型、优势乔木、坡向、坡位、食物丰富度、乔木密度、灌木密度、坡度、海拔高度、雪深、水源距离、人为干扰距离、裸岩距离和隐蔽级 )。结果表明 ,马鹿对 4种生态因子有选择性 :①植被类型 :偏好利用山地草原带和山地针叶林带 ,避免选择亚高山灌丛和草甸带 ;②优势乔木 :偏好利用混合型的生境 ,避免选择杜松、油松和无树的生境 ;③坡向 :偏好位于阳坡的生境 ,避免利用阴坡 ;④坡位 :偏好位于下坡位的生境 ,避免选择上坡位和中坡位。对利用样方和任意样方进行比较 ,发现马鹿的利用样方以灌木密度高、食物丰富、坡度小、接近水源、雪覆盖浅、远离裸岩和人为干扰为主要特征。对各种生态因子的主成分分析表明前 6个主成分的累积贡献率已经达到了 84 89% ,可以较好地反映马鹿的生境特征。第 1主成分反映出马鹿在选择生态因子方面与植被类型、乔木密度、灌木密度、坡向、坡度、距水源距离、雪深、海拔高度正相关。

Habitat selection of red deer (Cervus elaphus alxaicus) was studied from November to December,2003 in Helan Mountain which geographically locates in 38°21′-39°22′N,105°44′-106°42′E.Fourteen ecological factors of 87 sites used by red deer and 50 random plots were measured by locating from fresh sign or dung during 25 transects surveys crossing the whole study area.These factors included vegetation types,dominant tree,slope direction,slope location,food abundance,tree density,shrub density,slope degree,altitude,snow depth,distance to water resource,distance to human disturbance,distance to bare rock,and hiding cover.Red deer preferred montane grassland and montane conifer forest,and avoided subalpine shrubland and meadow;selected for mixture habitats,but rejection of habitats dominated by Juniperus rigida,Pinus tabulaeformis and no tree;utilized the paces with slopes exposed to the sun for lower slopes,and avoided shady slopes,upper and middle slopes.Comparing usage sites and random plots,usage sites were characterized by higher shrub density,higher food abundance,lower slope gradient,shallower snow cover and approach to water resource.Most sites were located farther away from bare rock and human disturbance.Results of principal component analysis showed that the 6 principal components explained 84.89% of the total variance.The first principal component was positively related to vegetation type,tree density,shrub density,slope direction,slope degree,distance to water resource,snow depth,and altitude.