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西藏慈巴沟自然保护区羚牛栖息地选择

吴鹏举,张恩迪   

  1. 东莞理工学院,东莞,
  • 出版日期:2006-06-07 发布日期:2008-07-07

Habitat selection of takin (Budorcas taxicolor)in Cibagou Nature Re- serve of Tibet,China

WU Pengju,ZHANG Endi   

  • Online:2006-06-07 Published:2008-07-07

摘要: 2001 年12 月至2002 年8 月,笔者在西藏慈巴沟自然保护区对羚牛栖息地选择性及其季节变化进行了调查研究。调查中,沿慈巴沟河谷随机选择起始点,系统地设置了187个10 m×10 m 的固定样方,记录了样方所在位置的植被类型、海拔、坡度、坡向、距水源距离、乔木密度、灌木密度、箭竹密度、郁闭度和隐蔽度等,并分别在冬、春、夏三季检查样方是否被羚牛利用。本文通过计算Vanderloeg 选择系数和Scavia 选择指数来研究羚牛对植被的选择性,结果发现羚牛冬季对杜鹃针叶林、箭竹针叶林和针阔混交林具有正选择性,春季则对箭竹针叶林和针阔混交林、夏季对高山灌丛草甸和杜鹃针叶林具有正选择性。对9 个数量化因子进行分组处理,利用Vanderloeg 选择系数和Scavia 选择指数,计算了这些因子在各个季节不同的选择性,进一步分析了羚牛对栖息地的选择性。对9 个数量化因子的判别分析表明,冬、夏及春、夏之间有极显著差异,海拔对判别函数的贡献最大,其它因子如箭竹密度、隐蔽度、郁闭度和乔木密度等贡献也较大,说明这些因子的季节分离明显。而羚牛的冬、春之间判别分析不显著,季节分离的程度较小。在结合其它分布区羚牛栖息地研究的基础上,本文探讨了食物和盐源在羚牛栖息地选择季节变化中的作用。

关键词: 羚牛, 栖息地选择, 季节性变化

Abstract: In recent decades most studies of takin (Budorcas taxicolor)have been conducted in Shaanxi,Sichuan and Yunnan. Relatively little work has been focused on habitat selection of takin and especially,that of the species in Tibet. From December 2001 to August 2002,we conducted a study on habitat selection of takin in Cibagou Nature Reserve, which lies in Zayu county,southeastern Tibet. Cibagou is characteristized by high mountains and deep valleys. We randomly placed fourteen transects oriented perpendicularly to elevation contours within the Cibagou valley. Within transects,we set a total of 187 sample plots (10 m×10 m)every 250 m from the bottom to the upper. At each plot,we quantified 10 variables (including vegetation and other quantitative factors). Plots were checked for fresh tracks of takin in winter,spring and summer. Vanderloeg coefficients and the Scavia indices were used to evaluate takin habitat selection. Takin used 44 plots in winter,39 in spring,and 20 in summer. Takin actively selected for Rhododendron-coniferousforest,Fargesia-coniferous forests and Theropencedrymion in winter,Fargesia-coniferous forests and Theropencedrymion in
spring,and Alpine meadow-shrubs and Rhododendron-coniferous forests in summer. Vanderloeg coefficients and Scavia indices confirmed these seasonal differences. Discriminant analysis of nine quantitative factors didn't show the significant difference between winter and spring,despite the significant differences among bamboo density,elevation and slope degree between the two seasons;the differences between spring and summer,winter and summer were highly significant in the analysis, and bamboo density,shelter,canopy cover,tree density,and especially elevation,also took on significant seasonal difference. Based on the comparison of researches on takin habitat between in Cibagou and elsewhere,we suggest that food might play a key role on vertical migration of takin,whereas salt might also influence takin movements in summer.

Key words: Habitat selection, Takin (Budorcas taxicolor), Seasonal changes