【摘要】 2006年3—10月,在广东省罗坑鳄蜥自然保护区利用直接观察法对鳄蜥春、夏、秋3季的生境选择进行研究。春、夏、秋3季各测定了31、71、31个有鳄蜥样方以及50、90、51个对照样方的14种生态因子。利用生态因子对比分析和逐步判别分析确定各季节生境选择的主要影响因素。结果表明,春季影响鳄蜥生境选择的主要影响因素是溪沟底质中沙的含量和植被盖度,正确判别率为97.5%;夏季影响鳄蜥生境选择的主要影响因素是溪沟底质中沙的含量、植被盖度、溪流宽度和枯枝百分比,正确判别率为94.4%;秋季影响鳄蜥生境选择的主要影响因素是溪沟底质中沙的含量、植被盖度和可利用食物量,正确判别率为97.6%。在区分春、夏、秋3季鳄蜥生境选择方面有一系列生态因子发挥作用,依照贡献值的大小依次为可利用食物量、干扰距离、枯枝百分比、溪水流速、溪沟坡度和溪宽等6个因子,由这6个变量构成的方程对春、夏、秋3季鳄蜥生境的正确区分率达到76.7%。判别函数的分析表明,春、夏、秋3季鳄蜥的生境选择具有较高的差异性,以判别函数建立的判别分类图表明,春、夏季以及夏、秋季鳄蜥的生境选择重叠较多,而秋季与春季的重叠较少。更多还原

【Abstract】 From March to October 2006,habitat characteristics of 31,71,31 crocodile lizard(Shinisaurus crocodilurus) samples and 50,90,51 comparing samples(no crocodile lizard was found in these samples) were observed in Luokeng crocodile lizard Nature Reserve,Guangdong in spring,summer,and autumn respectively,to determine the main ecological factors affecting habitat selection in this species.The main ecological factors affecting crocodile lizard habitat selection in each season were determined by comparison and stepwise discriminant analysis of fourteen ecological factors measured in crocodile lizard samples and comparing samples in each of the respective seasons.Analysis showed that in spring,percentage of sand in the stream and vegetation coverage were the two main ecological factors affecting crocodile lizard habitat selection.A stepwise discriminant model including only these two factors yielded a predicted accuracy of 97.5%,the highest when compared to alternative models involving combinations of other sampled factors.In summer,percentage of sand in the stream,vegetation coverage,width of stream and percentage of dry branch were the main ecological factors affecting crocodile lizard habitat selection and the predicted accuracy of the model is 94.4%.In autumn,percentage of sand in the stream,vegetation coverage and food availability were the main ecological factors affecting crocodile lizard habitat selection and the predicted accuracy of the model is 97.6%.Habitats selected by S.crocodilurus in each season could be predicted with 76.7% accuracy by a model including six main ecological factors(in order of importance): food availability,distance to human disturbance,percentage of dry branch,velocity of stream water,slope of stream,and width of stream.Analysis also showed that S.crocodilurus spring,summer,and autumn habitats overlap to some extent,but that overlaps between spring and autumn were very low.更多还原