大熊猫在原始林和次生林中生境利用的比较研究

在四川省宝兴县大熊猫栖息地中调查了 12种生态因子的 5 8种生境类型 ,利用Forageratio指数对大熊猫在原始林和次生林中的生境选择进行了比较研究 .在原始林 2 0 82个样方中发现有大熊猫痕迹样方 4 31个 ,有大熊猫痕迹样方数占调查样方数的 2 0 7% ;在 15 82个次生林样方中有大熊猫痕迹样方 15 2个 ,有大熊猫痕迹样方数占调查样方数的 9 6 % .研究结果表明 :①原始林中大熊猫回避大于坡度 4 0°的生境类型 ,而在次生林生境中对坡度没有表现明显的偏好 .②坡向和乔木郁闭度对大熊猫的生境选择没有明显影响 .③原始林和次生林中的大熊猫都偏好针阔混交林 ,但在次生林中还把选择范围扩大到针叶林和阔叶林 .④原始林中大熊猫偏好乔木胸径 30～ 5 0cm的生境 ,次生林中降至 2 0cm以上 .⑤大熊猫在原始林中回避竹类植物盖度低于 5 0 %的生境 ,在次生林则随机选择这类生境 .⑥大熊猫明显偏好原始林 .在全部 12个生态因子中 ,大熊猫对 11个因子的选择发生了改变 ,改变程度各不相同 .大熊猫在原始林中要回避的 9个生境类型 ,在次生林中变得随机选择 ;在原始林中随机选择的 6个生境类型 ,在次生林中变得偏好 .上述结果说明 ,对于原始林中回避或随机选择的生境特征 ,次生林中的大熊猫变成随机选择或偏好 .因此 ,大?

A comparative study on habitat preference of giant pandas in primary and secondary forests

The Forage ratio was used to compare habitat preference of giant pandas in primary and secondary forests in Baoxing (Muping) County, Sichuan Province, southwest China. The habitat selection spectrum of giant pandas is characterized by 58 categories of twelve ecological factors including degree, aspect, position of slopes, vegetation types, tree height, canopy, breast diameter, shrub height, shrub coverage, bamboo coverage, height, and growth status. Giant panda traces were found in 20.7% of 2 082 plots in primary forests and 9.6% of 1 582 plots in secondary forests. The results of comparison of habitat preference of giant pandas in primary and secondary forests show that: 1) the giant pandas in primary forests avoid slopes over 40 degrees, but pandas in secondary forests have no such preference; 2) slope aspect and canopy have no obvious influence on habitat preference of giant pandas; 3) the pandas in both primary and secondary forests prefer conifer-broadleaved mixed forests, but the giant pandas in secondary forests extend their selection to both conifer and broad-leaved forests; 4) in primary forests the giant pandas tend to select habitats having trees with breast diameter of 30～50 cm, in secondary forests breast diameter decreases to above 20 cm, in contrast; 5) the giant pandas in primary forests avoid habitats where bamboo coverage is less than 50%, but those in secondary forests have no such preference; 6) giant pandas prefer primary forests to secondary forests significantly. The giant pandas in secondary forests change their preference of 11 of 12 ecological factors. The giant pandas in secondary forests randomly select 9 habitat categories that are avoided by the giant pandas in primary forests. The giant pandas in secondary forests prefer 6 habitat categories that the giant pandas in primary forests randomly. The giant pandas in secondary forests randomly select or prefer the habitat categories that are avoided or random by the giant pandas in primary forests. Therefore, extending the habitat selection spectrum or shifting habitat preference is important approach of giant pandas to adapt secondary forests.