澜沧江流域北部中华蜜蜂食源和营养生态位随海拔梯度的变化特征

为了解澜沧江流域北部中华蜜蜂(Apis cerana cerana)的分布,探究中华蜜蜂的食源和营养生态位沿海拔梯度的变化特征,调查了澜沧江流域北部各海拔区域中华蜜蜂的种群分布,运用蜂蜜孢粉学(melissopalynology)分析了各海拔区域中华蜜蜂蜂蜜中花粉的组成特征和变化规律,并综合分析了海拔、中华蜜蜂营养生态位和蜂蜜中花粉的相关性,探讨了自然环境与中华蜜蜂的分布,海拔梯度与蜜粉源植物、中华蜜蜂的食源和营养生态位的关系。结果表明:澜沧江流域北部中华蜜蜂的食源种类丰富,中华蜜蜂种群主要分布于2200—2800 m海拔区域。不同海拔区域中华蜜蜂采食花粉的种类和数量不同,中华蜜蜂种群分布多的海拔区域,蜂蜜中花粉的种类较多,但花粉数量相对少。随着海拔梯度升高,中华蜜蜂蜂蜜中花粉的数量表现为先降后增,而花粉的种类则表现为先增后降。不同海拔区域的中华蜜蜂营养生态位存在差异,推测各海拔区域蜜粉源植物分布、中华蜜蜂种内和种间授粉昆虫及食草动物等竞争因素不同,但各海拔梯度间的变化差异不显著。海拔与中华蜜蜂营养生态位呈正相关(r=0.051),相关性不显著;海拔与蜂蜜中花粉数量呈正相关(r=0.047),与蜂蜜中花粉种类呈正相关(r=0.144),相关性都不显著;中华蜜蜂营养生态位与蜂蜜中花粉的种类呈负相关(r=-0.305),相关性显著(P!0.05);与花粉的数量呈负相关(r=-0.064),相关性不显著。蜂蜜中花粉的数量与种类呈正相关(r=-0.303),且相关性显著(P!0.05)。

Response of food resources and trophic niche of Apis cerana cerana to an altitudinal gradient in the north valley of the Lancang River

To further understand the distribution of Apis cerana cerana in the north valley of the Lancang River, as well as variations in food resources and trophic niche, we investigated honeybee distribution at different altitudes. Using melissopalynology, we studied pollen composition of the honey samples collected from different altitudes. We analyzed the correlations between altitude, food resources, and trophic niche. The associations between the natural environment and A. cerana cerana distribution, altitude, nectar and pollen plants, food resources, and trophic niche were addressed in this study. The results showed that food resources were abundant in the north valley of the Lancang River, and A. cerana cerana mainly inhabited areas between 2,200 to 2,800 m above sea level. The types and quantities of pollen consumed by A. cerana cerana differed by altitude. At the altitude that most A. cerana cerana inhabited, pollen was rich in type but low in quantity. With altitude increasing, the quantity of pollen first decreased and then increased, where as the types first increased and then decreased. Trophic niches of A. cerana cerana were different according to altitude, which might be caused by the differences in plants, pollinating insects, and herbivorous animals. No significant correlations were detected between altitude and trophic niches (r=0.051), altitude and pollen quantity (r=0.047), or altitude and pollen types (r=0.144). Trophic niches were positively correlated with pollen types (r=-0.305, P < 0.05), but not with pollen quantity (r=-0.064). Pollen types in the honey sample were positively correlated with pollen quantity (r=-0.303, P < 0.05).