Abstract: To investigate the distribution characteristics of mineral elements in the habitat soil-food-faeces continuum of wild giant pandas, we collected samples of soil, dietary bamboos, and feces from the core area of Foping National Nature Reserve in Shaanxi Province in the year of 2022. All samples were analyzed for the absolute and relative contents of nine nutritionally essential minerals: Fe, Mn, Zn, Cu, K, Ca, Mg, P, and Na. The results showed that the absolute content of mineral elements in soil-food-feces was not entirely consistent. The elements with high absolute content in the soil were not always rich in the food bamboos and feces, and minerals that were of less absolute abundance in the soil were not always low in the food and feces. Minerals in soil and bamboo leaves showed a close positive or negative correlation, whereas elements in the feces showed significant positive correlations without detected negative relevance. After the whole process of ingestion, digestion, and absorption of bamboo leaves by giant pandas, the relative contents of most minerals changed in the feces. The feces showed lower relative concentration of P and Na than in the food when feeding on Bashania fargesii; whereas there was no significant difference in the content of Ca, Mg, K, Mn, Cu, and Zn. Furthermore, Fe was significantly higher in feces than in food. When feeding on Fargesia qinlingensis, there was no significant difference in the relative content of Mn, the relative content of Fe in feces was significantly higher than in food, and the relative contents of the other seven elements in feces were significantly lower than in food. Therefore, the contents of mineral elements in soil-food-feces were not completely consistent. When giant pandas fed on different bamboo leaves of different species, their utilization rates of different mineral elements varied. Among the 9 essential elements, Fe had the lowest absorption rate. Our results illustrated the distribution characteristics of mineral elements in the habitat soilfood-feces continuum and the differences in the utilization of 9 essential mineral elements by giant pandas, which help us further understand the nutritional strategies of wild giant pandas and provide references for the mineral nutrition regulation on giant pandas in captive settings.

Key words: Giant panda, Minerals, Habitat soil-food-feces continuum

摘要： 为了解大熊猫栖息地内土壤-食物-粪便中矿物元素分布特征，本研究于2022年3月和8月，在陕西佛坪国家级自然保护区核心区内采集大熊猫栖息地土壤、食物和粪便样本。对样本中的钙(Ca)、镁(Mg)、磷(P)、钠(Na)、钾(K)、铁(Fe)、锰(Mn)、锌(Zn)、铜(Cu)9种动物必需矿物元素绝对含量进行检测，并对各元素在食物和粪便中的相对含量进行比较分析。结果显示：土壤中绝对含量高的元素，在食物和粪便中的绝对含量不一定高；土壤中绝对含量低的元素，在食物和粪便中绝对含量不一定低。土壤和竹叶中，各矿物元素之间存在广泛的正相关或负相关关系，粪便中各矿物元素呈现显著正相关。竹叶经大熊猫消化利用之后，各个元素的相对含量在粪便中发生变化。当大熊猫采食巴山木竹(Bashania fargesii)叶时，P和Na的相对含量表现为粪便低于食物，Ca、Mg、K、Mn、Cu和Zn在食物和粪便中的相对含量无显著差异，而Fe在粪便中的相对含量显著高于食物；当主食秦岭箭竹(Fargesia qinlingensis)叶时，Mn在食物和粪便中的相对含量无显著差异，Fe的相对含量表现为粪便高于食物，其他7种元素在粪便中的相对含量均显著低于食物。矿物元素在土壤-食物-粪便中的绝对含量不完全一致；大熊猫采食不同主食竹竹叶时，对不同矿物元素的利用率不同，在9种元素中对Fe的吸收率均最低。这些结果阐明了野外大熊猫栖息地土壤-食物-粪便中矿物元素含量和分布特征，以及大熊猫对必需矿物元素的利用存在差异，有助于进一步理解野生大熊猫的营养对策，并为圈养大熊猫矿物质营养调控提供参考。

关键词: 大熊猫, 矿物质, 栖息地土壤-食物-粪便