Mammal Research Institute, Faculty of Natural and Agricultural Sciences, University of Pretoria, South Africa.
Department of Economics, Universidad de Alcalá, Plaza Victoria, 2, Alcalá de Henares, 28802, Spain.
J Environ Manage. 2021 Sep 1;293:112820. doi: 10.1016/j.jenvman.2021.112820. Epub 2021 Jun 9.
The complex relationships that exist between terrestrial mammals and their habitats make African ecosystems highly interactive environments. Anthropogenic activities including climate change have altered geochemical cycles, which influence nutrient availability and deficiency at local, regional and global scales. As synergistic and antagonistic interactions occur between essential elements at both deficiency and excess concentrations, the differences in feeding strategy between trophically distinct groups of terrestrial vertebrates are likely to influence the degree to which overall nutrient needs are met or may be deficient. The overall aim of this study was to investigate and compare quantitative differences of nine essential elements in terrestrial vertebrates occupying different trophic levels within two protected areas; Tswalu Kalahari Reserve (TKR) and Manyeleti Nature Reserve (MNR) South Africa, using faeces as an analytical matrix. Results from linear mixed effects models highlight that concentrations varied widely between individuals. Overall, measured concentrations above their respective means were evident for B and Mn in herbivores, Fe in omnivores and Cu, Co, Fe, Se and Zn in carnivores. Measured concentrations of Mo and Ni did not differ significantly between trophic groups. Although site-specific differences were evident for specific elements, measured mean concentrations of B, Co, Cu, Fe, Mo, Ni, Se and Zn were significantly higher overall at the MNR study site compared to the TKR site. This is the first study to non-invasively assess essential element concentrations across trophic levels in free ranging African wildlife species within protected areas of the savannah biome. Combined with the assessment of environmental matrices, this approach can be used as an effective diagnostic tool for the assessment of animal welfare and the management of protected areas globally.
陆地哺乳动物与其栖息地之间存在着复杂的关系，使非洲生态系统成为高度互动的环境。人为活动，包括气候变化，已经改变了地球化学循环，从而影响了当地、区域和全球范围内养分的可利用性和缺乏程度。由于必需元素在缺乏和过量浓度下都会发生协同和拮抗相互作用，因此营养需求在不同营养层次的陆地脊椎动物之间的差异，可能会影响整体营养需求的满足程度或可能存在的缺乏程度。本研究的总体目标是通过粪便分析基质，调查和比较在南非两个保护区（特瓦卢卡拉哈里保护区和曼耶利蒂自然保护区）中不同营养层次的陆地脊椎动物中 9 种必需元素的定量差异。线性混合效应模型的结果表明，个体之间的浓度差异很大。总体而言，在食草动物中，B 和 Mn 的浓度高于平均值，在杂食动物中 Fe 的浓度高于平均值，在肉食动物中 Cu、Co、Fe、Se 和 Zn 的浓度高于平均值。Mo 和 Ni 的测量浓度在不同营养层次之间没有显著差异。尽管特定元素的站点特异性差异明显，但与 TKR 站点相比，MNR 研究站点的 B、Co、Cu、Fe、Mo、Ni、Se 和 Zn 的测量平均浓度总体上更高。这是第一项在保护区内对自由放养的非洲野生动物物种进行跨营养层次的非侵入性评估必需元素浓度的研究。结合环境基质的评估，这种方法可以作为评估动物福利和全球保护区管理的有效诊断工具。
