Harris Nyeema C, Garshong Reuben A, Gray Morgan
Department of Environmental Science, Policy and Management, University of California, Berkeley, USA.
Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, USA.
J Mammal. 2018 Feb 1;99(1):117-123. doi: 10.1093/jmammal/gyx158. Epub 2017 Dec 16.
Species reside in dynamic environments, simultaneously experiencing variations in climatic conditions, habitat availability and quality, interspecific interactions, and anthropogenic pressures. We investigated variation in foraging ecology of the small mammal community between land-use classifications (i.e., protected national parks and unprotected lands abutting them) in Mole National Park (MNP) and Digya National Park (DNP), representing distinct ecoregions of Ghana. In 5,064 trap nights, we sampled 153 individuals of 23 species within the 2 national parks and adjacent lands outside protected boundaries to describe variation in community composition. We also used δ C and δ N isotopic ratios from fresh feces to determine main effects and interactions between land use and ecoregion on trophic structure in species and communities of small mammals. Small mammals exhibited distinct community assemblages between ecoregions (i.e., national parks): , , , , , and were only captured in the dry savanna ecoregion of MNP. Additionally, isotopic signatures for nitrogen were significantly lower in MNP (2.83 ± 0.17‰) compared to DNP (4.97 ± 0.33‰), indicating that small mammals occupied different trophic levels between ecoregions. The most common species, exhibited variation in isotopic signatures between ecoregions and land use, with higher δ N found within MNP boundaries. We found no distinction in δ C at the community or species level within or across protected areas. Ultimately, understanding shifts in the ecology of species can inform predictions about community structure and ecosystem function under future environmental and anthropogenic scenarios.
物种栖息于动态环境中,同时经历气候条件、栖息地可用性和质量、种间相互作用以及人为压力的变化。我们调查了代表加纳不同生态区的莫尔国家公园(MNP)和迪贾国家公园(DNP)内土地利用分类(即受保护的国家公园及其毗邻的未受保护土地)之间小型哺乳动物群落觅食生态的差异。在5064个诱捕夜中,我们在这两个国家公园及其保护区边界外的相邻土地上对23个物种的153个个体进行了采样,以描述群落组成的变化。我们还利用新鲜粪便中的δC和δN同位素比率来确定土地利用和生态区对小型哺乳动物物种和群落营养结构的主要影响及相互作用。小型哺乳动物在不同生态区(即国家公园)之间表现出明显的群落组合: 、 、 、 、 以及 仅在莫尔国家公园的干燥稀树草原生态区被捕获。此外,与迪贾国家公园(4.97±0.33‰)相比,莫尔国家公园的氮同位素特征显著更低(2.83±0.17‰),这表明小型哺乳动物在不同生态区占据不同的营养级。最常见的物种 在不同生态区和土地利用之间的同位素特征存在差异,在莫尔国家公园边界内发现其δN更高。我们发现在保护区内或保护区之间,群落或物种水平的δC没有差异。最终,了解物种生态的变化可以为预测未来环境和人为情景下的群落结构和生态系统功能提供依据。