Chen Shiyu, Holyoak Marcel, Liu Hui, Bao Heng, Ma Yingjie, Dou Hongliang, Jiang Guangshun
Feline Research Center of National Forestry and Grassland Administration, College of Wildlife and Protected Area, Northeast Forestry University, Harbin 150040, China.
Department of Environmental Science and Policy, University of California, Davis, CA 95616, USA.
Sci Total Environ. 2022 Feb 1;806(Pt 1):150537. doi: 10.1016/j.scitotenv.2021.150537. Epub 2021 Sep 24.
Effects of climate warming on trophic cascades are increasingly reported for large herbivores occupying northern latitudes. During the last 40 years, moose (Alces alces) in northeast China have lost nearly half of their historical distribution through their habitat shifting northwards. There are many possible causes of bottom-up and top-down effects of temperature and for moose in northeast China they are poorly understood. Of particular relevance are the effects of extrinsic environmental factors on gene flow, nutritional adaptions, and gut microbiota that occur as moose populations retreat northwards. We combined molecular biology, nutritional ecology and metagenomics to gain deeper mechanistic insights into the effects of temperature on moose populations. In this study, we revealed that the direction and intensity of gene flow is consistent with global warming driving retreats of moose populations. We interpret this as evidence for the northward movement of moose populations, with cooler northern populations receiving more immigrants and warmer southern populations supplying emigrants. Comparison across latitudes showed that warmer late spring temperatures were associated with plant community composition and facilitated related changes in moose protein and carbohydrate intake through altering forage availability, forage quality and diet composition. Furthermore, these nutrient shifts were accompanied by changes in gut microbial composition and functional pathways related to nutrient metabolism. This study provided insights into mechanisms driving effects of spatial heterogeneous warming on genetic, nutritional and physiological adaptions related to key demographic rates and patterns of survival of heat-sensitive ungulates along a latitude gradient. Understanding such changes helps to identify key habitat areas and plant species to ensure accurate assessment of population status and targeted management of moose populations.
关于气候变暖对占据北纬地区的大型食草动物营养级联效应的报道越来越多。在过去40年里，中国东北地区的驼鹿（Alces alces）由于栖息地向北转移，其历史分布范围已丧失了近一半。温度的自下而上和自上而下的影响有许多可能的原因，而对于中国东北地区的驼鹿来说，人们对此了解甚少。特别相关的是外部环境因素对基因流动、营养适应和肠道微生物群的影响，这些影响发生在驼鹿种群向北退缩的过程中。我们结合分子生物学、营养生态学和宏基因组学，以更深入地了解温度对驼鹿种群的影响机制。在这项研究中，我们发现基因流动的方向和强度与全球变暖导致驼鹿种群退缩一致。我们将此解释为驼鹿种群向北移动的证据，较凉爽的北方种群接收更多移民，而较温暖的南方种群提供移民。跨纬度比较表明，晚春温度升高与植物群落组成有关，并通过改变饲料可用性、饲料质量和饮食组成，促进了驼鹿蛋白质和碳水化合物摄入量的相关变化。此外，这些营养物质的变化伴随着肠道微生物组成和与营养代谢相关的功能途径的变化。这项研究深入探讨了空间异质变暖对与关键种群动态率和热敏感有蹄类动物沿纬度梯度生存模式相关的遗传、营养和生理适应的驱动机制。了解这些变化有助于确定关键栖息地和植物物种，以确保准确评估驼鹿种群的现状并进行有针对性的管理。
