Linking landscape-scale differences in forage to ungulate nutritional ecology

Understanding how habitat and nutritional condition affect ungulate populations is necessary for informing management, particularly in areas experiencing carnivore recovery and declining ungulate population trends. Variations in forage species availability, plant phenological stage, and the abundance of forage make it challenging to understand landscape-level effects of nutrition on ungulates. We developed an integrated spatial modeling approach to estimate landscape-level elk (Cervus elaphus) nutritional resources in two adjacent study areas that differed in coarse measures of habitat quality and related the consequences of differences in nutritional resources to elk body condition and pregnancy rates. We found no support for differences in dry matter digestibility between plant samples or in phenological stage based on ground sampling plots in the two study areas. Our index of nutritional resources, measured as digestible forage biomass, varied among landcover types and between study ...阐明生境与营养状况对有蹄类动物（Ungulate）种群的作用机制，可为种群管理工作提供决策依据，尤其针对正处于食肉动物种群恢复阶段且有蹄类种群数量呈下降趋势的区域而言。饲用植物物种可获得性、植物物候期以及饲草丰度的差异，使得解析营养因子对有蹄类动物的景观尺度效应颇具挑战。本研究开发了一种集成空间建模方法，在两个生境质量粗尺度指标存在差异的相邻研究区域内，估算景观尺度下马鹿（Cervus elaphus）的营养资源状况，并探究了营养资源差异对马鹿体况及妊娠率的影响。基于两个研究区域的地面样方采样结果，本研究未发现植物样本间干物质消化率存在显著差异，也未观测到植物物候期的显著差异。本研究以可消化饲草生物量为量化指标构建的营养资源指数，在不同土地覆盖类型间以及两个研究区域间存在显著差异……