Vegetation characteristics and precipitation jointly influence grassland bird abundance beyond the effects of grazing management

Grassland birds have experienced some of the steepest population declines of any guild of birds in North America. The shortgrass steppe contains some of North America’s most-intact grasslands, which makes the region particularly important for these species. Grassland birds differentially respond to variation in vegetation structure generated by spatiotemporally-varying disturbance like grazing management. However, understanding how species respond to characteristics beyond vegetation structure or grazing could better inform management for these species in the shortgrass steppe. We analyzed point count data for 5 grassland bird species breeding on the Central Plains Experimental Range in northeastern Colorado from 2013 – 2017 to examine the predictive capacity of models representing fine-scale (~3-ha) vegetation attributes (vegetation structure and cover type) and topography, combined with interannual precipitation variability (i.e. vegetation-abiotic models). We then compared these mode...草原鸟类是北美各类鸟类功能群中种群下降幅度最为剧烈的类群之一。北美短草草原拥有该大陆保存最为完好的草原生态系统之一，因此该区域对于这类鸟类而言具有极高的保护价值。草原鸟类会对放牧管理这类时空动态干扰所塑造的植被结构差异产生差异化响应。然而，若能明晰草原鸟类对植被结构与放牧管理之外的环境特征的响应机制，将能为短草草原区域的该类鸟类保护管理提供更精准的科学依据。本研究以2013年至2017年在科罗拉多州东北部中部平原实验牧场繁殖的5种草原鸟类为研究对象，分析其点计数调查数据，旨在检验两类模型的预测效能：一类为表征精细尺度（约3公顷）植被属性（植被结构与覆盖类型）及地形的模型，另一类为结合年际降水变率的植被-非生物因子模型。随后本研究对上述模型进行了比较分析。