Yellow ground squirrel & fire, grazing in Kazakhstan

We aimed to understand the effects of changed grazing intensity and fire
frequency on a key ecosystem engineer, the Yellow Ground
Squirrel Spermophilus fulvus in Kazakhstan. Ground squirrels were
surveyed in an area of ca. 100,000 ha in the dry steppe of central
Kazakhstan, using hierarchical distance sampling at more than 200 random
points, stratified by fire frequency and livestock grazing intensity. We
modeled abundance as a function of different variables, grouped at the
landscape scale (fire and grazing), mesoscale (soil and vegetation
structure), and at burrow scale (plant traits such as palatability,
digestibility, and nutrient content).

本研究旨在探讨放牧强度与火灾频率的变化对哈萨克斯坦关键生态系统工程师——黄地松鼠（Yellow Ground Squirrel, Spermophilus fulvus）的影响。研究在哈萨克斯坦中部干旱草原约10万公顷的区域内开展，按火灾频率与家畜放牧强度进行分层，在200余个随机样点采用分层距离抽样法开展地松鼠种群调查。随后，将种群丰度作为多变量的函数进行建模，相关变量可归为三类尺度：景观尺度（火灾与放牧因子）、中尺度（土壤与植被结构）以及洞穴尺度（植物适口性、消化率及养分含量等性状）。