Biotic determinants of soil characteristics in the Northern Plains of Kruger National Park

The study investigates the effects that changing herbivory patterns in the Northern Plains of Kruger National Park have had on vegetation structure and composition and on soil characteristics, both chemical and physical. Type I herbivores such as zebra and buffalo have encroached into the area, which has been historically inhabited by type II herbivores such as roan and sable. The study found that the more intense and less selective grazing associated with type I herbivores has had a marked effect on vegetation and soil chemical characteristics. Overall grass and tree cover has decreased, and the size of the remaining trees is reduced. Colophospermum mopane seems to thrive especially under disturbance conditions. Calcium, available phosphorus, salinity, and pH have homogenized under the influence of type I grazers, while organic carbon and total nitrogen have diversified. Differential land use patterns and grazing habits of type I and type II herbivores may drive these changes. However, until these patterns are better understood, their role in determining vegetation and soil properties will remain unclear.本研究探究了克鲁格国家公园（Kruger National Park）北部平原草食动物取食模式的变化对植被结构、组成及土壤理化特性造成的影响。I型草食动物（如斑马、水牛）已侵入该区域，而该区域历史上以II型草食动物（如马羚、黑马羚）为主要栖息类群。研究发现，与I型草食动物相关联的高强度、低选择性取食，对植被及土壤化学特性产生了显著影响。整体而言，草地与林木覆盖率有所下降，留存林木的植株尺寸亦有所减小。莫帕内闭荚木（Colophospermum mopane）似乎在受干扰生境中尤为繁盛。在I型草食动物的影响下，土壤中的钙、有效磷、盐度及pH值均趋于均质化，而有机碳与全氮则呈现异质化特征。I型与II型草食动物差异化的土地利用模式与取食习性，可能是上述变化的驱动因素。然而，在尚未充分厘清此类取食模式的作用机制前，其对植被与土壤特性的调控作用仍有待进一步阐明。