Savanna is a species-rich biome, that includes many modern mammal lineages and C₄ grass (Poaceae) species. The greater productivity and grazing pressure associated with savannas is likely attributable to the foliar traits of the grasses they support. Thus, it is important to understand the complex relationships between the abiotic environment, foliar attributes and the floristic composition of savanna grasses, and the supported grazer densities. We sampled 37 grass communities in the Kruger National Park (South Africa) across three soil types and along a rainfall gradient and found that these communities lack strong phylogenetic structure. We then measured specific leaf area and leaf tensile strength for 384 individuals representing 66 species and found that both traits were strongly phylogenetically structured and associated with both rainfall and soil type. Finally, we found that grazer densities in the Park are correlated with the foliar traits of the associated grass communities, but the resolution of our data do not allow for a thorough analysis of this association. Our results demonstrate the complex interactions between climate, soils and grazer densities relative to C₄ grass functional traits.

稀树草原是物种丰富的生物群落，其中包括许多现代哺乳动物谱系和C ₄草（禾本科）种类。稀树草原带来的更高的生产力和放牧压力很可能归因于它们所支持的草的叶片性状。因此，重要的是要了解非生物环境，大草原草的叶属性和植物组成与所支持的放牧者密度之间的复杂关系。我们在克鲁格国家公园（南非）的37种草木群落中，对三种土壤类型和降雨梯度进行了采样，发现这些群落缺乏强大的系统发育结构。然后，我们测量了代表66个物种的384个个体的比叶面积和叶抗张强度，发现这两个性状在系统发育上均很强，并且与降雨和土壤类型有关。最后，我们发现公园中的放牧者密度与相关草丛的叶片性状相关，但是我们数据的分辨率无法对这种关联进行透彻的分析。我们的结果表明气候，土壤和放牧密度相对于碳之间的复杂相互作用₄种草的功能性状。