The small tree, Dichrostachys cinerea, occurs in dense patches within grasslands on gabbro-derived soils in the southern Kruger National Park. It is not known whether soil properties in the grasslands affect tree establishment. As a first step in identifying soil properties potentially underpinning differences in vegetation structure, we analysed the soil chemistry of the pedoderm (0–2 cm) in Dichrostachys patches and adjacent open grassland. Relative to the Dichrostachys patches, the pedoderm of the grassland was significantly richer in K (1.4-fold), Ca (2.6-fold), Mg (3.4-fold), Mn (1.7-fold), B (1.2-fold) and Na (1.6-fold). The pH of the grassland was also higher than in the Dichrostachys patches (6.45 ± 0.14 vs 5.53 ± 0.09). It is unlikely that the vigour of tree seedlings, tree ramets or grasses in the Dichrostachys patches would be constrained by the concentrations of K, Ca, Mg, Mn, B and Na, or the pH, at the study site. Greater concentrations of K, Ca, Mg, Mn, B and Na in the pedoderm of the grassland are, however, likely to be linked to relatively greater nutritive value of the grass sward and in turn greater herbivory pressure. This effect is a potential cause of the greater constraint of D. cinerea seedlings and/or ramets in the grassland than in the Dichrostachys patches.

这种名为 Dichrostachys cinerea的小树生长在克鲁格国家公园南部辉长岩衍生土壤上的草地中密集的斑块中。目前尚不清楚草地的土壤特性是否会影响树木的建立。作为确定可能支撑植被结构差异的土壤特性的第一步，我们分析了Dichrostachys斑块和邻近开阔草地中的土壤化学成分（0-2 厘米）。相对于Dichrostachys斑块，草地的土壤显着富含 K（1.4 倍）、Ca（2.6 倍）、Mg（3.4 倍）、Mn（1.7 倍）、B（1.2 倍）和纳（1.6倍）。草地的 pH 值也高于Dichrostachys补丁（6.45 ± 0.14 对 5.53 ± 0.09）。Dichrostachys斑块中树苗、树分株或草的活力不太可能受到研究地点 K、Ca、Mg、Mn、B 和 Na 浓度或 pH 值的限制。然而，草地表皮中 K、Ca、Mg、Mn、B 和 Na 的浓度较高，可能与草坪相对较高的营养价值以及较高的食草动物压力有关。这种影响是草地中D. cinerea幼苗和/或分株比Dichrostachys斑块中更大限制的潜在原因。