Quantitative ecological relationships in the alpine grassland of Lesotho

Abstract

A survey, based on 56 000 points at 102 sampling sites in the Tsehlanyane valley of the Oxbow (Madibamatso) Dam catchment in the alpine grassland of Lesotho, indicates that the area is generally in good condition. Physiographic and floristic criteria were measured and the association between pairs of criteria statistically tested. The simple (126 spp.) alpine vegetation had an average basal cover of 29% and it not significantly influenced by aspect, slope, or altitude within the study area. The effect of these topographic factors on soil surface components, namely, bare soil, organic matter, rock and animal dung and on soil depth, erosion and chemical soil properties, is analyzed. The role of the dominant grass species (Danthonia and Harpechloa) is discussed. The vegetation/habit relationships of the alpine region are compared with results for the adjacent montane region.

Keywords: quantitative analyses|ecology|grasslands|surveys|Tsehlanyane|catchment areas|physiographic features|floristic analyses|statistical analyses|vegetation|alpine environments|plant cover|field surveys|basal covers|topographical features|soil properties