Effects of animal activity on the absorption rate of soils in the southern Karoo, South Africa

Abstract

The rates of absorption into various microsites in Karoo soils were compared. The absorption of water by hard, bare intershrub soils was significantly increased by the presence of emergence holes of adult cicadas (Homoptera: Cicadidae) and near nest‐mounds of the harvester ant Messor capensis. Both these insects play an important role in raising the amount of water that penetrates into the soil after rains. Absorption rates were also high in the soils of heuweltjie mounds but were reduced by sustained use of an area by sheep and were particularly poor on sheep paths.

Die absorbeer tempo in Karoogrond van verskillende mikrohabitate is gemeet en vergelyk. Absorbering van water in harde, kaal grond is betekenisvol deur die voorkoms van nuwejaarsbesiesgate (Homoptera: Cicadidae) en die nes‐hope van die saadvretende mier Messor capensis verhoog. Beide insekte speel ‘n belangrike rol in die verhoging van die hoeveelheid water wat na ‘n reënbui in die grond sal infiltreer. Die absorbering tempo is ook in die grond op die heuweltjies verhoog, maar dit is deur volgehoue beweiding van ‘n gebied deur skape verminder en was besonder laag op gekompakteerde skaapvoetpaaie.

Additional index words:

• Heuweltjie
• rangeland
• soil‐fauna
• trampling