The indirect impact of encroaching trees on gully extension : A 64 year study in a sub-humid grassland of South Africa

Auteur(s) et Affiliation(s)



Description :
The AA. used aerial photographs to study Acacia sieberiana encroachment and gully erosion in a South African grassland (KwaZulu-Natal Province) for a period lasting 64 years. At the catchment scale, results showed that acacias started invading after 1976 and transformed the grassland into a savanna with 9.45% of tree cover in 2009. Gully area increased by 3.9% in the last 64 years and represented 12.76% of catchment area in 2009. A positive correlation between gully retreat rate and Acacia canopy area was measured between 2001 and 2009 when established tree encroachment was observed. These results, associated with the susceptibility of this soil to subsurface flow and the observation of pipe erosion systems in the field, showed that both surface and subsurface processes occur in this sub-humid grassland and that trees can be indirectly associated with increased gully erosion.


Type de document :
Article de périodique

Source :
Catena (Giessen), issn : 0341-8162, 2012, vol. 98, p. 110-119, nombre de pages : 10, Références bibliographiques : 2 p.

Date :
2012

Editeur :
Pays édition : Allemagne, Cremlingen-Destedt, Catena