Role of plant cover and stock trampling on runoff and soil erosion from semi-arid wooded rangelands [sheep; New South Wales]
1994
Breene, R.S.B. (Commonwealth Scientific and Industrial Research Organisation, Lyneham (Australia). Div. of Wildlife and Ecology) | Kinnell, P.I.A. (Commonwealth Scientific and Industrial Research Organisation, Canberra (Australia). Div. of Soils) | Wood, J.T. (Commonwealth Scientific and Industrial Research Organisation, Canberra (Australia). Biometrics Unit)
Relationships between plant cover, runoff and erosion of massive red earth were investigated in small experimental paddocks. There was a significant negative relationship between final runoff rate and plant cover. It is probable that the plants increase infiltration and decrease runoff by funnelling water down their stems and providing macropores at the base of the plant through which water can rapidly enter the soil. However, there was no significant effect of plant cover on sediment concentration. Probable reasons for this are given. At zero cover final runoff rates from paddocks with a high and low stocking rate were similar, i.e. 23.4 and 22.3 mm per h respectively. However, at zero cover, the sediment concentration from the high stocking rate paddock was significantly greater than that from the low stocking rate paddock. These results show that grazing by removing perennial grasses and pulverizing the surface soil can have a major impact on local water balances and erosion rates respectively within the intergrove areas. The implications of these results for the long-term stability of semi-arid mulga woodlands is briefly discussed.
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