Ecology of the Hardman Basin, N.T.
by C.S. Robinson.
Robinson, C. S.; Australia. Dept. of the Northern Territory. Animal Industry and Agriculture Branch
E-Publications; E-Books; PublicationNT
Made available via the Publications (Legal Deposit) Act 2004 (NT).
Ecological surveys -- Northern Territory -- Hardman Basin; Soil erosion -- Northern Territory -- Hardman Basin
Northern Territory Administration
54 p. in various pagings, 5 leaves of plates : ill. ; 30 cm.
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The red. sandy soils developed on the Elder sandstone formation have a high permeability, carry a generally dense grass oover are developed on very gentle slopes. They are thus relatively areas and beyond. local soalding and minor sheetwash there ha.s been little serious accelerated erosion. the shale formations that accelerated erosion reaches severe proportions. Destruction of the original cover . has laid. the soil surface open to the direct impaot Raindrop i~pact has had. two important effects. contributed to the removal of topsoil, either by splash movement or by sheetwashing. The subs~il thus exposed, although loose and crumbly when dry, readily seals when wet and has a very infiltration rate. Both these effects have in fact given the measure of protection. Removal of topsoil has concentrated on the surface and sealing prevents further high soil losses.. However the changed surface conditions have radically the environment for plant growth and there is now only minima.l obstruction to uncontrolled and excessive run-off of and type of erosion depends on the following faotors: Vegetative cover; of slope; IJength of slope; Topographic position; 5 Inherent stability; 6 Disturbance of the soil surface all these factors can be interacting and in general one cannot be discussed without reference to the others. The discussion will be based on topographic position with reference to the other factors as they affect the erosion. surfaces Areas of plateau surface are found round the eastern margins of the Nelson shale formation, being most extensive in the vicinity of the airstrip near Nelson Springs. That this surface is inherently stable is evidenced by the existence of a very hard of calcrete which has developed in the soil. Generally slopes are gentle and rarely exceed 2%. The vegetation is typically th~ En~eapogon-Chrysopogon Complex association. There is little evidence of serious erosion even where the pasture has deteriorat,ed, although in these areas many trees are dead which suggests .. that has at least been a deterioration in the soil surface characteristics. upper convex slopes The of the crests is at best the Enneapogon association,