CRYPTOGAM COVER AND SOIL SURFACE CONDITION - EFFECTS ON HYDROLOGY ON A SEMIARID WOODLAND SOIL

The response of infiltration to large changes in cryptogam cover was studied at three sites in a semiarid woodland in eastern Australia. The sites varied markedly in vegetation cover, soil physical condition, and degree of erosion, and represented a gradient from high condition (class 1) to low condition (class 3). Infiltration was markedly higher on sites with a high surface condition, but changes in cryptogam cover had little effect on infiltration. Infiltration rate on the degraded class 3 surfaces showed a significant positive response to cryptogam cover. Differences in the hydrological responses to cryptogam cover are attributed to differences in soil physical properties, particularly porosity and aggregate stability, and the different pathways by which infiltrating water accesses the soil profile. The results suggest that the role of cryptogam cover in controlling infiltration increases as soil surface condition declines.