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Scott, D.F., and Van Wyk" D.B., 1990, The effects of wildfire on soil wettability and hydrological beha~iour of an afforested catchment: Joumal of Hydrology, v. 121, p. 239-256. Thi5 study reported some of the complex hydrological responses' hat resulted during the first year after a high intensity wildfire on a South African rese arch catchment in the Jonkershoek State Forest. Prior to burnlng, approximately half of the catchment was vegetated with fynbos (the indigenous ~crub vegetation of South Alrica) and the remainder afforested with Pinus radiata for tinber harvesting. Soils were charac terized by friable, sandy to silty loams (with approximately 10% clay content), derived from sandstone colluvium, minor shale lenses, and deeply wea:hered granite. Researchers evallated pre..fire and post- fire stream flow and sediment datI in conjunction with tests for water repellency in the burned catchmem and in an unburned control. Widespread rc:pellency after the fIre occurred primarily below the surface. Some shallow, post-fire repe[ency occurred in areas of fynbos vegetation, whereas seongly repellent conditions (up to lSOmm itl depth) were found in burned soils of the pine plantation (the deepest and most severe repellency occurred beneath slash piles). Prior to burnlng, the latter soils alw exhibited some mild, infrequent water repellency asso,:iated with deep litter accumulations and fl!1gal mycelia. Although weekly stream flow value:; increased very little, quick flow volumes and peak flow rates increased by 201 % and 290%, respectively. "Pulses of rain" as small as Smm generated surface runoff during low imen sity storms of long duration. T his runoff occurred as saturation overland flow in wettabk soils with subsurface water-reF ellem layers. Four-fold increases in bedload and suspended sediment yields were attributed to the increased stream energy and overland flow. The author concluded that the natur ~ of fire-.lnduced water repellency was related to vegetation type and soil heating. He also r. oted that, in contrast to previous studies of burned South African fynbos catchments, pos'-fire sedi:nent yields in this study were much higher. He s Llggested that these differences v'ere due to variations in burn intensity and parent material 0 f the soils. The lower sediment yields occurred following low intensity prescribed bums in catchments dominated by granite-d :rived soils, whereas the this study involved a high intensity wildfire on sandstone derived soil s. Teramura, A.H., 1973, Relationllhips between chaparral age and watl~r repellency: Fullerton, California State University, M.A. thesis, 18 p. The purpose of this study was to examine the effects of stand age l pon water repellency in the chaparral of Southern California. Particular emphasis was place 1 upon the contribution of incorporated organic material in the soil to the intensity of wate! repellency with respect to dominant shrub species forming the vegetative cover. Results of water drop penetration time testing indicated an increase ir:. wal:er penetration times with in :reasing stand age. The author indicates that this naturally-occurring repellency may accumulate over time, and is directly related to the plant cover and the time between fires. T\!o explanations for this phenomenon, one based on microbial degradation of litter and tt e other based on plant physiology with maturity, are proposed. Further, the author indicltes that Ihe amount of incorporated organic matter ben~ath the canopy in comparis(.n to th,~ water drop penetration time remains relatively uniform between species and be tween sit.:s. Therefore, water repellency cannot be explained by simply expressing the total amount of incorporated organic matter in the soil.. Altbough organic matter may be the primary source of hydrophobic substances, only a small artlount of the total oxidizable organic matter contains substances capable of induclng water repellency. 36