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<br />Osborn, J.F., Pelishek, RE., Ki:ammes, J.S., and Letey, J., 1964, Soil wett:ability as a
<br />factor in erodibility: Soil Science Society of America Pro :eedings" v. 28, p.
<br />294-295.
<br />This investigation illustrate~, some of the potential effects of water repellency on erosion.
<br />The study focused on an area adjacent 1:0 the San Dimas Experime! ,tal Forest in Glendora,
<br />California, which was burned m'e! by a wildfIre in July of 1962 the previous summer).
<br />Pretire vegetation consisted of moderately dense chaparral that m: U1tled a shallow, sandy
<br />loam derived from granitic paren': material. The fire covered hillslol'es with half an inch of
<br />wettable ash, overlying a 2- to 3-inch layer of very hydrophoblc, partially ashed and
<br />decomposed material. Researcher,; measured the amount of mat, ,rial yielded after eight
<br />rainstorms (between Januarv and April; from slopes that had been treated with a wetting
<br />agent, and compared it to results on untreated slopes. They found that signifIcantly more
<br />erosion occurred on the untreated (water-repellent) plots. Photographs illustrate the intense
<br />rilling that developed in these areas. Analysis of vegetative stat IS showed that slopes
<br />remained relatively bare until Apri., and that the treated plots had much higher rates of
<br />vegetative establishment than urtteatecl plots. The author notes that, although the area
<br />studied was water repellent, there was also ash and soil outside of the study area that was
<br />wettable.
<br />
<br />Parks, D.S., and Cundy, T .W., 1989, Soil hydraulic characteristics of a small
<br />southwest Oregon watershed following high-intensity wildfire, in Berg, N.H.,
<br />ed., Symposium on Fire and Watershed Management: F acific S01l1thwest
<br />Forest and Range Experimem Station, Sacramento, Cali'., Octob,~r 26-28,
<br />1988, Proceedings, Gent:rd Te:chnical Report PSW-l09, 1'.63-67.
<br />This investigation was initiated b)llowing the Angel Fire in Septerr. ber, 1987, northeast of
<br />Grant's Pass, Oregon, to determloe fire effects on hydrological response and erosion in a
<br />small watershed. Researchers evaluated infiltration capaci~', saturated hydraulic
<br />conductivity, soil-moisture characteristics, and soil-water repellenc~' in an area with steep
<br />topography that experienced a high inte:o.sity bum. Vegetation prior to burning consisted of
<br />Douglas fir and mixed pine, witt grasses, ferns, forbes and shrubs in the understory. The
<br />soils were described as stony clay 10aJns derived from serpentine bedrock. The results
<br />indicated that fire had little effect on the hydrological response of :he watershed, and that
<br />the occurrence of water repellency was minimal. The authors suggest that future runoff
<br />patterns in the area will likely be cOlninated by subsurface flow.
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