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<br />Morris, S.E., and Moses, T.A., 1987, Forest Fire and the natural soil erosion regime in
<br />the Colorado Front Range: Annals of the Association of American
<br />Geographers, v. 77, no. 2, p. 245-254.
<br />This paper evaluates post-fire sediment yields along the Colorado Font Range, and in
<br />particular, includes information relating to the occurrence and duration of water-repellent
<br />soils following forest fires. The study looked at sediment flux rates from five forested
<br />catchments that included vegetation communities of Ponderosa pine/Douglas fir,
<br />lodgepole/ aspen, and Engelman spruce/subalpine fir. The sites spanned chronological
<br />times of burning, from new to four years old, and a fIfrh site which had not burned in
<br />several decades. Researchers found that erosion rates declined rapidly after burning. 'Since
<br />other variables between sites (i.e. vegetation cover, slope angle, and textural characteristics
<br />of undisturbed soil) were similar, a decrease in soil water repellency was considered to be a
<br />major factor in the decreased sediment flux. This was supported by tests of water repellency
<br />at the various sites.
<br />
<br />Morris, R.J., and Natalino, M., 1969, The chemical nature of the organic matrix
<br />believed to limit water penetration in granitic soils: Reno, University of
<br />Nevada System, Center for Water Resources Research, Desert Institute,
<br />Project Report No. 1313 p.
<br />This research was directed toward the identifIcation of some of the compounds in forest
<br />litter responsible for water repellency in granitic soils. Ethanol was used to extract tar-like
<br />substances from species of pine, snowbrush, and manzanita. These extractions were then
<br />processed, and the products analyzed, using thin layer, column, and gas-liquid
<br />chromatography, qualitative analysis, and infrared spectrophotometry. The study was
<br />inconclusive as to the exact nature of individual substances, but researchers determined that
<br />the organic material consisted of partially unsaturated aliaphatic carboxylic acids and side
<br />chain attachments of simple sugars (mainly pentose and hexose sugars).
<br />
<br />Osborn,J., Letey,John, DeBano, L.F., and Terry, E., 1967, Seed Germination and
<br />establishment as affected by non-wettable soils and wetting agents: Ecology,
<br />v. 48, no. 3, p. 494-497.
<br />The purpose of this study was to see how germination and vegetative establishment were
<br />affected by water-repellent soils and by wetting agents applied to the soil. Researchers used
<br />a naturally occurring, nonwettable sandy loam derived from granitic parent material. The
<br />soil had previously been occupied by a moderately dense stand of chaparral, burned in a
<br />1960 fire. They found that, on sloping prof1les, water-repellent soil samples had much lower
<br />rates of germination, due to less available inf1ltrated moisture. On level prof1les, water-
<br />repellent soils yielded reduced rates of vegetative establishment. Wetting agents increased
<br />both germination and vegetative establishment on these samples by increasing the amount of
<br />available moisture. However, on wettable sand, wetting agents appeared to have a toxic
<br />effect on seed germination. This characteristic was less evident when wetting agents were
<br />applied to a wettable soil, possibly due to interactions with colloidal surfaces and ash.
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