-19- 



Laboratory cultures of the common fungi 

 Penicillium nigricans and Aspergillus sydowi in 

 sand caused water repellency in the absence of 

 plant material. Subsequent heat treatment at 

 200-400 C increased the effect. The water 

 repellent substances were extractable by water and 

 methanol but not ether and acetone; they were not 

 extractable at all after heating. Numerous 

 organic compounds tested were capable of causing 

 water repellency in sand. The extent of water 

 repellency in soil could depend on soil factors 

 affecting fungal growth as well as litter 

 decomposition. 



59. Savage, S.M., J. Osborn, J. Letey, and C. Heaton. 



1972. Substances contributing to fire-induced 



water repellency in soils. Soil Sci. Soc. Am. 



Proc. 36:674-678. 



At 300-400 C, aliphatic hydrocarbons coming from 

 undecomposed and partially decomposed plant 

 materials heated in the lab induced 

 water-repellency in sand. The water-repellent 

 substances were not extractable with solvents and 

 were thought to be polar molecules. 



60. Scott, V.H. and R.H. Burgy. 1956. Effects of 

 heat and brush burning on the physical properties 

 of certain upland soils that influence 

 infiltration. Soil Sci. 82:63-70. 



Soil columns heated in a laboratory oven at 

 various tempertatures showed increased 

 infiltration rate, attributed to increased 

 water-stable aggregates. 



61. Scotter, G.W. 1963. Effects of forest fires on 

 soil properties in northern Saskatchewan. 

 Forestry Chron. 39:412-421. 



After forest fire, soil temperatures were 10.5 F 

 higher than in unburned soil at 2.5 cm, and 9.7 F 

 higher at 6.5 cm. Infiltration rates were 

 unchanged for sandy loams. CEC decreased on 3 of 

 4 sites, increased on 1; pH increased on all 

 burned sites. Exchangeable Ca increased on 3 

 sites, was unchanged on 1 . No change was found in 

 K, Mg , or Na. Total N was inconsistent , but 

 available P was greater on burned sites. 



