-24- 



75. White, E.M., W.W. Thompson, and F.R. Gartner. 

 1973. Heat effects on nutrient release from soils 

 under ponderosa pine. J. Range Manage. 

 26:22-24. 



Samples of litter, mor humus, and upper Al 

 horizons were heated in laboratory ovens to 

 temperatures ranging from 25-500 C. Water-soluble 

 P and K concentrations increased up to 200 C. At 

 higher temperature, water- soluble P and total N 

 decreased in all samples, but water-soluble K 

 increased in the Al material. 



76. Youngberg, C.T. 1953. Slash burning and soil 

 organic matter maintenance. J. Forestry 

 51:202-203. 



Slash burning in Douglas-fir forests contributed 

 to erosion during the winter rain season, and 

 substantial organic matter depletion. Slash 

 burning following 4-5" of rainfall resulted in no 

 o.m. loss and no soil damage. 



