-23- 



increase in P as a result of burning; the 

 possibility that P-fixation precluded the effect 

 in the other soil was suggested. 



72. Wagle, R.F. and J.H. Kitchen. 1972. Influence of 

 fire on soil nutrients in a ponderosa pine type. 

 Ecol. 53:118-125. 



Lettuce and ponderosa pine seedlings were used as 

 indicator plants and grown in soil from wildfire 

 and unburned areas to test the nutrient supplying 

 ability of sites with different fire histories. 

 Dry weight yields of ponderosa pine seedings 

 (among unamended soils only) were highest on soil 

 from a recently burned area. 



73. Wells, C.G. 1971. Effects of prescribed burning on 

 soil chemical properties and nutrient 

 availability, p. 86-97. in Proc. Prescribed 

 Burning Symp. USDA For. Serv. , Southeast. For. 

 Exp. Sta., Asheville, North Carolina. 



Effects were studied for 20 years after annual 

 burning in winter and summer, and after periodic 

 winter and summer burns. After annual burning, 

 effects were greatest in the first 10 years. 

 Summer burning was more severe than winter in 

 annual as well as periodic burns. Organic matter 

 and N increased by 30% in 0-2" of mineral soil, 

 while the 01+02 was diminshed by 65% in annual 

 burn plots. Periodic burns showed no significant 

 difference in total N; some annually burned areas 

 showed increases in N, attributed to microbial N 

 fixation in wet spots. P increased in the 0-4" 

 depth of soil in annual winter burns; K was 

 unchanged; Ca and Mg increased in 0-2". Average 

 pH increased from pH 3.5 to 4.0. Seedlings showed 

 greater uptake of P on burned plot soil, but less 

 N. 



74. Wells, C.G., R.E. Campbell, L.F. DeBano, C.E. 



Lewis, R.L. Fredriksen, E.C. Franklin, R.C. 



Froelich, and P.H. Dunn. 1978. Effects of fire 



on soil: a state-of-knowledge review. USDA For. 

 Serv. General Technical Report WO-7. 34 p. 



The authors of this current review have been 

 directly involved in research regarding fire 

 effects on soil. The report encompasses chemical, 

 physical, and microbiological aspects of burning, 

 and addresses management and nutrient cycling in 

 forest and rangeland. An extensive list of 

 references is included. 



