-20- 



62. Sharrow, S.H. and H.A. Wright. 1977. Effects of 

 fire, ash, and litter on soil nitrate, 

 temperature, and moisture, and tobosa grass 

 production in the Rolling Plains. J. Range 

 Manage. 30:266-270. 



Although burning induced higher grass yields and 

 higher soil temperature and nitrate than that on 

 unburned areas, moisture was usually the more 

 limiting factor. Therefore, in dry years, burning 

 may be a disadvantage. 



63. Sims, H.P. 1976. The effect of prescribed burning 

 on some physical soil properties of jack pine 

 sites in southeastern Manitoba. Can. J. For. 

 Res. 6:58-68. 



Prescribed burning was done for mineral seedbed 

 preparation after clearcutting . Temperatures 

 recorded during burns were 52 C at 5 cm depth and 

 300 C at the organic/mineral soil interface. Over 

 1/3 of the organic forest floor was burned, but 

 there was much variation. Organic matter 

 decreased in the Bt horizon, gradually increasing 

 during the following year. Soil moisture was 

 greatly reduced compared to a scarified mineral 

 seedbed. Temperature and moisture extremes 

 resulting from burns severe enough to create a 

 mineral seedbed, were too detrimental to jack pine 

 seedlings to be worth cost. Scarification still 

 must be done after light burns. 



64. Smith, D.W. 1970. Concentrations of soil nutrients 

 before and after fire. Can. J. Soil Sci. 

 50:17-29. 



Severe fire in northern Ontario with temperatures 

 exceeding 1000 C, burned most of the organic 

 forest floor in a jack pine community. Cations 

 released on burning were mainly water-soluble; 

 CEC increased for 3 months after the burn, then 

 decreased to preburn levels or lower. Organic 

 matter decreased in the upper few cm, but 

 increased in lower horizons. Water soluble K, Na 

 and Ca increased at first, then decreased to below 

 preburn levels. Acid-soluble K increased at 

 first, Na did not change; then both decreased to 

 below preburn level after 13 months. Fe and Al 

 increased in the 01+02, then Fe decreased to below 

 preburn. Extractable P initially increased, then 

 decreased in upper horizons and increased in 

 lower . 



