-13- 



analysis indicated higher P content than trees 

 from unburned sites. Burned soils had higher pH 

 and exchangeable Ca. Loss on ignition, total N, 

 ammonium, total P, exchangeable K, Mg , and Na were 

 the same for burned and unburned sites. Authors 

 felt that increased P availability resulted from 

 soil changes which altered the composition of soil 

 P, including pH and aluminum effects. 

 Additionally, higher soil Ca may have stimulated 

 root and mycorrhizal development. 



36. Jalaluddin, M. 1968. Micro-organic colonization of 

 forest soil after burning. Pak. J. Sci. 

 21:42-44. 



Burning of 1.5-2 m plots increased pH 3 units 

 initially, but pH returned to preburn level after 

 6 months. Soil was reinvaded rapidly from margin 

 areas and by air-borne spores. Species included a 

 number of pyrophilous fungi not found in adjacent 

 unburned areas. 



37. Jorgensen, J.R. and C.S. Hodges. 1970. Microbial 

 characteristics of a forest soil after 20 years of 

 prescribed burning. Mycologia 62:721-726. 



Sampling of the sites studied by Metz (1961) and 

 Wells (1971) in South Carolina showed no 

 significant effects on numbers of fungi, bacteria, 

 or actinomycetes in mineral soil. Organic layer 

 numbers were reduced considerably in proportion to 

 decreased depth of 01 and 02 horizons. Certain 

 species of fungi increased in annually burned 

 plots. 



38. Jorgensen, J.R. and C.G. Wells. 1971. Apparent 

 nitrogen fixation in soil influenced by prescribed 

 burning. Soil Sci. Soc. Am. Proc. 35:806-810. 



Acetylene-ethylene assay for N-fixation proved to 

 be more sensitive than carbon dioxide evolution or 

 Kjeldahl analysis. Samples from burned plots in 

 South Carolina showed an average of 10 times 

 greater N-fixing ability than those from unburned 

 plots in 0-1 cm soil. N-fixation was localized 

 since 2/3 of the samples showed little or no 

 N-fixation, and some fixed 50 times the amount in 

 unburned samples. Greater soil moisture 

 apparently favored such high rates of N-fixation. 

 Soil characteristics for this study area were 

 reported by Wells (1971). 



