Site preparation burning to improve southern Appalachian pine-hardwood stands: nitrogen responses in soil, soil water, and streams
1993
Knoepp, J.D. | Swank, W.T.
Three paired watersheds treated with a fell and burn prescription were studied to determine the effects on soil, soil water, and strewn water. Soil nitrification and mineralization were measured by in situ closed-core incubation. Soil water was collected with porous cup lysimeters placed at 30 and 60 cm depths, and water samples were collected from streams draining control and burned areas on one of the three sites. All data were collected for 6 months prior to and 12 months after treatment. Soil ammonium (NH4(+)) content increased significantly in all three sites after burning, but the magnitude differed greatly among sites. However, there was no change in soil nitrate NO3(-) content. In situ measurements of net mineralization showed increased rates with increasing bum severity. Net nitrification displayed no treatment response. Slight and nonsignificant increases in soil water NO3(-) concentration occurred after burning in two of the three sites. Stream water NO3(-) concentrations increased in the one stream sampled. Thus, while prescribed burning increased available soil N, there was little change in N transformation rates or movement of dissolved inorganic N off site during the first year after burning
显示更多 [+] 显示较少 [-]