PARENT SESSION
Oral Session # 40: Fire Ecology II: Forests.
Presiding: D Falk
Wednesday, August 6. 8:00 AM to 11:30 AM, SITCC Meeting Room 102.
Recovery of soil processes after wildfire in jack pine forests.
Yermakov, Zhanna *,1, Rothstein, David1, 1 Michigan State University, East Lansing, Michigan
ABSTRACT- We studied how biological, chemical and physical factors interact to influence the recovery of soil processes after wildfire in jack pine (Pinus banksiana) forests. We measured changes in soil organic matter (SOM) quality, quantity and mineralization rates across a chronosequence of eleven wildfire-regenerated jack pine stands in the northern Lower Peninsula of Michigan. The stands ranged in age from 1 to 72 years. Changes in C and N mineralization and SOM all conformed to a gamma function (Y=AXbecxd+E), in which all three processes initially declined to a minimum by 15 years since wildfire and later increased to an asymptote. Although both N mineralization and SOM quantity increased with age, the relative proportion of total soil N mineralized decreased, suggesting a decline in SOM quality. Changes in microclimate with stand age also influenced the recovery of soil processes after wildfire. In particular, the magnitude of seasonal fluctuations in C and N mineralization was greater in younger stands compared to older stands. Our results show that the recovery of C and N mineralization is predictable after wildfire and that the rate of recovery is controlled by the interaction of SOM quality and quantity, as well as microclimate.
Key words: wildfire recovery, nutrient cycling, jack pine