PARENT SESSION
Poster Session #31: Climate Change.
Wednesday, August 8, 2001. Presentation from 3:30 PM to 5:00 PM. Exhibition Hall

Soil surface CO₂ flux in boreal black spruce fire chronosequence.

WANG, CHUANKUAN¹, BOND, BEN¹, GOWER, STITH¹, ¹

ABSTRACT- A nested factor design on soil drainage and fire history was used to quantify soil surface CO2 flux and estimate annual soil surface CO2 emission in a black spruce fire chronosequence in northern Manitoba, Canada. The objectives of this study were: (1) to quantify the relationship between soil surface CO2 flux and soil temperature for boreal black spruce forests in well-drained and poor-drained soil conditions; (2) to examine short-term and long-term dynamics of soil surface CO2 flux following wildfire in this chronosequence; and (3) to estimate annual soil surface CO2 emission for these stands. Soil surface CO2 flux differed significantly between well-drained and poorly-drained sites and among different-aged stands (p < 0.05). In general, soil CO2 flux was greater at dry sites than the wet sites. Soil surface CO2 efflux tended to decrease immediately following fire disturbance, and then increase as vegetation recovered. The annual carbon emissions from soil surface ranged from 2.4 Mg C ha-1 to 3.5 Mg C ha-1 depending on stand successional stages and soil drainage.

KEY WORDS: soil surface CO2 flux, fire, boreal forest, chronosequence