Effects of fire severity on the chemistry and microbial activity in the rhizosphere
In 2003, fires burned 13 times more British Columbia forest than in an average year, with 90% of this being in the southern interior of the province. Because of the extremely low rainfall in 2003 (the lowest on record), which resulted in dry soils with very low thermal capacities, we expect the effects on the soil to be particularly severe.
We are studying the effects of fire severity on the chemistry and microbial activity in the rhizosphere of Douglas-fir seedlings as they regenerate after the fires. In particular, we will determine the effect of fire severity on ectomycorrhizal fungi. Wildfires are known to alter the species composition of these fungi. Our work is unique and innovative because we are studying ectomycorrhizal roots in situ and will integrate several factors on the same spatial grid:
- identity of the fungal symbionts (Jason Barker, Lenka Kudrna, and Dan Durall)
- presence of prokaryotic genes involved in N cycling (research group of Keith Egger, UNBC)
- activity of nutrient-mobilizing enzymes (Shufu Dong and Melanie Jones)
- rhizosphere chemistry and mineralogy (research group of Lito Arocena, UNBC)
Plexiglas root windows have been placed into the soil, with trap doors used to access the soil face. Nitrocellulose membranes will be used to bind DNA and enzymes for characterization in the lab, and soil solution will be sampled via microceramic cups embedded in the Plexiglas. DNA, enzymes and soil solution will then be spatially linked to the ectomycorrhizas as recorded on a high resolution digital image.
We are also studying the survival, growth, and water relations of the regenerating seedlings (Jason Barker and Suzanne Simard, UBC Vancouver) and will integrate these results with those in the rhizosphere. Using this approach we will increase our understanding of Douglas-fir regeneration after natural disturbance. This will provide an insight into problems with regenerating this species after logging.
Last reviewed 4/8/2015 12:34:08 PM