ABoVE: Fires in recently logged forestsJune 10th, 2016 by Kylen Solvik
Since our last post, our team has moved an hour south to the small village of Weyakwin, where the Philion fire burned last year. There is a lot of logging Weyakwin, and we are very interested in the interactions between fires and logging. We are comparing burned forests that grew back after people cut trees, to those that grew back after an earlier forest fire.
We believe there could be differences between the two in burn severity and the amount of carbon released by the fire. When a plot is harvested for lumber, the logs are removed but the soil remains. This is the opposite of burned areas, where fire burns into the soils but a lot of the trees remain standing, albeit charred. To study these differences, we are searching for areas of burn and harvest origin that are about the same age. We have seen some very young burned sites, many were less than 10 years old when they burned. This is surprising since forests in boreal regions typically burn when they are 50 to 100 years old. We were shocked to find a burned plot that had been harvested only a year or two earlier. Even without any significant trees or shrubs to carry the flames, the soil was able to sustain the fire.
At the sample sites, my job is to help characterize and quantify the aboveground biomass. This includes trees, shrubs, and dead trees that have fallen over, called “coarse woody debris.” I work with Brendan Rogers, our team leader, to measure every tree within a 2-by-30 meter sampling area. We identify the tree species, rate the amount of the canopy consumption, and measure the diameter. We will use these numbers to estimate how much carbon was released when that tree burned. Most of these tasks are fairly straightforward — although it can sometimes be tricky to differentiate between similar tree species after they have burned. We can measure individual trees pretty quickly, but it can still take one or even two hours to work through an entire site. At one site, we counted over 350 trees, measuring the diameter and estimating the canopy consumption for each and every one!
In Weyakwin, we are staying at a small bed & breakfast. Our host, a wonderful lady named Rita, takes great care of us. She cooks us breakfast and dinner, and she even packs us brown bag lunches for us to grab on our way out. After going out for dinner every night at our previous lodging in La Ronge, it has been a great change of pace eating home-cooked meals. We will be staying with Rita for the next week, and then we will be returning to Saskatoon to fly back to our respective homes. One of our team members, Catherine Dieleman, left early for her friend’s wedding. We will miss her and her soil expertise dearly.
But there are a lot more sites to sample before we are done!
Kylen Solvik is a research assistant at Woods Hole Research Center in Falmouth, Massachusetts.