Sampling has continued apace up in Wood Buffalo National Park this past week. We keep expanding the number of different ecosites we have visited, with the result being that I have now seen some very different types of plots. We’ve got to wait until all the data are in, of course, but it’s quite striking how different the recovery trajectories are in short-interval burns compared to longer fire intervals. Ecosystems up here are well adapted to regular fires, but when the next burn comes before the seedlings have a chance to grow up and produce a new generation of cones, the vegetation may shift.

Working in the field, we are still seeing lots of cool wildlife, like a bear eating some kind of carcass, longhorn beetles, which are a natural part of the local ecology [larva pictured], and tons of sweet fungi [pictured].

An important part of this experiment is making sure that the dates for the fires are correct. To do this, we look for fire scars [pictured]. Fire scars can look like many other types of bark damage – a cut in the trunk with overgrown sides curling in over it – and are caused when the fire damages the tree, but it survives, and grows over the damage.

You can see the inner rings where growth was normal, and then the outer rings that are curling around the centre rings, from after the fire. By analyzing the tree rings, experts can tell when the previous fire was.