When Dr Cameron Naficy invited me to participate on his field season this last summer I immediately said ‘yes’. “What a great opportunity to breathe fresh air and do some exercise, while I get more familiar with the ecosystems I’m supposed to be modelling and with dendrochronology field sampling techniques!” I thought, as my eyes got watery, not from emotion but from staring at my screen for too long1.
So, on the last week of June I joined Dr Cameron Naficy and his field crew in the southwestern Alberta Foothills to help them collect fire scars and tree-core samples as part of the Landscapes in Motion project (LIM). As the ecological modeller in the LIM team I don’t need (as in, my work doesn’t require me to) to carry out field work - I sort of parasitize my colleagues for their data. However, I think most will agree that going to the field at least once can be extremely helpful for a number of reasons.
Understanding the ecosystem being modelled
Every ecological modeller should see the ecosystems they model whenever possible. For me, this means that whatever I am trying to simulate becomes “real” and not just species names and a bunch of trait values. During that week in the field with Dr Naficy and his team, I gained a much better understanding of the different plant communities in the areas that we visited, and the fire-vegetation dynamics that shape them. For example, as we moved from the plains to the Rocky Mountain Foothills, it was fascinating to observe the transition from large expanses of grassland, towards relatively narrow aspen-dominated forest edges and, finally, conifer-dominated forests. These ecological transitions were in many cases visibly marked by interesting fire dynamics. In some locations fires seemed to have spread from the grasslands where dry fuels allow them to spread rapidly, and upon reaching aspen woodland edges higher moisture levels and lower fire sensitivity of these trees acted as a natural fire suppressant. Because aspen has high post-fire regeneration, it can quickly re-colonize the disturbed forest edges, closing a positive feedback loop between fire and vegetation that maintains the aspen-dominated forest edges. In these locations, we observed several aspen trees with multiple fire scars and an inner forest with uneven age structures (i.e. trees of different ages). This is an interesting self-maintaining fire-vegetation dynamics that seems relatively common in this region in the grassland-forest ecotone transition.
Every ecological modeller should see the ecosystems they model whenever possible
In other locations, like even-aged lodgepole pine forest stands, we saw indication of very different fire dynamics. There, relatively recent high severity fires had been responsible for replacing whole forest stands leaving fewer fire scars and generating a forest of relatively young and even-aged lodgepole pine. Depending on the severity of a potential next fire, these forests may evolve to uneven age stands if future fires cause partial mortality, or be totally replaced by a new cohorts of Lodgepole pine.
Getting to know the team better
Science is all about collaborating and good collaborations are easier when we get along with our colleagues. Being able to help the field team in their work is a great opportunity to get to know the people I collaborate with at a deeper level, beyond the occasional meeting or Skype call. It also motivates informal discussions and debates of ideas - how many great scientific papers started over a beer or during a hike to a sampling plot?
Meeting landowners and members of the local communities
Landowners need to be contacted in order to gain access to the plots both in private and provincial land and can be extremely helpful when it comes to knowing whether certain plots are within driving and walking distances. Members of the local communities can also tell us about their own perception of wildfires in the region and give us clues as to where fire scars are more likely to be found. I did not have much contact with the local people, as I was only in the field for a short time, but I was lucky to meet with a landowner who gave us their perspective of fire dynamics in the region. It was interesting to hear them highlight the importance of winter fires in the region, which to my knowledge are frequently ignored in the literature. In the southern Alberta Foothills, these off-season fires arise are caused by Chinook winds that bring masses of warmer air, which cause snowmelt and rapid drying of the grasslands. Although they can burn large expanses of grassland and become dangerous and disruptive for landowners, it is unlikely that these fires destroy much of the surrounding forest, which should be able to keep higher moisture levels. It is important to bear these different dynamics in mind when we are trying to model ecosytems, even if they are not going to be incorporated in the models - they could be important sources of model error!
“Unmodelled” dynamics can be important sources of model error.
Having a good time
I saw a number of species that I had never seen before. I learned how to whistle using a grass-blade. I saw elk amidst the trees only a few tens of meters away from me. I rode a helicopter (SOOOO FUN!). I tried elk meat for the first time. And I got some nice tree cores to add to my field-trinkets collection!
Field work is tiresome, but so gratifying! It teaches us so much and in the best way possible - hands-on!
Footnotes
although I use the wonderful stretchly app to remind me of moving and blinking, my body keeps screaming “enough screen time for today”!↩︎