Chris Schmidt: Entomologist/Biologist
"I can’t help but see non-native trees as missed opportunities, because they don’t support the same biodiversity as native trees do, since there are few or no local insects adapted to them. "
Interview by: Margo Nelson Photographs: Chris Schmidt
Q.1. From your perspective, why are trees important?
Trees play an immense ecological role for a significant part of earth’s land cover. Most people think of the ecosystem services that humans benefit directly from, such as carbon uptake, oxygen production, erosion control, or the huge array of economic products. From a biologist’s perspective however, it’s hard to over-emphasize their importance in most terrestrial ecosystems: they provide the structural fabric and are the primary producers that a myriad of other flora and fauna depend solely on, be it fungi, invertebrates, lichens, or birds.
Q.2 How do trees and their health impact insects, specifically butterflies and moths?
Many plant-feeding insects, particularly butterflies and moths, have a close dependence on a particular type of tree. Such insects cannot substitute other trees or plants as food sources, so the impact is very direct: if the health of the tree is compromised, so is that of the butterfly/moth that depends on it. Most often, this dependence is in the form of food for the caterpillar which feeds on some part of the tree, usually leaves. If the tree is unhealthy or declining, so too is the moth or butterfly. For example, several moth species dependent on ash are now thought to be in decline due to the impact of emerald ash borer.
Q.3. When you're looking at trees as an entomologist what do you consider and look for?
A tree can support a flora and fauna that enriches our biodiversity, because they provide food and shelter for plant-feeding insects and other parts of the food chain that inherently come with these insects. In urban settings, one of the first things that comes to my mind in this regard is whether or not it is a tree species that is native to the area. Trees that are not native may look appealing to us, or have some aspect desirable to humans like pest resistance, but I can’t help but see non-native trees as missed opportunities, because they don’t support the same biodiversity as native trees do, since there are few or no local insects adapted to them.
Q.4. I hear you've been known to spend large amounts of time on Google Maps looking for 'mothy' habitat to explore. Can you speak to how you look at trees as part of a landscape/habitat?
At the landscape level, trees are excellent habitat indicators because they require certain growing conditions, and because they usually give clues about the human disturbance history (such as agriculture, tree plantations and land clearing). For example, sparsely treed areas with lots of conifers usually indicate rock barrens (which despite their name, are very diverse biologically) with pines and oaks, and deciduous versus coniferous trees in wetlands usually indicate rich swamps versus peatlands or bogs. When I’m looking for a specific habitat in which to sample insects, trees are a surprisingly good indicator, even at the Google Map scale.
Q.5. Do you have a favourite tree species? If so, which one? Or: Do you have a favourite tree in Ottawa? If so, what species is it and where is it located?
I have favourite trees in different landscapes and different parts of the world, and I couldn’t choose an overall favourite. To me, certain trees are symbolic of the climate, geology, natural history and diversity in a given place. In eastern Ontario, the longevity, character, and elegance of an old white oak, together with the large cast of other creatures that it supports, is remarkable, while it is hard to surpass the fragrance and whispering winds in a stand of white pines on a root-gnarly rocky ridgetop.