Last year we bought a house in Richmond, Quebec, on the banks of the Saint-François River. We’ve got a big backyard, and a main source of joy for me in the last few months has been working in the garden. Inspired by The Ministry for the Future, a near-future scifi novel about climate change and biodiversity, I’ve been especially interested in planting indigenous species in our front and back yard. I’ve been drawn to trees that have grown in the region originally: bur oak, hop hornbeam, ash, sugar maple, basswood, red oak. But I’ve needed to read more about how and why to choose this kind of garden.
I was really glad to find Douglas Tallamy’s Bringing Nature Home. It’s a compelling case for using backyards, gardens, and private property to revive hard-hit ecosystems.
The major problem at hand is that we’re in the middle of a mass extinction of species on this planet. Pulling parts out of an ecosystem is like pulling parts out of a working engine; you might be able to pull out a few without noticeable effect, but at some sudden point it’s going to fall apart or explode.
He makes the great point that species depend on connected areas to survive; small patches, cut off from each other, can’t support making new species or replacing disappearing ones. And also, in North America, we have less than 5% of the land mass dedicated to preserving wildlife — only in isolated wilderness islands.
There isn’t time or political will to change that lifestyle. So, instead, the author suggests a different approach: use the huge amount of land dedicated to yards and gardens as a loosely-connected lifeline for native ecosystems.
Tallamy is an entomologist, and he roots his argument in the needs and behaviour of herbivorous insects. Insects are a crucial part of any ecosystem; turning indigestible plant matter into delicious insect protein for birds, mammals, and other creatures. But insects often specialise in particular host plants; the butterflies that live on goldenrod or milkweed just don’t know what to do with introduced species like azaleas. They don’t have the taste for the food, and they don’t have the ability to overcome any chemicals the plants use to protect themselves.
So, for insects, says Tallamy, a garden made up of introduced species might as well be full of plastic plants. Or, rather, the introduced species are worse than useless; they take up resources like sunlight, water and soil nutrients, but don’t re-introduce them into the rest of the food cycle. Microbes, fungi, worms, bugs, birds and animals are mostly stumped, and have to work harder to find the nutrients they need.
I’m moved by the argument at its base; it makes about as much sense to me as the Sesame Street animation where the man replaces torn-out water plants to re-stock his fish population. But Tallamy makes the further case against using introduced species: the high risks of them becoming invasive species, or bringing along a disease or parasite as a hitchhiker that rips through the local ecosystem.
But most of all, it just seems pleasing to use the flora of the area we’re in. Fortunately, Tallamy is in a similar part of the world to us, so his specific suggestions on which trees, shrubs and ground cover to plant are mostly applicable to our yard.
The book’s main weakness is a long chapter dedicated to describing the major insect families and orders in North America. It’s clearly something the author finds interesting, and many of the stories of katydids and sawflies are gross enough to be fun to read, but overall it feels like a wild swerve from the direct topic of gardening advice.
Overall, I think it’s a great book, and it’s definitely inspired me to focus primarily on native species in our yards. I think we’ll still have some food plants out there, but we’re going to try to put in oaks and basswood in the spring, and a wide variety of native shrubs, too. I’m energised by the project, and glad to be making our link in a chain of ecosystems for wildlife to use.