We are Nature’s Best Hope.
And that, says Doug Tallamy, is wonderful, encouraging and exciting.
Tallamy teaches entomology (the study of insects) at the University of Delaware. In his research, he has documented the stunning decline of insect populations across the planet as humans eliminate their habitat and food sources and attack them with weapons of mass destruction.
But in his latest book, Nature’s Best Hope - A New Approach to Conservation that Starts in Your Back Yard, Tallamy is confident that we as a species can repair the harm we’ve done and move forward to a bright and balanced future.
If you’re a gardener and haven’t yet read this book, you will love it. If you’re a novice and are wondering what to do on any piece of ground you may have access to, you will find this easy to read and an illuminating window into what’s going on around you.
A balding bespectacled professor with a subversive sense of humour, Tallamy has achieved cult status in the gardening world. A few years ago, author and horticultural activist Lorraine Johnson introduced him as a “rock star” to an enthusiastic audience at the Toronto Botanical Gardens. He was unfazed.
And he’s unfazed by the task we face in rebuilding the broken food web connections, from the below-ground mycorrhizal networks to the life-giving balance of gases in the atmosphere.
“Don’t worry about the planet,” he says. “That will drive you crazy.”
Instead, in Nature’s Best Hope, he urges us to take little steps to build what he has dubbed Homegrown National Park – the land mass gardeners can release back to nature by implementing some simple restorative measures. I’ll mention three of them.
Shrink the lawn
Tallamy has calculated that if all private property owners in the US were just to halve the dimensions of their lawns, 20 million acres could be quickly restored to viable habitat by untrained citizens at minimal expense and without any costly infrastructure, to create the equivalent of almost a quarter more of the total US National Park system, which covers more than 84 million acres.
Similar results could be achieved in Canada, transforming a blanket of ecologically dead zones to life-giving spaces of shelter and food for birds, bees, butterflies and all manner of creatures. Size doesn’t matter in the context of Homegrown National Park because it’s about creating corridors. A window box with native pollinator plants on an apartment balcony can play its part. Groundcovers like Pearly Everlasting (shade) or Field Pussytoes (sun) can provide the low-growing visual equivalent of a lawn, with no need to mow; just make some paths to wander through.
Plant keystone genera
I learned from Tallamy’s first book Bringing Nature Home - How You Can Sustain Wildlife with Native Plants (published in 2007) about the vital role played by insects in converting the energy captured from the sun by plants into fuel for the rest of the world’s food wed. And that native plants sustain more species of insect (into the hundreds) than non-natives (none, or a handful).
Now, there's new information.
In Nature’s Best Hope, Tallamy draws on his own research, recently published in Nature, to take things a step further. Some natives are better than others. He calls them keystone plants.
“Before discovering keystone plants we overestimated the degree to which most native plants contribute to the food webs and assumed that if a plant was native, it contributed a lot,” he writes. “We now know that a few native genera contribute much more than most others and we cannot ignore them if we are to produce a complex, stable food web.”
His study finds that only a few keystone or powerhouse plants support the majority of Lepidoptera (the moths and butterflies whose caterpillars provide the high-protein, easily digestible insect food that 96 per cent of bird species require to raise their young). Just 14 per cent of native plant species are host to 90 per cent of caterpillars. And just five per cent of the powerhouse plants provide 75 per cent of food.
“There are certain native plants, and there are actually not that many of them, that are doing the bulk of the work,” Tallamy says in a recent interview on the University of Delaware website. “So, if you build landscapes without these powerhouse plants that support caterpillars, the food web is doomed.”
There’s a website that allows you to identify the keynote genera that are best for you. The National Wildlife Federation plant finder is U.S.-based and requires a zip code. I selected locations in two Great Lakes states - Flint, Michigan (48502), and Rochester, New York (14614) - to help figure out a list for our area.
For sure it would include Oak (Quercus), Willow (Salix), Birch (Betula), Cherry (Prunus), Maple (Acer), Bramble (Rubus) and Cranberry / Nannyberry (Viburnum). Those are the all-important woodies. Herbaceous plants would include Goldenrod (Solidago), Sunflower (Helianthus), Fleabane (Erigeron), Lupine (Lupinus), Joe Pye / Bonesets (Eupatorium) and Strawberry (Fragaria). Working out the species within those genera will be a matter of observing what grows around us in the wild.
Stop the light killing
That white light above the entrance to your home or building kills insects by the thousands. They fly at it all night long, becoming exhausted, vulnerable to predators and incapable of completing their life cycle. So either turn it off; or replace the white bulb with a yellow one that attracts few insects; or attach a motion sensor so the light only turns on “when the bad man comes,” as Tallamy says.
There's more. Remove invasive species (a little at a time, if you have a lot); Don’t be too tidy; Tolerate "pests." Etcetera. Read the book, give it to a friend, and have a lovely time getting to know what the famous American naturalist E.O. Wilson calls "The Little Things that Run the World." He’s still alive, by the way, 91 years young. Here he is last year, calling for a global bioblitz in this interview with National Geographic. Here's looking forward to great outings next year for blitzers everywhere.
Merry Christmas, everyone.