Plant Choice Matters
What will it take to give our local animals what they need to survive and reproduce on our properties?
What will it take to give our local animals what they need to survive and reproduce on our properties?
Operation Pollination/Clatter article Sept 27, 2021
As we approach October – Harvest time, and Halloween-themed everything, I’m challenged this week to come up with “Fun Facts” about pollination. This is what I found instead (from Doug Tallamy, T. A. Baker Professor of Agriculture in the Department of Entomology and Wildlife Ecology at the University of Delaware, where he has authored 104 research publications and has taught insect related courses for 40 years) – warning – it’s really scary and disturbing:
“The population of the U.S., now over 330 million people, has more than doubled since most of us were kids, and it continues to grow by 4800 people each day. All those additional souls, together with cheap gas, our love affair with the car, and our quest to own ever larger homes, have fueled unprecedented development that continues to sprawl over 2 million additional acres per year (the size of Yellowstone National Park). The Chesapeake Bay watershed has lost 100 acres of forest each day since 1985. We have connected all our developments with 4 million miles of roads, and their combined paved surface is nearly five times the size of New Jersey. Somewhere along the way we decided to convert most of our living and working spaces into huge expanses of lawn. So far, we have planted over 62,500 square miles -some 40 million acres - in lawn. Each weekend we mow an area the size of New England to within one inch and then congratulate ourselves on a job well done. And it’s not as though those little woodlots and “open spaces” we have not paved or manicured are pristine. Nearly all are second-growth forests that have been overtaken by invasive Asian plants like autumn olive, multiflora rose, Oriental bittersweet, porcelain berry, buckthorn, privet, and bush honeysuckle.
To nature lovers, these are horrifying statistics. I stress them so that we can clearly understand the challenge before us. We have turned 54% of the lower 48 states into a matrix of cities, suburbs, roads, airports, power and pipelines, shopping centers, golf courses, infrastructure, and isolated habitat fragments, with 41% more of the U.S. into various forms of agriculture. That’s right: we humans have taken 95% of the natural world and made it unnatural. But does this matter? Are there consequences to using almost all our land to meet human needs without considering the needs of other species? Absolutely, both for biodiversity and for us. Our fellow creatures need food and shelter to survive and reproduce, and we need robust populations of our fellow creatures because they are what run the ecosystems on which we all depend. Although we like nature, we have always felt apart from it; humans are here, and nature is someplace else. The idea that we could coexist in the same place at the same time has never been part of the vast Western or Asian cultures.
Plant Choice Matters
What will it take to give our local animals what they need to survive and reproduce on our properties? Native plants - and lots of them. This is a scientific fact deduced from thousands of studies about how energy moves through food webs. The general reasoning goes something like this: All animals get their energy directly from plants, or by eating something that has already eaten a plant. The group of animals most responsible for passing energy from plants to the animals that can’t eat plants is insects. This is what makes insects such vital components of healthy ecosystems. So many animals depend on insects for food (e.g., spiders, reptiles and amphibians, rodents, 96% of all terrestrial birds) that removing insects from a food web spells its doom.
But that is exactly what we are doing in our landscapes. For over a century we have favored ornamental plants from Asia, Europe, and South America over those that have evolved right here. If all plants were created equal, that would be fine. But every plant species protects its leaves with a species-specific mixture of nasty chemicals. With few exceptions, only insect species that have shared a long evolutionary history with a particular plant lineage have developed the physiological adaptations required to digest the chemicals in their host’s leaves. They have specialized over time to eat only the plants sharing those particular chemicals.
In the past we designed landscapes as if they weren’t essential parts of our local ecosystems. But if your yard, your neighbor’s yard, your entire neighborhood and township, in fact, all the places in which we live, work, and play, are excused from contributing to our local ecosystems, then the natural world that supports us is whittled down to nonfunctional remnants of its former self. This must change if we hope to avoid the worst of Earth’s sixth mass extinction and to sustain the production of essential ecosystem services. Everyone who owns land has a golden opportunity to enhance, rather than degrade, local ecosystems by including ecological function as a criterion when we choose landscape plants. And everyone who does not own land can become a player in the future of conservation by volunteering for a local park or land conservancy.”
Ahhh. I don’t know about you, but it keeps me up at night.