Book Review: "Bringing Nature Home"

Last night, my mother and I attended a very enjoyable lecture by Douglas W. Tallamy, a professor of Entomology and Wildlife Ecology at the University of Delaware. We immediately bought his book, Bringing Nature Home: How Native Plants Sustain Wildlife in Our Gardens, and I spent the morning reading it.

As a lifelong resident of this tricky land right at the meeting of the Midwest and the Great Plains, I found both lecture and book to be somewhat Mid-Atlantic centric, but this is understandable as Tallamy was born and raised in the Mid-Atlantic region of the United States and conducts his research there. The principles, however, are relevent the world over.

I am not sure that I could credit Tallamy or his book with any genuinely new ideas, but what he has done is provided an extraordinarily thorough and convincing synthesis of a number of principles that natural and wildlife gardeners have suspected (and sometimes actively promoted) for years.

Tallamy writes passionately of the importance of sustaining biodiversity in the United States and around the world. After a rather grim and depressing outline of the many extinct and imperiled plant and animal species we have lost to deelopment and other factors, however, Tallamy points out that there is much room still for hope, and it lies in the hands, primarily of gardeners.

After detailing the flaws with the "Yellowstone Park" theory of conservation, which entails setting aside some natural lands - usually far smaller and more ecologically isolated than Yellowstone - as parks and preserves for wildlife and using the rest largely as we see fit, without regard for the needs of other species, Tallamy proposes an alternative: ecological corridors snaking through the backyards of ordinary folks like him, and me, and you. Such corridors could create a vast and interconnected safe space for wild creatures while providing natural beauty and many other environmental benefits to human residents.

The plants, however, should not be just any plants, but instead, plants native to your specific region and area. As an entomologist, Tallamy focuses particularly on the importance of insect herbivores, especially caterpillars. You won't help wildlife if you don't provide them with food, and caterpillars and other plant-eating insect "pests" are one of the most important food sources in any single ecosystem. Pound for pound, bugs provide more protein than beef, and an excellent source of fat and other nutrients as well. Everything from other insects and arthropods up to foxes and black bears eats insects. In North America, 96% of terrestrial birds feed their young almost entirely on insects, no matter what dietary preferences they might exhibit as adults.

And 90% of insect herbivores are highly specialized, some feeding on only one species of plant in the world. Not surpsingly, these species are specialized to the particular plants they evolved with, the plants native to their region. Tallamy rolls out data from a number of studies showing the remarkable difference between the wildlife populations (both insects and the birds, mammals, and other creatures that feed on them) sustained by alien ornamental plants versus native plants. For one striking example, the common reed, a Eurasian import to America that has become something of a noxious weed in some areas, supports over 170 species of herbivorous insects in Eurasia. In North America, it supports 5, despite having been one of the earliest imported plants. In contrast, the oak genus, which includes both native and alien species, supports well over 500 types of caterpillar alone.

Many types of alien ornamentals are completely useless to American wildlife because they are simply not recognized as food. Others, which may share a genus with a native American species, can be more helpful, but even this is not guaranteed. In the 80 million years since the popular alien tree Norway maple split from the American branch of the family, which includes sugar maples, red maples, and silver maples, the two groups diverged enough that most insects who can consume native maples can no longer utilize the European maple.

But, some of you might be saying, isn't that a GOOD thing? I don't want my plants to be all munched up! The truth is, that in a diverse and sustainable natural ecosystem, foliage loss is generally insignificant despite greater numbers of insect munchers. Why? Because biodiversity supports not only a great variety of munchers, it also supports a great variety of predators, who keep their populations in check. In recent years, many, many studies have demonstrated the greater productivity of organic farms, which support biodiversity and encourage beneficial insects and other animals as a significant part of their pest control, over monoculture plantings popular in traditional agriculture, which rely on powerful insecticides that kill the good guys as well as the bad, and become less effective every year. In 1948, when pesticide use was in its infancy, farmers used approximately 50 million pounds of pesticides, and suffered crop losses of about 7 percent. In 2000, they used nearly a billion pounds of pesticides, yet suffered crop losses of 13 percent. The same principle holds true for backyard landscapes.

After laying the philosophical and scientific foundations of his argument, Tallamy provides helpful information on a number of the plants that support the greatest levels of insect, and therefore arthropod, bird, amphibian, reptile, and mammal diversity, as well as tables detailing host plants for butterfly and moth species, suggestions for regionally appropriate plants, and many other useful guidelines and suggestions.

I recommend this book to anyone with an interest in wildlife, ecology, and gardening, and especially to those who wish to "make a difference" in their own backyards. Tallamy demonstrates convincingly that a landscaping revolution might just save the world, and it begins in our own backyards.

Please consider stopping by some of my other hubs on natural gardening and conservation: