Sunday, February 23, 2020

Nature’s Best Hope (The Book)

So many people want to find the solution for the declines of critters around us: native bees, monarchs and other butterflies, birds. It turns out, just like Dorothy, we had the power to fix it all along:  “The Scarecrow exclaims, “Why didn’t you tell her before?!” Glinda responds, “She wouldn’t have believed me. She had to learn it for herself.” I'm encouraged to see that people are learning—through numerous blogs and social media—that our own yards can make a difference, and the message is getting louder.

Doug Tallamy’s new book  “Nature’s Best Hope: A New Approach to Conservation That Starts in Your Yard” makes it clear that every yard—no matter how big or how small—is important to making the difference to the critters that need us. Getting regionally appropriate native plants into our yards, shrinking the non-productive turf-grass spaces (so we can add more native plants!), avoiding pesticides, convincing other people, removing invasive plants … small steps that add up to really big impacts for the ecosystem around us.

After the success of his book “Bringing Nature Home” in 2007, Tallamy has been speaking to groups around the country about why native plants are important from a scientific point view, most specifically because of insect herbivores or, as he likes to call them, ‘the little things that run the world.’ He has reached many a gardener, bird lover, and butterfly enthusiast with his message that native plant-native insect relationships are rooted in years of evolution that non-native plants can’t replace.

I loved reading this book – his sense of humor absolutely comes through. I can see how comfortable he is talking about the subject now. Yet, his sense of frustration is also there. The expanse of lawn is vast in America, and the pull to conform with neighbors by using the same non-native plants is strong. And the rate at which humans are converting wild spaces into unproductive plantings is rapid—we’re losing our chance to make a difference unless we change the mindset that nature lives somewhere else:

Although we must continue to protect good habitat where it still exists, we can no longer afford to ignore the ecological value of the land outside of our preserves—that is, the areas between isolated habitat fragments. (p. 61)

If you’ve not read his first book, I would say this one will suffice as he reviews many of his original concepts. While his first book leaned heavily on research pulled together from others, this book makes reference of new studies since then, including many executed by Tallamy and his graduate students. These studies specifically targeted some of the questions posed about non-native plant interactions with native insects.  In the “Are Alien Plants Bad” chapter, he summarizes a study that demonstrated how ‘introduced plants reduce both species and interaction diversity’ by measuring insect biomass in sites filled with invasive plants vs. primarily native sites.

By every measure, the caterpillar community, and by extensions, the community of insectivores that relied on caterpillars for food, were seriously diminished when introduced plants replaced native plants. […] there were 68 percent fewer caterpillar species,  91 percent fewer caterpillars, and 96 percent less caterpillar biomass than what we recorded in native hedgerows (Richard et al. 2018) (p. 111)

Boneset moth, a specialist
Someone who helps with extra insects
















With so many fewer insects, how do we expect birds to keep reproducing? Another study helped answer that. The consequence of these differences was that chickadee populations achieved replacement rate—that is, produced enough chicks each year to replace the adults lost to old age and predation—only in yards with less than 30 percent introduced plants. (p. 113)

A visual way to consider your plant portions in the Georgia Piedmont

In addition to some very valuable information that we can use when educating others, Tallamy gives us some useful terms to make our points. One of the best ones is “keystone plants,” a group of ‘hyperproductive’ plants that help sustain “70-75 percent of local Lepidoptera species.” His first book already identified that plants like oaks (Quercus) and several other top woody and perennial plants supported large numbers of butterflies and moths. Studies have continued to demonstrate that the plants we choose make a difference and that “to be richly productive, plant communities must contain at least some keystone plants.” (p. 142) I honestly always thought his next book was going to be called “Let It Be an Oak.”

Saving large oak trees in urban areas is important

Perhaps one of the best features of the book would be the many ways he helps to answer what he calls the ‘Suburban Challenge,’ especially in his appropriately named chapter: “Will it Work?” He’s had 12 years of watching (and listening to) people try to make changes in areas that want order and conformity. This plus 10 concrete steps in Chapter Eleven followed by 15 pages of frequently asked questions are the types of information and encouragement that people need to move forward with his message.

In the end, nature’s best hope is me, and you, and millions of other humans on this planet with the capability of planting or influencing the planting of native and appropriate plants.

Black swallowtail, raised on native Apiaceae plants

No comments:

Post a Comment