In the first blog post on the book, Nature’s Best Hope by Douglas Tallamy, the focus was on how individual efforts in restoring native landscaping of residential/corporate landscapes, city parks, hedgerows, and roadsides could reverse the deleterious impact of non-native plants. The author pointed out that homeowners remain clueless, through no fault of their own, regarding the human race’s reliance on ecosystem functioning. As a result, ecological health has been severely impacted by urban/suburban landscaping choices. In this post, we explore how we might accomplish buy-in for wholesale landscape change by tens of millions of homeowners and delve deeper into why this new approach is so necessary. Believe it or not, this all starts with our cute, wiggly, highly delicious caterpillar.
The Critical Caterpillar
96% of breeding terrestrial birds rear their young on insects not on seeds or berries. The author recounts a lot of evidence that catapults caterpillars ahead of all insects as the primary food that needs to be available in a relatively small area. This is due to the number of trips parents need to make to satisfy the incredibly fast growth rate of nestlings. Specifically, a male warbler, a small songbird, makes 240 nest visits a day and a female visits the same nest up to 570 times. Nestlings stay in their nest on average for 12-16 days. Are you doing the math?
Chickadee parents, another small songbird, feed their fledglings for up to 21 days even after they have left the nest. That is quite a demand for caterpillars brimming with proteins and fats. Imagine how many more trips would be needed if you were feeding nestlings tiny aphids or spiders. You still have to multiply that one nest by the number of different bird families in your neighbourhood needing food. That’s a truckload of caterpillars. Any wonder why our bird diversity and numbers are down? Have you noticed a predominance of seed eaters (finches, cardinals) and carrion feeders (crow family, gulls) in your neighbourhood? What you plant in your yard makes a difference!
Nutrients called carotenoids are twice as plentiful in caterpillars as in other insects. Birds need to get their carotenoids from insects that eat plants in order to produce brightly coloured feathers- key for attracting females and as a signal of health. Carotenoids also stimulate three biological processes: immune systems, antioxidants that protect DNA from oxidative damage and sperm vitality (remember signal of health-those females are a smart lot). This points to the fact that caterpillars are not optional but essential during the breeding season.
So, which plants are the best hosts for caterpillars? Suffice it to say, as Tallamy points out, native species are by far the best. Keystone species that make up about 5% of plant genera host 70-75% of the local moth/butterfly producing-caterpillars. If you would like to discover more, check out https://www.audubon.org/plantsforbirds
goldenrod-keystone species
Caterpillars are only one phase of the butterfly/moth life cycle requirements; they also must have the microhabitats their pupae need to survive. If the host trees are surrounded by sterile raked up lawn, their will be no leaf litter or rotting wood in which to spin cocoons. Similarly, they can’t tunnel into a concrete surface or into the soil if it is too compacted by regularly trammelling of feet or lawn mowers. We haven’t even touched proper landscaping for the egg or adult stages of life.
Ecological Elephant in the Room
But it does not end there. We have only looked at impact on caterpillar-bird interactions. There is a bigger elephant in the room, ecologically speaking. As we homogenize plant diversity around the world with a small plate of ornamental favorites, the insects that depend on local native species decline with a domino effect on other invertebrates and vertebrates dependent on them for food. Tallamy reports that 90 % of insects have restricted their development and reproduction to very specific plant lineages, so non-natives will not support a majority of them. In the mid-Atlantic region alone, there are 69 native bee species that need exclusively either goldenrod, aster, evening primrose, blueberry or willow pollen to rear their larvae. Is this just the tip of the iceberg?
To add insult to injury, we have created a culture where insects are maligned. We win the war against insects at out peril. Interpreters have their work cut out for them to counteract the position that many children are being taught to fear every insect they see, rather than respect those few that might sting to defend their nests.
So “how” do we go about starting to make some changes in our yards and gardens to counteract the aesthetic biological wasteland choice? Tallamy’s raison d’etre is about empowering all of us to make our planet a better place and kickstart a grassroots approach to perhaps the greatest conservation project of all time. We cannot confine all of our conservation efforts to patches of protected areas because that will never be enough. Parks are too small and too separated to accomplish viable biological corridors that connect preserved habitat fragments with one another.
The book’s premise relies on the fact that we can easily manipulate the land we own and it is the low hanging fruit for ecosystem restoration. The personal space landscaping paradigm must change and become synonymous with ecological restoration. Most landowners would have to make it a conscious effort to convert a significant percentage of their present sterile lawn and “restore it to much of its prehuman productive native plant glory.”
We worry about the destruction of the Amazon rainforest - 20 % of which has been logged. Who is getting upset with the destruction of the North American eastern forests - 70% of which has been transformed into pavement and lawn? “Every square foot dedicated to lawn is a square foot that is degrading local ecosystems.”
Why a New Approach?
Tallamy cites two major missteps whose correction must become part of our everyday culture.
1. The most serious misstep he claims has been to assume that people and biodiversity cannot co-exist.
2. The second misstep has been to leave conservation to conservationists - a tiny trained community of ecologists.
Leaving this responsibility to a few experts means the rest of us remain largely uninformed about why we need respect and care for the earth’s and its systems of life and how to practice that care and respect in our daily lives. “Land ownership is not just about privilege. It’s about responsibility.”
Tallamy believes it is critical for us to make nature relevant again in people’s lives and to reduce the fear factor of venturing outside. The media informs us that we may be attacked by a mountain lion, maimed by a coyote, struck down by West Nile of Zika virus or crippled by Lyme disease. We need to reverse the negative relationship with nature causing avoidance because of inaccurate safety concerns.
“Our misguided risk assessment has convinced us that tailgating a forty- ton trailer at 75 mph is of no concern, but revegetating our yards will surely result in a deadly bite from a rattlesnake species that in reality was extirpated 150 years ago.” The author relates how our ability to assess risk is really skewed. Benefits far outweigh the risks. Statistics tell us that we are far more likely to die from the common cold, falling out of bed, slipping in the shower or using a toaster for that matter, so why should we avoid contact with nature due to a miniscule chance of harm?
courtesy Bill Reynolds
Make Nature Relevant Again
Basically, there are two options to make nature relevant again: take people to nature or bring nature to people. The fallback strategy has been the former with trips to parks and the participation success rate has been small. We must ramp up support for the latter approach, emphasizing the surrounding of people with nature, where they spend most of their time, by using native plant suburban/urban landscaping. This should prepare people so they can capitalize on the few nature outings former approach. Will we be able to expose a majority of people to the countless species on this planet long enough for them to develop a caring and harmonious relationship with them? No one can be certain but let’s give it a try.
I agree with Tallamy’s assertion that native plantings in urban/suburban landscapes can become the norm, if logic-based peer pressure combined with financial incentives are promoted and implemented. Landscapes dominated by native plant species would become the new normal when more and more high-end properties demonstrate such attractive designs and gain community admiration. Heritage sites should play a role as frontrunners in piloting and encouraging paradigm shifts in plant community landscaping.
What needs to change? The traditional status symbol of the upstanding gold standard property, with its immaculate, weedless, inanimate, sterile lawn, maintained by “unspoken rules established by the tribe,” has got to go. We need to bring Home Owners Associations into the 21st century. Being good citizens with responsible community minded values means our properties must be productive from a watershed, climate, and biodiversity perspective. This also means landscapes must be designed to support diverse food webs, support generalist and specialist pollinators, and store as much carbon as possible in plants and soils.
The newly planned and cared for native- plant- dominated landscaping has less lawn, and more powerhouse species that drive food webs and support pollinators. It will be important to dispel the common viewpoint that using native communities represents a form of lawn neglect. Lawns as pathways rather than wall-to-wall carpeting, can be the transition to conscious design and attitude change toward nature. A neatly trimmed, defining grass border goes a long way towards opening the door to breaking gold standard stereotypes. Tallamy refers to websites and apps like YardMap and Nextdoor to help you coordinate conservation with neighbours.
The Problem with the Word “Weed”
In addition, he proclaims that we have a marketing issue with many of our native plants that needs addressing. They have been carelessly given common names with the word weed in them because of a subjective notion that where they grow is in the way of a cultivated crop, crowding an ornamental garden species or along a roadside. This has “stacked the emotional deck against them.” What if milkweed was called monarch’s majesty, New York ironweed was called Manhattan splendour, fireweed was called blazing torch, tickweed was called golden star, hawkweed was called orange delight or sneezeweed was called radiant sunset? Sneezeweed’s moniker encouraging avoidance is “not even up to snuff” as it does not make you sneeze unless you dry its leaves, crush them, and stuff the powder up your nose.
Moving forward, how do we reward the private landowner (83% of the US is privately owned) from the smallest city lot to the largest corporate landscape, if they rebuild much of the food web that once existed in their yard, by including plants that provide nourishment, cover, and forage?
As Tallamy points out the existing concept of a homeowner- driven certified habitat program was the brainchild of the National Wildlife Federation in 1973 and provided a model that has resulted in changing 2.5 million acres as of 2018. Tallamy has estimated 400 million acres in the US is in lawn, so there is still a way to go. The program includes college campuses, schoolyards, corporate landscapes, botanic gardens, zoos and entire communities.
In Canada I am aware of the international reward and recognition program called Communities in Bloom, that has been operating for at least a decade or two. After reviewing the evaluation criteria for this traditional civic pride beautification and green space enhancement program, nothing about native landscaping popped up. This indicated to me that they might be ripe for some new approaches.
E.O. Wilson brings the seriousness of our non- native landscaping home when he said,” If all mankind were to disappear, the world would regenerate back to the rich state of equilibrium that existed ten thousand years ago. If insects were to vanish, the environment would collapse into chaos.” He even predicted humans would last only a few months if “these little things that run the world” were eradicated.
Ecologically Sound Aesthetics
What is ahead of us? Luckily, Tallamy bounces back from some potentially depressing statements. Exciting times he says - to get involved in the hugely rewarding task of restoring ecological function to the land, and viewing it, ”…not as a commodity to be exploited but as the source of our continued existence.” Every day we are learning more about how to redesign landscapes to meet aesthetic, cultural, ecological and practical needs to place plants from the ground to the canopy that will sustain complex food webs, store carbon, manage our watersheds, rebuild our soils and support a diversity of pollinators. As interpreters, how do you plan to modify your site’s appearance and stimulate behaviour change in visitors when they return to their communities and yards?