Why Is Rewilding Important?

How to foster biodiversity by reestablishing native plants.

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by Adobestock/Garry

Healthy ecosystems contain a host of interacting native species of plants, animals, and other organisms that collectively perform important functions. These ecosystems provide food for insects, birds, and other animal species and attract bees and other pollinators. Diverse trees, shrubs, and other plants produce the oxygen we breathe and mitigate climate change by scrubbing carbon dioxide from the atmosphere. Healthy ecosystems can also provide sustainable harvests of timber, wild foods, and other economically or culturally valuable natural products. Further, many of us love the aesthetic beauty of healthy ecosystems, and we value them as places for recreation, nature study, refuge, and inspiration.

Unfortunately, throughout the United States and much of the world, most ecosystems have been destroyed or significantly harmed. A 2021 study in Frontiers estimated that only about 3 percent of Earth’s land-based ecosystems remain undisturbed by humans. Habitat destruction, spread of invasive species, climate change, and widespread use of herbicides and pesticides have caused population collapses and eliminated important native species from many ecosystems.

Most of our remaining wild areas are small, isolated remnants of formerly much larger ecosystems and are being overtaken by non-native invasive plants. These unconnected areas provide inadequate territory and resources (food, nesting sites, shelter from predators, etc.) for many native animal species. Consequently, here in Wisconsin, the populations of wood turtles, spruce grouse, Hine’s emerald dragonflies, cricket frogs, moose, and many others have declined alarmingly. Moreover, the lack of native vegetation corridors connecting habitat fragments restricts gene flow and may cause inbreeding. Small, isolated, inbred populations of native animal species often lack sufficient genetic diversity to survive serious infectious disease outbreaks or environmental changes. In Wisconsin, scanty genetic diversity jeopardizes populations of prairie chickens, sandhill cranes, ornate box turtles, American martens, and other animal species. Another concern about isolated habitat fragments is that many animals are killed by vehicles, lawn mowers, or other dangers adjacent to them.

However, there’s good news. Each of us can make choices that’ll positively affect ecosystems. Notably, landowners can “rewild” land that’s been cleared of native vegetation by helping reestablish a diversity of native plants, which in turn will help restore interaction diversity and ecosystem health.

How to Start the Rewilding Process

If you have a turfgrass lawn, you can replace some of it – as much as possible or practical – with an assortment of native trees, shrubs, and herbaceous species. Consult the National Wildlife Federation’s Native Plant Finder to determine which plant species are best for where you live. A major goal of rewilding is to establish food plants that are necessary for all life-cycle stages of native insects. Planting only flowering plants that provide nectar for adult insects is inadequate; we must also provide undisturbed pupation sites and native food plants for caterpillars and other insect larvae. For example, a non-native butterfly bush (considered invasive in many places) planted in a lawn will provide nectar, but it won’t offer food for caterpillars. (Learn more about butterflies and moths.) Further, most native ground-pupating insects can’t burrow into the compacted soil typical of most lawns. In contrast, nearly all native tree and shrub species support native insects; native oak, willow, cherry, plum, birch, crabapple, and maple trees support the greatest diversity of native moths, butterflies, and other insects. Reestablished native insect species will help restore ecosystem health by supporting many species of birds and other vertebrates.

When rewilding land to restore ecosystem health, eradicate as many invasive non-native plants as is practical and appropriate for your region. (Some invasives may be edible. Learn more in “Eat Your Invasive Plants“.) It may be neither practical nor necessary to remove all white clover plants, for example, but aggressively invasive plants – European buckthorn, multiflora rose, kudzu, Norway maple, Asian honeysuckle, and non-native Phragmites reeds – should be totally eradicated, if possible. Invasive non-natives often out-compete and displace the native food plants required by native insects and other animal species. Native herbivorous insects are also typically adapted to eat certain native plants with which they coevolved.

Over the past seven years, I’ve rewilded about half an acre of my property in a small rural subdivision in eastern Wisconsin. I maintain a small mowed area and an unfenced productive vegetable garden, but the rest of my land has been rewilded. When my subdivision was built in the 1960s, developers left some native trees as specimen trees but bulldozed the forest understory and replaced it with turfgrass. Only a narrow swath along my south property line next to an agricultural field was spared. In recent decades, many native oaks and elms in my neighborhood have died, and homeowners have cut down many healthy ones, eliminating food plants and habitat for native wildlife. Of the few trees that have been planted, most are non-native to my area – primarily blue spruce, Austrian pine, and invasive Norway maple.

To initiate the rewilding of parts of my yard, I simply stopped mowing the grass and removing fallen leaves and sticks, and I waited to see what plants established themselves. Most of the plants that grew, including many edible ones, were natives that spread from the south property line or grew from seeds deposited by birds. A large diversity of reestablished native plants supports the native predators of garden pests, but it’s also an excellent strategy for producing a host of nutritious wild foods. Of the food I harvest, about half comes from my garden and the other half from my rewilded land.

As native plants became reestablished throughout the rewilded areas of my property, they smothered much of the non-native fescue that was planted decades ago. Accumulation of fallen leaves and other decomposing plant matter also helped kill the turfgrass. Additionally, plant matter improves water absorption into the soil, replenishes groundwater, prevents soil erosion and flooding, enriches soil nutrients, keeps roots cool and moist, curtails invasion by some invasive plant species, and provides habitat and overwintering sites for native insects and vertebrates. As a bonus, eliminating turfgrass can help reduce the numbers of invasive Japanese beetles. Larvae of these garden pests eat turfgrass roots, so a reduction in turfgrass should hinder their population growth.

Prior to the widespread reestablishment of native plants on my property, rabbits sometimes ate my garden vegetables. My rewilded land now provides shelter from predators and a smorgasbord of native plants to eat, so they leave my garden alone. They’re wise not to venture near my garden, where they can be spotted by hawks or owls hunting for small mammals. A groundhog family also resides in my rewilded backyard, and they don’t seek my garden vegetables either. However, if I were to maintain most of my land as manicured lawn, as my neighbors do, then the rabbits and groundhogs would be incentivized to invade my vegetable garden; there would be nothing else for them to eat. I’ve yet to discover an effective deterrent for marauding chipmunks that eat some of my tomatoes, potatoes, and strawberries, but they cause much less damage than rabbits and groundhogs.

When the forest that would become my neighborhood was bulldozed, natural depressions in the land were filled, and any ponds that might have existed were destroyed. So, as a part of my rewilding plan, I dug a small ephemeral “pond” immediately below the discharge pipe for my sump pump. At 3 feet deep and 5 feet across, the pond holds water for a few weeks each spring and provides breeding habitat for American toads. Some of these toads find my vegetable garden and eat grazing insect pests.

Rewilding my yard has decreased the time I waste mowing turfgrass, reduced my carbon footprint, saved me money, and made my property much more visually interesting and attractive. It’s been rewarding to facilitate the transformation from boring lawn to a small community of diverse native plants and animals.

What’s next? Come back for Part 2 of this series in a future issue, where I’ll explore specific plants to consider reestablishing and future actions to take to help bring awareness to rewilding in our communities.

Ryan Paruch gardens, forages, and teaches college science courses in the Kettle Moraine region of eastern Wisconsin.

  • Updated on Jan 3, 2024
  • Originally Published on Dec 14, 2023
Tagged with: native flowers, native plants, native pollinators, native wildlife
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