One of the Most Threatened Plant Communities in the World
Biodiversity is a popular word in the world of conservation. It’s also a really important concept to understand to be able to both maintain it and increase it where possible. To put it simply, biodiversity is all of the different living things you find in one area. Think, plants, animals, microorganisms, and other life that make up the natural world. All of this life works together to maintain the balance in an ecosystem.
Biodiversity is so important that humans actually depend on its support to survive in the form of clean air, clean water, food, shelter, healthcare, and so much more. The different life around us, the communities that are being formed by that life, and the habitats they all live in make up what can be considered biodiversity.
Biodiversity is the umbrella in which all of the smaller pieces of the natural world fall under. Many different habitats come together to form natural communities.
What is a natural community? Typically, it can be described as a collection of interacting animals, organisms, plants, and the natural environment where they occur that’s shaped mostly by natural processes, and repeats across a landscape with similar natural conditions. Natural communities can vary with changes in the environment, but they have predictable patterns at a landscape scale - living things that live together in a specific area, a specific habitat, at a specific time.
In the U.S., different states are made up of different levels and types of natural communities. Being at the intersection of the Northern Boreal Forest, Eastern Deciduous Forest, and Temperate Grasslands, Wisconsin is full of life. Close to 2,000 native plants, 700 native vertebrates, and thousands of non-vascular plants and invertebrates call the state of Wisconsin home.
In Wisconsin (as well as in many other states), natural communities are monitored so that we can manage and conserve our natural resources for public benefit. Many of the same natural communities exist outside of the state of Wisconsin, so it’s important to consider work being done regionally, nationally, and even globally, to ensure these plant and wildlife communities continue to thrive.
There are more than 100 natural community types in the state of Wisconsin alone. At the state level, Wisconsin ranks natural communities based on many factors so that we can keep track of their status and ensure we are continuing to provide wildlife habitat, recreational opportunities, and human services (again, think clean water, clean air, and the things we need to survive). For the natural communities that have been assessed, this ranges from an S1, which is critically imperiled due to a very restricted range, few populations remaining, declining trends, and severe threats, to an S5 which is secure due to an extensive range, abundant populations, and very little threats.
A handful of community types are not only threatened locally (ranked S1) but also globally (ranked G1). A natural community that is critically imperiled at both levels means that it is at very high risk of extinction.
One of these rare community types is the Oak Opening, also known as Oak Savanna. These are oak-dominated, savanna communities that have an open tree canopy where native ground layer and vegetation live in harmony with the oaks. Canopy cover is usually found to be between 5% and 60% in an Oak Opening, which allows the ground layer to receive both sun and shade. This type of relationship permits a high range of biodiversity between grasses and wildflowers.
Some common native grasses and wildflowers you might find in an Oak Opening are big and little bluestem, switchgrass, multiple species of goldenrod and aster, purple coneflower, white wild indigo, and rattlesnake master.
Historically, Oak Openings were abundant in Wisconsin and the Midwest, but today, very few exist. Some scientists have estimated that less than 0.01% are left. There are many factors that have played into the decline of Oak Openings like development and invasive species but a large reason is fire suppression.
Prescribed Burn at Waukesha County Land Conservancy’s Meyer Preserve
Oak trees are fire dependent. Historically, wildfires were a natural occurrence in the state of Wisconsin both through lightning storms and Indigenous Peoples’ use of fire. Because of this, most of the natural communities in the state were developed and evolved to depend on periodic fires. Without fire, Oak Openings went from an open tree canopy to a closed-canopy, allowing woody vegetation and invasive species to take over by outcompeting native species.
Oak Openings are the most threatened plant community in the Midwest and one of the most threatened in the world. Again, less than 0.01% exist in Wisconsin today.
At this point, you might be wondering why this matters. Oak Openings are important pieces of habitat across the Midwest because they are dynamic, biodiverse natural communities with a variety of plant life and wildlife that have evolved together over time. The mixture of prairie and woodland allows for an extremely high amount of biodiversity which provides functioning ecosystem services like (third time’s a charm) clean air, clean water, flood control, food, shelter, wildlife habitat, recreation, nature access for future generations to enjoy, and so much more. When a natural community is lost, everything within that system is impacted.
What can we do?
Almost all present conservation efforts to preserve, maintain, and restore Oak Openings are habitat restorations by land managers. We use invasive species removal techniques like forestry mowing, prescribed burns/fire, removal of weedy trees, herbicide to eliminate woody invasive species like buckthorn, and steward remnant Oak Openings to maintain their ecological value. All of these methods encourage the suppressed native ground layer plants and wildlife. In some cases, we will reintroduce native plant species through seedings.
Even if you are not a land manager or working in conservation, you can also play a role in protecting Oak Openings and other important natural communities in your region. As a private landowner (even in an urban environment), you can:
plant native species in your yard and garden;
remove invasive species in your yard and garden;
reduce or eliminate the use of pesticides on your property;
replace your lawn with native plant species and create a butterfly garden;
work with a local land trust to create a conservation easement on your land or with a native plant nursery to pick out the right plants for your property;
hire a company that offers nature-based solutions to help you form a land stewardship plan for your property; and,
share what you learn with your friends, family, and neighbors so that they can become community conservationist on their own land!
This is not an exhaustive list, but a few ideas for you to get started in your own backyard. You might also be interested in volunteering with a local conservation organization to help them steward natural areas around you by removing invasive species, educating the public, restoring habitat, or monitoring plants and wildlife.
Whatever you choose, the first step is increasing your understanding of the natural world around you. If you’re still reading, you’ve done just that! Everyone has a different reason for loving the outdoors. Whether you want your children and grandchildren to be able to experience nature, you want to provide wildlife habitat, or you want to leave a lasting legacy in your community, your interest and passion for the environment can translate into real conservation impact.
