Keystone species are defined as species that other species depend on, and that if removed, would drastically change the ecosystem where they live. The species play such a fundamental role that they cannot be easily lost or replaced. This includes animals like beavers whose dams help protect and provide habitat for many other organisms and grey wolves who provide population control. Here in Florida, we have local examples that live across the state, including both animals and plants. Below are some of Florida’s major keystone species and how they help maintain the ecosystem around them.
American Alligator, Alligator mississippiensis
The American alligator is a well-known species here in Florida, especially around the Everglades. This species has been around for millions of years and has been hunted by humans and used for various things like food and fashion. Overhunting of alligators in the mid-20th century led to a rapid population decline. This decline resulted in a massive shift in the environment with other species being impacted. Scientists and researchers started studying this shift and found that alligators provide a vital ecological service to the ecosystem- alligator holes. These holes are dug by alligators and used by many different species including turtles, birds, fish, and insects. These holes are filled up during the wet season by rainwater and then hold water to provide habitat and water for other species during the dry season. Upon recognition of this service’s importance to the ecosystem, conservation plans were put in place to help improve the declining population of alligators and led to the recovery of the alligator population from the brink of extinction.
Gopher Tortoise, Gopherus polyphemus
The gopher tortoise is a tortoise species that spans the southeast US. This tortoise species is one of only 5 in North America and the only one found east of the Mississippi River. Like many other tortoise species, these animals are known for their burrows and will spend a lot of their time in them. These burrows are the reason these animals are keystone species. Their burrows are sheltered for themselves as well as over 350 other species. These include the eastern indigo snake and the burrowing owl among many others. This species, however, is regionally threatened due to its declining population. This is largely due to habitat loss and destruction due to urban development, but improper land management and increased car collisions play a role as well. Since the reclassification of these tortoises in 2007, the Florida Fish and Wildlife Conservation Commission (FWC) has put together a Gopher Tortoise management plan that is meant to “restore and maintain secure, viable populations of gopher tortoises throughout Florida so the species no longer warrants listing.”
Oaks, Quercus sp.
As mentioned above, keystone species includes both animals and plants. Native plants help to support different native species like insects and birds by providing shelter and food. While some may only be valuable to a limited number of species, tree species like oaks are valuable and essential for many different species. Animals like squirrels, woodpeckers, raccoons, hummingbirds, and white-tailed deer depend on oak trees. Oak species here in Florida are host to more than 350 caterpillar species. This includes different types of Duskywing (Horace’s Duskywing, Juvenal’s Duskywing) and Hairstreak caterpillars (red-banded hairstreak, white-banded hairstreak, oak hairstreak). Here in Florida, there are many different types of oaks including the Laurel Oak (Quercus laurifolia), the Live Oak (Quercus virginiana), the Chapman’s Oak (Quercus chapmanii), the Water Oak (Quercus nigra) and the Running Oak (Quercus pumila).