Ahhh, the oak savanna. One of my favorite ecosystems. A seemingly complex combination of woods and prairie mixed together. A rare, resilient, special ecosystem that has it’s own unique beauty year round. As we continue camping and hiking Minnesota State Parks and natural areas, we come across more and more acres of oak savanna than we realized still existed in Minnesota.
Being from Southern MN we’re in a perfect location to stumble onto them. As we continue to learn about these incredible places, we realize how much help they need to be preserved, strengthened, and restored. The places we’ve visited in Minnesota that have oak savannas include: Myre-Big Island State Park, Wild River State Park, Jay C. Hormel Nature Center, Fort Ridgely State Park, and the Highway 56 Wildflower Route and Scenic Byway. We’ve heard of a few other locations that have oak savannas although we haven’t camped these parks yet: Glendalough State Park, Glacial Lakes State Park, Chester Woods Park, and Fort Snelling State Park.
An oak savanna is defined as a lightly forested grassland or prairie interspersed with oak trees and oak groves. One park – Wild River State Park – even uses the term oak island, instead of oak groves, to describe their oak savanna…which I fell in love with…so my own personal definition of an oak savanna has changed to: oak islands scattered throughout a prairie.
The grasses typically seen within oak savannas include big bluestem, little bluestem, Indian grass, switch grass, and side-oats grama. Prairies are also well known for wildflowers or flowering plants which can include coneflowers, black-eyed susan, blazing star, prairie smoke, and prairie clover.
Oak savannas typically have a higher plant diversity than grasslands and woodlands combined because they have their own unique species mixed with grasslands and woodlands.
Although the definition of an oak savanna basically means trees in grasses and grasses with trees, it really is its own community with diverse flora and fauna. We’ll discuss the flora and fauna in more detail in future blog posts. Survival of savannas require periodic fire, poor soil, grazing, low precipitation or drought, or it can easily be lost to the forest – which will most definitely overcome it without some sort of maintenance.
Historically, periodic fires, grazing, and drought were the main ways the oak savanna survived. Periodic fires came from Native Americans or lightning and only the trees who had a higher tolerance for fire were able to survive their heat. With regular fires there’ll be the elimination of competitive trees and undergrowth. But, one issue with prescribed burns is there can be too much thinning because it could happen a little too often; is this better than nothing for the savannas that are being cared for in this way? Or do we need to temper how often prescribed burns happen to let some younger saplings get started? But would that then allow too many invasive species to take over? Maybe we should somehow protect a few saplings during burns until they build tolerance? Is that even possible?
Prescribed burns seem to be the most effective process at this time. But then again, I recently stumbled upon a discussion regarding how using bison to graze, rather than (what can be) intense fires (which could take out small oak trees and seedlings) could be more beneficial to the savannas. It was quite interesting, and I look forward to learning more about this practice.
I believe the reason I’m drawn to this particular ecosystem is that they’re now so rare. It’s exciting to stumble across one when you’re driving into a new-to-you park, like we did at Wild River State Park. I leaned out the window, in a bit of shock and excitement, that there was an oak savanna this far north! Until we drove through the park, towards the campground, I would have never known they had this extra special environment within their park.
How does one even begin to restore one of these treasured places? There’s plenty of information out there, and it takes time, planning, and a team effort. I’ve read about the cutting of secondary-growth trees that can crowd burr oaks. Once the secondary-growth trees are cut out, prescribed burns are used to spur new prairie plant growth and keep the competitive trees and plants at bay. You’ve probably also heard how some parks are using goats as a means to get rid of undergrowth like buckthorn. Restoration is a long but necessary process to manage this environment.
When Minnesota was settled by Europeans, oak savannas covered about 10% of the state. Now it is one of the rarest environments within the state and only about 1% of the those oak savannas that existed 200 years ago still remain. Between less wildfires, farming practices, and urban development we’ve lost many of these communities. Remnants of oak savannas remain within Minnesota at the places noted above. Have you come across oak savannas? If so, leave a comment below so we can visit it by adding it to one of our next adventures!
Being from Southern MN we’re in a perfect location to stumble onto them. As we continue to learn about these incredible places, we realize how much help they need to be preserved, strengthened, and restored. The places we’ve visited in Minnesota that have oak savannas include: Myre-Big Island State Park, Wild River State Park, Jay C. Hormel Nature Center, Fort Ridgely State Park, and the Highway 56 Wildflower Route and Scenic Byway. We’ve heard of a few other locations that have oak savannas although we haven’t camped these parks yet: Glendalough State Park, Glacial Lakes State Park, Chester Woods Park, and Fort Snelling State Park.
An oak savanna is defined as a lightly forested grassland or prairie interspersed with oak trees and oak groves. One park – Wild River State Park – even uses the term oak island, instead of oak groves, to describe their oak savanna…which I fell in love with…so my own personal definition of an oak savanna has changed to: oak islands scattered throughout a prairie.
The grasses typically seen within oak savannas include big bluestem, little bluestem, Indian grass, switch grass, and side-oats grama. Prairies are also well known for wildflowers or flowering plants which can include coneflowers, black-eyed susan, blazing star, prairie smoke, and prairie clover.
Oak savannas typically have a higher plant diversity than grasslands and woodlands combined because they have their own unique species mixed with grasslands and woodlands.
Although the definition of an oak savanna basically means trees in grasses and grasses with trees, it really is its own community with diverse flora and fauna. We’ll discuss the flora and fauna in more detail in future blog posts. Survival of savannas require periodic fire, poor soil, grazing, low precipitation or drought, or it can easily be lost to the forest – which will most definitely overcome it without some sort of maintenance.
Historically, periodic fires, grazing, and drought were the main ways the oak savanna survived. Periodic fires came from Native Americans or lightning and only the trees who had a higher tolerance for fire were able to survive their heat. With regular fires there’ll be the elimination of competitive trees and undergrowth. But, one issue with prescribed burns is there can be too much thinning because it could happen a little too often; is this better than nothing for the savannas that are being cared for in this way? Or do we need to temper how often prescribed burns happen to let some younger saplings get started? But would that then allow too many invasive species to take over? Maybe we should somehow protect a few saplings during burns until they build tolerance? Is that even possible?
Prescribed burns seem to be the most effective process at this time. But then again, I recently stumbled upon a discussion regarding how using bison to graze, rather than (what can be) intense fires (which could take out small oak trees and seedlings) could be more beneficial to the savannas. It was quite interesting, and I look forward to learning more about this practice.
I believe the reason I’m drawn to this particular ecosystem is that they’re now so rare. It’s exciting to stumble across one when you’re driving into a new-to-you park, like we did at Wild River State Park. I leaned out the window, in a bit of shock and excitement, that there was an oak savanna this far north! Until we drove through the park, towards the campground, I would have never known they had this extra special environment within their park.
How does one even begin to restore one of these treasured places? There’s plenty of information out there, and it takes time, planning, and a team effort. I’ve read about the cutting of secondary-growth trees that can crowd burr oaks. Once the secondary-growth trees are cut out, prescribed burns are used to spur new prairie plant growth and keep the competitive trees and plants at bay. You’ve probably also heard how some parks are using goats as a means to get rid of undergrowth like buckthorn. Restoration is a long but necessary process to manage this environment.
When Minnesota was settled by Europeans, oak savannas covered about 10% of the state. Now it is one of the rarest environments within the state and only about 1% of the those oak savannas that existed 200 years ago still remain. Between less wildfires, farming practices, and urban development we’ve lost many of these communities. Remnants of oak savannas remain within Minnesota at the places noted above. Have you come across oak savannas? If so, leave a comment below so we can visit it by adding it to one of our next adventures!