The Importance of Grasslands

The Black Oak Savanna site supports two types of endangered grasslands: tallgrass prairie and oak savanna. Why are these ecosystems so important? Just like forests and wetlands, grasslands have decreased dramatically. In fact, less than 3% of these habitats survive today in Ontario and throughout North America. Also similar to forests and wetlands, tallgrass ecosystems are highly effective carbon sinks. Carbon sinks are natural areas that absorb large amounts of carbon (CO2) from the atmosphere and store it through a process known as carbon sequestration. Tall grass ecosystems sequester on average 1.7 metric tons of CO2 per acre, per year. Based on this equation, the Alderville Black Oak Savanna site alone has an approximate carbon sequestering power of 91.8 metric tons of CO2 per year. What’s even better? Grassland ecosystems store carbon in their extensive root systems. When grasslands inevitably burn, the carbon remains safely stored below ground. Comparatively, forests store carbon above ground where it can be readily burned, releasing carbon back into the atmosphere.

Beyond carbon sequestration, deep root systems allow grassland ecosystems to remain tolerant in the face of drought and fire, providing resilience to increasing temperatures. For example, Big Bluestem has a root system that is, on average, 3 times as deep as the plant is high! That means if you have a 6-foot-tall Big Bluestem plant, their roots can be as deep as 18 feet below ground. These deep roots mean that the majority of the plant’s biomass is below ground, protected from fire, absorbing water.

Ecological Restoration

The bulk of our ecological restoration work centres around three main activities: prescribed burning, planting native species, and invasive species control.

There are many factors that are contributing to the destruction of grassland habitat including fire suppression, agriculture, development, invasion of non-native species and inappropriate recreational use. One of the most important restoration techniques is the reintroduction of fire. Prescribed burns are a key part of Alderville’s management plan and are carried out in a scientific manner each spring. Fire is a key element in our management plan because it helps reduce invasive species which have not evolved to withstand fire, while promoting native species which depend on fire to reproduce and thrive.

Another method of restoring grasslands is to remove invasive species such as Spotted Knapweed, Smooth Brome, Sweet White Clover, Dog Strangling Vine, and European Buckthorn. To maintain the open habitats of savannas and prairies, we also have to combat some native species as well such as Balsam Poplar, Trembling Aspen, and Staghorn Sumac. Without control of these species, natural succession would take place and the rare savanna habitats would become woodlands.

While removing invasive species, it is essential to reintroduce native species by sowing seeds or planting seedlings. Each year, our staff collects seed from the native grasses and forbs (flowering plants) on site. This seed is then grown into new plants throughout the winter and spring, and then replanted out on site the following year. This cycle ensures that the genetics of the plants on site stay as local as possible. Local genetics are key to ensure that the plants we introduce to the site have adapted to the unique ecoregion within the Rice Lake Plains and at the far eastern reach of the Oak Ridges Moraine.

Education & Outreach

Here at the Alderville Black Oak Savanna, education is extremely important. We strive to educate others on the complexity and importance of grassland ecosystems, and foster a life-long interest in nature.

Our team of educators and ecologists offer on-site guided tours and programming. We also travel to various events and conferences to network and engage the public about the importance of tallgrass prairie and savanna ecosystems. The Black Oak Savanna is beautiful in all four seasons, and we encourage multiple visits to truly understand the uniqueness of this place.

The Black Oak Savanna hosts class trips throughout the year for students from grades 1 through to post-secondary. Here at the Savanna, we also have public events to engage the community in pollinator monitoring, planting native species and much more. To learn more about the educational opportunities we offer, please visit our “Educational Programs” page. We also have many resources available upon request.

Research

Scientists refer to the Alderville Black Oak Savanna as “the Jewel” of the savanna/tallgrass prairies in Ontario. Its uniqueness makes our site of special interest for research. We endeavor to support applied and academic research. Through nurturing these projects, we enhance our knowledge and understanding of grassland ecosystems. A large amount of our own research at the Alderville Black Oak Savanna is long-term monitoring of ecological restoration.

Monitoring is a crucial component of ecological restoration. It helps gauge the impact that restoration efforts are having on the land. One of the main goals is to increase native plant diversity and decrease non-native or invasive plants. In order to assess plant community changes and diversity, several monitoring inventories are done throughout the season.

For more information visit www.aldervillesavanna.ca