Woodlands

Toronto is home to a wide range of woody and herbaceous plants that make up woodlands. The primary driver of which plants you encounter is ecological succession. Ecological succession is the natural progression from one dominant vegetation type to another over time in the absence of disturbance. As a result, woodland composition changes naturally as time progresses.

Early succession occurs following a disturbance such as a wildfire event or simply mowing. Early successional communities consist of grasses and shrubs that will give way to mid-successional communities consisting of yellow poplar, cherry, birch, pine, aspen, and sweetgum. These trees are intolerant of shade – as the woodland develops, these trees will be replaced by maples, oaks, beech, hickories and hemlocks that can survive under shady conditions. Different stages of succession provide unique habitats for different groups of wildlife.

The process of ecological succession is often driven by competition for sunlight. Trees that outgrow their competitors in height develop larger crowns that capture more light and shade out competing plants. When a tree falls, an opening in the canopy appears, allowing light to reach plants that otherwise would not have access. Trees such as oaks and hickories can grow under shady conditions, but growth accelerates when light becomes available. This is why mature forests often contain oaks and hickories.

Hardwood-dominated woodlands contain trees of different trunk diameters, but despite the size difference, these trees are often around the same age. Trees with larger diameter trunks are dominant trees that have won the competition for sunlight. As you take a walk through the woods, look up to see which tree species have been successful in becoming dominant.

Don’t overlook the plants that make up the floor of a woodland. The forest floor in Jefferson County is often made up of plants such as moss, trillium, mayapple, wild strawberry, and Pennsylvania sedge. Some trees prefer the shade of the forest understory. Dogwoods, eastern redbud, witch hazel, and eastern hophornbeam do well in these conditions.

Vines can grow upward from the forest understory into the canopy. Some vining plants include Virginia creeper, poison ivy and wild grapevine. In some cases, vines can become dense enough to smother trees.

FUN FACT: Jewelweed often grows alongside poison ivy and can help prevent dermatitis if applied immediately following contact. That said, research shows soap is more effective.

Be on the lookout for invasive plants – these are plants that are not native to an area but tend to thrive and outcompete native vegetation. Examples of common invasive species to woodlands include butterfly bush, multiflora rose, Oriental bittersweet, Japanese barberry, Japanese stiltgrass, bush honeysuckle, garlic mustard, and tree-of-heaven.

Learn more about the woodland resources here in Ohio: