">

IVEY TRAIL SIGN 21 – OAKS AND PINE

Post_21_-_Succession.pngThe vegetation here is typical of what is known as “old field”, but with one important difference.  Old field vegetation establishes on abandoned agricultural land. The dominant plants in the ground layer are grasses, almost none of which are native to Canada.  Most arrived in the area when they were brought in as pasture grasses.  They do very well in southern Ontario and behave as if they belong, reproducing quite happily in the wild.  Mixed among the grasses are a variety of broad-leaves herbs.  Asters, goldenrods and Common Milkweed (Asclepias syriaca) are native, but the Wild Carrots (Daucus carota) are another introduced species.

Post_21_-_Pine_Needles.pngGiven time shrubs will gradually establish in old fields, common types are dogwoodshawthorns Ninebark and Staghorn Sumac (Rhus typhina). A few trees like ashes and soft maple may start to seed in.  Poplars, aspens, willows and even White Pine (Pinus strobus) may also arrive if their seeds can find patches of bare earth; otherwise the dense mat of grasses will keep them out.  Once the shrubs are established the grasses begin to die back and conditions are right for trees like BasswoodBlack Cherry, oaks and maples to find a home.  This process of change is known as succession.  Under natural conditions Post_21_-_Oak_Leaves.pngit can take several to many decades to convert an old field to a forest.  Here you will notice that succession has been given a jump start.  Oak and White Pine trees are already present, planted among the other vegetation.  Mixed planting of White Pine and deciduous hardwood trees is one way to encourage reforestation.  The pines grow faster and will provide shelter and protection for the other species.  Compare these plantings with others along this section of the Ivey Trail. Reforestation is always a balance between planting native trees in a more natural setting and establishing plantations that are monocultures of a single species.