A five part series from Return the Landscape featuring the five habitats found in Lambton County: Tall Grass Prairie, Wetlands, The Carolinian Forest, The Rare Oak Savannahs & Coastal Dunes & Beaches.
Part 4: Coastal Dunes & Beaches
Coastal dune systems are considered to be among the most fragile ecosystems in North America. Great Lakes coastal dunes in Ontario are considered of national significance due to their extreme rarity and fragility. A dune is defined as a mound or ridge formed by the deposition of sand. These geological landforms develop when an abundance of sand combines with wind, vegetation and geography. American beach grass is important to the development of coastal dunes. The large sand dunes of the Great Lakes were laid down over the last several thousand years. These coastal dunes continue to develop and evolve as erosion from distant shores continues to support and build them. As stated previously, coastal dunes are very fragile systems and therefore have a very low threshold for disturbance. People can easily damage or destroy thousands of years of geological processes.
Shorelines are ‘living systems’. Coastal dunes and beaches are integral systems depending on and supporting each other. Dunes depend on beach sand for their formation, especially during low water levels. Beaches depend on the sand reserves held in dunes during high water levels and storm events. Coastal dunes and beaches must be managed together as one system.
Coastal dunes and beaches have extreme environmental conditions for living things. These extreme conditions include intense sun, extreme heat and cold, high winds, drought and nutrient poor sand soils. Sand can reach temperatures of up to 80° C. Specialized plants and animals have adapted to live under these harsh and difficult conditions. This results in a unique diversity of plants and animals including rare and endangered species such as pitchers thistle. Plant species here include American beach grass, long-leaved sand reed, fringed and plains puccoon and sand cherry.
Wildlife species of these ecosystems are very unique and interesting including ant-lion, digger wasps, eastern hog-nosed snake and wolf spiders. Beaches provide feeding grounds for migrating and nesting shorebirds such as dunlin, piping plover (an endangered species) and ruddy turnstone. Coastal dunes provide feeding and nesting habitat for birds such as bank swallows, chipping sparrows and eastern kingbirds as well as hunting grounds for birds of prey (raptors).
The great lakes coastal dunes and beaches are a complex web of interacting features, natural processes and ecosystems working in delicate balance. Since much of the shorelines are privately owned, proper stewardship practices must be followed by private land owners to ensure that the social and natural heritage values are balanced and the shorelines are protected for future generations. For more information on coastal systems and shoreline stewardship, contact the Lake Huron Centre for Coastal Conservation (519 523 4478) or Lambton Wildlife Inc.
By Larry Cornelis
Return The Landscape