Deep within Ruthven’s Carolinian forests there lies an undoubtedly under-appreciated habitat–the slough. Simply put this is a wetland area associated with trees (a swamp) and stagnant or slow-flowing water. Look past the bugs, the muck that swallows your boots, and the pungent aroma that emerges when you finally manage to extricate that boot, and you will see one of the prettiest habitats in southern Ontario. The hydrology and nutrient levels in these areas create unique associations of vegetation that include a diverse array of sedges, mosses, ferns, grasses, wildflowers, and shrubs that like to get their feet wet.
Some of these wetlands are ephemeral, meaning they are only full of water temporarily, usually drying up by the middle of the summer. Many species have adapted to these areas, also referred to as vernal pools. The short-lived nature of these habitats inhibits the establishment of fish populations, creating an ideal environment for frogs, salamanders, and invertebrates to breed and lay their eggs without the threat of aquatic predators. As a result, these habitats are usually heard before they are seen in the spring-time. The distinctive calls of Spring Peepers, Wood Frogs, and Chorus Frogs are the most common sounds you will hear.
A variety of other wildlife are also dependent on these unique wetlands for food and shelter including birds, reptiles, and mammals. Bursts of young amphibians and insects leaving the pools can attract hungry predators including raptors, wading birds, shrews, raccoons, snakes, and turtles. Abundant vegetation, and easy access to a drink, also draw in herbivores. Along with many common species, these wetlands are also important for species at risk. Over sixty species of birds listed as special concern, threatened, or endangered in Northeastern North America are thought to be associated with vernal pools in some way. The Jefferson Salamander, listed as threatened provincially and nationally, is dependent on the existence of these habitats for reproduction.
In addition to providing important wildlife habitat, sloughs also provide humans with a number of valuable ecosystem services. These include contributions to groundwater recharge, maintenance of water quality, and flood mitigation.
Urban development, agricultural practices, forestry, draining, aggregate extraction, and road construction are all significant threats to these habitats in Ontario. As knowledge is continuously gained about the importance of vernal pools to humans and wildlife, actions are being taken to mitigate these impacts and inform landowners. With an estimated 80% of the wetlands in southern Ontario destroyed since European settlement, the study and conservation of those remaining has become a high priority for a variety of stewardship organizations, including Ruthven Park. Continued appreciation of these areas will be essential to their long-term sustainability, particularly in locations of growing populations.
Below are a few pictures that highlight the beauty of these wetland habitats.
Author and photographer: Christine Madliger