Book SectionsTable of Contents
The Problem Puddle Power Frog-Friendly Backyard Why are we concerned about amphibians?
Wetlands - function/type Wetland issues
How to help amphibians
Community Green Plans
Urban Wetlands I
The 13th century Chinese referred to small lakes as
"ponds of mercy". As more and more wetlands disappear, the
remaining pools become important amphibian refuges, or
"ponds of mercy". With your help and that of other homeowners, there can be thousands of "ponds of mercy" and frog
-friendly backyards across Ontario. They symbolize our determination to ensure that we do not have a silent spring, and that
the health of the entire landscape is restored.
Even if you do not have an amphibian pond, your backyard can enhance the survival of amphibians by providing terrestrial habitat. Assuming that your community has a wetland where amphibians breed, your frog friendly backyard may provide a summer fern glade in which a frog or toad can find shelter and moisture (remembering they need to absorb water through the skin and avoid drying out). And for hibernating, a sand pit or large compost pile covered with leaves will provide a frost free sanctuary in which toads can bury to avoid winter's killing frosts.
Although building a pond in your backyard will increase amphibian habitat, it will not be of much help if the wetlands in your area are being destroyed. Despite our best intentions, backyard ponds cannot replace the functions of existing wetlands which are survivors of a long evolutionary history. Large constructed wetlands will reach a balance with the surrounding environment and develop their own character as they adapt to local changes. Most backyard ponds have a limited ability to change and adapt as the surrounding habitat changes. However, even small ponds will add value to or link landscapes with existing wetlands.
Urban habitats often have disrupted watersheds creating stress for wild life. Although any environment can be harsh if you are not adapted to it, parks, river valleys and your frog -friendly backyard can soften the edges of urban habitats. School groups learn this lesson by comparing the diversity of species in lawn environments with that of nearby fields. They lay a hoola -hoop on the ground and count all the species of plants and invertebrates within their circle. The field has three times as many species as the lawn. Your frog-friendly backyard may host as many species as the field.
In urban areas, the most successful wetland restorations may be for visual impact or demonstration purposes. Urban ecosystems are often degraded and wetlands may be hydrologically isolated (separated from a reliable water supply).
They must be robust enough to sustain the impact of intensive use. It may be more realistic in heavily urbanized areas where we cannot ignore the impact of millions of people to let wetlands find a new balance. Wetland habitats are popular in urban areas because they provide instant habitat with little time required for the development of a plant community. Resilient animal species may also surprise us by accepting the new habitat as home. However, pristine habitats hanging on in urban areas are worthy of remedial action to return the wetland to a previous state that can be maintained once the destabilizing conditions have been addressed.
Sometimes the low level of maintenance on successional sites is interpreted as neglect. We must seek to alter the expectations of an ideal landscape. Dead and decaying material is important to the self-regulating community. It provides the environment in which succession can occur.
We should not assume that degraded or early successional wetlands do not have existing important hydrological functions or value for wild life. Those engineered for storm water management can be designed for wild life with a variety of depths, slopes and substrates. Some ability to control water depth will assist in the control of invasive species and allow the colonization of edge species during the low water period. Permanent water over a metre will prevent cattails from dominating your wetland.
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