Introduction to Habitat Assessment and Grading
Habitat assessments are largely based on the natural heritage of the site being assessed. In plain terms natural heritage means that we are looking for sites that have plant species which are native to North America and more specifically to the habitat found in Winnipeg. There are many reasons why the presence of native species is important. One is that these species have combined to form well-defined communities that support a diversity of wildlife. The presence of these communities protect the survival of wildlife species that rely on them and also protect the uniqueness of our North American ecosystem. Another reason is Biodiversity. Preserving natural heritage helps to protect the plants and animals that live in these areas this maintains a greater diversity of living things that is both interesting and necessary for our survival.
The communities that these plants form are thought of as habitat types. There are five main habitat types naturally occuring in the City of Winnipeg. These are:
When habitat is assessed it is assigned a grade from A-D. "A" is a very good grade while "D" is not good (just like school). The definitions for these grades follow.
"A" Quality Habitat (Maximum sensitivity to disturbance): Virtually undisturbed by man or recovered to an extent where community structure and composition is intact and reflects historical natural vegetation and wildlife habitat. Other factors include soil disturbance, a high degree of native vegetation present and conversely, a lack of weedy or non-native plant species.
"B" Quality Habitat (High sensitivity to disturbance): Light to moderate disturbance, for example, encroachment of non-native species, may have a minimal amount of weeds but maintains a more natural condition where native species are still the major vegetation community.
"C" Quality Habitat (Low sensitivity to disturbance): Moderate disturbance, a significant number of weed species which have replaced native species, few native species present. For example, an old agricultural clearing that has not been used in recent times and native plant species are slowly returning, or an area that is occasionally mowed.
"D" Quality Habitat (Minimum sensitivity to disturbance): Heavily disturbed site, the vegetation is dominated by weed species or absent all together. None or very few native species present.