Story URL: http://news.medill.northwestern.edu/chicago/news.aspx?id=158850
Story Retrieval Date: 5/19/2013 7:40:49 PM CST
The floristic quality assessment measures the quality of native plant life in a given area. It rates a species of plants on a scale of zero to 10, also known as the coefficient of conservatism, or C value. The higher the number, the more conservative a plant species is. Conservative plants are defined as non-weedy, sustainable and representative of a high-quality habitat that existed before the presence of invasive species. Conservative plants help establish a balanced, healthy ecosystem.
After C values are calculated for individual plant species in a given area, the numbers are averaged to determine how valuable the land is. Again, the higher the number, the more valuable the land area is. And the better chance the land has of being restored.
Explaining C values further:
Exceptionally high-quality vegetation (greater than 5.0): Characterized by native plant species that retain significant quality and ecological integrity of the native plant life. These areas have a very high capability of being restored. For northern Illinois, these plants include mature trees, such as oaks, sugar maple, dogwood, northern bush honeysuckle and red honeysuckle.
High-quality vegetation (between 4.5 and 4.9): Characterized by native plant species that have the potential to be restored to the exceptionally high-floristic quality category. Plant species that usually receive this rating are black-haw shrubs and choke cherry shrubs. Dogwood and northern bush honeysuckle are also sometimes in this group for northern Illinois.
Moderate-quality vegetation (between 4.0 and 4.4): This category often sees high areas of shading due to dense shrubbery. These areas are more difficult to restore because native and non-native plants are in co-habitation.
Low-quality vegetation (less than 4.0): These areas show where significance invasive populations thrive. Full restoration of these areas is nearly impossible.
Source: Openlands Lakeshore Preserve, Conservation Design Forum