Page 66 - parks-master-plan

67

Non-native plants in landscaped environments should be limited to those that do not threaten natural areas.

Floristic assessments are one tool used to inventory a site’s plant community and perform a baseline health check. In scientific field studies, plants are evaluated based on a floristic quality assessment index. This system of reducing the subjectivity of a plant community study was developed by Swink and Wilhelm in 1979. The system ranks plant species from 0 to 10 based on their level of conservativeness. Plants ranked 0 have a wide range of ecological tolerances. They are either opportunistic invaders or are ruderal natives. Plants that scale 10 have a very narrow range of ecological tolerance. They have extremely limited suitable growing environments. Some of their restrictions include frequency and quality of water, soil pH, mycorrhizal soil availability, light conditions and companion plant presence.

A field person evaluates a site for its diversity and the quantity and frequency of conservative plants. The data is included in a mathematical calculation to render a plant community health judgment. The numerical answer helps the evaluator develop a management plan based on urgency and site goals.

There is a wide variety of results that come out of a floristic assessment, including a pristine

plant community that should be monitored and left untouched; a quality plant community that is being threatened or degraded by encroachment, requiring non-native and invasive plant removal; and a plant community that has been completely overtaken by invasives to the point of needing both invasive removal and restoration work.

The goals for a site also can vary greatly, including managing an area for certain

endangered or threatened plants, ensuring plant and wildlife diversity or appealing to human aesthetics. All plant communities — including wetlands, pond fringe, prairies and woods — should be evaluated and managed toward the established goals.

Wetland Communities

More than 85 percent of Ohio’s wetlands have been destroyed. They play an important role as nature’s filters, cleaning water and providing vital habitat for plants and animals. A plant community is deemed to be a wetland when two of three defining characteristics are present: presence of water, soil type and plants species. Swamps, marshes, vernal pools and ponds are a few wetland types. They all are inundated or saturated by surface runoff or groundwater frequently and for a duration that supports specialized vegetation adapted for life