02/27/2008 Env Bd Packet - Laserfiche WebLink

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• • • Appropriate seed mixes should be designed and purchased from native landscape nurseries to restore these three distinct community types. Wet prairie communities are less commonly restored within the Minneapolis/Saint Paul metropolitan area tan dry and mesic prairie types, due to limitations of suitable soil and hydrologic conditions. Native seed suppliers and nurseries may need to custom design a native wet prairie seed mix with the assistance of a professional and knowledgeable ecologist. However, mesic and dry prairies are commonly restored within the region, and quality seed mixes should be readily available from native plant suppliers. However, all seed mixes should be adjusted for the very sandy and relatively nutrient -poor soils typical of the Anoka Sand Plain and the Foxborough site. Seed mixes should be dormant seeded in September /October, or sown in the spring when the ground has thawed. To reduce costs and loss of plant material, seeds should be instead of plugs (potted plants); as plugs require more watering and protection from herbivory, and are generally more expensive to achieve a similar long -term result. Thinning and Management of Quaking Aspen along Wetland Edges The woodland edges that are prevalent along wetland edges in Foxborough's conservation areas are generally low - quality, species poor stands dominated by Quaking Aspen (Populus tremuloides). Such areas have likely established as a result of past land use practices, landscape - scale fire suppression, and partial drainage of wetlands. Furthermore, these woodland areas likely historically supported more diverse wet prairie and wet meadow natural communities. CCES has successfully restored similar aspen - dominated wetland edges to diverse prairie and wet meadow communities through selective thinning, removal, herbicide treatments, and prescribed burning of aspen. These management approaches often promote the re- establishment of diverse assemblages of herbaceous prairie and wetland species that require full to partial sun to germinate, reproduce, and persist along saturated wetland edges. Furthermore, in the absence of management, dense monotypic Aspen stands tend to promote the establishment of Buckthorn and Reed Canary Grass within the understory, and are prohibitive to prescribed burning due to fine fuel suppression. CCES recommends that selected areas of aspen woodland be carefully thinned and restored to more diverse and more easily managed natural community types such as wet prairie and wet meadow. However, selective thinning of aspen should first consider desired screening of adjacent land uses or other aesthetic considerations, and should balance restoration and management objectives with aesthetics. Maintain and Restore Soil Porosity in Developed Uplands Site grading and development of the residential lots at Foxborough will likely result in the pronounced compaction of surficial soil layers and reduced soil porosity within residential yards and conservation areas edges. CCES and the City of Lino Lakes recommend that prior to final landscaping of residential yards and installation of turf grass, sod, and other landscape plantings, compacted soil surfaces (upper 6 to 12 inches) of residential yards and edges of conservation areas should be roto -tilled and mixed with subsurface and topsoil layers to restore overall soil porosity and deep root establishment. Preparation of soils in this manner will increase overall soil porosity and stormwater infiltration, help to stabilize post - construction site hydrology, improve turf grass establishment, and reduce stormwater runoff and chemical runoff into the adjacent conservation areas. The City of Lino Lakes, Royal Oaks Reality, and the consulting Foxborough Conservation Development Restoration and Management Plan 29