Sedge/Grass Meadow Restoration on Former Agricultural Lands along a Lake Ontario Drowned-River-Mouth Tributary

Abstract

Restoration of sedge/grass meadow habitat was implemented on former agricultural lands adjacent to a Lake Ontario drowned-river-mouth tributary at an elevation that historically supports this community type. Four hectares of land were disked in spring and seeded with diverse wetland mixes containing sedges, grasses, and forbs, with additional Calamagrostis canadensis (bluejoint) and Carex stricta (upright sedge) seeds added. Seedling plugs of C. canadensis and C. stricta were also planted. Mowing at a height of 45 cm to control tall, invasive annual weeds prior to seed-set was conducted as an adaptive management practice. Three years after implementation, C. canadensis and C. stricta were not found, but seeded Carex vulpinoidea (fox sedge) was dominant, and seeded Carex lupulina (hop sedge) and Carex lurida (shallow sedge) were also present. Most invasive annuals were rare, but canopies created by larger perennials may pose future problems. Although a greenhouse seed-bank emergence study was conducted, field sampling suggested that plants growing on adjacent lands were a better predictor of future plant communities, with select seeded species serving as a secondary predictor. Failure of some sedges to survive after seeding likely was not related to stratification or diurnal temperature range. However, inadequate soil moisture related to soil type and a second-year drought likely played a role, as might loss of viability of seeds during storage. Future efforts on similar lands might use fresh Carex seeds broadcast in autumn for over-winter stratification, and specially developed seed mixes could focus on species that established at the site and native species found nearby, while avoiding some potential problem species.