Utilizing cool-season grasses in a native Mid-Atlantic flower visitor supporting meadow mix and testing its suitability for sod production
Date
2020
Authors
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Publisher
University of Delaware
Abstract
Due to human development, grasslands and meadows are the most endangered ecosystems in the United States. Within the Mid-Atlantic meadows are transitional ecosystems, requiring yearly management practices such as mowing or controlled burns. Meadows are essential for endangered pollinator species, support numerous trophic levels, and provide regulating ecosystem services with less inputs than other managed landscapes. Mimicking the prairies of the Midwest, designed meadows often contain native warm-season grass and forb species; however, regional meadow remnants have been shown to have greater richness of native cool-season grasses than warm-season. This research attempts to 1) identify the appropriate establishment time and rates for a cool-season grass dominant meadow; 2) determine whether cool-season grass meadows will support flower visitor communities; and 3) determine the suitability of a native cool-season grass dominant meadow mix for sod production. ☐ Native fescue and bentgrass-based meadow seed mixes, sown at 0.5x, 1x, and 2x densities, in spring and fall were used to evaluate establishment success via germination rates, vegetation composition, weed pressure, species richness and diversity. The fescue mix resulted in higher rates of germination, as did the 0.5x seeding rate. The most significant effect on germination and coverage was the season of sowing. Spring sowing resulted in greater forb coverage while cool-season grasses predominated the fall seedings. Spring sowing had less unoccupied plot space with fewer weeds and resulted in greater species richness. ☐ In year two, we monitored flower visitation (May to Sept) in spring sown plots to the insect morphospecies level. Plant species were the primary drivers of visitation. Anise hyssop accounted for most of these visits (55%). Some visitor interactions were highly specific, as documented between partridge pea and bumblebees. Bumblebees accounted for 97% of all visits received by this species. Our data indicates that insect morphospecies diversity is supported by plant species diversity. ☐ Simplified versions of the fescue and bentgrass mixes at the 0.5x, 1x, and 2x rate were then tested for their ability to create and establish forb-rich meadows via sod production in a greenhouse. The mixes were later revised for a field application grown in three cm of an engineered sandy loam spread evenly over four mil plastic. The greenhouse wildflower sod transplanted successfully, but early forb species predominated soon after, leading to a significant reduction in species richness. The mixes were revised to be less species rich and utilize a fescue or a bluegrass base for the field application at 0.5x, 1x, and 2x rates. These mixes resulted in fairly low species richness, but did not lose richness as a result of transplant. While still a new area of investigation, meadow sod production shows enough promise to warrant further research. ☐ Certain native cool-season grasses are a viable alternative to warm-season grasses as a base when establishing meadows and flower visitor habitat in the Mid-Atlantic. Our data supports that the diversity of flower-visiting morphospecies is supported by the diversity of forbs. A spring sowing is the best method to establish and support forb-rich meadows that attract a diverse group of flower-visiting morphospecies in the Mid-Atlantic.
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Keywords
Cool-season, Flower visitors, Meadow, Mid-Atlantic, Pollinator