Temperate grasslands and the services they provide are threatened with severe degradation from human-driven land use changes. Among the worst affected services is pollinator support with grassland degradation contributing to the global decline in insect abundance due to habitat loss and a lack of floral resources. This has prompted conservation organizations to support pollinator conservation on working landscapes by increasing floral resources, but gaps remain in the consistent establishment of native forbs in intensively managed agricultural areas. We evaluated factors that influence native forb establishment during seed-based enrichment planting of tall fescue-dominated cattle pastures in two separate experiments: one testing a range of site preparation treatments with different seasons of sowing and comparing their effects on tall fescue suppression and seeded native plant establishment and the other investigating the effects of seed rate and pre-seeding cold stratification on native forb establishment on separate plots. For the site preparation experiment, we observed a mean target plant density of 0.12 target plants per m2 (SD = 0.247) The greatest target plant stem density (P < 0.0001) and species richness (P < 0.001) was in plots treated with a 2% glyphosate solution and sown with native seeds in early summer with the next five best treatments composed solely of fall sown replicates. For the seed and stratification experiment, we observed a mean target plant density of 88 target plants per m2 (SD = 73.9). Higher seeding resulted in greater target plant abundance in plots (P < 0.0001) with a seed rate of 56 kg/ha-1 resulting in almost three times as many target plants compared to 2.24 kg/ha-1. Pre-seeding stratification resulted in an increase in target plant abundance (P < 0.01). Target species richness was consistent between treatment levels. Results suggest that native forb establishment can be enhance by eliminating pasture grasses prior to seeding and the use of high seeding rates sown in the fall or using stratified seed. / Master of Science / Temperate grasslands and the services they provide are threatened with severe degradation from human-driven land use changes. Among the worst affected services is pollinator support with grassland degradation contributing to the global decline in insect abundance due to habitat loss and a lack of floral resources. To reverse this decline, conservation groups are encouraging the use of native plants throughout the landscape especially on farms and ranches to provide more resources for insect pollinators. One exciting opportunity exists in planting wildflowers into tall fescue-dominated cattle pastures that occupy millions of hectares of land in the Southeastern United States to provide food for pollinating insects. However little information exists on how to successfully establish wildflowers as much expertise is based on work done in the tallgrass prairie region of the Midwest. This study's goal was to investigate what control wildflower establishment by evaluating the success of an existing establishment experiment testing several site preparation techniques and different sowing seasons. A separate experiment was set up looking at the effect different seed rate and cold moist stratification had on establishment success of wildflowers. For the site preparation experiment, establishment was low for all treatments with a mean target plant density of 0.12 target plant per m2 (SD = 0.247). Summer sown 2% glyphosate had the highest wildflower richness and abundance at 0.35 target plants per m2 (SD = 0.247) and fall sown treatments were found to have higher sown wildflower abundance and richness than summer sown treatments. For the seed and stratification experiment, we observed a mean target plant density of 88 target plants per m2 (SD = 73.9). Target plant abundance did change between treatment levels with the highest and second highest seed levels yielding nearly three times and twice as many sown wildflowers as the lowest treatment respectively. Stratification resulted in an increase in sown wildflower abundance and sown wildflower richness did not differ significantly between treatment levels. Results suggest that native forb establishment can be enhance by eliminating pasture grasses prior to seeding and the use of high seeding rates sown in the fall using stratified seed.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/113883 |
| Date | 20 February 2023 |
| Creators | Bellangue, David Nsame |
| Contributors | Crop and Soil Environmental Sciences, Reid, John Leighton, Barney, Jacob, Tracy, Benjamin Franklin |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | ETD, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
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