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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Producer stated preference for hypothetical new winter wheat varieties on the Canadian Prairies

Cole, Jesse Unknown Date
No description available.
2

Producer stated preference for hypothetical new winter wheat varieties on the Canadian Prairies

Cole, Jesse 06 1900 (has links)
This research project gauges producer demand on the Canadian Prairies for the attributes of new hypothetical varieties of winter wheat. Data collected from a survey of producers in Western Canada is used to determine the values and attitudes of producers regarding new winter wheat variety traits with a focus on increased winter survival rates and increased waterfowl nesting habitat. Increased nesting habitat was found to have a small negative but significant impact on the decision to adopt hypothetical winter wheat varieties; however winter kill rates and gross profit had a large positive effect on its adoption and expansion. Other important drivers of the decision to adopt hypothetical winter wheat varieties are also analyzed. Policy implications include potential guidance of incentives for environmentally friendly farming practices, and the provision of information to winter wheat breeding programs about the needs of producers.
3

The Tenants of Apple Orchards: Evaluating the Effects of Additional Nesting Habitat on Bee Populations

Hyjazie, Batoule 29 September 2022 (has links)
Identifying the resources that limit bee populations is essential both for bee conservation and pollination management in agroecosystems. Land-use change typically leads to decreased habitat availability for wild pollinators including loss of nesting habitat, which is an essential but often-overlooked resource for wild bees. Cavity-nesting bees, such as many Osmia spp. (Hymenoptera: Megachilidae), occupy holes in wood or reeds to build their nests; due to their nesting habits, they are frequently scarce in agricultural settings, although, under the right circumstances, these bees can be ideal pollinators of apple and other orchard crops. Artificial nesting structures (“bee hotels”, “trap nests”, or “nest boxes”) are used to study cavity-nesting bees and have been posited as solutions for promoting bee conservation. To evaluate the effects of additional nesting habitat on the local abundance of Osmia spp., and on bees more generally, artificial nesting structures for cavity-nesting bees were installed at 24 sites in apple orchards around Ottawa in 2021 and 2022. Each site had two treatments: one with nest boxes, and one without (control). Transect walks were conducted to measure overall bee contact (including contact by Osmia spp.) with apple blossoms and, after the end of apple bloom, with flowers in the undergrowth and/or in shrubs. Numbers of apple buds and developing fruit were also recorded. Osmia spp. and overall bee numbers were both significantly higher in the treatment with nest boxes (44% and 15% higher, respectively, in 2021, and 113% and 47% higher, respectively, in 2022); however, there was no difference in fruit set (apple count/bud count) between the two treatments. Thus, nest boxes seem to locally increase Osmia spp. numbers as well as total bee numbers, but they have no apparent effect on apple yield, likely because apple production was not pollinator limited in the years of this study. These findings suggest that bee populations in apple orchards are limited by nesting resources, which has important implications for orchard management practices and bee conservation policy.
4

Spatial Ecology of Inter- and Post-nesting Green Turtles (Chelonia mydas) on Bioko Island, Equatorial Guinea

Emily K Mettler (6620087) 10 June 2019 (has links)
<p>Effective conservation strategies for sea turtles require knowledge of animal movements and protection of biologically important habitats and life history stages. For breeding adult sea turtles, understanding both their inshore and pelagic spatial patterns is imperative to the successful protection of the species and the accurate identification of their vulnerabilities. This study provides insight into the inter-nesting, post-nesting, and foraging movements of green sea turtles (<i>Chelonia mydas</i>) that nest on Bioko Island, Equatorial Guinea, by using satellite telemetry to track green turtles (n=12) during two nesting seasons (2017-18, 2018-19), and as they migrated to foraging grounds after the nesting season. These tracks were fit with a switching state space model to characterize movements, and then analyzed in relation to environmental and anthropogenic factors. Dive depth data was also used to determine utilization patterns within the water column. The 12 tagged turtles migrated for an average of 1064 km to two distinct foraging grounds, with 10 migrating west for an average of 1115 km to the coastal waters of Ghana, and 2 migrating south for an average of 1563 km to the coastal waters of Angola. Migrating turtles used both direct, pelagic migration strategies, and biphasal, coastal strategies, which included intermittent foraging throughout migrations. Dive depths varied depending on behavior, with an average of 19.3 m during inter-nesting, 12.6 m during migration and 8.5 m during foraging. Knowledge of inter-nesting habitat use, migration patterns, and foraging ground locations will be critical for the development of marine conservation management plans in the Gulf of Guinea and aide in sea turtle conservation efforts throughout the area. Additionally, spatial and dive depth data can inform zonal fishing regulators and provide information needed for modifications to fishing practices and gear that is most likely to reduce sea turtle bycatch. These data will provide a more complete understanding of marine areas critical to sea turtle conservation and aide in sustainable economic development in the Gulf of Guinea.</p><br>

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