Life Sciences Commons^™

Swede Midge, Contarinia Nasturtii (Diptera: Cecidomyiidae), Response To Brassica Oleracea In Simulated Intercropping Systems, Gemelle Laureen Brion

Graduate College Dissertations and Theses

Monoculture agriculture has developed as a result of the Western agricultural growth model, which emphasizes reduced on-farm labor and maximum yield. As a result soil health, which is reliant on a diversity of soil-dwelling organisms, is compromised, pest problems are intensified, and biodiversity is lost when vast land areas are devoted to simplified vegetation schemes. There has been a tremendous rise in interest in alternative cropping schemes. The traditional practice of intercropping has received renewed interest as the emphasis on agricultural growth shifts from a purely development-based model to one of conservation and enhanced biodiversity.

Although intercropping has shown promising …

Determinants Of Termite Species Taxonomic, Phylogenetic, And Functional Diversity In The Amazonian Forest, Cristian De Sales Dambros

Graduate College Dissertations and Theses

The distribution of species in space is determined by the species dispersal capacity, adaptation to environmental conditions, and response to predators and competitors. To determine the importance of dispersal limitation, environmental filtering, and species interactions on the distribution of species in the Brazilian Amazonian forest, I sampled termites in a large area of Brazil. I investigated patterns in species occurrence that could indicate competition and predation structuring termite communities, and analyzed the association of termite abundance and species richness with the density of ant predators. The spatial distribution of termites, and their association with climatic and edaphic conditions were also …

Lidar Remote Sensing Of Forest Canopy Structure: An Assessment Of The Accuracy Of Lidar And Its Relationship To Higher Trophic Levels, Christopher Felix Hansen

Graduate College Dissertations and Theses

Light detection and ranging (LiDAR) data can provide detailed information about three-dimensional forest horizontal and vertical structure that is important to forest productivity and wildlife habitat. Indeed, LiDAR data have been shown to provide accurate estimates to forest structural parameters and measures of higher trophic levels (e.g., avian abundance and diversity). However, links between forest structure and tree function have not been evaluated using LiDAR. This study was designed and scaled to assess the relationship of LiDAR to multiple aspects of forest structure and higher trophic levels (arthropod and bird populations), which included the ground-based collection of percent crown and …

Fixed Versus Plastic Partial Migration Of The Aquatic Macroinvertebrate, Mysis Diluviana, In Lake Champlain, Peter Thomas Euclide

Graduate College Dissertations and Theses

Partial migration, whereby populations consist of residents and migrants, is common among migrating organisms. Partial migration of aquatic organisms, however, remains largely under-studied even though many aquatic animals exhibit horizontal and vertical migrations during their lifetime. Macroinvertebrates of the genus Mysis exhibit diel vertical migrations (DVM). Some species have recently been observed to exhibit partial diel migrations where some individuals reside on the bottom throughout the night while others migrate into the water column. To test the hypothesis that individuals are fixed as residents or migrants, we compared demographic information and C and N isotope compositions of M. diluviana caught …

Thermokarst And Wildfire: Effects Of Disturbances Related To Climate Change On The Ecological Characteristics And Functions Of Arctic Headwater Streams, Julia Rose Larouche

Graduate College Dissertations and Theses

The Arctic is warming rapidly as a result of global climate change. Permafrost - permanently frozen ground - plays a critical role in shaping arctic ecosystems and stores nearly one half of the global soil organic matter. Therefore, disturbance of permafrost will likely impact the carbon and related biogeochemical processes on local and global scales. In the Alaskan Arctic, fire and thermokarst (permafrost thaw) have become more common and have been hypothesized to accelerate the hydrological export of inorganic nutrients and sediment, as well as biodegradable dissolved organic carbon (BDOC), which may alter ecosystem processes of impacted streams.

The biogeochemical …