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Full-Text Articles in Life Sciences
A Comparison Of Community Composition Analyses For The Assessment Of Responses To Wood-Ash Soil Amendment By Free-Living Nematodes, Paul B.L. George
A Comparison Of Community Composition Analyses For The Assessment Of Responses To Wood-Ash Soil Amendment By Free-Living Nematodes, Paul B.L. George
Electronic Thesis and Dissertation Repository
Land-use changes can have far-reaching consequences for resident communities and ecosystem functioning. Developing appropriate assessment methods to observe and quantify this change is an important application of community ecology. Here I compare four methods of community assessment for free-living soil nematodes under forest harvesting disturbance and wood ash application. Neither morphological assessment (richness, abundance, diversity) nor molecular assessment (morpho-richness using T-RFLP) was responsive to experimental treatments. Trait-based approaches (Maturity Index (MI) and Body Size Spectra (BSS)) were more sensitive to forest harvest and wood-ash amendment treatments. The efficacy of these methods was also qualitatively compared. Of all methods, the BSS …
Nitrogen Fixation By The Cyanobacterium Nostoc Punctiforme In Response To Variation In Nitrogen Availability, Temperature, And Atmospheric Co2 Concentrations, Danielle A. Griffith
Nitrogen Fixation By The Cyanobacterium Nostoc Punctiforme In Response To Variation In Nitrogen Availability, Temperature, And Atmospheric Co2 Concentrations, Danielle A. Griffith
Electronic Thesis and Dissertation Repository
The predominant input of available nitrogen (N) in boreal forest ecosystems originates from moss-associated cyanobacteria, which fix unavailable atmospheric N2, contribute to the soil N pool, and thereby support forest productivity. Although increases in N availability, temperature, and atmospheric CO2 concentrations are expected in Canada’s boreal region over the next century, little is known about the combined effects of these factors on N2 fixation by axenic cyanobacteria or the associated mechanisms. I assessed changes in N2 fixation by Nostoc punctiforme under different global environmental change scenarios and examined correlations between the response and changes in …
Identifying The Role Of Non-Native Species In The Enhanced Trophic Transfer Of Mercury In The Food Web Of Lake Erie, A North American Great Lake, Kaylin M.S. Liznick
Identifying The Role Of Non-Native Species In The Enhanced Trophic Transfer Of Mercury In The Food Web Of Lake Erie, A North American Great Lake, Kaylin M.S. Liznick
Electronic Thesis and Dissertation Repository
Increasing mercury (Hg) concentrations in top predatory fish is concerning for human and wildlife health. This study examined the amount of Hg available to the food web of Lake Erie, and explored the role that two recently established non-native species, dreissenid mussels and round goby, have played in the trophic transfer of Hg to sport fish. A comprehensive sampling of total Hg (THg) and methylmercury (MeHg) within Lake Erie water, sediment and seston with high temporal and spatial resolution describes environmental concentrations. In addition, biotic THg and MeHg are quantified in benthic invertebrates and three fish species. A steep spatial …