Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 38 for “"Trophic Structure"”.
-
An Ecosystem Model with Evolutionary Adaptive Trophic Structure
… deeper understanding of the factors determining trophic structure. The individual-based approach permits the inclusion of traits to model heritable attributes. Population-level models imple- ment a mean-�eld approximation that led to the competitive exclustion principle. The addition of a trait …
-
Organic Matter Dynamics and Trophic Structure in Karst Groundwater
… should be important energy sources to higher trophic levels in the aquifer. The ecosystem expansion and contraction model, originally developed to describe surface streams, may be a good descriptor of spatial and temporal patterns of microbial films in karst aquifers. The process of leaf and …
-
Fatty Acids as Biomarkers of Plankton Trophic Structure in Table Rock Lake, Missouri
… an alternative to stable isotopes for measuring trophic linkages in freshwater food webs. An advantage of fatty acids is that many different compounds can be resolved and most of these are conserved, providing a "signature” of different food resources in consumers. I examined the fatty acid …
-
The effect of recreational fishing on targeted fishes and trophic structure, in a coral reef marine park
… to overfishing. These same fishes play a role in trophic structure by regulating prey species. Despite increasing numbers of fishers, few studies have investigated the potential effects of recreational fishing on fish populations and subsequent trophic effects. This project investigated whether …
-
Effects of shoreline development and freshwater discharge on nekton assemblage and trophic structure in a northern Gulf of Mexico estuary
… use of living shorelines (LS), erosion control structures incorporating native plantings, to mitigate ecological consequences of marsh loss. However, post-restoration climate changes may shift habitat templates and negate positive effects of ecosystem restoration. I evaluated the ecology nekton …
-
Assessing the effects of internal (trophic structure) and external (fishing and environment) forcing factors on fisheries off central Chile : basis for an ecosystem approach to management
… to strongly depend on internal food web structure (i.e., who eats and controls whom). This thesis approaches relevant ecological considerations for an ecosystem approach to fisheries in the upwelling ecosystem off central Chile (33ºS-39ºS). The main objective is to assess the effects of …
-
A Spatial and Multivariate Approach to Examining Effects of Urbanization on Nitrogen Sources, Organic Matter Inputs, and Trophic Structure in Streams of Cobb and Paulding Counties, Georgia.
… and organic matter inputs play a role in trophic structure within aquatic ecosystems by examining isotopic food webs; and (3) to see if these variables could be utilized for spatial predictability of urban impacts on streams. We found support for the notion that high levels of developed …
-
An Isotopic Examination of Cave, Spring and Epigean Trophic Structures in Mammoth Cave National Park
… ISOTOPIC EXAMINATION OF CAVE, SPRING AND EPIGEAN TROPHIC STRUCTURES IN MAMMOTH CAVE NATIONAL PARK</p> <p>Name: Zacchaeus Greg Compson Date: October 15, 2004 Pages: 56</p> <p>Directed by: Philip Lienesch, Doug McElroy, Michael Stokes and Richard Bowker</p> <p>Department of Biology Western Kentucky …
-
Nematofauna da planície de maré de Coroa Grande, Baía de Sepetiba, RJ
Determine the generic composition, trophic structure and community structure of marine nematodes on the Coroa Grande tidal flat, Sepetiba bay, Rio de Janeiro. Brazil (22º55'00"S e 43º05' 30''W). Monthly samples were taken during Iow tides, using a corer with 1cm², from may-98 to april-99. Samples …
-
The structure of pelagic seabird assemblages in the African sector of the Southern Ocean
… by means of shipboard observations. The trophic structure of seabird assemblages was assessed according to the diversity, biomass and abundance of 35 seabird species according to four principal diet-classes. The ecological structure of seabird populations was defined in terms of …
-
Biological and chemical monitoring of three streams in the area of Blacksburg, Virginia
… diversity index was applied to two trophic levels of aquatic organisms and the results were compared to ascertain whether this diversity index is applicable to all levels of the trophic\structure or of greater use for a particular level. Two diversity indices, Cairns-Dickson …
-
The ecology, life history, and phylogeny of the marine thecate heterotrophic dinoflagellates Protoperidinium and Diplopsalidaceae (Dinophyceae)
Marine thecate heterotrophic dinoflagellates likely play an important role in the consumption of primary productivity and in the trophic structure of the plankton, yet we know little about these species. This thesis expanded our understanding of the autecology and evolutionary history of the …
-
Investigating the importance of different sources of organic matter as food for the benthos on three Arctic shelves
… – lipid biomarkers<br/>produced with distinct structures in sea ice and the water column – were used to calculate<br/>the ratio of sympagic-to-pelagic organic matter assimilated by the benthos in the Barents Sea<br/>and Northeast Greenland Shelf. In the Barents Sea, the proportion of organic …
-
Patterns and causes of intertidal community structure around the coast of Southern Africa
… in species composition, abundance and trophic structure were found between 15 different rocky shores along ca. 5000 km of coast. These differences allowed the division of South African coast into three major biogeographic provinces. The large-scale variations were due to geographical …
-
Development of methodology for community level toxicity testing using the fathead minnow seven day survival-growth impairment test
… three level food chain that was used to address trophic level interactions (feeding reduction and growth impairment) in the final phase of this research. The end result is an experimental procedure in which environmental parameters (water quality, temperature, etc.) and trophic structure …
-
Zooplankton population variability in a warming ocean: Modeling spatiotemporal patterns and drivers within a dynamic shelf ecosystem
… web by mediating the flow of carbon to higher trophic levels and providing a valuable food source for commercially and ecologically important fish and large mammals. This thesis develops data-driven statistical models to shed light on the patterns and mechanisms influencing the population …
-
Hydrological and ecological observations along the eastern Beaufort Sea coast of Alaska
… stable C and N isotopic analysis to determine trophic structure and assess dependence of fauna on terrestrial (CT) vs. marine sources of carbon, with particular focus on animals widely used by local subsistence hunters. Our mixing model results suggest that terrestrial carbon (CT) may be …
-
Impacts of Tamarisk Biocontrol (Diorhabda Elongata) on the Trophic Dynamics of Terrestrial Insects in Monotypic Tamarisk Stands
… provides an opportunity to evaluate how the trophic spectra of terrestrial insects respond to a herbivorous biocontrol. To evaluate this restoration approach and the interaction biocontrol may have with terrestrial insect populations, I quantified trophic unit richness and abundance and …
-
Chemosynthetic communities in the deep sea : ecological studies
… in discrete regions of hydrothermal flux. The trophic structure of chemosynthetic communities can be complex. Primary production by chemoautotrophic bacteria can take place within host tissues of some invertebrates as well as on surfaces and in the water column and subsurface conduits. Carbon …
-
Marine Communities of North Sea Offshore Platforms, and the Use of Stable Isotopes to Explore Artificial Reef Food Webs
… methods offer a powerful means of investigating trophic<br/>interactions, allowing assessment of the relative importance of multiple nutrient<br/>sources to biological assemblages, as well as estimation of the trophic positions of<br/>consumers. Differences in the isotope ratios of consumers …
Page 1 of 2