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Full-Text Articles in Life Sciences
Contrasting Patterns Of Nutrient Limitation In The Littoral And Pelagic Zones Of Mesotrophic Maine Lakes, Grace C. Neumiller
Contrasting Patterns Of Nutrient Limitation In The Littoral And Pelagic Zones Of Mesotrophic Maine Lakes, Grace C. Neumiller
Honors Theses
Intense nutrient loading of nitrogen (N) and phosphorus (P) causes sudden regime shifts in freshwater ecosystems from clearwater to turbid conditions with frequent cyanobacterial blooms. Characterization of nutrient limitation patterns of primary productivity in these ecosystems is necessary for effective management of algal blooms. However, much of this research has focused on pelagic habitats. The influence of lake habitat (i.e. benthic littoral versus pelagic zones) on nutrient limitation of primary production in mesotrophic lakes is largely unknown, particularly in contrast to research on pelagic nutrient limitation in eutrophic systems. Using paired nutrient diffusing substrata and mesocosm experiments, we measured chlorophyll- …
Impact Of The North American Monsoon On Molt Migrant Passerines, Liuqingqing Yang
Impact Of The North American Monsoon On Molt Migrant Passerines, Liuqingqing Yang
Honors Theses
Breeding, molt, and migration place considerable yearly demands on migrating passerines in North America. Due to conflicts in energy allocation, many species have evolved migration strategies that prevent temporal overlap in these processes. However, there is recent evidence that some passerines which breed in western North America migrate to intermediate stopover sites to carry out molt, conflating molt and migration. Factors influencing the evolution of such a strategy are believed to include both aridity on breeding grounds and dependable flushes of late-summer productivity in the southwestern United States and northwestern Mexico. This productivity occurs due to the brisk rainfall of …
Morphological Variance In Mouthparts And Foraging Behavior In Bumblebees, Ye Jin Lee
Morphological Variance In Mouthparts And Foraging Behavior In Bumblebees, Ye Jin Lee
Honors Theses
Bumblebees (Hymenoptera: Apidae: Bombus) show an incredible degree of size variation within and between species. Individuals from the same hive may vary up to 10-fold in mass. This variation allows individuals to specialize in foraging on different flowers suited to their morphology. However, as different species have different foraging behaviors, their variation in mouthparts and scaling of mouthparts to body size may have been under different kinds of stabilizing selection as they adapted to collect nectar from flowering plants over evolutionary time. Here, we examined the scaling relationships between body size and mouthpart structures, and the variation in mouthpart shape …