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Hydrology and biogeochemistry are coupled in all systems. However, human decision-making regarding hydrology and biogeochemistry are often separate, even though decisions about hydrologic systems may have substantial impacts on biogeochemical patterns and processes. The overarching question of this dissertation was: How does hydrologic engineering interact with the effects of nutrient loading and climate to drive watershed nutrient yields? I conducted research in two study systems with contrasting spatial and temporal scales. Using a combination of data-mining and modeling approaches, I reconstructed nitrogen and phosphorus budgets for the northeastern US over the 20th century, including anthropogenic nutrient inputs and riverine fluxes, for ~200 watersheds at 5 year time intervals. Infrastructure systems, such as sewers, wastewater treatment plants, and reservoirs, strongly affected the spatial and temporal patterns of nutrient fluxes from northeastern watersheds. At a smaller scale, I investigated the effects of urban stormwater drainage infrastructure on water and nutrient delivery from urban watersheds in Phoenix, AZ. Using a combination of field monitoring and statistical modeling, I tested hypotheses about the importance of hydrologic and biogeochemical control of nutrient delivery. My research suggests that hydrology is the major driver of differences in nutrient fluxes from urban watersheds at the event scale, and that consideration of altered hydrologic networks is critical for understanding anthropogenic impacts on biogeochemical cycles. Overall, I found that human activities affect nutrient transport via multiple pathways. Anthropogenic nutrient additions increase the supply of nutrients available for transport, whereas hydrologic infrastructure controls the delivery of nutrients from watersheds. Incorporating the effects of hydrologic infrastructure is critical for understanding anthropogenic effects on biogeochemical fluxes across spatial and temporal scales.
Further, I investigated the effect of precipitation variation on functional diversity on the same experiment and found a positive response of diversity to increased interannual precipitation variance. Functional evenness showed a similar response resulting from large changes in plant-functional type relative abundance including decreased grass and increased shrub cover while functional richness showed non-significant response. Increased functional diversity ameliorated the direct negative effects of precipitation variation on ecosystem ANPP but did not control ecosystem stability where indirect effects through the dominant plant-functional type determined ecosystem stability.
Analyses of 80 long-term data sets, where I aggregated annual productivity and precipitation data into five-year temporal windows, showed that precipitation variance had a significant effect on aboveground net primary production that is modulated by mean precipitation. Productivity increased with precipitation variation at sites where mean annual precipitation is less than 339 mm but decreased at sites where precipitation is higher than 339 mm. Mechanisms proposed to explain patterns include: differential ANPP response to precipitation among sites, contrasting legacy effects and soil water distribution.
Finally, increased precipitation variance may impact global grasslands affecting plant-functional types in different ways that may lead to state changes, increased erosion and decreased stability that can in turn limit the services provided by these valuable ecosystems.
The primary perspective from which people are depicted in media today is shaped by the male gaze. The male gaze is comprised of patriarchal ideals and relies on the understanding that the spectator or viewer is a standard human being, which heteronormativity tells us is a man. From this perspective, the scope of visual representations of men and women in media has been molded after the hierarchized gender displays within which masculinity has primacy over femininity. By presenting a limited spectrum of behavior acceptable for men and women, the media hegemonically manipulates the social constructs of gender and gendered behavior across all levels of society.
This honors thesis applies semiotic and feminist methodologies to engage visual forms of media through art, film, and social media to challenge the social constructs of gender perpetuated and reinforced by dated stereotypes of gender and gendered behavior. First, the theoretical foundation will provide a framework for semiotic and feminist analysis of visual representations of gender in media. Then, I will present data representing the real-world impact that this social construction of gender has on adolescents in America using The State of Gender Equality for U.S. Adolescents, published by Plan International Inc. I will then bring together the explicated methodologies and evidential data alongside my own experiences as a female consumer of visual media to reveal alternative practices of looking that do not revolve around patriarchal norms, looking for a female gaze. In doing so, I hope to present recourse in the face of persistent use of sexist imagery across all levels of our culture and every medium of visual self-expression by providing tools that can be used to interrogate gendered perceptions and inform self-examination in pursuit of a feminist practice of looking.