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.
Intrinsic to the development of modern zoo designs are the interwoven concerns of naturalism and animal welfare. Animal welfare, in particular, has become the paramount responsibility for professionally run zoological institutions as they seek to become centers of conservation and education without compromising animal wellbeing. Animal welfare and naturalism (understood as a design feature in zoo exhibits) are typically harmonious objectives, but these goals have occasionally clashed in implementation. While animal welfare and naturalism are defined in various (and not always consistent) ways in the literature, in-depth interviews of leading professionals and scholars in the zoo community and multi-dimensional case studies of exemplary, accredited institutions (including the Phoenix Zoo, the San Diego Zoo, Woodland Park Zoo and Arizona-Sonora Desert Museum) provide unique insight into the shifting meaning of these terms and how welfare and naturalism have and continue to shape the
development of modern zoo enclosures. This study concludes by suggesting a possible
future trajectory for innovative and alternative zoo designs that incorporate both animal welfare and naturalism without sacrificing either goal.