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- All Subjects: Urbanization
- Creators: McGraw, Kevin
- Creators: Georgescu, Matei
Numerical simulations using a state-of-the-science regional climate model are utilized to address a trio of scientifically relevant questions with wide global applicability. The importance of an accurate representation of land use and land cover is first demonstrated through comparison of numerical simulations against observations. Second, the simulated effect of anthropogenic heating is quantified. Lastly, numerical simulations are performed using pre-historic scenarios of land use and land cover to examine and quantify the impact of Mexico City's urban expansion and changes in surface water features on its regional climate.
The first paper of this dissertation found that divergent design intentions lead to unique trajectories for LSA, the urban heat island effect, and bird community at two urban riparian sites in the Phoenix metropolitan area. The second paper examined institutional shifts that occurred during Cuba’s “special period in time of peace” and found that the resulting land tenure changes both modified and maintained the LSA of the country, changing cropland but preserving forest land. The third paper found that globalized forces may be contributing to the homogenizing urban form of large, populous cities in China, India, and the United States—especially for the ten largest cities in each country—with implications for surface urban heat island intensity. Expanding knowledge on social drivers of land system and environmental change provides insights on designing landscapes that optimize for a range of social and ecological trade-offs.
Bioindicators of wildlife health are useful tools for studying the viability of various organisms and populations, and can include a range of phenotypic variables, such as behavior, body size, and physiological parameters, such as circulating hormones and nutrients. Few studies have investigated the utility of total plasma protein as a predictor of environmental or nutritional variation among birds, as well as variation across different seasons and life-history stages. Here I examined relationships between plasma protein and season, urbanization, sex, body condition, molt status, and disease state in house finches (Haemorhous mexicanus). I sampled blood from house finches across three seasons (winter, summer and fall 2021) and measured plasma protein levels using a Bradford assay. I also collected data including condition, sex, and poxvirus infection state at capture, as well as fecal samples to assess gut parasitism (coccidiosis). During the fall season I also estimated molt status, as number of actively growing feathers. I found circulating plasma protein concentration to be lower in the fall during molt than during winter or summer. I also found a significant relationship between circulating protein levels and capture site, as well as novel links to molt state and pox presence, with urban birds, those infected with pox, and those in more intense molt having higher protein levels. My results support the hypotheses that plasma protein concentration can be indicative of a bird’s body molt (which demands considerable protein for feather synthesis) and degree of habitat urbanization, although future work is needed to determine why protein levels were higher in virus-infected birds.