Friday Philosophicals

Globally, soils store more carbon than vegetation and the atmosphere, combined, mitigating climate change through carbon sequestration. In addition to climatic variability, human activity through land use has caused a massive quantity of soil carbon to be liberated and released into the atmosphere. There is uncertainty surrounding soil carbon modelling due to the dynamic and complex nature of soil carbon cycling, and recent shifts in theory realize microbial communities as a leading factor in organic carbon stabilization. My research will use field and laboratory methods alongside an existing robust data set to demonstrate the legacy of historical and current land use in soil organic carbon variation and identify how land use influences microbial community structure. My work has important implications for carbon modelling and land management, especially related to long-term effects of land use on soil carbon and the importance of using microbially-explicit carbon models.

Insects rely on external temperatures in order to properly function, however high temperatures combined with extended periods of activity can easily push butterflies into heat stress. The species Parnassius smintheus, or Rocky Mountain Apollo, lives in exposed meadows found along the Rocky Mountains, and are thus subject to direct sunlight and high temperatures for the majority of their flight season. In order to mate, some butterflies will travel between meadows, with distances between meadows ranging between 1 and 10km. Dispersing individuals are relatively rare to find, and so my research seeks to determine whether or not individuals who undergo this short distance migration are better equipped to withstand higher temperatures, due to how intense this flight is. Through use of a flight mill outfitted with a heating element and a thermal camera, performance curves will be assembled to compare individuals who disperse between meadows, and those who do not.

Bluegill sunfish (Lepomis macrochirus) are native to North America and exhibit male parental care and alternative mating strategies, leading to two types of males: parental and cuckolders. Parental males are larger and take care of the young, while cuckolder males are smaller and steal fertilization from parental males using either a sneaking or female mimicry tactic. Previous research has shown that the presence of cuckolder males around nests during spawning reduces the parental male’s perceived paternity, subsequently reducing circulating concentrations of prolactin, an important hormone regulating parental care in many species. These males then provide less care to the offspring in their nest. My research aims to determine if administration of prolactin reverses the cue of reduced paternity (the presence of cuckolder males around the nest) that ultimately leads to less parental care, providing insight into the relationships between all three variables, and the underlying mechanisms for parental care decisions.