Phenological change and the implications of temporal mismatch

The timing of seasonal events (phenology) plays an integral role in ecosystem functionality. Organisms must often time key life-history events to coincide with favorable environmental conditions and/or peaks in resource availability. As a result of recent climate change, phenological patterns are changing, leading to temporal mismatches in ecological interactions. The principal goals of my work in this area are to: 1) quantify phenological change across time, space, and trophic levels, 2) asses the role of abiotic conditions in driving these patterns, and 3) evaluate the demographic consequences of such changes. Current work is focused on North American-breeding forest-dwelling songbirds, as a part of the NSF Macrosystems Program-funded Phenomismatch Project, with past efforts focused on Southern Ocean seabirds.

Large-scale environmental change is shifting the composition of food webs. However, assessing these changes over ecologically relevant scales remains difficult. By assessing dietary shifts in predators, such as penguins, we can better understand how food web dynamics are changing across time and space. This NASA-funded work uses a multi-tiered approach, employing satellite remote sensing, spectroscopy, and stable isotope analysis of Adélie penguin guano, to quantify penguin diet from satellites on decadal, continental scales. This work seeks to link these spatiotemporal food web dynamics to demographic processes (also partially estimated using satellite remote sensing) across the Adélie penguin's global range. Collaborative, complementary dietary work using a DNA metabarcoding approach is also ongoing.

Environmental forcing and demographic processes

Understanding the factors that drive population dynamics is key if we are to assess the impacts of environmental change on ecological systems. However, demographic processes are complex, often having non-linear associations with relevant environmental conditions. My work in this area aims to answer questions related to community-level synchrony in demographic processes, the roles of environmental variability and extreme events in population dynamics, and what these might tell us about the resilience of these systems to future environmental change. This research uses a variety of data streams, from bird banding data to remote time-lapse camera images, to address these questions.

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