Project timeline and status: 2019 - 2021, manuscript accepted and published in Annual Review of Ecology, Evolution, and Systematics.
Climate Change
When climate change alters the timing of life cycle events, many outcomes for populations are possible, ranging from population decline to population increase. The outcome in part depends on what demographic vital rate is affected: survival, growth, or reproduction. The goal of this project is to review and synthesize the evidence that climate change affects populations by shifting the timing of species life cycle events (phenology).
Altered Timing
We find many examples of altered timing having both positive and negative consequences for vital rates. Yet, few studies link phenological shifts to changes in vital rates known to drive population dynamics, especially in plants. When this link is made, results are largely consistent with life history theory: shifts in timing have population-level consequences when they affect survival in longer-lived organisms and reproduction in shorter-lived organisms. In other cases, demographic mechanisms like density-dependence prevent changes in vital rates from affecting population dynamics.
Current and Future Research
Given the abundant evidence that altered timing can affect demographic vital rates, future studies that link these impacts to population growth will provide us with the additional ability to generalize how shifts in timing may or may not alter population dynamics. This is an important area of future research because we have a limited understanding of how climate change can affect population persistence.
Project Goal
