Disconnects between ecological theory and data in phenological mismatch research

Climate change may lead to phenological mismatches, where the timing of
critical events between interacting species becomes de-synchronized, with
potential negative consequences. Evidence documenting negative impacts on
fitness is mixed. The Cushing match-mismatch hypothesis, the most common
hypothesis underlying these studies, offers testable assumptions and
predictions to determine consequences of phenological mismatch when
combined with a pre-climate change baseline. Here, we highlight how
improved approaches could rapidly advance mechanistic understanding. We
find that currently no study has collected the data required to test this
hypothesis well, and 71% of studies fail to define a baseline. Experiments
that clearly link timing to fitness and test extremes, integration across
approaches, and null models would aid robust predictions of shifts with
climate change.