Shih-fan Chan
Climate change is known to modify both climatic mean and variability. Environmental
variability has long been considered an important regulator of species interactions,
particularly interspecific competition. However, although increasing studies have
focused on the biological impacts of changing climatic mean and variability, their
interacting effects on species interaction, and hence species’ distribution, were less
explored. Here, we investigate how changing thermal variation and mean influence
the competition and coexistence between burying beetles, Nicrophorus nepalensis,
and blowflies along a large elevational gradient in central Tai wan. Our field study
shows that habitat alteration increased daily temperature range (DTR)—a short‐term
thermal variation—and the effect was more pronounced in higher elevation. This
higher DTR negatively impacted the breeding success of N. nepalensis through
altering the competitive interaction between N. nepalensis and blowflies, which, in
turn, promoted the competitive exclusion of N. nepalensis. We further integrated the
thermal performance curve and Lotka‐Volterra model to explore the general
relationship between climatic mean and variability on the competitive relationship
between species. Results from the model showed that temperature variability can
cause both coexistence and competitive exclusion depending on its interacting effect
with mean temperature. Our lab experiment on the competitive interaction between
N. nepalensis and blowflies further supported these model predictions. Together, our
study provides a general theoretical framework predicting how competitive
interaction changes with temperature mean and variability, which could be
particularly useful for predicting the changes of biotic interactions under climate
change.