Data and code for: The role of indirect interspecific effects in the stochastic dynamics of a simple trophic system

Understanding indirect interspecific effects (IIEs) on population dynamics
is key for predicting community dynamics. Yet, empirically teasing apart
IIEs from other interactions and population drivers is data-demanding. We
used stochastic population models parameterized with long-term vital rate
time series to simulate population trajectories and examine IIEs in a
high-arctic vertebrate trophic chain: Svalbard reindeer, its scavenger
(Arctic fox), and a migratory fox prey (barnacle goose). Reindeer carcass
supply shaped fox abundance fluctuations, subsequently affecting goose
fluctuations. Yet reindeer and goose population growth rates were only
weakly correlated, probably due to stochasticity, density dependence, and
life history traits. However, by isolating the effects of individual
processes within our simulation model, we demonstrate the presence of
strong IIEs on goose population fluctuations and extinction probability.
Thus, we highlight the long-term impact of species interactions, including
IIEs, on species coexistence and communities, beyond immediate effects and
short-term fluctuations.