  Representing ecosystems at equilibrium has been foundational for building
ecological theories, forecasting species populations and planning conservation
actions. The equilibrium "balance of nature" ideal suggests that populations
will eventually stabilise to a coexisting balance of species. However, a
growing body of literature argues that the equilibrium ideal is inappropriate
for ecosystems. Here, we develop and demonstrate a new framework for
representing ecosystems without considering equilibrium dynamics. Instead, far
more pragmatic ecosystem models are constructed by considering population
trajectories, regardless of whether they exhibit equilibrium or transient (i.e.
non-equilibrium) behaviour. This novel framework maximally utilises readily
available, but often overlooked, knowledge from field observations and expert
elicitation, rather than relying on theoretical ecosystem properties. We
developed innovative Bayesian algorithms to generate ecosystem models in this
new statistical framework, without excessive computational burden. Our results
reveal that our pragmatic framework could have a dramatic impact on
conservation decision-making and enhance the realism of ecosystem models and
forecasts.
