  Humans are increasingly stressing ecosystems via habitat destruction, climate
change and global population movements leading to the widespread loss of
biodiversity and the disruption of key ecological services. Ecosystems
characterized primarily by mutualistic relationships between species such as
plant-pollinator interactions may be particularly vulnerable to such
perturbations because the loss of biodiversity can cause extinction cascades
that can compromise the entire network. Here, we develop a general restoration
strategy based on network-science for degraded ecosystems. Specifically, we
show that network topology can be used to identify the optimal sequence of
species reintroductions needed to maximize biodiversity gains following partial
and full ecosystem collapse. This restoration strategy generalizes across
topologically-disparate and geographically-distributed ecosystems.
Additionally, we find that although higher connectance and diversity promote
persistence in pristine ecosystems, these attributes reduce the effectiveness
of restoration efforts in degraded networks. Hence, focusing on restoring the
factors that promote persistence in pristine ecosystems may yield suboptimal
recovery strategies for degraded ecosystems. Overall, our results have
important insights for designing effective ecosystem restoration strategies to
preserve biodiversity and ensure the delivery of critical natural services that
fuel economic development, food security and human health around the globe
