  Having control over species abundances and community resilience is of great
interest for experimental, agricultural, industrial and conservation purposes.
Here, we theoretically explore the possibility of manipulating ecological
communities by modifying pairwise interactions. Specifically, we establish
which interaction values should be modified, and by how much, in order to alter
the composition or resilience of a community towards a favorable direction.
While doing so, we also take into account the experimental difficulties in
making such modifications by including in our optimization process, a cost
parameter, which penalizes large modifications. In addition to prescribing what
changes should be made to interspecies interactions given some modification
cost, our approach also serves to establish the limits of community control,
i.e. how well can one approach an ecological goal at best, even when not
constrained by cost.
