ALT Estimation of the biologically constrained feasibility domain. A) We show the mathematical feasibility domain given a hypothetical competition matrix with intraspecific competition coefficients αii = αjj = 1 and interspecific competition coefficients αij = αji = 0.5. Points sampled in this region of parameter space lead to both species having positive equilibrium densities. Note that, mathematically, this region extends infinitely in the positive quadrant. B) Some of these mathematically feasible points, however, may correspond to equilibrium abundances that are greater than empirically informed abundance constraints. C) Part of the the parameter space may also fall outside model-based constraints. D) The space of the mathematical feasibility domain that does not overlap with any abundance or model-based constraints gives the biologically constrained feasibility domain