Herbivore community function shapes resilience and bistability of coral reefs
Fig 6
Impacts of herbivore community composition on coral reef bistability and hysteresis.
Bistability plots (A-D) showing final coral cover for each combination of fishing pressure and initial coral cover conditions. Bistability is evident when, for a given fishing pressure, both low (<0.2) and high (>0.6) final coral covers occur, depending only upon the initial coral cover. Hysteresis plots (E-H) showing the final coral cover as fishing pressure is increased (forward) or decreased (reverse). Hysteresis is evident when there is a range of fishing pressures where the forward (red) and reverse (black) lines do not overlap. We examined four scenarios using our expanded model parameter values from Table B in S1 Appendix with different initial herbivore community compositions: herbivore groups even (A,E): generalists = grazers = browsers = 0.3; generalist-dominated (B,F): generalists = 0.6, grazers = 0.15, browsers = 0.15; browser-dominated (C,G): browsers = 0.6, generalists = 0.15, grazers = 0.15; or grazer-dominated (D,H): grazers = 0.6, generalists = 0.15, browsers = 0.15. See Fig 3 caption or Table B in S1 Appendix for other parameter values.