Figure 4: Pattern of trophic level management from optimal or greedy approach for six real food webs.

For a budget set at 25% of the total budget required to manage all species in the food web, the proportion managed at each trophic level from 100 simulations of species extinction risk (drawn from a Beta distribution with α=2 and β=8) and strength of interaction between species (drawn from a lognormal distribution with log-mean—3.0 and log-s.d. 1.5). Management reduced extinction risk of a species to zero. Alaskan (a), Baltic Sea (b), Lake Vattern (c), Chesapeake Bay (d), Arizona Montane Forest (e), and Long Island Salt Marsh (f). Inset shows the structure of the real food web and illustrates the number of trophic levels and species per trophic level, note some links have been removed from larger webs for visual clarity.