Questions to ponder

• What do you think of Walker's [7] claim that ``because functional substitutability in the ecosystem has allowed it to continue functioning in much the same way it did before grazing pressure, the probability of all other species in the ecosystem persisting remains high''?
  • If a dominant species of grass declines, aren't herbivorous insects associated with it likely to decline, too?

  • To what extent can an ecosystem continue to function in the same way, in terms of rates of flow through the nitrogen cycle for example, with different species compositions?

• Is it likely that ``most ecosystems are structured by a few, dominant processes''? How would you tell?

• What do you think of Risser's [6] claim that Goldstein concocted the idea that some ecosystem scientists develop ecosystem management plans in which ecosystem properties replace species specific information in setting conservation priorities? Think about south Florida as an example of ecosystem management. What are the endpoints for management in south Florida?