OK mdmull, we'll let you decide which species to keep and which to let die. Perhaps you are the expert the planet needs? I'm certainly not. If I had to make these decisions I'd do what any good leader does. Consult with a various experts, ask for reports, weigh the information, count the cost and make a decision that is guarenteed to piss off some and please others! Such is the nature of leadership, one man takes the fall, or reaps the glory.
OK, times up. Which species live and which ones die? Your call.