Sounds like a great idea! You could cross breed some African bees with honey bees, and release them....wait, someone already did that.
Seriously, import some wildebeasts and zebra's to eat the grass. If they get out of control, just bring over a few lions, leopards, cheetah, and crocodiles. If any die, we'll go fetch some hyenas, jackals, and vultures. If the predators get ahead of the wildebeasts and zebra, we'll go back and get some Tommys, impalas, cape buffalo, elephant, and kudu. If we get enough game, we can bring in some people to eat them. If the people get out of hand, back to Africa for a bit of AIDS, Ebola, Malaria, sleeping sickness, famine, and war.
Sounds easy enough to me!