Office ecosystem.

These days people spend much of their time in the office and apart from a few dying potplants around the place the only inhabitants are human, the only sounds are papers shuffling, printers printing, phones ringing ect. In an office ecosystem a large number of speciecs could be introduced into a office block built especially for the purpose. This office block would include a giant atrium in the middle of the block that has trees and plants in petitions along the wall and on the ground so as the building gets higher the atrium gradually steps outwards so one canopy reaches to the next forest floor, this would mean that the whole atrium is forested and there is maximum room at the top for sunlight to come though. There would be a large pond at the bottom of the atrium on the ground floor and waterfalls cascading down the inside to water each level. The ponds would be stocked with fish and crayfish. As you gaze out your office window a herron grabs his lunch from the 10th floor stream. Birds sing and lemurs chase each other through the canopy, you forget about your work for a few seconds and feel refreshed. Animals would be introduced according to how dangerous they are to humans. Any species that die out will not be reintroduced as it is supposed to be self susstaining with the only thing provided by humans being water, although some of the larger animals might need to have food provided for them.