Urban ecologist Alexander Felson proposes a new kind of ecological practice, one that moves from analyzing nature to shaping it and embeds scientific experiments into the design process.

Biologist and plant scientist Paul Mankiewicz explains the Gaia Hypothesis, the inherent environmental productivity of organisms, and why the city's waste stream is our greatest untapped ecological and economic asset.

The city’s watershed includes 19 reservoirs, three lakes, 7,000 miles of water pipes, tunnels and aqueducts, and 7,400 miles of sewer lines — and perhaps many megawatts of untapped energy.

Tim Maly takes us on a tour of New York City's landscapes of dredge, and explores how the city's past, present and future are shaped by technologies and processes of what he calls "the greatest unrecognized landscape architecture project in the world."

Steve Duncan — historian, photographer and explorer — reflects on wastewater infrastructure, underground rivers, and the thrills and urban lessons he's discovered beneath the surface of cities.

Photographs showcase Five Borough Farm, an initiative which sets out to understand urban agriculture across the city.

Tyler Caruso and Erik Facteau explain their scientific study of the value of urban farms, an effort to produce hard data that can challenge nay-sayers and inform policies and regulations that support agriculture in the city.

"The city can be likened to a living microbe."