India, April 1 -- From the heart of Mumbai's green lung, steadily depleted by human activity, comes a story of hope and renewal. "It's back to being a forest," says V Shubhalaxmi, of the five hectares she and her team have nursed back to life in the Sanjay Gandhi National Park (SGNP).

Until four years ago, the land, at the Mulund edge of the national park, was barren. Like so many other areas in the 103-sq km national park, scarred by encroachments which includes thousands of slum dwellings, this portion too had been destroyed. It housed cricket pitches, a slum settlement, a small garbage dump, and had become a place where locals loitered as they came and went, at will, through a gap in the boundary wall.

Four years on, the canopy in th...