The city axed more than half a dozen tree houses in Prospect Park in an attempt to save a delicate lakeside ecosystem — but then tossed the lumber into the water, creating a whole new environmental no-no, environmentalists allege.
To prevent a small colony of homeless people from living inside rotting trees, the Parks Department deployed forestry workers to chop down the sickly arbors on the east side of the lake and turn them into mulch.
But workers instead dumped at least two of the trees into the already-fragile urban watercourse — a move that could threaten aquatic life in the lake by knocking lake oxygen levels out of whack.
“Excessive nutrients [from trees] can lower oxygen levels and kill fish,” said John Gross an ecologist with the National Park Service.
The tree trunk dump-and-run comes a few months after a thick pea-soup colored bacterial slime appeared on the lake, cutting off some oxygen to water-dwelling creatures.
That concerns wildlife advocates, who say anything that further depletes those fragile chemical levels is an affront to Brooklyn’s backyard — and its winged and gilled residents.
“All lake life is suffering,” said park watchdog Anne-Katrin Titze. “The lakeside looks like it was hit by a tornado.”
Park spokesman Paul Nelson said the city instructed crews to mulch the trees on-site and to take large ones to a Greenpoint facility to be chipped. But workers ran out of time and were forced to revert to plan B.
Nelson confirmed that the forestry team left one willow tree in the lake.
“The crew was unable to remove the entire tree [because] they started work late in the day, it rained overnight and the ground was too wet to return to the site,” said Nelson, of the Prospect Park Alliance spokesman
Nelson says having trees in the lake can be good for the ecosystem, providing nutrients and “shelter to fish, turtles, frogs and birds.”
But nature experts say it isn’t that simple.
“It’s a balance,” said Gross, explaining the way oxygen levels in aquatic environments work. “It’s a lot like sugar: Your body needs a little — but too much is not good.”
Reach reporter Natalie O'Neill at email@example.com or by calling her at (718) 260-4505.