New research suggests not all trees are “green.” Some trees cause pollution. A new study out of Japan suggests some forests are polluters on par with industrial farms and urban expanses. The problem is nitrogen — too much of it. The forests are leaching it, and it’s ending up in local waterways, causing algae blooms that damage local ecosystems.
These tree plantations, made up of aging timber, aren’t forests. They’re abandoned farms.
Because these forests were planted in a way that allowed for natural maturation, they are dominated by mature timber. The abandoned tree farms are overcrowded, meaning little sunlight can reach the forest floor and encourage undergrowth. As a result, there is a glut of excess nitrogen in the form of decaying needles lining the forest floors.
With the aging, slow-growing trees requiring less nutrients, more nitrogen collects on the forest floor. And with no smaller trees, plants and shrubs to suck it up, it quickly washes away with each new rainstorm — much as runoff may carry excess fertilizers, spawning massive algal blooms.
— source upi.com