Stopping pollution with pine needles

KILLING TWO birds with one stone is a desirable objective, but rarely an achievable one. However, Dinesh Mohan of Nehru University, in Delhi, thinks he may have worked out how to do it in the case of a pair of local environmental problems. One is the risk of fire in the pine forests cloaking the foothills of the Himalaya. The other is pollution by heavy metals, particularly lead, of some of the country’s water supply.The fire risk comes from pines’ needle-like leaves. These decay only slowly once shed, and thus build up on the ground into thick, inflammable layers. Nor are they just a fire hazard. They also slow down the replenishment of groundwater and make the soil more acidic than it otherwise would be, discouraging the growth of grass and other non-arboreal plants.