substance acide

CONT: Jusqu'à ces dernières années, on considérait que les pluies étaient le mécanisme principal par lequel les substances acides se déposaient.

CONT: Dissolved salts and minerals in the ground water are carried away by rivers and streams to the oceans. Although plants slow down this process by taking up the dissolved material from the ground water and returning it to the soils as they drop their leaves or die, litter as well as acid substances from the atmosphere add acidic materials to the soils.