Einstein Science Reporting for Kids
[ E-mail ]

Contact: Science Press Package
American Association for the Advancement of Science

Deforestation: Making the world a wetter place

Little Llangothlin Lagoon, Australia. Clearance of the forest around this wetland after 1840 by European settlers changed it from an ephemeral wetland to a semi-permanent lake.
[Credit: Craig Woodward]

The removal of trees from wetlands around the world, such as swamps, bogs, and marshes, is making these environments even wetter, according to a new study. Actually, researchers say that the ongoing deforestation of wetlands may even be creating new wetlands in certain parts of the world. But this phenomenon goes largely unnoticed because most studies of the environment have not been designed to look for it, they say.

Traditionally, studies have focused on the quality of water in the world's wetlands after they've been deforested--and the most commonly reported impact has been higher levels of nutrients. But now, Craig Woodward and colleagues show that the deforestation of wetlands also brings a lot more water to the region. And in some cases, the amount of extra water delivered is equivalent to 15% more rainfall each year, they say.

The researchers used a detailed model and hundreds of reports from around the world, as well as fossils from Australia and New Zealand, to show that deforestation has been expanding wetlands--and creating brand new ones--for thousands of years now. They suggest that between 9 and 12% of the world's wetlands are currently affected.

These findings suggest that conservation efforts to preserve the world's wetlands need to be updated to take this effect into account. Otherwise, the reforestation of wetlands--a strategy that is planned for many regions of the world--might lead to unexpected results. If it's not done right, some of the world's wetlands could disappear completely, the researchers say.