Researchers in Australia studied links between native forest cover and flooding during the 1990s in 56 developing countries across Africa, Asia and Latin America.
They found that 100,000 people in the developing world were killed, and another 320 million displaced by floods, with economic damages exceeding $1 trillion over a period of 10 years.
Removing a tenth of the existing forest cover would increase the frequency of floods by 4-28 percent and lengthen their duration by up to eight percent, shows the study by the team led by Corey Bradshaw of Charles Darwin University.
Countries like Bangladesh, India, China and Nepal, which often face severe flooding, have already invested in forest protection or reforestation projects, reported science portal SciDev.Net.
Forests may reduce the severity of floods in a number of ways.
Firstly, rainwater is taken up by tree roots and released through their leaves. Roots also make the soil more porous, increasing the amount of water it can absorb.
The process of deforestation itself reduces soil's absorbency, Bradshaw noted. 'Removing forests compact the soil, so there are fewer gaps underground and less capacity for absorbing water, affecting the run off,' he explained.
Bradshaw hopes that by demonstrating the benefits of ecosystem conservation, his team's study would encourage developing countries to protect their forests.