In a study published in the journal Science, researchers say the damage done to the forests of nine countries is significantly greater than previously known.

For the study, the authors examined the effects of fires, logging, drought, and habitat changes along forest boundaries, known in ecology as edge effects.

Most previous research on the Amazon ecosystem has focused on the effects of deforestation.

This study found that between 2001 and 2018, fires, logging, and edge effects led to the degradation of at least 5.5% of the Amazon’s remaining forests, or about 364,748 square kilometers.

Degradation is different from deforestation, in which a forest is completely removed and a new land use, such as agriculture, is established in its place, experts are quoted by the journal Sciencie. Although severely degraded forests may lose almost all trees, the use of the land itself does not change, experts say.

Scientists propose to create a system for monitoring forest degradation, as well as preventing and combating illegal logging and controlling the use of fire.