The total area of Brazilian Amazon forest that has been degraded — through selective logging, understory fire, forest edges and fragmentation — is larger than the total deforested area, according to a recent study published in the journal Science.
During the 1992-2014 study period, 337,427 square kilometers (130,000 square miles) suffered a loss of vegetation, compared to 308,311 square kilometers (119,000 square miles) that was completely cleared for timber or pastures, a finding that has serious implications for global greenhouse gas emissions and biodiversity loss.
Eraldo Matricardi of the University of Brasilia and David Skole of Michigan State University led an international team of researchers in analyzing 23-years of satellite data covering the entire Brazilian Amazon to map areas of deforestation and degradation. They analyzed the light spectra in each pixel of 1,200 Landsat satellite images, each representing a 30 meter (98 feet) square of forest, to determine the proportion of green vegetation and therefore the extent of degradation.
“The reflected light at any pixel is the combination of light from bare soil, photosynthetic vegetation and non-photosynthetic vegetation [such as] the stems and branches of trees,” explained Skole. Estimating the fraction of green vegetation in each pixel allowed the team to visualize forest degradation over a large scale. The team mapped degradation caused as a direct consequence of deforestation (such as edge effects and fragmentation) as well as indirect forest degradation (such as selective logging and understory fires) and complete land conversion for timber, pastures, cropland, or other human activities.
https://www.google.com/amp/s/news.m...orestation-in-the-brazilian-amazon-study/amp/
During the 1992-2014 study period, 337,427 square kilometers (130,000 square miles) suffered a loss of vegetation, compared to 308,311 square kilometers (119,000 square miles) that was completely cleared for timber or pastures, a finding that has serious implications for global greenhouse gas emissions and biodiversity loss.
Eraldo Matricardi of the University of Brasilia and David Skole of Michigan State University led an international team of researchers in analyzing 23-years of satellite data covering the entire Brazilian Amazon to map areas of deforestation and degradation. They analyzed the light spectra in each pixel of 1,200 Landsat satellite images, each representing a 30 meter (98 feet) square of forest, to determine the proportion of green vegetation and therefore the extent of degradation.
“The reflected light at any pixel is the combination of light from bare soil, photosynthetic vegetation and non-photosynthetic vegetation [such as] the stems and branches of trees,” explained Skole. Estimating the fraction of green vegetation in each pixel allowed the team to visualize forest degradation over a large scale. The team mapped degradation caused as a direct consequence of deforestation (such as edge effects and fragmentation) as well as indirect forest degradation (such as selective logging and understory fires) and complete land conversion for timber, pastures, cropland, or other human activities.
https://www.google.com/amp/s/news.m...orestation-in-the-brazilian-amazon-study/amp/
