Data gathered by NASA satellite revealed the intense loss of greenness in Africa's Congo rainforest over the last ten years.

The study, conducted by Liming Zhou of University at Albany, State University of New York and his team, discovered that between 2000 and 2012, forest area decline in the area has increased. This study is the most comprehensive observational study that maps the rate of forest cover decline in the area as well as identifies the effects of a long-term drought that affected the Congo rainforest.

"It's important to understand these changes because most climate models predict tropical forests may be under stress due to increasing severe water shortages in a warmer and drier 21st century climate," Zhou said in a press release.

The greenness of a forest region is one of the main indicators used by researchers to assess a forest's health. This study focused on how the drought affected the forest cover in the Congo area but it also concluded that if the drought continues, it might start an alteration of the Congo forest in terms of structure and composition. When this happens, the biodiversity in the area will be heavily affected.

To gather data for their study, Zhou and his teams analyzed the trend in satellite images taken by the Enhanced Vegetation Index. This measure of forest cover is derived from the data created by the Moderate Resolution Imaging Spectroradiometer (MODIS), an instrument included in NASA's satellite.

Their observation of the trend revealed that there is a decreasing forest cover in the Congo area. This phenomena, also called "browning" shows that the forest is slowly adjusting to decreased irrigation caused by the drought. The browning of the forest is complimenting the data gathered from the area such as the moisture available to plants, the amount of stored groundwater, and the amount of water easily accessible by vegetation.

Further details of the study can be read on the April 23 issue of Nature.