US researchers said Thursday they have created the first high-resolution global map of 21st century changes in forest cover, offering a detailed view of which areas of the world are losing and gaining these natural resources.

Researchers from the University of Maryland, Google and US government found that between 2000 and 2012, 2.3 million square kilometers of forest, an area slightly smaller than the entire country of Argentina, were lost, while 0.8 million square kilometers were reforested in that time.

While there are instances of forest gains and loss all over the globe, the tropics were the only climate domain to show a significant trend, with forest loss increasing by 2,101 square kilometers per year, the researchers said.

Brazil was the country with the largest annual decline in forest loss over this period, cutting annual forest loss in half, from a high of approximately 40,000 square kilometers in 2003 to 20,000 square kilometers in 2010, the researchers said.

Indonesia had the largest increase in forest loss, more than doubling its annual loss during the study period to nearly 20,000 square kilometers in 2011, they said.

The study, published in the US journal Science, built the map using satellite images of the Earth's surface on a 30-meter resolution scale.

"This is the first map of forest change that is globally consistent and locally relevant," University of Maryland Professor of Geographical Sciences Matthew Hansen, team leader and corresponding author of the study, said in a statement.

"Losses or gains in forest cover shape many important aspects of an ecosystem including, climate regulation, carbon storage, biodiversity and water supplies, but until now there has not been a way to get detailed, accurate, satellite-based and readily available data on forest cover change from local to global scales, " Hansen said.

Hansen and colleagues said the global data sets of forest change they have created contain information that can provide a " transparent, sound and consistent basis to quantify critical environmental issues," including the causes of the mapped changes in the amount of forest; the status of world's remaining intact natural forests; biodiversity threats from changes in forest cover; the carbon stored or emitted as a result of gains or losses in tree cover in both managed and unmanaged forests; and the effects of efforts to halt or reduce forest loss.

"Now, with our global mapping of forest changes every nation has access to this kind of information, for their own country and the rest of the world," Hansen added.