The planet now has more trees than it did 35 years ago
Tuesday, December 4, 2018
Posted by: Dana Walker
Despite ongoing deforestation, fires, drought-induced die-offs, and insect outbreaks, the
world's tree cover actually increased by 2.24 million square kilometers—an area the size of Texas and Alaska combined—over the past 35 years, finds a paper published in the journal Nature. But the research also confirms large-scale loss of the planet's most biodiverse ecosystems, especially tropical forests.
The study, led by Xiao-Peng Song and Matthew Hansen of the University of Maryland, is based on analysis of satellite data from 1982 to 2016. The researchers broke land cover into three categories: tall vegetation consisting of trees of at least 16 feet in height; short vegetation under 16 feet in height including shrubs, grass, and agricultural crops; and "bare ground," including urban areas, sand, tundra, and rock. While the classification may seem simplistic, powerful conclusions can be drawn from the data, including assessing agricultural expansion, climate-driven expansion and contraction of ecosystems, and forest clearing and recovery.