EurekAlert October 20, 2020
A large proportion of dryland trees and shrubs grow in isolation, without canopy closure. These non-forest trees have a crucial role in biodiversity, and provide ecosystem services such as carbon storage, food resources and shelter for humans and animals. An international team of researchers (Denmark, USA – NASA Goddard Space Flight Center, Germany, France, Senegal, Belgium) mapped the crown size of each tree more than 3 m in size over a land area that spans 1.3 million km in the West African Sahara, Sahel and sub-humid zone. They detected over 1.8 billion individual trees. Although the overall canopy cover is low, the relatively high density of isolated trees challenges prevailing narratives about dryland desertification and even the desert shows a surprisingly high tree density. Their assessment suggests a way to monitor trees outside of forests globally, and to explore their role in mitigating degradation, climate change and poverty…read more. TECHNICAL ARTICLE
Dryland landscape in West Africa. Credit: Martin Brandt