Monitoring forest dynamics in Africa during 2000-2020 using a remotely sensed fractional tree cover dataset

Africa is covered with extensive woodlands, savannas and rainforests. The tree cover of these biomes has been undergoing substantial changes in recent decades. However, the dynamics of forests in Africa are currently unclear, particularly in the woodlands and savanna areas covered by sparse trees. Here, we assessed the spatio-temporal trend of African forests from 2000 to 2020, using a 250-m resolution fractional tree cover product that can capture the variation of forest density in the widespread mixed vegetation landscapes of the continent. The tree cover trends, interannual change and hotspots of forest gain and loss were evaluated. Results showed that the African forest area increased at a rate of 3.59 million ha/year over the study period, reaching 589 million ha in 2020. Considerable forest gain and loss both occurred in Africa. The net change rate in woodlands' forest area was the fastest (2.28 million ha/year), followed by rainforests (0.80 million ha/year) and savannas (0.34 million ha/year). Hotspots of forest gain were concentrated in the north belt of woodlands and savannas, while forest loss primarily clustered in East and South Africa. This work would help African countries to monitor forest change and promote forest management to achieve the Sustainable Development Goals.

Automated summary

Africa's extensive woodlands, savannas, and rainforests have been experiencing significant changes in tree cover over the past few decades. This study assessed the spatio-temporal trend of African forests from 2000 to 2020 using a high-resolution tree cover product, revealing an increase in forest area at a rate of 3.59 million ha/year. The study also identified hotspots of forest gain in the north belt of woodlands and savannas, while forest loss was concentrated in East and South Africa. This research is crucial for monitoring forest change and promoting sustainable development in African countries.