A landmark new study combining the expertise of African scientists and practitioners, high-resolution land-use imagery and the knowledge of local people has generated the most accurate estimate yet of Africa’s tree resources. Among its key findings, the study estimates that the continent supports 43 billion trees – constituting an asset of immense value to its people, land and biodiversity. The study has also enabled the identification of vast areas of degraded lands in need of restoration.

A global first for Africa

Implemented on a previously unattained scale, the science-based analytical survey – known as the Africa Open DEAL – involved 30 African countries, supported by the Pan African Agency of the Great Green Wall (GGW) and the Southern African Development Community. FAO and the African Union Commission provided technical support and continental engagement respectively. Africa is the first continent to complete the collection of such an accurate, comprehensive and harmonized set of data on land use and land-use change.

Drawing on the GGW’s restoration model and its unique knowledge and biophysical baseline data created through the Action Against Desertification (AAD) programme, the detailed panorama of Africa’s tree cover is the product of 350 African experts, who spent two years between 2018 and 2020 capturing 300 000 sampling points of approximately 0.5 hectares in size from very-high-resolution satellite imagery. Measuring 100 parameters at each point, the raw data produced by the project was subsequently reviewed by local analysts trained in the use of Collect Earth, an open-source tool developed by FAO with the support of Google.

African tree numbers revealed

The study found that:

• 26 percent of land in Africa is forested.
• The continent supports a total of 43 billion trees.
• There are almost 7 billion previously unrecorded trees outside forests (16 percent of the total) distributed over 537 million ha.
• Forests contain 36 billion trees (84 percent of the total).
• Africa has more restorable lands than any other region; the area of the continent-wide GGW initiative has 393 million ha of land with restoration potential and opportunities.
• The GGW is the essential core area of the 1 billion ha of the continent’s drylands, comprising 780 million ha in the Sahara and the Sahel and 228 million ha in southern Africa.
• 350 million ha of cropland is cultivated in Africa, more than double that of the European Union.
• Between 2000 and 2019, land-use change involved mostly a reduction of forests (-2 percent) and grasslands, other lands and wetlands (-1 percent) in favour of settlements (+18 percent) and croplands (+5 percent)

Why do these data matter?

Trees have vast economic, social and environmental significance and provide many benefits. Used judiciously, the Africa Open DEAL information and analyses could orient land restoration interventions in response to climate-change adaptation and mitigation needs. These data could also help in designing policies with transformative benefits for Africa’s rural poor, particularly those living in drylands, which cover1 billion hectares of Africa’s land area; dryland forests and woodlands are estimated to meet a large part of the needs of 320 million people.[i]In identifying areas of increased human expansion and settlement, data generated by the survey can help in assessing the key factors propelling deforestation and the loss of natural grasslands, wetlands and other habitats.

The survey’s findings will also resonate beyond forestry, informing and providing important inputs into broader natural resource and land-use planning and management. Thus, the Africa Open Deal will help ensure informed decisions on the allocation of natural resources and provide opportunities for targeting actions designed to sustainably and equitably restore degraded lands, reduce poverty and hunger, increase biodiversity and combat climate change.

Similarly, the data can be used to help increase Africa’s preparedness for climate change and improve reporting on progress towards international land-use targets and goals.

Other benefits Africa stands to reap from the Africa Open DEAL

Africa Open DEAL provides a powerful opportunity to train national experts in accessing, interpreting and analysing land-use data and information, thus increasing the continent’s capacity in the application of geospatial technologies. The success of the project shows the importance of investment in the science, research and agriculture sectors and of encouraging young Africans to pursue careers in these fields. Not to be underestimated, thanks to Africa Open DEAL, Africa’s natural-resource policymakers, experts and practitioners can gain greater confidence in planning holistic strategies and policies to attenuate the impact of forest degradation and loss on hunger, malnutrition and poverty, desertification and climate change.