The Upper Guinea Forest (UGF; West Africa), a global biodiversity hotspot, has lost more than 90% of its original area since 1900, threatening endemic species such as the endangered pygmy hippopotamus (Choeropsis liberiensis). However, little is known about the proximate causes of this deforestation. We classified Sentinel-2 data using the random forest algorithm to differentiate between three main human processes (shifting agriculture, intensive agriculture or urban expansion) driving deforestation between 2000 and 2019 across the pygmy hippopotamus distribution area. Out of c. 89 600 km2 in the year 2000, 15 900 km2 (17%) of forest were lost, primarily to shifting agriculture (14 900 km2). Côte d’Ivoire and Liberia accounted for 14 900 km2 (94%) of the net area of forest lost, c. 15 times greater than deforestation in Sierra Leone and Guinea combined (953 km2). Forest loss inside protected areas is pervasive, and it is essential to prioritize conservation efforts in areas where deforestation is still low (e.g., Taï, Sapo and Gola Rainforest national parks). We suggest that the preservation of the UGF will face challenges associated with people’s demand for food and income. Continued landscape-scale planning and action to reduce deforestation are urgently needed to limit the impact of shifting agriculture on pygmy hippopotamus habitat.

上几内亚森林（UGF；西非）是全球生物多样性热点地区，自 1900 年以来已损失了 90% 以上的原始面积，威胁到濒临灭绝的侏儒河马 ( Choeropsis liberiensis ) 等特有物种。然而，人们对这种森林砍伐的直接原因知之甚少。我们使用随机森林算法对 Sentinel-2 数据进行分类，以区分 2000 年至 2019 年间导致侏儒河马分布区森林砍伐的三种主要人类活动（农业转移、集约农业或城市扩张）。出c。2000 年，89 600 km 2森林消失，15 900 km 2 (17%)，主要是由于轮作农业(14 900 km 2 )。科特迪瓦和利比里亚占森林损失净面积的14 900 km 2 (94%)，c。比塞拉利昂和几内亚森林砍伐面积总和（953 平方公里2）还要多 15 倍。保护区内的森林丧失现象普遍存在，因此必须优先考虑森林砍伐率仍然较低的地区（例如塔伊、萨波和戈拉雨林国家公园）的保护工作。我们认为，UGF 的保护将面临与人们对食物和收入的需求相关的挑战。迫切需要持续的景观规模规划和行动来减少森林砍伐，以限制农业转移对侏儒河马栖息地的影响。