This study analyzes tree diversity and its ecological importance value in silvopastoral systems in the Sumaco Biosphere Reserve (SBR), Ecuador, along an altitudinal gradient of 400-2000 masl. Twenty-six plots distributed in low (400-700 masl), medium (701-1600 masl) and high (1601-2000 masl) zones were used. The Shannon index and the Importance Value Index (IVI), based on abundance, dominance and relative frequency, were estimated. The results show variations in the diameter structure of the trees, influenced by factors such as settlement history and pasture management. The lower and middle zones showed higher tree density and diversity, linked to regeneration and the presence of nearby forests. Species of high commercial value, such as Cedrela odorata and Jacaranda copaia, were common, reflecting knowledge of the local timber market. In the lower and middle zones, the 10 most important species accounted for more than 70% of the trees, and up to 96% in the upper zone, indicating the need for further research on abundance factors and promotion of diversification in pastures. A total of 51 tree species were identified, mostly native, 64.7% are classified by the IUCN as "Least Concern", 31.4% as "Not Evaluated", and 3.9% as "Vulnerable", specifically highlighting Cedrela odorata and Cedrela Montana. The study concludes with policy recommendations related to the importance of trees in silvopastoral systems for the conservation of species and the livelihoods of local communities, highlighting the need for responsible management of Amazonian pasturelands.