Conservation and sustainable development of forests are mitigation mechanisms against climate change due to the forest carbon sink capacity. Therefore, biomass estimation allows to assess forest productivity and control carbon budgets. In Ecuador, biomass and carbon sequestration studies are scarce. Thus, we estimated and forecasted changes in biomass of Ecuadorian forests through the Mathematical Spatial Model of Global Carbon Cycle and the Normalized Differential Vegetation Index. The mathematical model describes the processes of growth and decay of vegetation in terms of carbon exchange between the atmosphere, plants and soil under anthropogenic impacts. The vegetation map and the biomass of 2017 (4,86 Gt) were developed with remote sensing methodology in ENVI 5.3 and ArcGIS 10.3 programs. The observed biomass decrease between 2000 and 2010 was due to the high deforestation rate. Thanks to conservation and reforestation policies and the compensatory effect between the atmosphere and forests, a biomass increase is expected until 2060. According to the vegetation map, Amazon region has a better plant vigor, followed by Andean and Coast regions, where scattered vegetation predominates. This information is useful for planning environmental practices such as forest conservation and reforestation in order to increase carbon storage. © The Authors, published by EDP Sciences 2019.