Background Białowieża forest (Puszcza Białowieska) is the last natural forest in Central Europe. Around half of its area is currently protected and excluded from direct human influence. No forest management is carried out in stands of trees older than 100 years. Therefore, the Białowieża forest is a unique nature site, because it is subject to only marginal anthropogenic influence. The determination of forest dynamics, such as the changing competitiveness of tree species with different thermal requirements, indirectly reveals current trends in climate change. The observed changes in the tree species composition of semi-natural forests can therefore be the basis for adaptation of forest management practices to changing climate conditions and for conservation of valuable natural habitats that are sensitive to climate change. Objectives The aim of the ForBioSensing project is to develop and apply a monitoring methodology for large forest areas using innovative techniques. This will involve point-scale monitoring (field measurements on sample plots) through to large-scale area monitoring using remote sensing techniques. This information will improve the efficiency of operations carried out for forest ecosystems protection and will further the study of forest biodiversity. Identification of changes in forest structure and tree species composition that occur in the forest stands will help to identify the determinants and dynamics of these processes, and help national park and forest district managers implement relevant protection activities. Therefore, the project can contribute to modifications of forest management and nature conservation practices in Polish forests that take into account projected climate change. The main project objectives are: Monitoring of stand dynamics in Białowieża forest, including analysis of tree species composition, monitoring of forest stand changes caused by spruce and ash dieback, and hornbeam expansion; Analysis of natural forest regeneration and rejuvenation, including the role of gaps; and Identification of the combination of various remote sensing techniques and datasets that would be optimal for forest monitoring needs. Expected results: Creation of monitoring methods for Białowieża forest dynamics that combine data from field sample plots and ancillary remote sensing data covering the whole study area; Mapping of plant communities with identification of different tree species; Implementation of a geo-portal with all gathered and produced spatial data on the forest; Maps showing the following information: growing stock and biomass, tree height, tree diameter at breast height (DBH), canopy cover and its diversity, forest diversity, tree species composition, vertical structure, biomass, number of dead standing trees, location and size of gaps, location and size of dying spruce stands, locations of ash dieback , natural forest regeneration dynamics, quantity of lying dead wood, large scale spatial distribution of forest stands in different age classes and of different structure; and Increase in the density of the existing network of meteorological stations for the analysis of the Białowieża forest microclimate, and the creation of an online weather service that will help promote the project and be useful for tourists visiting the forest.