The Ny-Ålesund Terrestrial Ecology Flagship program is one of the four NySMAC flagship programs and aimed at coordinating and integrating research activities on tundra, lake and soil ecosystems in Ny-Ålesund. This proposal will reinforce the Terrestrial Ecology Flagship by establishing a core team of experts from different disciplines. The activities will be organised in 6 working groups. WG1 will focus on animal adaptations and the interaction among monitored species (reindeer, geese, foxes and their predators) for elucidating the factors that determine their population sizes. WG2 will deal with vegetation dynamics and use data on individual plant adaptations, succession, diversity, functional groups and the effects of snow, ice and grazing to further our knowledge on their dynamics and interactions. WG3 will work on biological activities occurring in soils and combine data on the diversity and functioning of their food webs dominated by microbes. It will assess the effect of micro- and mesoscale variability in the permafrost, hydrology and organic matter concentration on soil functioning. WG4 will focus on the measurement of greenhouse gas (CO2, CH4, NOx) dynamics in soils and sediments, and identify the main actors responsible for the emissions and uptake of C and N. WG5 will provide baseline data on the biodiversity and functioning of freshwater communities in the water column, the benthos and the sediments of lakes, wetlands and rivers. WG6 is aimed at integrating the results of the other WGs and assessing the sensitivity and resilience of the terrestrial biome. Two workshops will be organized [Ny-Ålesund (2018) and Longyearbyen (2019)] to further develop the collaboration and cooperation between groups, identify knowledge gaps, and write joint research proposals. During the workshops the collaboration with the other flagship programs will be reinforced and new collaborations will be established between scientists at different locations in Svalbard.