Arctic ecosystems and people are especially vulnerable to ongoing rapid climate change, resource development, and changing patterns of subsistence land use. New integrated adaptive-management approaches that utilize remote-sensing products are needed to help local leaders, land managers and policy makers adjust to the changes. Towards this end, we propose to archive and synthesize a wide variety of geoecological, remote-sensing and social data that have been collected during five NASA-sponsored Land-Cover Land-Use Change (LCLUC) expeditions along an 1800-km Eurasia Arctic Transect (EAT) and combine these with related social-ecological information collected in other studies by collaborators in Northwest Siberia and Alaska. The three primary goals of the research are to: 1) Use the abundant detailed ground and remote-sensing information from the EAT to formulate a new hierarchical understanding of the patterns of the spectral-reflectance change observed in the satellite-derived records 2) assess the cumulative landscape effects of multiple forces of LCLUC in the two most heavily developed Arctic oil and gas regions at Bovanenkovo, Russia, and Prudhoe Bay, Alaska, and use the information derived from this assessment in combination with interview data collected by social scientists to develop new methods of adaptive management and 3) use the data to further develop predictive models of vegetation change in the circumpolar Arctic. The mapping and model results are used in the interviews with local stakeholders to provide insights regarding impending changes and to help improve planning and responses to the impending changes. The project consists of the three science components: Component 1: Synthesis of Eurasia Arctic Transect (EAT) Data: We will examine the EAT data hierarchically by first developing a well-designed data management system consisting of a data archive, catalog, and portal for the data collected during the project and other related data. The data will then be used in a series of papers that synthesize the information from the EAT. We will also address science questions related to landscape and spectral-reflectance variation along the EAT in comparison to a similar transect in North America, which has a more continental Arctic climate and is less heavily grazed. At a circumpolar scale, we will develop a more refined conceptual framework of the causes of the observed difference in the spatial and temporal differences in the Normalized Difference Vegetation Index (NDVI) in continental vs. maritime parts of the Arctic. Component 2: Synthesis of Social-Ecological Data: This component will focus on the reindeer-herding culture of the Yamal Nenets people compared to the hunting culture of the Ińupiat people in Alaska, and more specifically the social-ecological changes associated with climate change and the expanding networks of oil and gas infrastructure in both regions. Earlier social-ecological studies in these two regions and others in the Arctic have made extensive use of remote sensing. A synthesis paper will focus on how remotely sensed products can be used in adaptive management of Arctic LCLUC. Component 3: Synthesis of Modeling Studies: ArcVeg is a plot-level, tundra vegetation dynamics model that focuses on the response of a suite of common tundra plant functional types to changes in temperature and soil nutrients. The modeling component of our previous LCLUC projects helped develop the ArcVeg Model for application to questions related to climate change and reindeer herding on the Yamal Peninsula. The field observations along both the NAAT and EAT were used to improve the parameterization of the ArcVeg Model. This component will synthesize the earlier studies and apply the ArcVeg model to a circumpolar synthesis. Another task of this component will be to synthesize information from our and other studies regarding tall-shrub-expansion across Russia.