Land-use impacts on the quantity and configuration of ecosystem service provisioning in Massachusetts, USA.
Meeting fundamental human needs while also maintaining ecosystem function and services is the central challenge of sustainability science. In the densely populated state of Massachusetts, USA, abundant forests and other natural land cover convey a range of ecosystem services. However, after more than a century of reforestation following an agrarian past, Massachusetts is again losing forests, this time to housing and commercial development. We used land-cover maps, ecosystem process models and land-use data bases to map changes (2001, 2006, 2011) in eight ecosystem service variables and to identify 'hotspots', or areas that produce a high value of five or more services, at three policy-relevant spatial scales. Water-related services (clean water provisioning and flood regulation) experienced local declines in response to shifting land uses, but changed little when measured at the state level. General habitat quality for terrestrial species declined statewide during the study period as a consequence of forest loss. In contrast, climate regulation (carbon storage) and cultural services (outdoor recreation) increased, driven by continued forest biomass accrual and land protection, respectively. Timber harvest volume had high interannual variability, but no temporal trend. The scale at which hotspots are delineated greatly affects their quantity and spatial configuration, with a higher density in eastern Massachusetts and 10-12% more hotspots overall when they are identified at a town scale as compared to a watershed or state scale. Synthesis and applications. Ecosystem service hotspots cover a small percentage of land area in Massachusetts (2.5-3.5% of the state), but are becoming more abundant as urbanization concentrates ecosystem service provisioning onto a diminished natural land base. This suggests that while ecosystem service hotspots are valuable targets for conservation, more are not necessarily better since hotspot proliferation can reflect the bifurcation of the landscape into service and non-service provisioning areas and subsequent loss of diversity across the landscape.