Development of scenarios for land cover, population density, impervious cover, and conservation in New Hampshire, 2010–2100

Abstract

ABSTRACT. Future changes in ecosystem services will depend heavily on changes in land cover and land use, which, in turn, are shaped by human activities. Given the challenges of predicting long-term changes in human behaviors and activities, scenarios provide a framework for simulating the long-term consequences of land-cover change on ecosystem function. As input for process-based models of terrestrial and aquatic ecosystem function, we developed scenarios for land cover, population density, and impervious cover for the state of New Hampshire for 2020-2100. Key drivers of change were identified through information gathered from six sources: historical trends, existing plans relating to New Hampshire's land-cover future, surveys, existing population scenarios, key informant interviews with diverse stakeholders, and input from subject-matter experts. Scenarios were developed in parallel with information gathering, with details added iteratively as new questions emerged. The final scenarios span a continuum from spatially dispersed development with a low value placed on ecosystem services (Backyard Amenities) to concentrated development with a high value placed on ecosystem services (the Community Amenities family). The Community family includes two population scenarios (Large Community and Small Community), to be combined with two scenarios for land cover (Protection of Wildlands and Promotion of Local Food), producing combinations that bring the total number of scenarios to six. Between Backyard Amenities and Community Amenities is a scenario based on linear extrapolations of current trends (Linear Trends). Custom models were used to simulate decadal change in land cover, population density, and impervious cover. We present raster maps and proportion of impervious cover for HUC10 watersheds under each scenario and discuss the trade-offs of our translation and modeling approach within the context of contemporary scenario projects.

A coupled terrestrial and aquatic biogeophysical model of the Upper Merrimack River watershed, New Hampshire, to inform ecosystem services evaluation and management under climate and land-cover change

“…We next describe the integrated terrestrial-aquatic model that projects aquatic environmental indicators, including scenarios, parameterizations, and data sets needed to project aquatic indicators to 2100. Finally, to understand how aquatic and terrestrial processes control the projected environmental conditions, we evaluate model sensitivity to a suite of climate and land-cover change (Thorn et al 2017).…”

“…By 2100, population increases by 170% in the Backyard/High scenario and declines by 5% in the Small Community Food/Low scenario. The increase in agricultural land relative to population under the Small Community Food/Low scenario (~1.0 acres per person in 2100 compared with 0.2 in 2010) increases the potential for per capita local food production compared with the contemporary period (Thorn et al 2017). The Maple Presence indicator, which primarily represents the geographic distribution of suitable habitat for Acer saccharum , declines from 49% of total forest cover in the present day to 27% and 31% in the Backyard/High emission and Small Community Food/Low emission scenarios, respectively.…”

“…Changes in the land indicators (Table 2; Agricultural Cover per person and Forest Cover) directly reflect the land-cover scenarios (Thorn et al 2017) and have important direct ecosystem service implications. Briefly, in the Backyard scenario, watershed forest cover declines from 80% in 2010 to 60% in 2100, to accommodate increased rural and suburban development (Fig.…”

“…The model was first applied to historical conditions (2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013)(2014)(2015) to test against field observations using downscaled reanalysis meteorological observations and current land cover. Meteorological forcing for future scenarios used statistically downscaled climate data from , and land cover from Thorn et al (2017). A detailed summary of the model input data for contemporary and future scenarios is described in Appendix 2.…”

“…Candidate indicators had relevance to climate, land, and water domains. Terrestrial indicators were based on land-cover scenarios (Thorn et al 2017) and the Northern Research Station Climate Change Atlas . Climate indicators were based the Geophysical Fluid Dynamics Laboratory (GFDL) CM2.1 global climate model (GCM) simulations using the SRES A1Fi (higher) and B1 (lower) emissions scenarios (Nakicenvoic and Swart 2000) that were statistically downscaled using the asynchronous regional regression model (Stoner et al 2012, Wake et al 2014.…”