David Foster Harvard Forest Harvard University Petersham, MA 01366 drfoster@fas.harvard.edu
J. Morgan Grove U.S. Forest Service Northern Research Station Burlington, VT 05403 mgrove@fs.fed.us
Diane Pataki Dept. of Earth System Science University of California Irvine, CA 92697-3100 dpataki@uci.edu
Nancy B. Grimm School of Life Sciences Box 874501 Arizona State University Tempe, AZ 85287-4501 nbgrimm@asu.edu
Charles S. Hopkinson Ecosystems Center Marine Biological Laboratory Woods Hole, MA 02543 chopkins@mbl.edu
Debra Peters USDA ARS Las Cruces, NM 88003 505 646 2777 debpeter@nmsu.edu
Peter Groffman Institute of Ecosystem Studies Millbrook, NY 12545 groffmanP@ecostudies.org
Knute Nadelhoffer University of Michigan Ann Arbor, MI 48109 knute@umich.edu
Beyond climate, land use and its manifestation as land-cover change and pollution loading is the major factor controlling the structure, function and dynamics of Earth’s terrestrial and aquatic systems, from local to continental scales. Recognizing the complex interactions and feedbacks between the direct manifestations of human activity and their diverse ecological consequences, this response integrates land change, urbanization (and associated sprawl) and pollution as integrated environmental-change phenomena that vary on local, regional and continental scales as a consequence of connectivity of social, physical and biological systems. We propose five hypotheses to drive the deployment of NEON resources: 1) Human socio-demographic changes are the primary drivers of land-use change, urbanization, and pollution; in turn, these patterns are influenced by a continental template of climate and by proximity to the coasts; 2) Urbanization will generally increase connectivity via wind and animal vectors, but will disrupt connectivity via water vectors, especially at local to regional scales; 3) Urbanizing regions will be less vulnerable to future changes in climate than wildland ecosystems due to human adaptive capacity; however, this adaptive capacity will exacerbate climate change impacts on linked wildland ecosystems; 4) Humans fundamentally change biogeochemical inputs, processing, flow paths, and exports in areas undergoing development, as well as in ecosystems connected via wind or water (i.e., ‘sink’ regions) ; 5) Within urbanizing regions, landscape alteration and management result in a relative homogenization of form and function of urban land cover across climate zones; and 6) Human activities and their legacies interact with gradients of air pollution and N loading to produce substantial variation in ecosystem patterns and processes, at sub-continental and regional scales.
The changes in physical, biological and social connectivity caused by urbanization have continental-scale effects that can only be studied with a coherent network of measurement, modeling, and remote-sensing techniques. We propose to compare major regions across the continental US using relocatable systems from the domain and continental toolbox at five megapolitan regions representative of the major classes of urbanization. Further, a large network of sites from the NEON domain toolboxes will allow evaluation of terrestrial and aquatic responses to land-use change across continental temperature and precipitation gradients. Within each of nineteen domains, one to three sites have been selected as urban/suburban (population density of 400 - 4000 persons/km2, 10 - 30% impervious surface) or urban fringe (40 - 400 persons/km2, < 10% impervious surface) sites. These are intended to be contrasted with wildland sites in each domain, and to be examined over time to assess changes owing to continued urban-suburban expansion over the next 30 years. “Wall-to-wall” (continental) coverage of land cover change from the NEON Land Use Package will provide an essential framework for assessing and interpreting the dynamics of land change across scales.
Understanding the continental-scale of effects of urbanization-induced changes in atmospheric and hydrologic connectivity and how the effects of cities on surrounding wildlands vary with climate and climate change are essential for developing a predictive capacity for how human settlement patterns will alter ecosystem services and resource utilization at the continental scale. NEON has the potential to transform forecasting of land change and its effects, catalyzing a move from empirical modeling based on statistical extrapolation of historical trends, toward a forecasting foundation based on general principles governing land change. This predictive capacity is essential for a wide range of social, economic and environmental national policy making and management efforts.