Charles S. Hopkinsons Ecosystems Center Marine Biological Laboratory Woods Hole, MA 02543 chopkins@mbl.edu 508 289-7688
Merryl Alber Marine Sciences University of Georgia Athens, GA 30602 706 542-5966
Ariel E. Lugo USDA Forest Service International Institute of Tropical Forestry Jardin Botanico Sur 1201 Calle Ceiba Rio Piedras, PR 00926 787 766-5335 alugo@fs.fed.us
We identify a continental network of coastal and inland sites to advance our understanding of how sea level rise and intensification of intense windstorms will influence the structure, functioning, and capacity to deliver services (e.g., carbon sequestration, storm protection, pollution control, habitat support, and food for human consumption) of coastal and inland forest ecosystems. The network consists of 14 coastal wetland and 47 inland forest sites in 14 NEON Domains. The network is representative of continental-level gradients of precipitation (20 to 182 cm/y), temperature (4° to 26° C), vegetation (marsh grasses, mangrove trees, inland forests, shrublands, and woodlands), frequency of occurrence of major windstorms (< 1 to > 24 severe storms since 1926), the value of insured properties ($0.7 - $1.9 billion), latitude (17 to 60° N), tidal range (0.3 to 8.0 m), and sediment availability. This broad coverage will allow a rigorous assessment of wetland response to sea level rise and wetland and inland forest response to intense storm disturbance. This assessment will be critical for predicting the effects of climate change on coastal and inland forest ecosystems. We present different protocols and approaches for assessing the response of coastal wetlands and inland forests.
Six hypotheses are addressed among the many more that a NEON network enables:
H1: Regional geology and topography and human protective barriers are the primary limits to inland transgression of wetlands and estuaries as sea level rises. Areas with limited ability to migrate will see marked reductions in ecosystem services provided and will be increasingly vulnerable to intense storm damage in the future.
H2: The capacity of coastal wetlands to maintain elevation relative to sea level will decrease as the rate of sea level rise increases, as climate warms and droughts become more severe and frequent, and as continental sediment and nutrient inputs change.
H3: Windstorm strength, duration, and capacity to impose ecosystem change diminish with latitude.
H4: Intense windstorms cause shifts in species composition and replacements of species in proportion to their biomechanical strength.
H5: Intensive windstorm effects on forested ecosystems are proportional to the structural complexity of vegetation, inversely proportional to windstorm frequency, and modified by land use/land cover change.
H6: The capacity of forest ecosystems to support human activities will decrease with increasing windstorm frequency and strength because of directional changes in species composition and ecosystem structure. Increasing storm frequency will also accelerate rate of ecosystem change.
Understanding and predicting the responses of coastal wetland and inland forests to climate change will require a coherent network of measurement, modeling, and remote sensing activities distributed across the full range of coastal and inland gradients found in the coastal region of the Continent. For the first time, NEON will allow us to measure real-time characteristics and strength of tidal and windstorm events as they change over time and space and to observe the responses to these events at the large scales associated with sustainability of ecosystem services. This precision and extended scale will improve understanding of hurricane and coastal phenomena as a whole and enhance our capacity to model future events in light of climate change scenarios, including impacts such as forest fragmentation of watersheds, changes in composition and function of riparian and aquatic species, flooding, and soil movements (landslides) that disrupt ecosystem services for long periods. Moreover, the critical role and ecosystem services provided by coastal ecosystems to the Nation as a whole justify their inclusion in NEON.