Collaborative Research: Multi-Scale Drivers and Effects of Biotic Change in the Global Mangrove-Saltmarsh Ecotone

Smithsonian Institution, Washington DC

Investigators

Abstract

Mangrove forests that dominate tropical coastal wetlands globally are expanding their latitudinal ranges and invading areas historically dominated by temperate zone salt marshes. Both mangroves and salt marshes provide critical ecosystem services that include filtering water, retaining nutrients, buffering shorelines from storms, supporting unique biodiversity, and serving as nurseries for commercially and recreationally important fisheries. However, the two habitats differ dramatically in structure and are likely to differ substantially in the rates and magnitudes of these ecosystem services. Funds provided by this award will support a multidisciplinary approach to understand the consequences of climate variation, nutrient enrichment, and land development on the rapid and ongoing conversion of salt marshes into mangrove forests at regional to continental scales. Aerial and satellite remote sensing will be used to document the rate and extent of mangrove spread within tropical/temperate boundary zones over the last half century. Large scale field experiments replicated across biogeographic regions will test alternative mechanisms for these shifts in coastal wetland composition and determine the effects on nutrient cycling, carbon sequestration, and food web dynamics. Statistical and simulation modeling will be used to predict future changes in coastal wetland communities. By identifying the relative importance of environmental and biotic factors across local to global scales of organization, data and models developed in this study will help wetlands management by resource managers, fisheries agencies, and conservationists. Findings from this study will be made available through highly visible exhibits and online sites for educators through the Ocean Portal, a collaborative effort among the Smithsonian, NOAA, and the Ocean Conservancy. Postdoctoral researchers, graduate students, and undergraduate students will be trained in a variety of interdisciplinary techniques, resulting in a collaborative effort that brings together researchers from universities, government, and federal agencies.