Sea-level rise and landscape change influence mangrove encroachment onto marsh in the Ten Thousand Islands region of Florida, USA

The state of the world’s mangroves in the 21st century under climate change

“…For example, it was once thought that sea-level rise involved gains associated with inland encroachment of mangroves in the Everglades region of Florida that balanced appreciably by losses along the seaward fringe from submergence (Egler, 1952). Rather, mangroves moved inland and adjusted vertically along the fringes, resulting in a 35% increase in total mangrove coverage in some portions of the Ten Thousand Islands region of Florida (Krauss et al, 2011). Such sea-level-rise induced expansion has also been documented along the coasts of the Gulf of Mexico, southeast Australia, and the Pacific coast of Mexico (Rogers et al, 2006;Saintilan et al, 2009;López-Medellín et al, 2011).…”

Florida Land Use and Land Cover Change in the Past 100 Years

“…For example, in the Ten Thousand Islands, between 1927 and 2005 mangrove encroachment occurred upstream into salt and brackish marshes resulting in a roughly 35% increase in mangrove coverage (Krauss et al 2011). Within the Tampa Bay region, Raabe et al (2012) have documented conversion of marsh to mangrove habitat by comparing digitized nineteenth century topographic and public land surveys with 2005 digital land cover.…”

“…Depending on location, there are varying and interrelated reasons for these shifts that have been cited, including construction of waterways and interruption/reduction of freshwater flows (Krauss et al 2011;Raabe et al 2012), sea level rise (Krauss et al 2011;Raabe et al 2012), and changes in temperature resulting from climate change (Raabe et al 2012;Williams et al 2014) Storm disturbances have been a historic driver of change in forest structure (Doyle et al 1995), and future changes may also be driven by precipitation (Ward et al 2016), South to north shifts in mangrove ranges seem particularly telling of the influence of climate change because, at least in Florida, the northern distribution of mangroves is limited by temperature. When mangroves begin to migrate further north, it is an indication that freeze events are no longer limiting colonization of mangroves in places where they have not recently existed.…”

Coastal Habitats of the Gulf of Mexico

“…In contrast, at the seaward edge of Rhizophora mangle (red mangrove) forests, a narrow fringe of Spartina alterniflora (smooth cordgrass) can occur (Figure 6.121) (Montague and Wiegert 1990). In the Ten Thousand Islands region of southwestern Florida (Figures 6.80 and 6.81), mangrove coverage has increased by approximately 35 % over 78 years, probably due to sea-level rise and possibly altered freshwater input (Krauss et al 2011). Hence, the prevalence of coastal herbaceous marsh in the South Florida Ecoregion may be at risk.…”

“…Subsidence in coastal Louisiana has converted large areas of marsh in Barataria Bay, Timbalier Bay, and other embayments to open-water habitat (Britsch and Dunbar 1993;Couvillion et al 2011), resulting in reductions in primary productivity but increases in subtidal habitats and populations of infauna and epifauna. Work in Florida found that mangrove areas in the Ten Thousand Islands National Wildlife Refuge had increased 35 % from 1927 to 2005; this increase was attributed to sea-level rise as well as factors such as subsidence, enhanced propagule dispersal via new waterways, and reduced freshwater delivery from overland flow (Krauss et al 2011). Mangroves are also predicted to replace freshwater forests in the eastern Gulf (Doyle et al 2010).…”