Sea-Level Rise and the Reduction in Pine Forests in the Florida Keys

Material Information

Title:
Sea-Level Rise and the Reduction in Pine Forests in the Florida Keys
Series Title:
Ecological Applications Volume 4 Number 1
Creator:
Ross, Michael S.
O'Brien, Joseph J.
da Silveira Lobo Sternberg, Leonel
Affiliation:
National Audubon Society -- Tavernier Science Center
Audubon Society -- Tavernier Science Center
University of Miami -- Department of Biology
Publisher:
Ecological Society of America
Publication Date:
Language:
English

Subjects

Subjects / Keywords:
Climate Change ( lcsh )
Florida Keys (Fla.) ( lcsh )
Florida ( lcsh )
Pines ( lcsh )
Sea Level Rise ( lcsh )
Slash Pine ( lcsh )

Notes

Abstract:
Forests dominated by Pinus elliottii var densa have undergone a reduction in area in the Florida Keys (USA). A previous investigation interpreted the presence of halophytic species in a former pine forest in Key Largo as evidence of sea-level rise. We therefore examined aerial photos and field evidence to learn how the 15-cm rise in local sea level over the last 70 yr had affected the distribution of pines on a second island, where intact pine forests still remained in 1991. The distribution of in situ dead pine stems showed that the area occupied by pines on Sugarloaf Key was 88 ha at some time prior to the earliest available aerial photographs, in 1935, The area of pine forest was reduced to 46 ha by 1935, and continued to decrease through 1991, when it covered 30 ha. The pattern of pine mortality was related to topographic position, with the areas where pines died earliest occupying the lowest elevations. Our analsysis of current vegetation patterns showed that the areas of earliest pine mortality are now populated by a higher proportion of halophytic plant assemblages than areas of more recent pine mortality. We also compared the physiological responses of pines in two portions of the island: one where pine forest reduction had been most pronounced, and a second where the extent of the forest had changed little over the past 50 yr. Both groundwater and soil water salinity were higher in the area of rapid pine forest reduction, and the pines sampled tthere exhibited higher physiological stress, as indicated by pre-dawn water potential and stemwood carbon isotope ratios. These results suggest that the salinization of ground- and soil water that occurs as sea level rises is a major factor in the reduction of pine forests of Sugarloaf Key. If sea level continues to increas, the Florida Keys will experience a decline in both landscape and species diversity, as species-rich upland communities are replaced by simpler mangrove communities. This pattern may also occur in other low-lying island ecosystems with limited freshwater resources.

Record Information

Source Institution:
Florida International University
Rights Management:
Please contact the owning institution for licensing and permissions. It is the user's responsibility to ensure use does not violate any third party rights.
Resource Identifier:
10.2307/1942124 ( doi )