OOS 24-5
Conservation options for species and natural communities threatened by sea-level rise: An analysis for Florida (USA)
With limited resources, conservationists must focus on the species and ecosystems most vulnerable to anthropogenic threats or most important ecologically or economically. In Florida (USA) and other low-lying coastal regions, sea-level rise is an immediate and severe threat to natural and human communities. Nevertheless, existing Vulnerability Assessments do not adequately account for the unique problems associated with sea-level rise in combination with changes in climate and land-use (e.g., urbanization). We evaluated plant, vertebrate, and invertebrate species and natural communities in Florida with coastal or near-coastal distributions, in terms of their vulnerability to these combined threats. We developed a novel assessment tool based on 30 criteria distributed across four types of information: Vulnerability (Exposure and Sensitivity), Adaptive Capacity, Conservation Value, and Information Availability. We applied this assessment to >300 species and infraspecific taxa and >30 natural communities identified as being at risk of extinction or substantial reduction in population or distribution over the next century. For those species with sufficient data available on habitat relationships, we developed niche models. For taxa for which sufficient information existed on distribution and life history, we evaluated potential options for adaptation and conservation in the face of sea-level rise and interacting threats.
Results/Conclusions
The taxa most vulnerable to sea-level rise and interacting threats in Florida are primarily range-restricted (endemic) taxa on islands, especially the Florida Keys, such as the Florida semaphore cactus (Opuntia corallicola), Miami blue butterfly (Cyclargus thomasi bethunebakeri), mangrove terrapin (Malaclemys terrapin rhizophorarum), and Key deer (Odocoileus virginianus clavium). For most island species, the only alternative to extinction with 1-2 m sea-level rise is ex situ conservation. Many mainland coastal taxa, such as aboriginal prickly pear (Harrisia aboriginum) and loggerhead turtle (Caretta caretta) are also highly vulnerable. For mainland taxa restricted to largely developed coastlines, conservation options include (1) protect and manage existing habitat for as long as possible; (2) protect projected future habitat landward of coastal development; and (3) provide assisted colonization to recipient habitat. The coastal regions with the greatest adaptation potential are those with the least human development, including the Everglades/Big Cypress/Ten Thousand Islands region and the “Big Bend” coast where the Florida peninsula meets the panhandle. Additional conservation options for these regions include (4) protect and manage existing habitat corridors to projected future habitat; and (5) restore/create corridors to recipient habitat. Landward movement of natural communities, such as salt marshes and mangroves, should be facilitated where possible.