Wetland Conservation in the Gulf of Mexico: The Example of the Salt Marsh Morning Glory, Ipomoea sagittata

Abstract

Global climate change will have major effects on wetlands, ecosystems with elevated biodiversity and of enormous economic importance. Using ecological niche modeling and genetic data from three plastid DNA markers sequenced from 96 plants, we studied the salt marsh morning glory, Ipomoea sagittata, to understand the impact that future global warming and increasing sea level may have on aquatic plant conservation, distribution and genetic connectivity on the Gulf of Mexico. Data suggest that genetic variation is low and lacks structure; probable causes include high gene flow, clonal reproduction or use of ineffective molecular markers. Global warming models for its potential distribution in the year 2080 predict a loss of suitable habitat in its northern inland distribution (Cuatro Ciénegas Basin), while its coastal and southern habitats increase. Genetic connectivity decreases along the coast owing to a rise in sea level (Yucatán, Laguna Madre Basin, Usumacinta Basin). Three zones are identified, each requiring a different conservation strategy: 1) A saltwater intrusion zone where most protected areas are; 2) A stability zone which may offer optimal conditions for the creation of protected areas; 3) A zone of range expansion that may cause ecological instability, reducing species richness and promoting colonization by opportunistic species.