At a freeze frequency of 12 years,
mangroves replaced salt marsh. Along the Louisiana
coast, freezes historically occurred about every
4 years. By the spring of 2004, however, a killing
freeze had not occurred for 15 years and small
mangroves occur over a large area near the coast. If
this trend continues, mangroves will probably spread
over much of the northern Gulf and part of the south
Atlantic coast. In fact, mangroves are already
becoming established and more widespread due to
warming (Day et al. 2005).