Ecology and Restoration of Mangrove Shorelines in Florida

Abstract

Mangroves play an important role in estuarine ecological systems as well as in shoreline protection. Such large areas of mangroves have been lost by dredging, land-filling, and other means, that it has become important to develop techniques for restoring or replacing them. Such techniques are needed both for the sake of restoring the mangroves as a valuable shoreline habitat and to estimate their monetary value, which must at least equal the restoration cost. It is accordingly suggested that future destruction of mangroves be permitted only if they are subsequently replaced at the same site or at some appropriately developed alternative site. Mangroves have been planted at several sites in Florida, and planting success has been evaluated. Mangroves of several sizes have been planted at a variety of sites that differed in shoreline energy, tidal depth, root-parasite prevalence, substrate type, salinity, and public access. Counts and measurements made after periods of up to 4 years indicated that shoreline energy, tidal depth, and vandalism, were the most important factors limiting mangrove establishment and survival. Planting costs were estimated from collecting and planting by research assistants and from estimates of the price of larger (3-years-old) nursery-grown trees. Planting cost estimates were $462/acre ($1,140/ha) for unrooted Red Mangrove propagules spaced 3 feet (91 cm) apart, $1,017/acre ($2,500/ha) for established Red, Black, or White, Mangrove seedlings spaced 3 feet (91cm) apart; and $87,500/acre ($216,130/ha) for 3-years-old trees of Red, Black, or White, Mangroves spaced 4 feet (123 cm) apart.