Present state of mangrove forests along the Eastern Cape coast, South Africa

Seventeen estuaries that are permanently open to the sea provide habitat for mangrove forests along the Eastern Cape coast, South Africa. These mangroves are of interest as they occur at one of the most southerly distributions in the world. Climate change will influence future distribution patterns while present anthropogenic impacts are causing mangrove loss. Mangrove area and species distribution in 2012 were compared with results from previous studies in 1982 and 1999. Anthropogenic impacts were noted and showed that harvesting of mangrove wood, livestock browsing and trampling and footpaths occurred in more than 70 % of the estuaries. Browsing on trees by cattle resulted in a clear browse-line and browsing on propagules mainly by goats reduced seedling establishment. Over the past 30 years, a total loss of 31.5 ha of mangroves was observed for all 17 estuaries. However in three estuaries mangroves had re-established where they had been previously lost. Extreme events such as floods and closure of the estuary mouth to the sea caused large changes in mangrove area in small estuaries. In contrast in the larger forests which occurred in the larger estuaries, anthropogenic pressures such as harvesting reduced the area of mangroves. Predicted climate changes coupled with anthropogenic impacts are likely to accelerate the loss of mangroves. More sustainable practices are urgently needed to protect biodiversity and the ecosystem services that these forests provide.