The ecology and management of temperate mangroves

Previous reviews of mangrove biology focused on the more extensive and diverse tropical examples, with those of temperate regions generally relegated to a footnote. Temperate mangroves are distinctive in several ways, most obviously by the lower diversity of tree species. Their occurrence in relatively developed countries has created different issues for mangrove management from those in the tropics. Mangroves in several temperate areas are currently expanding, due to changes in river catchments, in contrast to their worldwide decline. Information derived from the greater body of research from tropical regions has sometimes been applied uncritically to the management of temperate mangroves. The growing body of information on the ecology of temperate mangroves is reviewed, with emphasis on productivity, response to anthropogenically enhanced rates of sediment accumulation, and potential effects of climate change. There is no unique marine or estuarine fauna in temperate mangroves, but the poorly known terrestrial fauna includes mangrove-dependent species. Although productivity generally declines with increasing latitude, there is overlap in the range of reported values between temperate and tropical regions and considerable within-region variation. This, and variation in other ecologically important factors, makes it advisable to consider management of temperate mangroves on a case-by-case basis, for example, when responding to expansion of mangroves at a particular location.