MARSHES AND ESTUARIES IN DIFFERENT LATITUDES

Physiographic features in estuaries and marshes are deeply influenced by differences in climate. The study of these contrasts demands interdisciplinary teams of climatologists, botanists, hydrologists, geochemists, oceanographers, human geographers, geomorphologists and geologists. In temperate countries a dense carpet of herbaceous vegetation grows on high marshes, while low marshes bear plants which disappear in winter; mud-liats haveno flowering plants. In colder regions, for example Quebec and the surrounding areas in north-east America, sea waters freeze for a long time every winter. This results in a particular evolution of tidal marshes, as ice crafts either pickup blocks of sediment from marshes, or, conversely, drop on them stones of foreign origin. In intertropical areas mangrove trees grow instead of herbaceous vegetation although in some places true marshes can be found. © 1979 Maney Publishing.