Ecological parameters of the mangroves of semi-arid regions of Mexico: Important for ecosystem management

Abstract

The Pacific coast of Mexico is predominantly arid and semi-arid with a brief and highly seasonal rainfall (July-October) presenting brief but strong intermittent showers which are mainly related to the influences of hurricanes and tropical storms. Mangrove ecosystems are associated with small coastal lagoons with permanent or ephemeral inlets without or with river flow during a short period of the year. Mangroves also border big coastal lagoons with permanent river flow or open bays with low wave energy. Mangrove distribution is defined mainly by the frequency of rainfall, the duration and severity of cold winter temperatures and the physiographic characteristics of the Pacific coast which is discussed in this work. The mangroves of this region, with few exceptions, are limited to a narrow fringe bordering the coast discontinuously; they are poorly developed (basal characteristics between scrub and basin forest but with high litterfall (more than 1.0 kg m-2) similar to a riverine forest. We consider that groundwater seepage that is near to the surface and hurricanes play an important role in the high litterfall and low structure of mangroves of this region. The litterfall seasonality and structure characteristics in a coastal lagoon with permanent (Barra de Navidad) and ephemeral inlet (El Verde) are discussed and compared to mangroves from a subhumid region (Agua Brava) along the same coast.Keywordsmangrove managementMexicosemi-arid climatestructurelitter productionmangrove ecosystem