phytogeographical analysis of coastal vegetation in the Yucatan Peninsula

• Published in: Journal of biogeography 1987-11, Vol.14 (6), p.499-519
• Main Author: Espejel, I
• Format: Article
• Language: English
• Subjects: Beaches; biogeography; Biological and medical sciences; Chorology; Coastal ecology; Coasts; duneland plants; Dunes; ecological zones; environmental factors; Flora; Fundamental and applied biological sciences. Psychology; Gulfs; habitats; Peninsulas; Plant cytology, morphology, systematics, chorology and evolution; Plants; Sand dunes; Vegetation
• ISSN: 0305-0270; 1365-2699
• DOI: 10.2307/2844877

Distribution patterns of 237 species belonging to sixty-three families of the coastal dunes of the Yucatan Peninsula were analysed. Cosmopolitan families like Gramineae, Compositae and Leguminosae are best represented. Other families are mainly tropical. For a geographical synthesis the coast of the Yucatan Peninsula was divided into five natural sections according to differences in climate, substrate, water-table, distance to the sea and proximity of adjacent backdune vegetation. These factors explained the presence or absence of particular species which were related to the different physiognomy of the stabilized dune vegetation. The five sections are Campeche and Quintana Roo with a humid climate and West, Middle and East Yucatan where a semi-dry climate prevails. A higher floristic richness was found on the coasts facing the Caribbean Sea where hurricanes occur and neighbouring tropical rain forest influences the floristic composition of the dune vegetation. The zonation of species along the sea-inland gradient showed differences in morphology and life history. The species attributes characterize the different habitat zones. Species adapted to salt-spray and exposure are widely distributed herbs with abiotic dispersal modes. The sheltered habitats of the dunes are densely covered by palms, trees with broad entire leaves, epiphytes and armed and succulent shrubs. These species show narrow distribution patterns and zoochorous dispersal modes. Herbs are most tolerant to saline habitats, whereas shrubs and trees thrive in the nonsaline dune environments. The flora of the sand dunes of the Yucatan Peninsula is equally characterized by two elements: (a) Caribbean species and (b) South Mexican and Central American species which together form the Meso-American element.