WOODY SPECIES STRUCTURE, DIVERSITY AND FLORISTIC AFFINITIES IN SEASONALLY DRY FOREST IN THE UXMAL ARCHAEOLOGICAL ZONE

Archaeological zones in Mexico effectively preserve the vegetal diversity within them. An analysis and description were done of woody vegetation structure, diversity and floristic affinity in the Uxmal Archaeological Zone, in the Puuc region of Yucatan, Mexico. Twenty quadrants measuring 10 x 10 m (100 m2) were placed throughout the zone to sample its diverse substrates. Height and diameter at breast height (DBH) of woody species with DBH >1cm were measured in each quadrant. Floristic affinities were analyzed with a dendrogram generated using the Morisita-Horn index. A total of 1,622 individuals were recorded which belonged to 101 species and 76 genera from 31 families. The richest families were Fabaceae, Rubiaceae, Malvaceae, Polygonaceae and Euphorbiaceae. The species with the highest relative importance values were Bursera simaruba, Piscidia piscipula, Diospyros anisandra, Thouinia paucidentata, Gymnopodium floribundum and Lonchocarpus xuul. The most frequent species were B. simaruba and D. anisandra, those with the greatest density were D. anisandra and L. xuul, and the most dominant were G. floribundum and P. piscipula. Floristic affinity analysis identified three floristic groups: dry tropical forest; mixed seasonally flooded forest; and semi-evergreen tropical forest. Although relatively small in area, Uxmal has highly diverse microclimates and substrate types which support a diverse woody species composition, structure and physiognomy within the same seasonally dry tropical forest.