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MOSSES OF EL EDÉN ECOLOGICAL
RESERVE, QUINTANA ROO, MEXICO
Claudio Delgadillo M. The moss flora of the Yucatan Peninsula has been studied for more than 100 years. The exploration has been sparse and haphazard, with some incidental reports of a few specimens in general floristic studies. Recently, available data on the peninsular mosses were compiled and supplemented with collections from the states of Campeche, Quintana Roo and Yucatán (Delgadillo et al. 1982, Delgadillo & Cárdenas 1982, Delgadillo 1984). From these studies and the Moss Flora of Mexico (Sharp et al. 1994) it is now evident that there are about 70 moss species and varieties within the political subdivisions of the Yucatan Peninsula. Despite up-dated information, no single site is adequately known and further studies are required to identify moss diversity and regional patterns of distribution. In early October, 2000 the authors collected mosses in El Edén Ecological Reserve. Although a large portion of the site was underwater because of seasonal flooding, specimens recovered from the forest and secondary growth vegetation in the Reserve may be representative of the local moss flora. The list given below contains the names of taxa followed by specimen numbers preceded by the collector's initials. A complete set of specimens has been deposited at MEXU; an additional set will be sent to the University of California at Riverside.
Twenty-two moss were collected in El Edén Ecological Reserve. This small size of the flora may be attributed to human occupation and disturbance in modern and historic times. Fire, agriculture and other forms of interference have apparently resulted in a depauperate moss flora in El Edén and in the entire Yucatan Peninsula. The role of other such factors as topographic uniformity, high near-ground insolation, poor water holding capacity and other features of the substrate cannot be established at this time. The small stature of the vascular plant vegetation, partly as a consequence of human occupation since historic times, may be also responsible for diminished moss habitats. Most mosses in El Edén grow as epiphytes or as saprophytes on decaying logs. Notable exceptions are Barbula agraria and Neohyophila sprengelii that are apparently obligate saxicolous; Bryum apiculatum usually grows on soil in disturbed habitats, as for instance, around human dwellings. Although frequent, most species have limited growth and biomass in El Edén. This may be due to their life form, but mostly to continued habitat disturbance and the youth of the shrubs in the second growth vegetation. Groutiella tumidula, Leucobryum incurvifolium and Octoblepharum albidum cover the largest substrate surface. The latter two are easily distinguished by their whitish color due to numerous hyaline empty leaf cells. The number of moss species in El Edén may not be significantly higher even after the inundated areas are visited. The small size of the flora may be advantageous for an in-depth study of the biology of the species, as in the analysis of succession on trees and decaying wood. The sequence of successional events is usually difficult to follow because of the large number of participating species in temperate or tropical ecosystems, but clearly, taxon identification would be comparatively easy in El Edén. The mosses of El Edén are part of a generalized flora that is well represented throughout the Yucatan Peninsula. Their distribution is now part of a broader analysis that includes their range in Mexico, Central America and the Caribbean Islands. Acknowledgements. Thanks are extended to Dr. Arturo Gómez-Pompa and field station personnel, for support and for making field work possible in El Edén. Dr. Ronald A. Pursell, Pennsylvania State University, identified various Fissidens specimens. LITERATURE CITED Delgadillo M., C., A. Cárdenas S. & A.J. Sharp. 1982. Mosses of the Yucatán Peninsula, Mexico. I. Bryologist 85: 253-257. Delgadillo M., C. & A. Cárdenas S. 1982. Mosses of the Yucatán Peninsula, Mexico. II. Bol. Soc. Bot. Méx. 43: 35-37. Delgadillo M., C. 1984. Mosses of the Yucatán Peninsula, Mexico. III Phytogeography. Bryologist 87: 12-16. Sharp, A.J., H. Crum & P.M. Eckel. 1994. The Moss Flora of Mexico.
Mem. New York Bot. Gard. 69: 1-1113.   |