Mehltreter, Klaus .
Impact of land use change on the fern diversity of Mexican montane forests.
Montane forests in the State of Veracruz, Mexico, are heavily endangered because of land conversion mainly into coffee plantations and pastures, leaving actually only 10% of the original primary vegetation. Because this tropical ecosystem contains the highest fern diversity, its continuous decline has an immediate effect on local fern communities. To study the impact of land use change from primary forest into shade coffee plantations and pastures in the surroundings of the state capital Xalapa, fern diversity (species richness, abundance, and dominance) was assessed for each of the three vegetation types at three different sites with ten replicates in plots of 10 x 10 m each. Changes in fern diversity and composition were evaluated by means of Bray-Curtis similarity at three taxonomic levels, multi-dimensional ordination and indicator values. Species richness declined in shade coffee plantations to 50%, and in pastures to 15% of the original values of primary forests, few species become more dominant and introduced species (e.g. Macrothelypteris torresiana and Thelypteris dentata) increased their abundance. The composition ofÂ fern communities changed considerably from shade loving forest species (e.g. Arachniodes denticulata, Diplazium franconis, Polypodium falcaria) into sun-tolerant and weedy colonizers (e.g. Thelypteris resinifera); only 10-15% of the species were shared with the primary forest. In coffee plantations and pastures the fern communities were reduced to epiphytes (e.g. Pleopeltis crassinervata, Polypodium pyrrholepis) on the remaining or cultivated shade trees and occasional weedy or riparian species, and fern abundance declined to less than 50% or 5%, respectively. Fern communities of the two converted land use types shared about 40% of the species. In conclusion, land use change transforms fern communities significantly and preserves only a low proportion of the original fern flora at local scale.
Log in to add this item to your schedule
1 - Instituto de Ecologia, A. C., Ecologia Funcional, km 2.5 antigua carretera a Coatepec No. 351, Congregacion El Haya, Xalapa, Veracruz, 91070, Mexico
land use change
Presentation Type: Oral Paper:Papers for Sections
Date: Monday, July 28th, 2008
Time: 11:15 AM