One of the challenges in ecology is to understand how genetic attributes within the arboreal dominant species can determine community and ecosystem level processes. Mexico is considered the center of oak diversification, with 161 species from which 109 are endemic. Hybridization is a frequent phenomenon between oak species (Quercus spp.) due to its weak reproductive barriers. Hybrid zones represent interspecific systems that are genetically diverse, which makes them the ideal systems to study the effects of genetic variation from the host plant over associated communities. In general, it has been found a positive and significant relationship between the genetic diversity of the host plant and the diversity of associated species. One of the closely associated communities to oaks, are lichens, which have a specificity to the substrate of the host plant. In this study the structure of the community of lichens related to the genetic diversity of two species of red oaks (Quercus crassifolia and Q. crassipes) and its putative hybrid (Q. dysophylla Benth pro sp.) is analyzed. The taxa was examined genetically using 4 microsatellite nuclear primers (SSRs). The lichen communities from 30 individuals (10 individuals of each taxa) were collected in each of the three hybrid zones for identification.
Results/Conclusions
The highest genetic diversity was shown in the hybrid populations, followed by Q. crassifolia and lastly Q. crassipes. The values of genetic diversity between hybrid zones register the following pattern: Canalejas >Tlaxco > Acajete. Preliminary results show that in the hybrid zones of Canalejas, State of Mexico, Mexico and Tlaxco, Tlaxcala, Mexico, the lichen community is dominated by the family Parmeliaceae. A significant effect from the taxa over the percentage of lichen coverage was found, but there was not a significant effect over the species richness. In the hybrid zone of Canalejas the more representative genera are Lecanora, Usnea and Heterodermia; in Tlaxco the dominant genera are Parmotrema, Ramalina and Punctelia. The index of lichen diversity register the following pattern: Q. crassifolia > Q. x dysophylla > Q. crassipes (Canalejas); Q. x dysophylla > Q. crassipes > Q. crassifolia (Tlaxco). We found that the genetic diversity in the hybrid complex and the environmental variation between hybrid zones significantly influenced bark lichen community composition. The data found in this work is important in terms of conservation, because efforts to maintain the mechanisms that promote genetic diversity in foundation species is fundamental to preserve the diversity of the associated communities.