The effect of plant genetic diversity on plant and spider community in the tropical dry forest of the Sierra de Huautla Biosphere Reserve, Mexico

Background/Question/Methods The relationship between spiders and plants have been a topic long studied and It´s well known that spiders respond to plant phenology, architecture, morphology, diversity and composition, but one approach that hasn’t been studied is how genetic diversity (GD) of one plant can have cascade effects on spider communities. It´s well known that foundation species can modify their associated communities and even the ecosystem processes, but how this extended effect of the phenotype of foundation species affects the ultimate trophic level is an area of research that hasn´t been touched. The main objective of this work is to evaluate the effect that GD of one putative foundation species, Bursera copallifera (Burseraceae) has on their associated communities of plants and spiders. The study was carried out in a tropical dry forest in south Morelos, Mexico, in the Sierra de Huautla Biosfere Reserve (REBIOSH), we collect spiders with the techniques of direct search and vegetation beat, and plants in nine plots of 10x10 m, where at least one individual of B. copallifera was present, in two localities inside the REBIOSH: Quilamula in the municipality of Tlaquiltenango, and El Limón in the municipality of Tepalcingo. All the material was determined to species in the case of the plants and to the lowest possible taxonomic status in the case of spiders.

Results/Conclusions At the moment we report 34 families and 68 genera of spiders, being the family Salticidae the richest one, with 11 genera. In the case of plants we report 22 families and 54 genera, from which Fabaceae is the richest one, with 18 genera. In general, the GD of Bursera copallifera has a positive influence on plant diversity, but not in their density and coverture. In the other hand the GD doesn´t affect the spider density or diversity, but we detect a significate effect of genetic diversity when spiders were grouped in trophic strategies. This suggest that the extended effect of the phenotype of B. copallifera affects indirectly the spiders and directly their associated plants