Animal-plant interactions vary greatly across environmental heterogeneity (EH) spatial scales. Factors such as canopy cover, temperature and rainfall have a key role in determining the richness and abundance of ants. Ants (Hymenoptera: Formicidae) are one of the most prominent animals in the world. There has been estimated that ants represent up to 10-15% of the entire animal biomass in terrestrial ecosystems. On this premise alone, studying ant ecology would be essential for understanding the structure and function of terrestrial communities. In western North America, ant communities are diverse and are primarily composed of native harvester ants, bigheaded ants, pharaoh ants and some invasive species such as fire ants. To understand patterns of interaction, species composition, and distribution, studies should analyze variation among vegetation types, canopy cover and spatial distribution in ant densities and richness.
In this study, we examined common ant species present in different habitats (i.e. deer exclosure and outside (location), shaded and exposed area (area), abiotic conditions (i.e. temperature, soil, rainfall) their abundance and spatial distribution along with observations of activity in harvester ant (Pogonomyrmex barbarous) nests. To address our objectives, we used pitfall traps (n=16) in a canopy cover gradient in a deer exclosure and outside. We also used hemispherical photography to calculate canopy cover percentage using Gap Light Analyzer. We performed generalized linear models and Akaike Information Criterion(AIC) in R Studio to compare interactions between the variables and all the possible models.
Results/Conclusions
We recorded >1,000 ants from 12 genera. In our field observations we found the foraging pattern shifted to night time, a case that has been reported in the Mediterranean with no records in North America or Texas Hill Country. We found a higher abundance of ants in the shaded area outside of the deer exclosure. Our preliminary data suggest that there is a significant correlation between ant abundance and the location (exclosure and outside) and area (canopy cover gradient) (AIC 9530.4). There is no suggestion that ant species richness has a significant interaction with the area. There appears to be a correlation with the ant species richness and the location (exclosure and outside). Further data analysis should be performed to have better conclusions.