Altitudinal distribution of alpha, beta, and gamma diversity of pseudoscorpions (Arachnida) in Oaxaca, Mexico

In this study, we describe the spatial and temporal variation in the diversity of pseudoscorpions along an altitudinal gradient in Santiago Comaltepec, Oaxaca, Mexico. Four altitudinal levels were selected (150, 989, 2177, and 2990 m a.s.l.). Species were recorded through monthly sampling from April 2016 to April 2017. Alpha and beta diversities were estimated at every altitude, and gamma diversity was calculated for the entire gradient; diversity was then related to temperature and precipitation. The highest species richness was observed at 989 m a.s.l. and the lowest at 2990 m a.s.l. The months with the lowest number of species and specimens were January, March, and April. The highest Shannon index value was observed at 989 m a.s.l. (H′ = 1.724) and the lowest at 2177 m a.s.l. (H′ = 0.692). Gamma diversity was 2.15 and was mainly affected by the average alpha diversity. Alpha diversity was higher during the dry season and was slightly regulated by precipitation. Moreover, higher species replacement was observed in the dry season than in the wet season, which was mainly associated with changes in temperature. Overall, with the increase in altitude, the diversity of pseudoscorpions decreases.