Litter and soil arthropods diversity and density in a tropical dry forest ecosystem in Western Mexico

The composition and temporal changes of edaphic microarthropods in both litter layer and soil were analyzed in a tropical dry forest ecosystem in Western Mexico. Sampling was carried out from June 1991 to July 1992 in two small watersheds at the Chamela Biological Station (Jalisco State, Mexico). At each watershed 10 random cores samples, 11 cm in diameter and 5 cm depth, were taken monthly from each biotope from an area of 100 m². Fauna was extracted by Berlese-Tullgren funnels and preserved in 75% ethanol. The total abundance of arthropods was 96,338 specimens, belonging to 33 taxa. Numerically dominant groups were Prostigmata, Cryptostigmata, Collembola and Mesostigmata, which constituted 92.6% of the total abundance. The effect of current monthly precipitation and temperature on density of total Arthropoda and different Orders was also investigated. Precipitation and temperature were significantly correlated with Collembola and Mesostigmata densities and also with total arthropod. The seasonal variation in the amount of litterfall was also significantly related to the abundance of arthropod in the litter layer biotope.