Abstract
Leaf litter arthropod population changes were monitored by means of extensive can trapping over a thirteen month period at a lowland evergreen forest site in Costa Rica. Samples were taken within an undisturbed forest plot and an adjacent fallow cacao plantation. Comparisons of abundance were made between nocturnal and diurnal samples as well as between months. The dominant arthropod groups in the samples in order of abundance were the Formicidae, Apterygota, Orthoptera and Arachnida. Total numbers of individuals in all major groups were consistently greater in the initial stages of the rainy season and remained relatively constant throughout the remainder of the year. It is suggested that numbers increase in response to the onset be the rainy season. Greater numbers of individuals were collected in the undisturbed forest than the fallow cacao plantation. Significant diel differences in abundance were found for many of the major groups included in the study. Maximum arthropod abundance corresponded to the time of greatest leaf litter depth within the study plots.References
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