Seasonal distribution of Xenylla brevispina (Collembola) in the canopy and soil habitat of a Cryptomeria japonica plantation

We investigated the life cycle and habitat use of an arboreal collembotan species, Xenylla brevispina, in the canopy and soil of a conifer (Cryptomeriajaponica D. Don) plantation. The adaptive significance of migration between arboreal and soil habitats in the maintenance of its population in relation to the vertical structure of the forest is discussed. We sampled dead branches with foliage in the canopy (canopy titter) and on the forest-floor (soil titter). X. brevispina had one generation a year throughout the 3 years of the study. The mean densities of X. brevispina were similar in the canopy titter (0.06 to 14.57 g(-1) dry weight) and the soil titter (0.44 to 18.99 g(-1) dry weight). Seasonal patterns of density and relative abundance indicate that individuals of X. brevispina in the canopy were closely associated with those in the soil. These results suggest that vertical migration between the canopy and the soil might be a strategy allowing X. brevispina to be a predominant collembotan species in this forest. (c) 2006 Elsevier GmbH. All rights reserved.