A matrix model for predicting seasonal fluctuations in field populations of Paronychiurus kimi (Collembola: Onychiruidae)

A matrix model for the population dynamics of Paronychiurus kimi in the field, based on life table statistics of P. kimi in a laboratory at constant temperature under optimum environmental conditions is described. The temperature-dependent development and fertility schedule of P. kimi were estimated in terms of degree-days (for temperatures greater than or equal to 7.83 degreesC. The model simulates reasonably accurately the seasonal fluctuation of P. kimi in Ichon, Korea. It predicted a significantly higher density than that observed in the field between mid April and early June, when the soil moisture content was lowest and with high variance. Our results suggest that soil moisture content is the limiting factor suppressing the population below the density level predicted. The validity of the model as a standard phenology of R. kimi in the field is discussed, including the capability to account for factors other than temperature. (C) 2002 Elsevier Science B.V. All rights reserved.