Acta zoológica mexicana
versión impresa ISSN 0065-1737
MOMO, Fernando R. y FALCO, Liliana B.. Spatio-temporal dynamics of a multi-specific earthworm population in an oak woodland. Acta Zool. Mex [online]. 2010, vol.26, n.spe2, pp. 203-2010. ISSN 0065-1737.
We studied the spatial dynamics of endogeic earthworms in a Quercus robur forest. Samples were taken using a 30 point grid every three months during a year plus a summer. Growth rates were estimated for each point based on abundance data. Abundances appeared to be correlated in the direction NW-SE showing a net movement of the organisms to the SE region of the studied field. The migration speed of earthworms was 1.2 m month-1. We fitted the spatial dynamics to several growth mathematical models; the most accurate models were the logistic model of Smith, that is a model with physiological constraints, and the non-symmetric logistic equation, that considers inter-specific competition. The models revealed a significant non-hierarchic diffuse competition and a low rate of individual resource consumption. Moreover, growth rates were high at low population densities but remained roughly constant at densities above 20 individuals m-2.
Palabras llave : Oligochaetes; spatial and temporal dynamics; correlation; growth models.