Factors controlling soil macrofauna spatial pattern in a pure beech and a mixed beech-hornbeam forest

The soil macrofauna of a pure beech (PS) and a mixed beech-hornbeam (MS) stand was recorded using a sample design spatially explicit at stand level. Humic epipedon morphological and chemical properties, relative irradiance, soil bulk density, and the specific composition of the litter in MS were also investigated. The taxonomic diversity is nearly similar on both sites, but the average by sample is greater under PS. The main factors controlling soil macrofauna spatial variability were: litter quality under MS and humus form activity under PS. These results suggest a distal control (i.e. external to humic epipedon) of macrofauna spatial variability when the litter quality is variable and a proximal control (i.e. internal to humic epipedon) when it is uniform at the spatial scale of the study. (C) 2004 Academie des sciences. Publie par Elsevier SAS. Tous droits reserves.