SOIL COLLEMBOLA DIVERSITY, ENDEMISM, AND REFORESTATION - A CASE-STUDYIN THE PYRENEES (FRANCE)

The diversity of soil Collembola was studied in two sites of the centr al Pyrenees (France). In each site a seminatural beech forest was comp ared to a conifer plantation. At the Rifle site planted spruce and nat urally regenerated beech forest were established on ancient meadows, a nd at the Carmil site a fir plantation had locally replaced the natura l beech forest. Thirty-two, soil cores of 250 cm(3) were collected in each forest type at each site, and core fauna were extracted with a Be rlese-Tullgren funnel. Differences in structure and composition of col lembolan communities were observed from original to planted forest, an d these changes followed different patterns at the two sites. In both cases, however, the diversity of the fauna was impoverished in the pla ntation. The endemic component suffered a particularly severe loss in species richness and abundance, whereas non-endemic species were more weakly affected. Endemic biota, which from a conservation perspective represent the most valuable element of the fauna, were Its most vulner able component. Endemic species and endemic areas therefore deserve pa rticular attention when biodiversity fluctuations caused by reforestat ion are studied. This could lend to reassessment of the potential effe cts of artificial reforestation on the biodiversity of temperate fores ts. There is a general need for a systematic inventory and protection of forests with endemic soil biota.