Reanálisis de las comunidades de opiliones del macizo de San Juan de la Peña (Jaca, Huesca, España)

Résumé

Before the generalisation of computerised statistical tools, ecological analyses were strongly limited, so the reanalysis of old data permits to corroborate previous conclusions. Harvestman communities characterised in the study carried out by Rambla (1985) based on 5209 harvestmen of 11 species sampled in the San Juan de la Peña massif are statistically analysed. Species accumulation curves suggest a reliable sampling. The most abundant species was Oligolophus hansenii, although it has a low niche breadth index value (N2), and the most frequent Odiellus troguloides. The existence of two groups of stations is corroborated: forest stations (with three indicator species: O. hansenii, Anelasmocephalus cambridgei and Leiobunum blackwallii), with greater internal similarity and species diversity, and open habitats (with Phalangium opilio as indicator species), with less internal similarity and species diversity. According to the diversity indices, the most diverse stations are the beech forest, the holm oak forest, the mixed forest and the low fir forest. The beech forest and high fir forest had unique species. Within the forests, the mixed forest and the high pine forest show the greatest significant differences