Resilience of epigeal spiders (Araneae) after clear-felling for agriculture in a Central African rainforest

Abstract

Epigeal spiders were collected in five lowland rainforest habitats of the Masako Reserve (Kisangani, RD Congo): primary forest (>200 y. old), old secondary forest (± 80 y.), young secondary forest (40 y.), old fallow (12 y.) and young fallow (5 y.). The density and spatial distribution of spider populations were estimated by means of nocturnal distance sampling performed in all habitats except young secondary forest, and by pitfall trapping, applied in all five habitats. The epigeal spiders of the Masako forest belong to 62 species in 25 families. The most frequent families are Ctenidae, Lycosidae, and Sparassidae in the distance samples, and Zodariidae, Salticidae, and Corinnidae in the pitfalls. The density of the Ctenidae increases in an ascending sequence from 0.007 ind. m-2 in young fallow to 0.103 ind. m-2 in primary forest. For Lycosidae the sequence is inversed. They are by far the most common in young fallow (0.028 ind. m-2) and virtually absent in primary forest. Typical forest spiders, absent from open habitats, are common in old fallow which means that after 12 years, the typical forest fauna is already re-established. Only the young fallow fauna is clearly different from that of the other habitats, which confirms the high resilience and recolonization potential of epigeal spiders.