POSTFIRE ARTHROPOD ASSEMBLAGES IN MEDITERRANEAN FOREST SOILS IN ISRAEL

The presence of soil micro- and macroarthropod species was surveyed af ter severe fire in a mixed forest dominated by Aleppo pine on Mt. Carm el, Israel. Arthropods were sampled, and separated into 19 taxa (mainl y orders or classes). The effects of 2nd-5th post-fire years, seasons, habitats (burned and unburned) and tree species (pine or oaks) on the relative abundance of soil arthropods were analyzed by linear redunda ncy analysis. Arthropod distribution along the first axis of the analy sis was non-random, so all these factors influenced arthropod communit y composition. Arthropod composition in the 2nd and 3rd postfire years was different from later years, demonstrating outbreaks of pioneers. After five post-fire years arthropod populations were not completely r ecovered. Significant seasonal differences in population size were det ected, indicating summer, and to lesser extent also winter, as unfavor able periods in that region, as was well demonstrated with Collembola. The resilience of arthropods under burned oaks differed from the arth ropods sampled under burned pines. Seven taxa were highly correlated t o the unburned zone and included the main microarthropod groups (Colle mbola, Protura, Acari, and Pauropoda) and Coleoptera, Thysanoptera and Chilopoda. Only two orders showed a distinct association with-the bur ned zone: Psocoptera and Homoptera; the latter was represented almost solely by specimens of a pioneer species, Rhizoicus sp. (Pseudococcida e).