Nematode colonisation of artificial water-filled tree holes

Abstract

Nematodes inhabiting artificial water-filled tree holes were monitored over 16 months by placing 300 plastic cups in four forest areas. For the first time we investigated the importance of forest soils for nematode dispersal and colonisation of tree holes. On average, 91% of the cups were settled by a total of 35 species (maximum 58 336 individuals 100 cm−2). They were dominated by the bacterial feeder Dolichorhabditis dolichura (32.4%) and the hyphal feeders Laimaphelenchus penardi (23.6%) and Laimaphelenchus sp. (13.4%); 84.4% had lengths < 0.75 mm and in only 6% of the water-filled tree holes were male nematodes found. None of the most common species was detected in the soils of the sampling sites. However, a meta-community analysis revealed a random turnover. The properties of the identified nematodes (small body size, anhydrobiosis, parthenogenesis) made them highly amenable to dispersal by wind and account for their rapid colonisation of a wide range of habitats.