Soil Nematode Communities in Managed and Natural Temperate Forest

Forest management and the stand age play key roles in determining the composition of soil biota, including nematodes. We analysed the effect of the interaction between stands of natural forest and stands influenced by human activity on nematode communities, necessary for realistically assessing the specific potentials of forest soils, plant protection, forest management, and land use management. Nematode communities were evaluated and compared in managed beech and spruce forests in three age classes (0-20, 40-60, and 100-120 years old) and an unmanaged old-growth temperate forest. A total of 51 nematode genera were found in the forests. The number of nematode genera was the highest (46) in European beech forests, dominated by Rhabditis and Filenchus. In contrast, the number of nematode genera was the lowest (37) in a Norway spruce forest, but where nematode abundance was the highest due mostly to the high abundance of bacterivorous nematodes such as Acrobeloides, Plectus, and Rhabditis. The unmanaged old-growth forest had the lowest nematode abundance and total biomass but the highest abundance of herbivorous nematodes of the order Tylenchida, especially Filenchus, Malenchus, and Paratylenchus, and a high abundance of identified genera of predators. The number of identified nematode genera, abundance, total biomass, and diversity index were the highest in young 0-20-year-old stands, and the lowest in 100-120-year-old stands. Enrichment, structure, and basal indices were influenced by both the stands and the ages of the forests.