Recovery of soil nematode populations from cropping stress by natural secondary succession to meadow land

Abstract

The spectrum and densities of soil nematode species were studied in an extensively managed sub-thermophilous meadow and in conventionally managed and abandoned fallow fields left to natural succession. In the meadow, 115 species and 71 genera of soil nematodes were found and the total mean nematode abundance was 1019×10 3 individuals/m 2. The dominant feeding groups were root-fungal feeders (31%, mainly Filenchus), bacterivores (26%; variety of genera, mainly Panagrolaimus, Rhabditis, Acrobeloides, Bursilla, Plectus, Anaplectus, and Eucephalobus), and fungivores (16%, Aphelenchoides). The cultivated field had 66 species and 41 genera of nematodes and a mean nematode abundance of 546×10 3 individuals/m 2. The eudominant trophic group was bacterivores (53%; mainly Panagrolaimus and Acrobeloides) accompanied by fungivores (28%, Aphelenchoides). During 2 years of natural succession in an abandoned field, the total mean nematode abundance rose to 938×10 3 individuals/m 2, and the number of species and genera increased to 73 and 46, respectively. Omnivores (25%, Aporcelaimellus and Eudorylaimus), fungivores (24%, Aphelenchus) and bacterivores (21%, Eucephalobus and Panagrolaimus) became the leading trophic groups, and the values of the Shannon Index of diversity and the Maturity Index increased. The development of soil nematode populations in the early successional stages of abandoned cambisol fields in Central Europe is discussed.