Ref ID : 6176
Robert McSorley and John J. Frederick; Effect of extraction method on perceived composition of the soil nematode community. Applied Soil Ecology 27:55-63, 2004
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Methods for extraction of nematodes from soil vary in their efficiency and therefore may affect perception of nematode community structure. An active extraction method (Baermann incubation) was compared with a passive method (centrifugation) for all taxa of the nematode communities in sandy soils in five experiments. Baermann incubation recovered only 30% of the numbers of herbivores recovered by centrifugation, and was particularly inefficient for recovery of Acrobeles, Alaimus, Hemicriconemoides, Hoplolaimus, and Mesocriconema. In contrast, centrifugation recovered only 22% of the number of omnivores and 12% of predators that were extracted by Baermann incubation, and was inferior in recovery of Aphelenchoides, Eudorylaimus, Nygolaimus, Tylencholaimellus, Tylencholaimus, and Xiphinema. Percent composition of the nematode community was consistently affected by extraction method, with a higher percentage of omnivores and predators recovered by Baermann and a higher percentage of herbivores recovered by centrifugation. A combination of extraction methods is proposed to optimize recovery efficiency for every taxon in the community. Baermann incubation for 96 hr, rather than 48 hr, increased the detection of uncommon taxa in samples.