Fluctuations of nematode populations in pine forest soil. Influence by clear-cutting

The dynamics of nematode populations following clear-cutting of a pine forest stand in central Sweden were recorded during two periods: 1-5 years and 14-19 years after the cutting. The effects of slash removal were included in the study. The fluctuations in animal abundance were great during the first period and several species increased in numbers especially in plots with. slash. During the second period most taxa occurred in lower abundance in the cut area than in a forested reference stand. The rates of increase or decrease of various species and genera were compared to a classification of nematodes (c-p scale) used for calculation of the maturity index (MI), which is used to indicate soil disturbances. It was concluded that clear-cutting is a kind of disturbance which promote nematode species that tolerate harsh climatic conditions. Several genera and species that generally increase after other types of disturbances such as forest fertilization decreased in the cut area. This gives a type of response of MI in the cut area, which does not correspond to model predictions.