CHARACTERIZATION OF NEMATODE COLONIZATION AND SUCCESSION IN DISTURBEDSOIL USING THE MATURITY INDEX

Nematode colonization and succession were studied over 60 weeks in fie ld plots which had been disturbed by combinations of fumigation and ma nuring. It was expected that the Maturity Index, which is based on the composition of the nematode fauna, would decrease after disturbance, and subsequently increase with recovery and succession. The results sh owed that in all treatments, the initial colonization and growth were due to taxa scaled in colonizer-persister (c-p) group 1, resulting in a low Maturity Index. An increase in this index followed when these ta xa were gradually replaced by c-p group 2 which thereafter remained th e dominant group. C-p groups 3-5 developed only in the non-fumigated t reatment. Manuring caused characteristic changes in the nematode fauna which could be described as a cycle, starting with an increase in enr ichment opportunists (c-p 1), which were succeeded by general opportun ists (c-p 2) which, in turn, were supplemented with persisters (c-p 3- 5). It is expected that the same cycle will be observed as a result of other disturbances that cause temporary increase in food supply.