engleski

Antropogenic influence on nematode communities in ecosystems

Nematode communities were used as bioindicators of changes in agroecosystems caused by antropogenic factors. The aim was to determine 1. effect of mechanical disturbances ; 2. effect of chemical disturbances ; 3. combined disturbances mechanical + chemical ; 4. differences between the treatments with and without any anthropogenic influences. Research was conducted in the year 2000 and 2001, on the area of Osijek and Kneževo. The sampling was done before and after any disturbances caused by anthropogenic factor. The treatments include nematode communities under wheat and corn with differences in tillage regimes: standard and "no tillage" . Poplar treatment was one without human impact. Total number of nematodes, number of genera, MI, PPI, PPI/MI as well as trophic structure in treatments showed the most disturbed nematode communities in treatments with mechanical and in those with mechanical + chemical disturbances. Chemical disturbances affected nematode communities less, while the poplar treatment was the least disturbed. Effect of mechanical and chemical disturbance showed differences in occurrence of some genera. Aphelenchoides was very sensitive to mechanical disturbance, while Mesodorylaimus showed tolerance. Tolerance to chemical disturbance showed following genera: Tylencholaimellus, Mylonchulus, Clarkus and Aphelenchoides. Genuses Cephalobus, Eucephalobus, Acrobeloides, Metateratocephalus and Plectus showed tolerance to both, mechanical and chemical disturbances. In all examined treatments 5 trophic goups occured. Bacterial feeding nematode and plant parasitic nematodes were most abundant, followed by fungivorous nematodes. Omnivorous nematodes and predators were present in small percentage. MI, PPI and PPI/MI, did distinguished the impact of antropogenic disturbances on nematode communities, evendo not always with stitistical significant differences.

nematode comunities ; antropogenic influence ; ecosiystems

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