Diversity of the Microorganism Population

Coleman [23] states that the composition of the microorganism community in soil (but it should be valid for sediments too) changes if organic material is introduced (leave litter, crop residues or organic fertilisers). Depending on the chemical nature of the introduced material some species are supported and others will be suppressed. That is a natural phenomenon, which happens several times or at least once a year in every natural ecosystem. 

If biodegradable materials are introduced to an ecosystem nothing different should happen. But consider that any shift of the population may activate certain microorganisms, which can be pathogenic to crop plants or soil animals. That whole paragraph should be seen as theoretical derivation as far as no specific literature is available dealing with such effects caused by synthetic polymers. It was intended to mention the possibility but the appearance should be confirmed or excluded either in ecosystem level tests or in real scale experiments. 

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