NEMATODE POPULATIONS AS INDICATORS OF SOIL STATE: LIMITS AND PROSPECTS

摘要

This paper focuses on the often overlooked, but fundamental difference between (1) proving "forward" the effects of environmental or anthropogenic impacts on soil nematode populations, and (2) inferring "backward" the operation of such impacts in the soil from changes in nematode populations. Numerical simulations are used to illustrate that the forward detection of effects on nematode populations can be achieved with a standard sampling design, whereas the backward prediction of an unknown impact from observations on nematode populations requires extraordinary effort in order to obtain a reasonable level of accuracy. It is concluded that in the majority of empirical investigations, successful bio-indication is confined to the forward mode, i.e., to analysing the biological and ecological consequences of known impacts.