New indices for quantifying the resistance and resilience of soil biota to exogenous disturbances

The stability (resistance and resilience to disturbance) of a soil system is a key factor influencing ecosystem properties and processes. To compare the stability of different systems, it is necessary to have indices that provide a relative quantitative measure of both the resistance and resilience of a response variable in all possible scenarios. However, the indices currently in use are frequently unable to do this, or are difficult to interpret. Here, we present new indices that avoid these problems. We compare our indices with previously published indices of stability, and also test their performance by using a real data set. We show that our indices accurately represent the response of soil properties (e.g. soil microbial biomass) to a disturbance, and that they are capable of determining differences in stability between contrasting soils. (C) 2004 Elsevier Ltd. All rights reserved.