Ants as bioindicators of soil function in rural environments

Farmers are being encouraged to redress the problems of land degradation by implementing a series of changes in their land management. However, there are few tools to monitor soil condition which can reliably inform farmers of the state of their soil. This paper examines ants and their importance in ecosystem functioning, principally their ability to maintain or restore soil quality in rural environments, and their value as bioindicators of soil quality. The reader is provided with a summary of those studies which have recorded the species composition and activity of ant fauna in agricultural soils and naturally vegetated environments. However, it is rare to find studies which sample both environments concurrently. An overview of the types of measures available to assess ant biodiversity is followed by a discussion of the current status of biopedological research into ant-soil relationships and the trends and gaps in current research knowledge, principally in the areas of water and soil movement and nutrient effects. Lastly the paper seeks to forecast the future directions of ant biopedological research, and to identify the type of research required to fully appreciate the value of ants as soil quality indicators to monitor the sustainability of the soil resource. Ants should be considered an important group of soil fauna, yet they have received meagre attention in comparison with other soil fauna such as earthworms. There is a need for specific experiments to test the hypothesis that ants can be used as bioindicators of soil quality. (C)1999 Elsevier Science B.V. All rights reserved.