Ants (Hymenoptera: Formicidae) pass the bioindicator scorecard

Majer, J.D.; Orabi, G.; Bisevac, L.

Abstract: Invertebrates are increasingly being used as biological indicators of land restoration success, land degradation, the conservation value of tracts of land, and much more. They are either used as indicators of the health and functioning of the environment (ecological and environmental indicators) or as surrogate indicators of the overall diversity or assemblage composition of other groups within an area (biodiversity indicators). In both cases, the particular taxonomic group that is used tends to be related to the preference of the researcher or to currently favoured taxa. This paper summarises the findings from two field studies that evaluated how well a series of invertebrate taxa performed as environmental or biodiversity indicators in regard to each other, and also to vertebrates and plants. These studies were performed on restored bauxite and mineral sand mines in Western Australia. At the bauxite mine, assemblage composition of spiders, true bugs (Hemiptera) and beetles tracked biophysical changes in the environment more faithfully than did birds, although the performance of plants was the best, and terrestrial vertebrates and ants were intermediate. Assemblage composition of ants, and to a lesser extent true bugs, beetles, and spiders all reflected trends in the composition of other groups to a greater extent than did plants, terrestrial vertebrates and birds. In terms of data-yield per hour spent in field and laboratory, most invertebrate groups represented a better return for effort than did terrestrial vertebrates, but not plants. Trends were similar at the Iluka mineral sand mine. Overall, taking into account the data-yield per hour of effort, and the problem of dealing with immature forms in the case of spiders and true bugs, we conclude that ants perform moderately well as environmental, and extremely well as biodiversity indicators. The applicability of these results to other regions of the world and to other land-uses is discussed.

Myrmecol. News 10: 69-76; printable