The enormous taxonomic richness of insects is indicative of their importance to every aspect of ecosystem functioning, so the big payoff from their investigation is their potential to provide understanding of not only the status of biodiversity, but also of all aspects of system processes and mechanisms. Taxonomic groups with greatest claim to 'indicate' biodiversity must be species rich, functionally diverse, relatively well understood and able to provide pragmatic samples representative of systems. Beetles fulfil these criteria and appear to provide nearly half of insect species in many if not most geographic areas. In New Zealand systems, Malaise trapped beetles taken over a four week period in summer have been found to provide samples characteristic of systems and habitats. The site specific nature of the approach enables close habitat linkages to be established and interpreted using species autecology.
Further discussion is given in the references below.
As communities change with time, monitoring requires temporal definition. Annual cycles are an appropriate first point on the time gradient. The beetle sampling time mentioned above reduces temporal variation within the yearly cycle to a level where spatial variation can be meaningfully evaluated against it during classification. System level research increasingly shows that within the abiotic environment, it is the particular biotic linkages that enable a particular configuration of life to persist. Although we may regard competition within closely related taxa to be the primary lesson from evolution, collaboration potential defines individual genotype fitness.