Arthropods as ecological indicators of sustainability in Canadian forests

Abstract

The high functional and unmatched biological diversity represented by arthropods demand that these organisms be considered as ecological indicators of sustainable forest management. Successful use of arthropods in this capacity will require a systematic and rigorous process, including selection of potential indicators, definition of relationships between indicators and disturbance variables, optimization of the useful range of the indicator and application of the indicator(s) in monitoring. In Canada, the single greatest impediment to the use of arthropods as ecological indicators is the importance of accurate species-level identification and the difficulty achieving it. Consequently, most work has focused on a few relatively well-known groups (e.g., epigaeic carabid and staphylinid beetles and spiders, saproxylic beetles, butterflies and larger night flying moths).Many recent studies have provided baseline data about the range of natural variation and have begun to quantify arthropod responses to natural and anthropogenic disturbances in the context of preplanned experiments or through various retrospective approaches. Carabid beetles are the best-studied group and sufficient sets of data now exist to permit a meta-analysis of the robustness of carabids as indicators across multiple spatial scales and in terms of how well they represent broader ecological responses to disturbances. There is good potential to incorporate arthropod indicators into monitoring programs in Canada, but it is necessary to first complete a scientifically credible selection process for specific ecological indicators. Future research should focus on completing the process for taxa under current study as this develops the best presently understood opportunities for using arthropod indicators in assessing various aspects of environmental change. Researchers should also consider other means of monitoring arthropod biodiversity by the use of surrogate ecological parameters such as ecological land classification and habitat classification systems. Key words: arthropods, ecological indicators, monitoring, biodiversity, taxonomy, sustainability