Inventory and monitoring of biodiversity : an assessment of methods and a case study of Glacier National Park, MT

Abstract

Biodiversity is currently threatened around the world, yet humankind knows little about its distribution or rates of loss. Because biodiversity can be defined at the level of species, habitats, or genes, temporal changes can be assessed at several different levels. These changes may indicate responses to natural disturbances, human-induced changes, or long-term environmental trends. However, no standard analysis techniques for biodiversity assessment have yet been developed. In order to protect biodiversity or to use it as an indicator of environmental change, baseline data must be collected and analysis techniques must be developed. This research applies and evaluates sampling and analysis techniques for inventory and monitoring of biodiversity. Glacier National Park is used as a case study. Birds and butterflies were chosen to demonstrate species diversity inventory. The butterfly, Euphydryas gillettii, was used to demonstrate genetic diversity assessment. Biodiversity assessment sites were established throughout a range of habitats and monitored during the summers of 1987, 1988 and 1989. Thirty-three sites were monitored for birds and twenty-four sites were monitored for butterflies. Presence/absence sampling was used to classify species commonness and rarity. Goals accomplished included 1) describing the current species composition, 2) identifying diversity hotspots and sites supporting rare species, and 3) creating a baseline for assessing change. A discourse on biodiversity assessment would not be complete, however, without addressing the problems inherent in biodiversity assessment and management. Replication in both time and space is necessary to distinguish natural background variation in species distribution from true changes and sampling artifact. It is often difficult to reconcile the need for sampling replication within a habitat type with the need to survey a large, highly diverse ecosystem. Further, it is extremely difficult to use biodiversity as an environmental indicator unless relationships between species and environmental changes are specific and well-understood. Finally, management for biodiversity requires a large-scale perspective on ecosystem management and a modest understanding of the natural history of the species examined. Unless biodiversity assessments are done thoroughly and carefully, they will have limited descriptive or predictive value.