Biological assessment of wetlands:testing techniques - preliminary results

Abstract

To protect and manage wetlands there is a n eed for scientifically rigorous and reproducible techniques to assess their ‘health’ or ‘condition’. Any technique must be tested for robustness of method on a range of wetland types. Optimum sampling methods need to be assessed, for example, the relative benefits of cover class versus presence/absence; the consequences of misidentification at the species level, genus level and at the native versus introduced level; and the comparisons of results from using identifications above the species level as input data. The different methods now in use need to be reviewed and compared to determine whether they are additive (i.e. the corroborate) or contradictory or whether they each perform better under certain conditions. We need to be able to compare assessments using different methods on the same wetland over time. This project aims to address these questions. Early results show a large difference in species area curves for plant sampling from different wetlands, and difficulties in adapting published invertebrate sampling methods (AUSRIVAS) for wetlands, making it clear that one ‘standard’ method may never be enough. The ideal outcome of this project will be a list of methods to choose from for various situations.