The inventory of bryophytes at sites: completeness and survey effort

Abstract

Knowledge of the species present within a site is often used to inform decisions that have significant implications for biodiversity conservation. This study surveyed eight woodland sites in north-west England for bryophytes. Searches for species within each site continued until all areas had been approached to within a minimum of 50 m and at least 60 minutes had elapsed since the discovery of a new species. Survey data were used to build predictive models that provided an estimate of the total number of species present at each site and the time required to compile a complete inventory. The ‘50 m 60 minutes stopping rule’ consistently produced comprehensive inventories for sites, judging by the numbers of species found and model predictions of the total number of species present. The study suggests that a minor alteration to conventional survey practice and a small amount of data analysis can provide useful assessments of the completeness of bryophyte inventories for sites.