Tracking ecosystem decline in an uncertain and changing alpine landscape

Abstract

This study investigated regional and site level diversity for alpine and subalpine systems. The aim was to assess whether differing analytical methods could track diversity through time. The study was undertaken within Kosciusko National Park in south-eastern Australia (6900 km²) which encompasses most of the alpine zone (~2500 km² or 48% of its occurrence on mainland Australia). Multivariate ordination, species richness and the relationship of diversity to landscape patterns were assessed and considered in relation to changes predicted to impinge upon these systems over coming decades. Species richness had limited capacity to detect predicted changes; however, ordination based on floristic patterns may have more capacity to detect change if adequate replication is applied. Complex patterns across landscapes and at the site level contributed to these analytical challenges. Species richness is commonly used to assess ecosystem status and to provide benchmark values, but it had very limited capacity to do so in the assessed alpine and subalpine ecosystems, including the most threatened. Government agencies often rely heavily on species richness to assess ecosystem change and this urgently needs re-evaluation.