DNA Barcoding to Enhance Conservation of Sunshine Coast Heathlands

Abstract

Conservation priorities and decisions can be informed by understanding diversity patterns and the evolutionary history of ecosystems, and phylogenetic metrics can contribute to this. This project used a range of diversity metrics in concert to examine diversity patterns in the Sunshine Coast heathlands, an ecosystem under intense pressure. The species richness and composition of 80 heathland sites over nine regional ecosystems of heathland on the Sunshine Coast were enhanced with phylogenetic metrics, determined by barcoding 366 heath species of the region. The resulting data were added to an existing phylogeny of regional rainforest species. The diversity metrics for sites and regional ecosystems were compared using univariate and multivariate statistics. The phylogeny from this study, and the low phylogenetic diversity of the heathlands, is consistent with the theory that heath species evolved on the fringes on a wider Australian rainforest flora. Distinctive heathland communities were highlighted, and the existence of geographically scattered, but compositionally similar, phylogenetically even sites points to a possible “refugial environment”, characterised by moisture and instability. This suggests contrasting conservation implications: the protection of distinctive communities but also the management of the dynamic processes in other wet and alluvial “refugial environments”. The potential for more focused conservation priorities is enhanced.

Abiotic correlates with diversity and distinctiveness in Sunshine Coast heathlands: Moisture, volcanic landscapes and patterned mounds

“…As well, Reside et al (2019) also advocate the identification and protection of 'refuges' which may be temporary or shifting, relieving species from stressors over shorter, spatial and ecological time scales. Given the previous finding of phylogenetic even sites in moist and wet areas in the Sunshine Coast heathlands (Pearl et al, 2022) and the possible relevance of OCBBIL theory to the montane heaths, it is expected that refugial or refuge sites may be correlated with these factors, and this would inform the ongoing protection and management of these areas.…”

“…At each site, flora species lists and plant material were collected to derive phylogenetic metrics and to explore the distribution of species across the species pool phylogeny as described in Pearl et al (2022). In brief, a three-marker barcode (rbcL, matk, trnH-psbA) was used for each Sunshine Coast heath species as a measure of genetic distance (Kress, 2017;Kress et al, 2015) to generate a rooted, dated phylogeny following the methods outlined by Shapcott et al (2015) and Howard et al (2016).…”

“…In brief, a three-marker barcode (rbcL, matk, trnH-psbA) was used for each Sunshine Coast heath species as a measure of genetic distance (Kress, 2017;Kress et al, 2015) to generate a rooted, dated phylogeny following the methods outlined by Shapcott et al (2015) and Howard et al (2016). The phylogeny for the Sunshine Coast heath included 366 species and the species list, vouchers and GenBank accession numbers are listed by Pearl et al (2022). The species lists for each site, along with the dated phylogeny, were used to calculate the diversity metrics for each site of species richness (SR), genus richness (GR) and family richness (FR); phylogenetic diversity (PD, Faith, 1992) as well as the phylogenetic dispersion metrics of mean phylogenetic distance (MPD), mean nearest taxon distance (MNTD), net relatedness index (NRI), nearest taxon index (NTI) and significant phylogenetic evenness or clustering for each site (Pearl et al, 2022;Appendix S1).…”

“…Study sites are coloured by their moisture status, as determined on site. (Pearl et al, 2022). These metrics were used in this study to explore abiotic correlates with the diversity of the Sunshine Coast heathlands.…”

“…The Sunshine Coast heathlands were defined as extending from Cooloola in the north, 150 km south to Bribie Island and west up to 30 km to Mapleton and the Glasshouse Mountains (Figure 1). Eighty sites were sampled, comprising an existing dataset of 13 sites from the Queensland Herbarium CORVEG database (Queensland Herbarium, 2019) and 67 other sites selected to encompass the range of environmental variation (Pearl et al, 2022). This study utilized our previous derived metrics of the diversity, phylogenetic dispersion and distinctiveness of the Sunshine Coast heathlands (Pearl et al, 2022).…”