Montane mire vegetation of the New England Tablelands Bioregion of Eastern Australia

Vegetation Classification and Survey 1: 37–51 doi: 10.3897/VCS/2020/48765 International Association for Vegetation Science (IAVS) RESEARCH PAPER Montane mire vegetation of the New England Tablelands Bioregion of Eastern Australia John T. Hunter1, Vanessa H. Hunter2 1 School of Environmental and Rural Science, University of New England, Armidale, New South Wales, Australia 2 Hewlett Hunter Pty Ltd, Armidale, New South Wales, Australia Corresponding author: John T. Hunter () Academic editor: Jürgen Dengler ♦ Received 28 August 2018 ♦ Accepted 18 November 2018 ♦ Published 4 May 2020 Abstract Aims: To use unsupervised techniques to produce a hierarchical classification of montane mires of the study region. Study area: New England Tablelands Bioregion (NETB) of eastern Australia. Methods: A dataset of 280 vascular floristic survey plots placed across the variation in montane mires of the NETB was collated. Vegetation types were identified with the aid of a clustering method based on group averaging and tested using similarity profile analysis (SIMPROF) and through ordinations using Bray-Curtis similarity and non-metric multidimensional scaling (NMDS). A hierarchical schema was developed based on EcoVeg hierarchy and was circumscribed using positive and negative diagnostic taxa via similarity percentage analysis (SIMPER) and importance based on summed cover scores and frequency. Results: We defined one macrogroup to include all montane mire vegetation of the NETB and within these two groups and twelve alliances. Conclusions: Our study re-enforced the separation of bogs from other montane mire systems and confirmed the separation of fens and wet meadows, a distinction that previously had not been independently tested. Based on our results many existing montane mire communities of the NETB have been ill-defined at multiple hierarchical levels, leading to confusion in threat status and mapping. Additionally, nearly half of the alliances we recognise were found to have no correlates within current classification systems, which necessarily has implications for the effectiveness of current conservation planning. Taxonomic reference: PlantNET (http://plantnet.rbgsyd.nsw.gov.au/, accessed June 2016). Abbreviations: BC Act = Biodiversity Conservation Act; EPBC Act = Environmental Protection and Biodiversity Act; NETB = New England Tablelands Bioregion; NMDS = non-metric multidimensional scaling; PCT = plant community type; RE = regional ecosystem; SIMPER = similarity percentage analysis; SIMPROF = similarity profile analysis. Keywords Australia, bog, EcoVeg, fen, marsh, New England Tableland Bioregion, similarity percentage analysis (SIMPER), wet meadow, unsupervised classification Introduction The first step in understanding the distribution, rarity and interrelationships of vegetated systems is description and classification (Franklin et al. 2016; Jensen et al. 2016). This is particularly true for systems that are under greatest threat and impact from human activities and which provide significant ecosystem services. Unfortunately, vegetation within many areas of the globe have poor sur- vey coverage and/or inconsistent survey protocols, leading to insufficient or poor data hampering classification (Gellie et al. 2017; De Cáceres et al. 2018). Even within areas considered relatively well surveyed, many highly restricted and/or ephemeral systems are likely to be poorly sampled and incompletely treated within current classification systems, leading to misunderstandings of their Copyright John T. Hunter, Vanessa H. Hunter. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. 38 John T. Hunter & Vanessa H. Hunter: Montane mires of New England Australia placement, function, importance and rarity (Hunter and Hunter 2017; Hunter and Lechner 2017). Not all classification systems are hierarchical in nature, and many have no clear analytical proof of conceptual links (De Cáceres et al. 2018; Gellie et al. 2017). Ideally, hierarchical classification systems facilitate integrated understanding of relationships between vegetation assemblages and also allow conceptualisations at different ranks to match scales at which management and investigations may be applied, from local to global (Faber-Langendoen et al. 2018). Australia is a dry continent, and thus, the more common and widely distributed wetlands are those that are impermanent in nature; that is, they may ‘wet-up’ once a year, multiple times a year or once within several decades, often not associated with seasonal patterns, but are dry more often than they are wet (Paijmans et al. 1985; Bell et al. 2008; Bell et al. 2012; Hunter and Lechner 2017). Such wetlands may contain shallow water less than 2 m depth, but more commonly only have saturated soils or seasonally standing water a few centimetres depth. Montane areas within Australia are limited and thus montane wetlands, in particular, are sparsely distributed and rare within the continent and poorly sampled across their range (Wahren et al. 1999; Whinam and Hope 2005). The montane region bordering northern New South Wales and south east Queensland has been defined as the New England Tableland Bioregion (NETB) based on its unique biological and environmental elements (Thackwell and Creswell 1995). The Hunter Valley to the south of the NETB creates a break in the Great Dividing Range and separates the NETB from more southern montane environments in south eastern Australia. Within the NETB a number of semi-permanent and ephemeral mire systems locally known as bogs, fens, lagoons (marshes) and sod tussock grasslands (wet meadows) occur (Hunter and Bell 2007; 2009; Bell et al. 2008; Hunter and Hunter 2016a). Whinam and Chilcott (2002) showed through unsupervised analyses of floristic plots that the NETB bogs were dissimilar floristically from other montane bogs further south in eastern Australia. Hunter and Hunter (2016) also highlighted the distinct floristic differences between montane sod tussock grasslands (wet meadows) and those of other south eastern Australian montane districts. Lechner et al. (2016), in an analysis of environmental data associated with montane wetlands, found the NETB was largely encompassed by a unique montane wetland ecoregion. Bogs of the NETB are characterised by altitudes above 850 m a.s.l, commonly on nutrient poor sites with low pH, saturation occurring seasonally or sporadically, and shallow standing water infrequent (Hunter and Bell 2007) (Suppl. material 1: Plate 1). Peat often forms but is largely created by sedge debris and at times Sphagnum (Hunter and Bell 2007; Hunter and Bell 2013; Hunter 2016a). Due to frequent fires, peat accumulation is often thin but can develop to depth where fires are excluded for long periods of time (Hunter and Bell 2007) (...truncated)