Commonwealth of Australia

Inclusion of ecological communities in the list of threatened ecological communities under section 181 of the Environment Protection and Biodiversity Conservation Act 1999

I, PETER ROBERT GARRETT, Minister for the Environment, Heritage and the Arts, pursuant to section 184(1)(a) of the Environment Protection and Biodiversity Conservation Act 1999, hereby amend the list referred to in section 181 of that Act by:

including in the list in the endangered category

Alpine Sphagnum Bogs and Associated Fens

as described in the Schedule to this instrument.

Dated this…seventeeth.....................day of…........December................2008

Peter Garrett

Minister for the Environment, Heritage and the Arts

SCHEDULE

Alpine Sphagnum Bogs and Associated Fens

The Alpine Sphagnum Bogs and Associated Fens ecological community occurs primarily within the Australian Alps, the Tasmanian Central Highlands and the Tasmanian Southern Ranges IBRA bioregions.  It is also found in a small area of the Bondo subregion of the South Eastern Highlands IBRA bioregion on mainland Australia, and may be present within the Ben Lomond and Tasmanian South East IBRA bioregions in Tasmania.  The ecological community occurs in small pockets across Tasmania, Victoria, New South Wales and the Australian Capital Territory. 

Although it is not always the dominant genus, the Alpine Sphagnum Bogs and Associated Fens ecological community can usually be defined by the presence or absence of Sphagnum spp., the most common of which is Sphagnum cristatum.  The absorptive properties of Sphagnum spp. and the underlying peat regulate the lateral spread of moisture within this ecological community and ultimately define its boundaries.  A common definition of a ‘Sphagnum bog’ ecological community is one where Sphagnum spp. cover more than thirty per cent of the ground.  However, there are some sites in the Alpine Sphagnum Bogs and Associated Fens ecological community that are dominated by shrubs or Restionaceae spp., where Sphagnum spp. are only a minor component, and others where Sphagnum has been depleted or lost due to disturbance.  In these cases, the site may still be considered to be part of this ecological community if other key species are present (see Table 1) and a peat substratum is evident. 

Bogs are found in permanently wet areas, such as along streams, valley edges and valley floors.  They are also situated on slopes where soils are waterlogged.  The key to bog formation is a good supply of groundwater and an impeded drainage system that keeps the water table at or near the surface.  Under these conditions, the decomposition of organic materials is incomplete, eventually forming the peat that underlies the Alpine Sphagnum Bogs and Associated Fens ecological community. 

The Alpine Sphagnum Bogs and Associated Fens ecological community contains a number of recognised variants, changing in a predictable progression from the hillsides down to the valley floor.  Permanently wet slopes provide suitable habitat for the growth of Epacris spp. shrubs.  Along with Sphagnum spp., these plants form a slightly domed ‘raised’ bog.  This is a dynamic community which oscillates through a cycle of herbs and shrubs on the hummocks and hollows which characterise this landscape.  At the edges of valleys, Carex sedges may replace some shrubs.  In these locations, the vegetation forms a flatter, more concave ‘valley’ bog.  In the wettest areas, generally along watercourses or on valley floors, semi-permanent to permanent pools of surface water, commonly referred to as fens, can be found.  These conditions do not favour the growth of Sphagnum spp., so here the ecological community is dominated by sedges.  The vegetation of these fens is distinct from the surrounding bogs, but due to the ecological interdependence of the two communities, they are considered as inseparable in the current context.  It should also be noted that whilst fens do occur within other alpine and subalpine ecological communities, such as Epacris glacialis heathland, these other fens are floristically different and are not included with the community currently being considered. 

Alpine Sphagnum Bogs and Associated Fens ecological community can be found across alpine, subalpine and montane environments, often (but not always) above the climatic treeline.  The climatic treeline is generally identified as the 10ºC isotherm (average summer temperature), which marks the point above which trees do not survive.  From a geographical perspective, alpine and subalpine regions are found above 1600 metres above sea level (asl) on the mainland, and above 800 m asl in Tasmania. 

However, it is important to note that the climatic treeline and the limit of tree vegetation are variable depending on topographic features and localised climatic conditions such as the degree of cold air drainage at individual sites which may prevent the growth of trees.  Inverted treelines are common.  Consequently, the Alpine Sphagnum Bogs and Associated Fens ecological community also occurs at sites with lower elevations, where local conditions and vegetation are equivalent to those of true ‘alpine’ sites.  The ecological community is known to exist at 1200 m asl in Victoria and as low as 1000 m asl in parts of the ACT and NSW, even though these locations are geographically montane rather than alpine or subalpine. 

Table 1. Typical native plant species found in alpine sphagnum bogs and associated fens

This list is only indicative of plant species common to alpine bogs and fens, and as such, is not comprehensive. The plants identified below may not occur in every alpine bog, and other species may also be present.              

Table 1 (continued)