Figure 1. Schematic representation of proposed vegetation classification framework. This involves a greater number of more homogeneous vegetation subgroups, which are assignable to structural vegetation groups (dashed ellipses) on the basis of their structural features (represented by shared colours of the objects) and to ecological vegetation groups (dashed rectangles) on the basis of their floristic and ecological features (represented by shared shapes of the objects). Unbroken lines represent the membership of subgroups to structural and ecological groups, respectively. Hatched shapes represent vegetation subgroups with a wide range of structural expressions, and which are therefore assignable to two or more structural groups.
The potential benefits of this dual system include the following:
MVSs could be aggregated into either:
major structural groupings (consistent with the current concept of MVGs) or;
major ecological groupings,
providing users with alternative products that serve different applications more effectively than any single product could.
MVSs would be fully nested within major ecological groupings
With some relatively minor adjustments to some MVGs, revised MVSs would reduce the current overlaps whereby some MVSs are represented within multiple structurally based MVGs
Enhanced ecological homogeneity at the MVS level would facilitate:
more detailed descriptions of the units;
explicit diagnostic keys for identification; and
successful modelling of their distributions using environmental spatial data due to the tighter relationships between the occurrence of the subgroups and environmental variables.
A proposed typology of ecological subgroups and their relationships to existing structurally defined Major Vegetation is given in Table 2. The proposed subgroups are unlikely to represent the full range of variation within all major groups. Detailed recommendations for subgroup classifications within each MVG are given below. The currently proposed classification includes 82 subgroups, fewer than the notional practical limit of c. 100 units, allowing some flexibility to further resolve heterogeneous units. At this stage the proposed classification (Table 2) does not resolve major ecological vegetation groups, but such groups could be developed with a modest amount of further work. Further input and consultation with jurisdictional experts will also produce a more comprehensive typology of subgroups that corresponds well with established state typologies within a parsimonious number of approximately 100 subgroups. See detailed recommendations for each MVG for specific options to develop the subgroup level of the classification.
Table 2. Proposed subgroups within Structural Vegetation Groups (MVGs). Note: subgroups have been matched as closely as possible to existing MVS numbers, although there may be some variation in concepts (see Recommendation 3 below).
Regrowth or modified chenopod shrublands, samphire or forblands
Regrowth or modified graminoids
Other Open Woodlands
Calcareous sandplain woodlands
Tropical sandplain woodlands
Callitris forests and woodlands
Other open woodlands
Desert oak woodlands
Mallee Open Woodlands and Sparse Mallee Shrublands
Updated descriptions for Major Vegetation Groups Updated fact sheets for 30 MVGs and new fact sheets for two MVGs are given in Appendix A. The descriptions of MVGs include proposed subgroups that represent ecological variation within the structurally defined major groups (Table 2). Where appropriate, additional photographs (licensed under creative commons by attribution) have been added to illustrate the range of variation within MVGs. In some cases, existing photos have been replaced to give a more balanced illustration of characteristic vegetation within an MVG. For example, the existing fact sheet for MVG 22 included two photographs of alpine herbfield and bolster heath, yet a large majority of the mapped distribution of MVG 22 comprises arid chenopod shrublands. In this case, the alpine photos were replaced with photos showing the range of variation in chenopod shrublands (see also specific recommendations below for MVG 22).
Diagnostic keys for subgroups within Major Vegetation Groups Dichotomous keys to assist the identification of subgroups within each Major Vegetation Group are presented in Appendix B. These require testing and refinement to ensure optimal reliability of identification outcomes.
Recommendations Strategic development of the classification system The following recommendations are to support development of the Major Vegetation classification system to serve traditional and emerging needs. Some may be implementable over relatively short time frames. Others may be implemented over medium time frames as resources permit.