Assessment of the Central Highlands flora has involved an analysis of the distribution and viability of individual species and their populations within the region. The purpose of this assessment is to assist in determining whether:
viable populations of all terrestrial and aquatic plant species are maintained throughout their natural range in the region;
representative populations of each species are included in the reserve system; and
populations and their habitats both within and outside the reserve system are subject to management appropriate for their long-term maintenance.
A total of approximately 2,000 species of vascular plants have been recorded for the Central Highlands region, including 67 species of conservation significance and 500 exotic species.
5.1.1 Priority flora species
The focus of assessment of flora species in the Central Highlands has been on those taxa which have been identified as being at risk because of rarity, depletion or the continued action of threatening processes. Rare or threatened species are often at the forefront of the debate regarding the balance between conservation and resource utilisation. They are significant because their intrinsic value as unique forms of life and their potential utility is enhanced by their rarity and the higher likelihood of their permanent loss. In addition, the fate of rare or threatened species may also indicate the health of the ecosystems and communities on which they depend and the direct or indirect impact of human activities on these ecosystems and communities.
Rare or threatened plants may exhibit a range of life histories, life-forms, reproductive strategies and distribution patterns. Included among the plants considered rare or threatened in the Central Highlands region are:
long-lived trees and short-lived herbs;
endemics which may be locally abundant but occur in a restricted area and those which occur over a large area but are rarely common;
sub-alpine and lowland species;
forest-dependent species, grassland species, heathland species; and
species which are naturally rare but appear stable and species which were more common at the time of European settlement but which have declined significantly since, usually as a result of habitat loss or degradation.
This review of the conservation of rare or threatened species in the Central Highlands region addresses:
plants listed as threatened under the Victorian Flora and Fauna Guarantee Act 1988 (FFG Act),
plants listed as presumed extinct, endangered or vulnerable under the Commonwealth Endangered Species Protection Act 1992 (ESP Act),
plants included in the Victorian Rare or Threatened Species list for plants (VROTS), and
plants included in the national list of Rare or Threatened Australian Plants (ROTAP) (Briggs and Leigh 1995).
Non-vascular plants have not been considered in this assessment, nor have those taxa where their continuing occurrence within the Central Highlands could not be confirmed in terms of accurate identification or location, or where they are hybrids.
5.2 Life history and population parameters for priority flora species
5.2.1 Assessment methods
For each of the plants evaluated in this review, the following questions were considered:
how abundant is the plant, in which habitat(s) does it occur, and what is its pattern of distribution;
how vulnerable is it to further decline and extinction; and
NRE databases, expert opinion and available scientific literature were used to compile the following information for each species: conservation status (according to each of the lists mentioned above); the approximate proportion each species’ total Australian range that occurs within the Central Highlands region; the number of Victorian and Central Highlands records held within NRE databases; the number of populations and individuals known to occur in the Central Highlands region; any trends which may be apparent in the demography of the plant; the geographic range of the plant within the Central Highlands region; the locations of the largest number and the second largest number of individuals in regard to land tenure, (based on records confirmed within past 10 years) within the Central Highlands region.
The land tenure categories used are conservation reserves (National Parks, State Parks, Flora Reserves, Flora and Fauna Reserves), other public land (State forest including Special Protection Zone, Special Management Zone and General Management Zone, public land reserved for other purposes and uncommitted public land), and private land.
These data are presented in Table 5.1. More details for plants listed under the FFG Act or ESP Act can be found in Appendix E.
It should be noted that while a number of species are listed as being found on ‘other public land’, the Ecological Vegetation Class in which they occur are not suitable for timber harvesting or are riparian vegetation types which are excluded from timber harvesting.
5.2.2 Patterns of abundance, distribution and habitat
Several distinct groups of plants emerge when considering abundance, distribution and habitat:
Plants of sub-alpine habitats which are highly localised and naturally rare
In the Central Highlands, sub-alpine habitats are restricted to the Baw Baw Plateau, Lake Mountain, Mt Bullfight and Mt Torbreck. Such habitats are also relatively uncommon in Victoria and Australia in general, and therefore tend to support a higher proportion of rare or threatened plants than more common and/or extensive habitats. In the Central Highlands, such plants include Richea victoriana, Tasmannia vickeriana, Monotoca oreophila, Coprosma moorei, Coprosma perpusilla var perpusilla, Brachyscom obovata, Erigeron pappocromus var oblongata, Epacris glacialis, Epacris coriacea, Lycopodium scariosum, Juncus antarcticus and Mitrasacme montana.
Plants of moist forests which are endemic to the Central Highlands and which may be locally common
Any region of the size of the Central Highlands is likely to contain the major populations of plants which have adapted to the prevailing environmental conditions to the point where they may be locally common, but which are nevertheless considered rare on a statewide basis. Included in this category are Persoonia arborea, Wittsteinia vacciniacea, Carex alsophila, Oxalis magellanica and Lastreopsis hispida. Table 5.1: Conservation Status and Distribution of Rare or Threatened Plants in the Central Highlands Regional Forest Agreement region
(a) Plants listed as threatened under the Commonwealth Endangered Species Protection Act 1992
Notes: ‘reject’ in FFG column indicates species considered for listing but rejected by the FFG Committee as not meeting criteria.
ROTAP categories: R - rare; V - vulnerable; E - endangered; K - insufficiently known.
VROT categories: e - endangered; v - vulnerable; r - rare; d = depleted; k - insufficiently known.
Plants which are widespread but rarely common
Wet forests and rainforest
These plants typically have narrow habitat requirements - fern gullies, rainforests - but may occur in other regions where these habitats are found, such as East Gippsland, the Otways and Tasmania. Included in this category are Tmesipteris spp, Huperziavaria, Cyathea cunninghamii, Thismia rodwayi and Gahnia grandis.
Dry and damp forests
Several rare or threatened species of dry forest habitats occur sparsely in the Central Highlands: Ozothamnus rogersianus, Lindsaea microphylla, Acacia howittii, Eucalyptus neglecta, Eucalyptus alligatrix and Pteris comans.
Plants of moist forests which are Central Highlands endemics and occur in a few, scattered populations
Some of the rare or threatened plants of the Central Highlands appear never to have been common, even though their preferred habitat appears to be relatively common. Subtle but critical habitat differences may in part explain this phenomenon, as might elimination from suitable habitat by one or a series of catastrophic events. Included in this group are Eucalyptus crenulata, Astelia australiana, Grevillea barklyana ssp. barklyana and Phebalium wilsonii.
Plants of a variety of habitats which are marginal to the Central Highlands
Habitats such as grasslands, grassy woodlands and riverine plains occur within the Central Highlands region, but are marginal to it, being more widespread beyond the region. Several of the rare or threatened species being considered here occur in these habitats including - Senecio macrocarpus, Senecio laticostatus, Hypsela tridens, Carex tasmanica, Cullen tenax and Amphibromus fluitans.
Plants of habitats which have been depleted in the Central Highlands
At the time of European settlement, the Central Highlands contained a range of vegetated habitats such as river valleys and lower slopes which have been substantially cleared in the intervening period. Notable in this context are the lower sections of the Yarra, Goulburn (including the Yea and Acheron valleys) and La Trobe Rivers. Plants which occurred in these habitats are more likely to be rare or threatened species as a result of the clearing. Included in this category are Eucalyptus yarraensis, Eucalyptus strzeleckii, Epilobium pallidiflorum, Pultenaea weindorferi and Burnettia cuneata.