Contents
1. Introduction to Bioregions
3.
The Ecological Vegetation Classes of the Strzelecki Bioregion
3a. The major Strzelecki
forest types
3b.
The other Strzelecki forest types
4.
Strzelecki Bioregion Vegetation Maps
Bioregion is a shortening of
the term Bio –Geographic Regions. They are a way of dividing the land up
into regions on the basis of geographic and natural characteristics. There are
solid physical and natural features that set bioregions apart. Shire
boundaries, State borders, and other political and administrative boundaries do
not apply. Bio-Geographic regions are used as the natural framework for
recognising and responding to biodiversity values and to provide a regional approach
to conservation. In other words, when looking at and dealing with conservation
of native flora and fauna across the country, the best way of dividing the
country up into sections is to use Bioregions.
Bioregions developed from
IBRA regions: Interim Bioregionalisation for Australia. These were developed in
1995 at the request of the
Australian and New Zealand Environment Conservation Council (ANZECC).
The RFAs and the Regional Native Vegetation Plans brought about a great deal of refinement of maps and data regarding our biodiversity, and as things progressed, things were assessed more and more on a Bioregional basis. Boundaries were adjusted, some bioregions were split into two, and the facts and figures became more refined. It showed that of the 22 Bioregions in, or partly in Victoria, 9 retain more than 75% of original vegetation cover, but 13 retain less than 35% of original vegetation cover
As well as simply being a
basis for cataloguing data, Bioregions became the basis by which to assess
whether or not we had enough of our natural areas protected in reserves
A document called the
“Nationally agreed criteria for the establishment of a Comprehensive,
Adequate and Representative reserve system for Forests in Australia,
1997” was published, setting out targets for reserves. This was adopted by the State and Federal
Governments It required
“that the reserve system should sample each forest ecosystem within a
region", and set percentage targets for reserves, as well as a list of
other criteria that must also be considered.
Its known as the CAR
criteria.
Botanists were set the task
of defining “each forest ecosystem” and attempting to classify all
of our native vegetation accordingly . Different native vegetation communities
were now known as “Ecological Vegetation Classes” or EVCs for
short.
It all comes together in
the form of spreadsheets, maps and EVC descriptions. The spreadsheet lists all
the EVCs for each bioregion. For each EVC, the spreadsheet indicates how much
they think there used to be; how much there is left; how much is in reserves,
on unreserved public land, or on private land; how much needs to be in reserve
(using CAR criteria), as well as targets for potentially extending the range of
threatened EVCs. The maps show where all these EVCs are and the EVC
descriptions refer everything back to the natural elements that distinguishes
this particular EVC.
In
West Gippsland, the bioregions are set out like this
The Gippsland Plains is
shown in Grey. About 20% of the
bioregion retains native vegetation.
The Strzelecki Ranges is shown in purple
About 20% of this bioregion
retains native vegetation also.
The other bioregions
within (or partially within) the West Gippsland Region have retained more than
80% of their vegetation cover
The
Strzelecki Bioregion is basically the Strzelecki Ranges. Botanically, there is
some overlap between the forest types in the Strzelecki foothills and the
surrounding Gippsland plains, but at higher elevations, the Strzelecki
vegetation becomes distinct.
The
Strzeleckis was once totally forested, with little in the way of woodland,
grassland, shrubland, or wetland, etc. It is a cool temperate area with most
areas receiving at least a Metre of rain in a year.
There
appears to be ongoing fine tuning as to the exact borders of the Bioregion, but
basically they are set where the hilly land reaches down to meet the flat land
of the surrounding plains
At last count the
bioregion covered approximately 340,000 ha.) is the fifth most depleted
bioregion in the state, and the most depleted forest bioregion in the state.
It also has the lowest
amount of reserves in the State in terms of % of total area (under 2%), % of
current extent (around 7%), and in terms of number of EVCs adequately
represented in reserves (nil, save for 2 ha. Of Coast Heathland Scrub). The
percentage of Public land in reserves (around 7%) is also well below state
average (around 49%)
The current extent of
native vegetation remnants in the Strzelecki Ranges Bioregion is something in
the order of 60,000 hectares (more if hardwood reforestation is included). This is roughly 19% of the original
extent of native vegetation for the whole bioregion. Wet Forest, Rainforest (cool temperate and warm temperate),
and Damp Forest make up 50,000 hectares.
The remaining 10,000 hectares is predominantly Shrubby Foothill Forest,
Herb-rich Foothill Forest and Lowland Forest.
Despite it being a heavily
depleted Bioregion, the majority of the remaining native vegetation forms a
reasonably continuous mass following the upper parts of the Eastern Strzelecki
Ranges. This takes in the vast
majority of the Wet, Damp and Rainforest, which in many cases join and
interlink. Many of the other EVCs
occur in a more isolated state, more than half of which are scattered
throughout the Eastern Strzelecki foothills.
The Eastern Strzelecki
Ranges, which represent around half of the Bioregion contain more than 90%
of the remaining Wet Forest and Rainforest; more than 80% of the remaining Damp
Forest and more than 50% of the areas covered by the other extant EVCs. In all, some 50,000 hectares of the
bioregion’s 60,000 hectares of the remaining native vegetation. Of this, around 30,000 ha is on Public
and leased Public Land
The Western Strzelecki
Ranges has a very small proportion of public land and a small proportion of
native vegetation left (around 10,000 ha.). However, the remnants that do exist are significant. Around
half is on public and leased public land.
The
Ecological Vegetation Classes of the Strzelecki Bioregion
The Major
Strzelecki Forest Types
Around 94% of the Strzeleckis
carried 7 main forest types.
All except Lowland forest
are vegetation types which form on hills and mountains and as such don’t
occur, or are far less likely to occur on the surrounding Gippsland Plains.
Lowland Forest, however, occupied vast areas of the Gippsland Plains, but
comfortably covered a significant area of the Strzeleckis as well, around much
of its lower lying fringes.
31 Cool Temperate
Rainforest 1888 ha, now 494 ha.
Described by some as a
Gondwanaland relic
Upper reaches of ranges,
usually in gullies. Replaced by Wet Forest in some cases, due to human
interference, but equally capable of reclaiming areas of wet forest over time
Great examples are to be
found throughout the upper Eastern, such as the Franklin, Agnes, Jack, Tarra,
Morwell River Gullies.
30 Wet Forest 82034.,
now 37646 + reforestation
This is the only EVC in the
Bioregion not considered threatened or rare, due to there being about half
left.
Trees of several kinds grow
taller or larger than in other forest types Upper reaches, extensive. Mountain
Ash, Blackwood Wattle, Hazel, Tree ferns of all kinds, etc…..
Great examples are to be
found throughout the upper ranges, especially the Eastern Ranges.
29 Damp Forest
76,773 Ha, now 10,500 ha.
Occurs at drier edges of wet
forest. Trees less tall. Less Ash, but more of the other types of Eucalypts. In
gullies of lower ranges
Species? Where?
32 Warm Temperate
Rainforest 3084 ha. , now 93 ha.
Red
Small pockets throughout, at
all elevations, adjacent to many other forest types
In valleys. Capable of
re-establishing itself without any help and relatively quickly.
45 Shrubby Foothill
Forest 86972 ha., now 346 ha.
Hallston, Mirboo Nth
Vicinity, Dickies Hill…
Occupied much of the tops of
hills in the less lofty parts of the ranges, with adjacent valleys carrying
Damp, Wet or Riparian forest types.
…. Narrow leafed
Peppermint, Messmate, Mt Grey Gum, Silvertop, Narrow leafed Wattle, Handsome
Flat Pea. Ground layer poor apart from Bracken, Ivy Leafed Violet, Tall Sword Sedge,
Wiregrass. Little remains of this once extensive Forest type
23 Herb Rich Foothill
Forest 9884 ha. , now 1703 ha.
Morwell NP, Boolarra,
Woomera to Alberton West.
Lower rainfall areas.
Absence of ground ferns. Yellow Stringybark, Bluegum, Varnish Wattle, Clematis,
Wonga, bracken, and many grasses. Related to Shrubby Foothill Forest but with less shrubs and a richer layer of lower,
ground dwelling plants instead.
16 Lowland Forest 21420 ha., now 8757 ha.
Prevalent on surrounding
plains, overlapping into low parts of Strzelecki Ranges. Hallston??, Mirboo Nth
Area has good examples. Low to intermediate rainfall.
Messmate, Grey Gum,
Peppermint, Yertchuk, Swamp Gum, Wattles, Hairpin Banksia, Bushy Hakea
The other Strzelecki forest types
The remaining 6% of the
bioregion carried the following EVCs
Riparian
and Swamp Vegetation of various
kinds made up around 13000 ha. Riparian zones are the thin strips of land
either side of a waterway. There are hundreds, possibly thousands of kilometres
of waterways in the bioregion, but these strips of riparian land are very
narrow and barely show up on maps.
In the upper reaches of the
ranges much of the network of riparian zones is under vegetation classed as Wet
Forest, Damp Forest or Rainforest. In the lower reaches, these riparian zones
had / have vegetation types which have been classed as follows:
123 Riparian Forest /
Warm Temperate Rainforest mosaic
1932 ha., now 0Ha.
Particularly NE of Welshpool
126 Swampy Riparian
Complex 6557 ha., now 151 ha.
Warragul and Thorpedale and
north of Toora – Poor drainage areas of Wet and Damp Forest on Red Soil.
Swamp Gum, Blackwood, Swamp and Scented Paperbark, hazel, hop, prickly currant,
soft tree fern, ferns and sedges, herbs
83 Swampy Riparian
Woodland 2583 ha., now 0? ha.
Formerly?? found in Powlett, Tarwin, Flynns and
Morwell streamsides
53 Swamp Scrub 1937 ha., now 171
ha. Found in parts of the lower slopes of the Strzeleckis where seepage occurs,
adjacent to Lowland Forest.
Swamp Paperbark overstorey. Small patches close to plains.
18 Riparian Forest
104 ha., now 45 ha. Tall on
river flats, terraces or perennial streams, across many elevations. Manna,
Messmate, Wattle Blackwood, tall shrubs common to Wet and Damp
17 Riparian Scrub 36 ha., now 103 ha.
639 Swamp Scrub /
Plains Grassy Forest Mosaic 125
ha., now 0 ha ?
688 Swampy Riparian
Woodland / Swamp Scrub Mosaic 31 ha., now 0 ha ?
687 Swamp Scrub /
Plains Grassland Mosaic 16 ha.,
now 0 ha ?
Coastal EVCs.
Due to the Strzelecki
bioregion reaching to the coast along the Walkerville – Cape Liptrap
area, there were around 800 ha. of coastal vegetation. 450 ha. Remains. Most of
these veg types were and are far more prevalent in Gippsland Plains and the
Prom.
2 Coast Banksia
Woodland 130 ha., now 48 ha. Cape Liptrap
Sallow
wattle , Boobialla, Swamp Paperbark, Coast Ti Tree, Kidney Weed, Sedges, Ivy
Leafed Violet
8 Wet Heathland 259 ha., now 155
ha.
Poor Fertility sand with
high water table. Liptrap to Walkerville (inland).
More common at Prom, Tarwin
and Port Welshpool Coast Manna, Bog Gum, Heath, Sheoak, Paperbark, Bush Pea
161 Coastal Headland
Scrub 331 ha., now 243 ha.
Liptrap to Walkerville
Coast. Coast Ti Tree, Heath,
Sheoak, Hop, Tussock etc.
73 Rocky Outcrop
shrubland / Herbland mosaic 0
ha., now 23 ha.
163 Coastal Tussock
Grassland 6 ha., now 9 ha.
307 Sand Heathland /
Wet Heathland Mosaic 85 ha., now 154 ha
Walkerville area.
74 Wetland Formation 0 ha., now 76 ha.
Other
EVCs
48 Heathy Woodland 380 ha., now 219 ha.
Near Won Wron Grows on the most infertile sandy gravely soil
55 Plains Grassy
Woodland 258 ha. now 0 ha ? Tiny patches existed NE of
Boolarra. Redgum overstorey, with grasses, herbs sedges and lillies
151 Plains Grassy
Forest 1637 ha., now 0 ha ?
Around Boolarra and near Won Wron. Closely related to Herb Rich Foothill and
Lowland Forest.
128 Grassy Forest ??? 304 ha., now 0 ha ? Drouin vicinity Not mapped on Extant map.
Messmate and Peppermint. Many grasses on ground.
233 Wet Sand Thicket 65 ha., now 0 ha ? Limited to the Gravel Mine North of Toora. Similar to Lowland
Forest
Strzelecki
Bioregion - vegetation - EVC distribution before the land was cleared. At
this scale not all EVCs show up