Download Ecological Values and Conservation significance of Crown Land

Ecological Values and Conservation significance of Crown
Land adjoining Black Hill Conservation Park
Report compiled by Dr Wendy Stubbs, Luke Price and Janine
Kraehenbuehl
September 2013
Executive summary
Recent preliminary surveys of plants, birds, amphibians and reptiles on two parcels of
crown land adjoining Black Hill Conservation Park have revealed a quality suite of
species not recorded elsewhere in the state. The addition of these two parcels of land
to Black Hill Conservation Park would be significant as it would greatly increase the
viability of local plant and animal populations and thus the capacity of the reserve to
conserve species into the future. Particular qualities to note include:
 Breeding population of Mt Lofty Ranges chestnut-rumped heathwrens – a
regionally endemic species listed as endangered under the EPBC Act and one
of the states most threatened birds.
 Unusually high diversity of reptiles not seen elsewhere in the region.
 A unique assemblage of plant species not seen anywhere apart from on these
two parcels of crown land due to the unusual presence of limestone bedrock.
 Stands of ancient grass trees which are expected to predate colonisation.
 Forty four plant species threatened at a state or regional level (with additional
surveys likely to detect more).
Looking east along Gorge road on crown land parcel F171413 A91. Photo: S. Collard.
Uniqueness of these parcels
The area encapsulated within the crown land parcels F107799 A6 and F171413 A91
(Figure 1) is unique in the region as it represents the only area of a dryland
community within a high rainfall zone observed within the state. This area consists of
rocky shallow alkaline soils across mainly north facing slopes. While the Adelaide
Mount Lofty Ranges (AMLR) typically has acidic soils, these two parcels of land are
dominated by limestone, a feature not observed within Black Hill Conservation Park
itself, and not conserved within the reserve system anywhere else within this region.
The distinctiveness of these two parcels therefore represent a critical addition to Black
Hill Conservation Park.
Figure 1: Selected broad vegetation associations within crown land parcels F107799 A6 and
F171413 A91. Area A = drooping sheoak and yacca heath, Area B = drooping sheoak
woodland with grey Trymalium and Mount Lofty grass trees, Area C = grey Trymalium
shrubland, Area D = grey Trymalium and dryland teatree shrubland, Area E = drooping
sheoak and mixed Eucalyptus woodland, Area F = Mount Lofty grass tree with sticky hop
bush low open shrubland, Area G = mallee box woodland , and Area H =. silver banksia low
woodland with drooping sheoak, See Price et al. (2013a) for a full description of each
vegetation association.
Large expanses of these parcels of land are dominated by grey Trymalium (Trymalium
wayae) shrub-land (Figure 2) with a variety of co-dominant plants including dryland
tea tree (Melaleuca lanceolata),drooping sheoak (Allocasuarina verticillata) and
grass trees (Xanthorrhoea semiplana ssp. semiplana and Xanthorrhoea
quadrangulata) (Figure 1). This association of species is extremely rare and this
crown land represents the only area within the AMLR region where it exists. While
some of the same species are found further north within the Flinders Ranges, the
vegetation association found within this crown land differs significantly from similar
vegetation associations in the Flinders Ranges making this area quite unique (Brewer
2001). This association contains several species that have limited distribution at a
state, district and local level, and it contains many species typically found within
mallee systems which are not common in the AMLR (Brewer 2001).
Figure 2: A patch of grey Trymalium shrubland containing Mount Lofty grass-trees in
F171413 A91. Photo: L. Price
Scattered across these two parcels of land are numerous stands of large grass trees,
with some individuals over 6 feet in height (Figure 3). Due to the slow growing
nature of these plants, it is believed that these individuals would be more than 100
years old, and they are likely to predate European settlement (H Vonow 2013, pers.
comm. SA State Herbarium). While the two species of grass trees are also found
within Black Hill Conservation Park, the individuals found within the crown land are
significantly larger than any found within the park and are larger than any preserved
anywhere else in this region or the Flinders Ranges.
Figure 3: A stand of Mount Lofty grass-trees which stand over 6 ft tall in F171413 A91.
Photo: L. Price.
Several other community types found within these parcels of land are considered
threatened at a state and regional scale. For example, Banksia marginata grassy low
woodland which is found in the northernmost tip of F107799 A6 (area H on figure 1)
is considered endangered across the state and is very significant for this region
(Wilson and Bignall 2009). Mallee Box (Eucalyptus porosa) grassy woodland which
is found in the north western section of F107799 A6 (area G on figure 1) is also
considered threatened within the region.
The lower drainage lines of F171413 A91 contain redgum (Eucalyptus camaldulensis)
grassy woodlands while the ridge top in the eastern section of F107799 A6 consists of
SA blue gum (Eucalyptus leucoxylon) grassy woodland (Brewer 2001). While these
communities are not listed as threatened, grassy woodlands per se are particularly
under-represented in the AMLR. Grassy woodlands used to occupy 47% of this
region, with only 7% of this area now remaining (representing 27% of the remnant
total). Despite historically covering nearly half of the Mount Lofty Ranges, only
3,709 ha is currently under formal protection (14% of the remaining 7%) (DEH
2009). Due to this disproportionate clearance and the limited extent formally
protected, a DENR publication identifies both grassy woodlands and shrublands as
two of the three most important community types for formal protection (out of 13
community types).
Birds
While extensive fauna surveys have not yet been conducted across this crown land, an
initial bird survey undertaken by NCSSA in September 2013 identified 41 species of
native bird utilising this site. Observations of the habitats across this area suggest
another sixteen species are likely to inhabit this area and may well be detected if
subsequent surveys were undertaken at other times of the year (Collard 2013, J. van
Weenen 2013, pers. comm.). The vegetation found throughout these two parcels of
land are dominated by dry low open shrubs. This open low shrubby habitat is
particularly important for a suite of birds that is found along the dry ridge tops along
the spine of the Mount Lofty Ranges, and due to the limited availability of this habitat
is now in decline.
Of the forty one species observed during the spring 2013 bird survey, six species had
federal, state or regional conservation ratings (Table 1). Nine of the species likely to
be detected if more surveys were undertaken are also considered in decline within this
region (including elegant parrot, sacred kingfisher, white-naped honeyeater, and
dusky woodswallow), with one species being considered rare across the state (scarlet
robin). All of these species have shown marked declines in response to fragmentation
and modification in the highly fragmented and modified Mount Lofty Ranges
landscape (Paton et al. 1994).
Table 1. Threatened bird species recorded in the study area during the survey in September
2013. Taken from Collard (2013). E = endangered, V = vulnerable, R = rare, U = uncommon.
EPBC ratings range from critically endangered, endangered to vulnerable; State ratings range from
endangered, vulnerable to rare and AMLR ratings range from endangered, vulnerable, rare to
uncommon (Wilson and Bignall 2009).
Species
Chestnut-rumped heathwren
Yellow-tailed black-cockatoo
Peregrine falcon
Fan-tailed cuckoo
Shining bronze-cuckoo
Yellow-rumped thornbill
EPBC
E
SA
E
V
R
AMLR
V
V
R
V
R
U
Mount Lofty Ranges Chestnut-rumped heathwren – endangered under EPBC Act
The Mount Lofty Ranges Chestnut-rumped heathwren which is listed as endangered
under both the Commonwealth Environment Protection and Biodiversity Act 1999
(second most threatened rating) and the South Australian National Parks and Wildlife
Act 1972 (highest threat rating), has been recorded on both of these parcels of land
(Collard 2013). This subspecies, Hylacola pyrrhopygia parkeri (Figure 4), is only
found within the Mount Lofty Ranges, and the preservation of this species is one of
the region’s highest conservation priorities, as fewer than 1,000 individuals are
believed to remain. Unfortunately this species appears to be experiencing ongoing
decline, with a reduction in total population from 2,500 to 1,000 over seven years
(2000 to 2007). The primary cause of this decline is believed to be habitat loss and
fragmentation outside of the reserve system (Long and Bentley 2010). Therefore,
preserving all remaining suitable habitat for this species is critical to ensure their
survival.
Figure 4: Juvenile Mount Lofty Ranges chestnut-rumped heathwren in Scott Creek
Conservation Park. Photo: D. Moise.
Two observations were made of Mount Lofty Ranges chestnut-rumped heathwren
within the subject land, both within dense shrubby habitat in rocky areas with
Trymallium wayi, Allocasuarina verticillata and Dodonea viscosa the dominant plant
species. This species occupies a very small home range so as one of the two birds
observed was a juvenile, it is evident that chestnut-rumped heathwren are breeding
within this subject area. Previous studies have identified that the largest population of
this species exists within the area from Black Hill Conservation Park to Cleland
Conservation Park (Pickett 2007), making this area a priority for conservation of this
species. Moreover, these parcels of crown land provide an extremely important
linkage between populations of this species found in Anstey Hill Recreation Park to
the north and populations within Black Hill and Moriatla Conservation Parks to the
south (Collard 2013). An EPBC Act referral would need to be lodged with the
Commonwealth Government before any modifications could be made to this area. As
bird calls thought to be made by the chestnut-rumped heathwren were also heard
within the southeastern corner of parcel F171413 A91, further surveys would be
required to determine if a referral was be required for activities in this far corner.
Reptiles and amphibians
Thirteen species of reptile and one species of amphibian were detected in an initial
survey conducted in spring 2013 (Price et al. 2013b). This very high reptile diversity
is atypical of the region, with senior curator of reptiles at the South Australian
Museum, Dr Mark Hutchinson stating that he would not expect to find so many
reptiles with such minimal search effort in any other location within the AMLR. The
varied landscape throughout these parcels of land, with scattered rocks within open
vegetation over a combination of clay and rocky soils, gives rise to a large number of
habitat types, a fact which is thought to be responsible for this unexpectedly high
reptile diversity (Figure 5). Based on the high diversity of habitat types observed
within this crown land, it is believed that additional surveys are likely to yield twenty
or more reptile species (M Hutchinson 2013, pers. comm.). This number of reptiles
within such a small area is unlikely to be replicated in the adjacent Black Hill
Conservation Park.
Figure 5: Clockwise from top left: Ranges stone gecko (Diplodactylus furcosus), olive
legless lizard (Delma molleri), barking gecko (Underwoodisaurus milii) and little whip snake
(Parasuta flagellum) in F171413 A91. Photos: L Price.
While the Cunningham skink (state endangered, regionally vulnerable) has not yet
been detected within the subject land, ample potential habitat was observed and
further studies during the right conditions are likely to detect this species (Price 2013).
Cunningham skinks exist as an isolated sub-population in the AMLR, with the nearest
related colonies occurring in the Great Dividing Range in Victoria (DEH 2008).
Additional surveys are also likely to detect the eastern water skink (regionally
vulnerable) along the northern fringes of the subject area, and pygmy copperheads
(regionally vulnerable) within the yacca / drooping sheoak heath (area A in Figure 1).
Pygmy copperheads are found only within South Australia, and both pygmy
copperheads and eastern water skinks are found within only a few locations within
this region, making any potential habitat important for the conservation of these
species.
Mammals
Echidnas (Tachyglossus aculeatus) were detected by remote cameras deployed within
the subject area (Price et al. 2013b). However no formal mammal surveys have been
undertaken on the subject land and thus little is known about the mammal species
which may be present within this crown land.
Plants
Over 150 species of native plant have been recorded across these two parcels of land,
including seven species considered threatened at state and regional levels and another
36 species considered threatened at a regional level (see Table 2). These threatened
species include the dainty maiden-hair fern (Adiantum capillus-veneris, Figure 6)
which is listed as vulnerable within the state and which has a very restricted
distribution within the AMLR (DEH 2008). The population of rock Logania
(Logania saxatilis, Figure 6), which is listed as rare within SA, is found within this
crown land is also extremely regionally significant and this is likely to be the largest
population existing within the AMLR region (T Jury 2013, pers. comm.). These
parcels of land are also regionally significant for a number of other species, as
populations on this crown land represent the only (in the case of Eucalyptus rugosa)
or one of only a few (in the case of Ajuga australis form A and Lasiopetalum behrii)
known locations for these species within the AMLR (K Brewer 2013, pers. comm.).
Figure 6: Rock Logania (Logania saxatilis) on the left and dainty maiden-hair fern
(Adiantum capillus-veneris) on the right within F171413 A91. Photos: L Price within F171413
A91.
Further surveys conducted across the seasons are likely to detect many more plant
species, including a number of regionally significant plants. In particular the habitats
found within these parcels of land are ideal for a newly discovered but currently
undescribed greenhood orchid, Pterostylis “rock ledges” (T Jury 2013, pers. comm.).
This plant is considered nationally endangered, but is yet to be listed under the EPBC
Act as it is awaiting formal classification. Threatened plant expert (Threatened Plant
Action Group) Tim Jury believes that it is very likely that further studies conducted
within the right season would detect this species within this crown land.
Table 2: Threatened plant species recorded on these parcels of crown land. This list is
compiled from Brewer (2001) and Jury (2013). E = endangered, V = vulnerable, R = rare, U =
uncommon, K = status of concern. SA ratings from NPW Act Schedules 7, 8 and 9; AMLR ratings
from Wilson and Bignall (2009) and SL ratings from Lang and Kraehenbuehl (2008).
Scientific name
Common
name
Acacia rupicola
Adiantum capillusveneris
Rock wattle
Dainty maidenhair
Ajuga australis form A
Australian bugle
Anthocercis angustifolia
Narrow-leaf rayflower
R
R
Anogramma leptophylla
Anthocercis angustifolia
Annual fern
Narrow-leaf rayflower
Brush wire-grass
Pink fingers
Pink purslane
River bottlebrush
R
R
R
R
Aristida behriana
Caladenia latifolia
Calandrinia calyptrata
Callistemon sieberi
Cheilanthes distans
Cullen australasicum
Cymbopogon ambiguus
Cymbopogon obtectus
Eucalyptus porosa
Eucalyptus rugosa
Goodenia albiflora
Goodenia pinnatifida
Lasiopetalum behrii
Logania saxatilis
Lomandra sororia
Malva behriana
Melaleuca brevifolia
Melaleuca lanceolata
ssp. lanceolata
Myoporum petiolatum
Ophioglossum
lusitanicum
Phyllanthus saxosus
Pimelea curviflora
Pimelea micrantha
SA
V
Australian
hollyhock
Short-leaf honeymyrtle
Dryland tea-tree
Sticky boobialla
Austral adder'stongue
Rock spurge
Curved
riceflower
Silky riceflower
V
U
V
R
U
U
U
U
Bristly cloak-fern
Tall scurf-pea
Lemon-grass
Silky-head
lemon-grass
Mallee box
Coastal white
mallee
White Goodenia
Cut-leaf
Goodenia
Pink velvet-bush
Rock Logania
AMLR SL
R
U
V
R
U
V
Comments
Found in spring adjoining Gorge Road
Northern section of F171413 A91, only 1 other
local population in Anstey Hill RP and 1 of only a
handful left in the state.
3 small populations on lower slopes of F171413
A91. One of the most southerly records of this
mid North/Flinders Ranges species.
Rocky steep situations on lower slopes. Possibly
the largest population within the Southern Lofty
District.
SA endemic
Common in grassy areas throughout site
Found by LP, near Gorge Road
Rocky sites above gorge road and creek line in
F107799 A6
Rocky creek lines and occasionally on hillsides
Common throughout area.
North eastern part of F107799 A6. This is the
only local and possibly only Southern Lofty
District conserved population
U
U
R
R
R
Under Allocasuarina verticillata
Isolated plants and patches occur mostly on lower
slopes. Largest regional population.
U
U
R
U
Outlier to adjoining population on the Torrens
river.
Several hundred scattered shrubs and small
shrubby trees occur with Trymalium wayae
U
U
V
R
R
Small shrub found under Trymalium principally in
F171413 A91. Common at this site but rare
locally.
Pleurosorus rutifolius
Pomaderris paniculosa
ssp. paniculosa
Prostanthera behriana
Pterostylis biseta
Pterostylis dolichochila
Ptilotus spathulatus f.
spathulatus
Pultenaea acerosa
Rubus parvifolius
Schoenus nanus
Senecio hypoleucus
Spyridium spathulatum
Thysanotus tenellus
Triptilodiscus pygmaeus
Trymalium wayi
Blanket fern
Mallee
pomaderris
Tall mintbush
Veined
greenhood
Mallee shellorchid
Pussy-tails
U
U
U
K
K
Very rare in region
R
Bristly bush-pea
Native raspberry
Little bog-rush
Pale groundsel
Spoon-leaf
Spyridium
Grass fringe-lily
Small yellowheads
Grey Trymalium
Small population in the north eastern part of
F107799 A6
U
U
R
U
R
R
R
E
U
V
V
Small population in F107799 A6. Common in
other parts of Black Hill Conservation Park
Many thousands of individuals in dense stands.
Only known population within the region and
only population with the potential to be conserved
in line with the AMLR Regional Recovery Pln
objectives.
References
Brewer, K 2001, Black Hill Conservation Park: Torrens Gorge vegetation
management action plan. A report prepared for National Parks and Wildlife SA.
Collard, S 2013, Bird surveys in crown land parcels adjacent to Black Hill
Conservation Park. A report prepared by Nature Conservation Society of South
Australia.
DEH, 2008, Threatened species profiles for the Adelaide and Mount Lofty Ranges,
South Australia. A report prepared by the Department for Environment and Heritage.
DEH, 2009, Informing biodiversity conservation for the Adelaide and Mount Lofty
Ranges region, South Australia: Priorities, strategies and targets.
Jury, T 2013, INTERIM Indigenous flora species for Black Hill Crown Lands. A
report prepared by the Threatened Plant Action Group.
Lang, P & Kraehenbuehl, DN 2008, Plants of conservation significance. A report
prepared by the Department for Environment and Heritage.
Long, K & Bentley, J 2010, Threatened species action statement: Mt Lofty Ranges
chestnut-rumped heathwren Hylacola pyrrhopygia parkeri. Department for
Environment and Heritage.
Pickett, M 2007, Assessment of the Distribution, Habitat and Conservation Status of
the Chestnut-rumped Heathwren Hylacola pyrrhopygia parkeri in the Mount Lofty
Ranges. A report prepared for the Department for Environment and Heritage.
Price, L, Jury, T, Bates, B & Johnson, S 2013a, Photographic guide of selected broad
vegetation associations in crown land parcels adjacent to Black Hill Conservation
Park. Report prepared by the Department of Environment, Water and Natural
Resources.
Price, L, Matejcic, P & Johnson, S 2013b, Fauna survey of crown land parcels
adjacent to Black Hill Conservation Park. Report prepared by the Department of
Environment, Water and Natural Resources.
Wilson, A & Bignall, J 2009, Regional recovery plan for threatened species and
ecological communities of Adelaide and the Mount Lofty Ranges, South Australia.
Department for Environment and Heritage, South Australia.