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Ephemeral wetlands of the Pilliga Outwash, northwest NSW.


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3 Office of Environment & Heritage, Baradine, NSW 2396 AUSTRALIA Abstract: The floristic composition and vegetation partitioning of the ephemeral wetlands of the Pilliga Outwash within the Pilliga National Park and Pilliga State Conservation Area (30˚30'S, 149˚22'E) on the North Western Plains of New South Wales are described. SPOT5 imagery was used to map 340 wetlands across the Pilliga Outwash. A total of 240 plots within 31 wetlands explored composition and species richness in relation to water depth and wetland size. The predominant community described is the species-rich herbfield of shallow basin wetlands, along with the structurally distinct but the less common sedgeland/herbfield of the deeper 'tank' wetlands and a single wetland with a floristically depauperate Diplachne fusca wet grassland. A total of 131 taxa were recorded including three species listed under the NSW Threatened Species Conservation Act (1995): Eriocaulon australasicum, Lepidium monoplocoides and Myriophyllum implicatum. New records for an additional six taxa were recorded for the North Western Plains. 11% of taxa were exotic in origin.
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Cunninghamia: a journal of plant ecology for eastern Australia © 2012 Royal Botanic Gardens and Domain Trust
A journal of plant ecology for eastern Australia
ISSN 0727- 9620 (print) • ISSN 2200 - 405X (Online)
Date of Publication:
Wetland conservation and management requires adequate
knowledge of wetland distribution (Kingsford et al. 2004),
extent and floristic composition. In Australia impermanent
wetlands are far more common and widely distributed than
are permanent lakes and swamps (Paijmans et al. 1985)
yet in a global review of ephemeral wetlands (Deil 2005),
plot-related data were only available in the literature for
Western Australia; for the rest of the continent only general
classifications of wetland types were available at that time
(Pressey & Adam 1995). To our knowledge, since 2005,
information on temporary and ephemeral wetlands has only
been collated for some areas of New South Wales (Hunter
& Bell 2007; Bell et al. 2008; Hunter & Bell 2009). In other
areas such as western New South Wales, such information
is often only available as part of localized vegetation
description (McGann et al. 2001), regional vegetation
description (Benson et al. 2006; Benson et al. 2010), or from
descriptions of communities establishing from seed banks
(James & Capon 2007; Porter et al. 2007). Wetland covers
5.6% of New South Wales; of this portion 96% is in western
New South Wales (Kingsford et al. 2004). Kingsford et al.
(2004) list six types of spatially derived wetland groups for
New South Wales: Freshwater Lakes, Floodplain Wetland,
Estuarine Wetland, Saline Lake, Coastal Lagoons and Lakes
and Reservoirs. However in the Pilliga Scrub, south west of
Narrabri, exist a group of small ephemeral wetlands, that do
not conform to these broad wetland types, nor, unsurprisingly,
to the broad categories of wetlands described by Keith (2004).
The vegetation of these Pilliga wetlands was first described
by Benson et al. (2010), who named these wetlands Pilliga
Ephemeral wetlands of the Pilliga Outwash, northwest NSW
Dorothy M. Bell1, John T. Hunter2 & Lisa Montgomery3
1Botany, School of Environmental and Rural Science, University of New England, Armidale, NSW 2351,
2School of Behavioural, Cognitive and Social Sciences, University of New England, Armidale, NSW 2351,
3Office of Environment & Heritage, Baradine, NSW 2396 AUSTRALIA
Abstract: The floristic composition and vegetation partitioning of the ephemeral wetlands of the Pilliga Outwash
within the Pilliga National Park and Pilliga State Conservation Area (30˚30’S, 149˚22’E) on the North Western Plains
of New South Wales are described. SPOT5 imagery was used to map 340 wetlands across the Pilliga Outwash. A total
of 240 plots within 31 wetlands explored composition and species richness in relation to water depth and wetland
size. The predominant community described is the species-rich herbfield of shallow basin wetlands, along with the
structurally distinct but the less common sedgeland/herbfield of the deeper ‘tank’ wetlands and a single wetland
with a floristically depauperate Diplachne fusca wet grassland. A total of 131 taxa were recorded including three
species listed under the NSW Threatened Species Conservation Act (1995): Eriocaulon australasicum, Lepidium
monoplocoides and Myriophyllum implicatum. New records for an additional six taxa were recorded for the North
Western Plains. 11% of taxa were exotic in origin.
Cunninghamia (2012) 12(3): 181–190
doi: 10.7751/cunninghamia.2012.12.015
182 Cunninghamia 12(3): 2012 Bell, Hunter & Montgomery, Ephemeral wetlands of the Pilliga
“tank gilgai” wetland sedgeland rushland, Brigalow Belt
South Bioregion (Veg. Comm. ID 416), and considered them
to be endangered. Coincidentally this wetland community
was also described as a separate vegetation community, Tank
Herbfields, by floristic analysis within the Pilliga National
Park and Pilliga State Conservation Area (Hunter 2010).
These initial descriptions were based on a limited amount
of data and observation and a limited knowledge of wetland
The climate of the Pilliga is dry subtropical with moderately
dry winters (Benson et al. 2010) and the majority of wetlands
are likely to fill at most once a decade. Large rainfall events
in 2010 through to early 2011 repeatedly filled the wetlands
and provided an opportunity for investigation, the intention
of which was to circumscribe the location, type and extent
of these wetlands, to describe their floristic composition and
to put them in context with other wetland types within the
Study area
The area studied falls within the Brigalow Belt South
Bioregion south of the Namoi River Floodplain and forms
part of the north western portion of the 500 000 ha Pilliga
Scrub which occurs between Coonabarabran, Narrabri and
Pilliga. Most of the study area comprises outwash sands,
loams and clays resulting primarily from the erosion
of upland sandstones further to the south (Keith 2004).
Benson et al. (2010) described the wetlands as occurring on
alkaline sodic grey clay soils with sodic sandy soils in the
surrounding Buloke (Allocasuarina luehmannii) woodland.
Two ephemeral waterways, Goona Creek and Coghill Creek,
cross the study area from east to west.
We chose locations within Pilliga National Park and part of
the adjoining Pilliga State Conservation Area, in order to
investigate wetlands within an area managed for conservation
Fig. 1. Distribution of ephemeral wetlands in the Pilliga Outwash. The dotted line indicates the extent of the ephemeral wetlands area;
wetlands themselves are shown in black, borders are thickened for visibility. Wetlands occur in Pilliga National Park (Pilliga NP), in the
surrounding Pilliga State Conservation Area (Pilliga SCA) and in lands to the north and northwest of these. The area bounded by the dotted
line measures approximately 40 km by 8 km.
Cunninghamia 12(3): 2012 Bell, Hunter & Montgomery, Ephemeral wetlands of the Pilliga 183
where disturbance is assumed to be more limited. Pilliga
State Conservation Area surrounds Pilliga National Park
along its eastern, southern and western boundaries (Fig. 1).
Pilliga National Park lies approximately 44 km southwest
of Narrabri (30˚ 30’ S, 149˚ 22’ E). Rainfall in 2010 was
approximately twice the yearly average with the Bureau
of Meteorology recording a total of 1119 mm in 2010 for
Baradine, southwest of Narrabri, on the western edge of the
Pilliga (30˚ 36’ S, 148˚ 58’ E, elevation 211 m, mean annual
rainfall 576 mm).
Wetland locations were identified using SPOT5 imagery (Fig.
1). Each location was digitized and mapped with ArcGIS 9.3
and Geo-referenced SPOT5 imagery in order to measure
areas of individual wetlands using polygons. Wetland size
was verified in the field. Ground truthing of all mapped
wetlands within Pilliga National Park and Pilliga State
Conservation Area was carried out on quad bikes in the early
part of the sampling period, to distinguish depressions capable
of holding water from other bare but sloping areas such as
scalds. From the 107 depressions identified as wetlands, 31
wetlands were chosen for sampling; these covered a range of
wetland sizes and locations within the reserves.
In spring–summer 2010–2011, in each of the 31 wetlands,
up to three transects were placed in random positions across
depth gradients from the edge of the surrounding trees, to the
deepest parts of the wetland. Each transect was permanently
marked with small posts to allow sites to be revisited. The
cover abundance of all vascular species and charophytes on
a modified Braun-Blanquet (1982) scale (1–6) was assessed
in 2 m x 2 m (4 m2) plots. These plots were placed within
visually distinct vegetation bands along each transect (2 to 4
per transect; 240 plots in total). Plot water depths and distance
from the starting point were also recorded. Conductivity and
pH were measured in five wetlands in March 2011.
Appropriate plant specimens were retained for lodging in the
N. C. W. Beadle Herbarium, University of New England with
duplicates to the National Herbarium of NSW. Nomenclature
follows that of PlantNet (2011) except where recent changes
have been published elsewhere.
Two data sets were prepared, the first of all plots separately,
the second of summed plot data for individual wetlands.
Analyses and data exploration were performed using options
available in the PATN Analysis Package (Belbin 1995a, b).
All species and their cover abundance scores were used and
the analysis performed using the Kulczynski association
recommended for ecological applications (Belbin 1995a, b)
along with flexible UPGMA fusion strategy and the default
PATN settings. Community dissimilarity was determined at
the 0.85 level.
340 wetlands were mapped within the broader study area
of which 107 occurred within the Pilliga National Park and
State Conservation Area (Fig. 1). The total area covered
by these wetlands is approximately 121 ha with 92% of
wetlands being under 1 ha in size. Wetlands occurred
across a 40 km by 8 km ellipse from the Pilliga National
Park northwest to near the township of Pilliga (Fig. 1).
The wetlands occurred within a mosaic of woodlands and
shrublands largely dominated by Allocasuarina luehmanii,
Eucalyptus chloroclada, Eucalyptus pilligaensis, Eucalyptus
sideroxylon and Melaleuca densispicata (Benson et al. 2010;
Hunter 2010).
The wetlands fall into two distinct morphological types;
‘tank’, and shallow basin wetlands. ‘Tank’ wetlands are
roughly circular to irregularly oblong basins with a distinct
lip to 30 cm high, on yellowish soils with higher clay
content, often in Melaleuca densispicata tall shrubland
Fig. 2. ‘Tank’ wetland, Pilliga NP, September 2011 (Wetland 96
West, 30˚30’24”S, 149˚20’15”E).
Fig. 3. Shallow basin wetland on Old Coghill Road, Pilliga NP,
October 2010 (Wetland 37, 30˚30’26”S, 149˚22’16”E).
184 Cunninghamia 12(3): 2012 Bell, Hunter & Montgomery, Ephemeral wetlands of the Pilliga
where extensive scalds are common (Fig. 2). ‘Tank”
wetlands usually contain turbid, more permanent water than
that of shallow basin wetlands, and can hold water for two
to three months. Shallow basin wetlands are on yellowish
soils of higher sand content especially at margins. There is
a sharp boundary at the woodland edge and shallow basin
wetlands are more commonly surrounded by Allocasuarina
luehmannii (Fig. 3). Water is often, but not always, clear and
the smallest wetlands dry in a matter of weeks.
A total of 131 vascular plant taxa in 49 families and 97
genera were recorded in plots and from opportunistic
sightings. Four charophyte taxa in the genera Chara and
Nitella were recorded. Families with the most taxa overall
were Asteraceae (21 species), Cyperaceae (19 species) and
Poaceae (12 species). The richest genera were Cyperus (8
species), Juncus (6 species) and Myriophyllum (4 species).
Vegetation Assemblages
Three communities were defined in the whole wetland
analysis (Figure 4):
Community 1: Cyperus gunnii subsp. gunniiNymphoides
crenata sedgeland/herbfield.
Wetland type: ‘Tank’ wetland. Turbid open water with a usually
continuous 1–2 m wide margin dominated by the tall sedge Cyperus
gunnii subsp. gunnii (height to 1.5 m), occasionally with floating-
leaved Nymphoides crenata populations in deepest part of basin. As
water recedes, a low (0.1–0.2 m) herbfield of ruderal species appears
on damp mud.
Terrestrial and semi terrestrial: Eragrostis elongata, Hypericum
gramineum, Commelina cyanea, Chloris truncata, Alternanthera
denticulata, Sporobolus caroli, Fimbristylis dichotoma, Eragrostis
parviflora, Cyperus gracilis, Dichelachne crinita, Dianella revoluta
subsp. revoluta.
Ruderals and mud flat colonisers: Glinus oppositifolia, Epaltes
australis, Eleocharis pusilla, Lipocarpha microcephala, Cyperus
difformis, Chenopodium pumilio, Portulaca filifolia, Fuirena incrassata.
Emergents: Cyperus gunnii subsp. gunnii, Myriophyllum simulans,
Juncus subsecundus, Eleocharis macbarroni, Juncus psammophilus,
Philydrum lanuginosum, Eleocharis plana, Mitrasacme paludosa,
Diplachne fusca, Cyperus betchei subsp betchei.
Floating-leaved: Nymphoides crenata.
Submerged: None.
Exotics: Bidens pilosa, Gomphrena celosioides, Spergularia rubra,
Xanthium occidentale.
Variability: Sometimes Cyperus gunnii subsp. gunnii margin not
intact, margins not so distinctly lipped. Generally less species-rich (9 to
20 species per wetland) than Community 2.
Community 2: Eleocharis pusillaMyriophyllum
simulansNymphoides crenataMarsilea hirsuta –
Pseudoraphis spinescens herbfield/sedgeland with an
ephemeral component dominated by Goodenia gracilis
Centipeda minima subsp. minimaGratiola pedunculata
Alternanthera denticulata.
Wetland type: Shallow basin wetlands.
Terrestrial and semi terrestrial: Eragrostis elongata, Hypericum
gramineum,Wahlenbergia tumidifructa, Wahlenbergia gracilis,
Bulbine semibarbata, Commelina cyanea, Ophioglossum lusitanicum,
Fimbristylis dichotoma, Walwhalleya subxerophylla, Chamaesyce
drummondii, Murdannia graminea, Rumex tenax, Plantago turrifera,
Lepidium monoplocoides, Portulaca oleracea, Chloris truncata.
Ruderals and mud flat colonisers: Goodenia gracilis, Centipeda
minima subsp. minima, Epaltes australis, Gratiola pedunculata,
Alternanthera denticulata, Myriophyllum implicatum, Calandrinia
pumila, Peplidium foecundum, Calandrinia eremaea, Brachyscome
goniocarpa, Crassula sieberiana, Ranunculus sessiliflorus var.
Fig. 4. Summary dendrogram of 31 ephemeral wetlands surveyed within Pilliga NP and Pilliga State Conservation Area using Kulczynski
association and flexible UPGMA fusion strategy. Communities have been defined at a dissimilarity level of c. 0.85.
Cunninghamia 12(3): 2012 Bell, Hunter & Montgomery, Ephemeral wetlands of the Pilliga 185
pilulifer, Carex inversa, Cyperus flaccidus, Elatine gratioloides,
Cyperus squarrosus, Centrolepis strigosa subsp. strigosa, Centipeda
thespidioides, Eriocaulon australasicum, Lipocarpha microcephala,
Drosera indica, Isolepis hookeriana, Myriocephalus pluriflorus,
Centrolepis eremica, Helichrysum luteoalbum, Lachnagrostis filiformis,
Cyperus difformis, Callitriche sonderi, Triglochin calcitrapa, Juncus
bufonius, Portulaca filifolia, Fuirena incrassata, Calotis hispidula,
Senecio glossanthus, Plantago turrifera, Myriocephalus rhizocephalus,
Myosurus australis, Triptilodiscus pygmaeus, Polygonum plebeium,
Cyperus sanguinolentus, Lythrum hyssopifolia, Euchiton sphaericus,
Brachysome multifida var. multifida, Portulaca bicolor var. rosea,
Drosera peltata, Drosera burmanni.
Emergents: Eleocharis pusilla, Myriophyllum simulans, Cyperus
gunnii subsp. gunnii, Glossostigma diandrum, Marsilea hirsuta,
Pseudoraphis spinescens, Isoetes muelleri, Hydrocotyle tripartita,
Juncus subsecundus, Mimulus gracilis, Mitrasacme paludosa, Isotoma
fluviatilis subsp. borealis, Eleocharis plana, Marsilea costulifera,
Myriophyllum verrucosum, Diplachne fusca, Cynodon dactylon,
Eleocharis pallens, Utricularia dichotoma, Schoenus apogon,
Philydrum lanuginosum, Rorippa laciniata, Juncus psammophilus,
Juncus aridicola, Juncus flavidus, Eryngium paludosum, Eleocharis
macbarronii, Amphibromus nervosus, Cyperus rigidellus, Cyperus
gymnocaulos, Cyperus betchei subsp. betchei, Juncus ochrocoleus.
Floating-leaved: Nymphoides crenata, Nymphoides geminata,
Potamogeton sulcatus, Ottelia ovalifolia subsp. ovalifolia, Damasonium
minus, Triglochin multifructa.
Submerged: Najas tenuifolia, Vallisneria australis, Chara fibrosa,
Chara sp., Nitella sonderi, Nitella sp.
Exotics: Soliva anthemifolia, Schoenoplectus erectus, Sisyrinchium
sp. A, Sagina apetala, Conyza bonariensis, Cuscuta campestris,
Gamochaeta coarctata, Spergularia rubra, Veronica peregrina,
Anagallis arvensis, Gomphrena celosioides, Xanthium occidentale,
Vulpia bromoides, Sonchus oleraceus, Gamochaeta calviceps,
Centaurea melitensis.
Variability: This community occurred in wetlands varying greatly in
both size (<0.05 to 3.6 ha) and depth (0 to >70 cm, although the lower
limit is misleading since a few very shallow wetlands were dry when
sampled). Species richness per wetland was also highly variable (8 to
42 species) and appeared to bear no relationship to either wetland size
or wetland depth. Some quite small wetlands were species-rich, others
species-poor; the most species-rich wetland was relatively large but
other large wetlands were species-poor.
Community 3: Diplachne fusca grassland.
Wetland type: Sampled at a single site. Species-poor, very shallow
basin wetland, sandy sloping margins.
Terrestrial and semi terrestrial: Lepidium monoplocoides.
Ruderals and mud flat colonisers: Calandrinia eremaea, Epaltes
Emergents: Diplachne fusca, Cynodon dactylon.
Floating-leaved: None.
Submerged: None.
Exotics: Spergularia rubra.
Variability: Not known.
Species richness
Plot species richness across wetland depth gradients (as
distinct from richness in whole wetlands) was highly
variable. Plots in the deepest parts of the wetlands generally
had lower species richness (1–5/4m2) but variability in plots
on damp soil was very high (3–27/4m2) and did not appear
to vary with wetland size. Whole wetland richness varied
from eight in one of the smallest wetlands to 54 in one of
the largest.
The water in wetlands sampled in March 2011 was slightly
acid to slightly alkaline (pH 6.4 to 7.9). Water quality in
partially dry wetlands was good with conductivity ranging
from 181 uS/cm to 510 uS/cm.
Two distinct communities relating to basin geomorphology
(and an additional depauperate single wetland community)
are described for the wet phase of these wetlands.
Community 2 (Eleocharis pusillaMyriophyllum simulans
Nymphoides crenataMarsilea hirsuta – Pseudoraphis
spinescens herbfield/sedgeland) occurs in broad gently
sloping basins. As water recedes from the edges of this basin,
the species-rich ephemeral component (Eleocharis pusilla,
Goodenia gracilis, Centipeda minima subsp. minima,
Epaltes australis, Isoetes muelleri) is established towards
the margins and in central deeper areas, a few true aquatics
(submerged, floating-leaved and emergents e.g. Najas
tenuifolia, Potamogeton sulcatus and Triglochin procera) are
found especially in clear water (Fig. 5). In some wetlands the
deeper water has a monoculture of Myriophyllum simulans
with the edges a monoculture of Eleocharis pusilla with a
smattering of other species. Species richness per plot is much
reduced in the dry phase; in one of the largest wetlands, the
wet phase had more than twice the species richness of the
dry phase (Benson et al. 2010; Hunter 2010). There are
also some compositional differences between wet and dry
phases (see Appendix). These ephemeral wetlands are more
species rich than the semi-permanent upland wetlands of
the Northern Tablelands (Bell et al. 2008). In this sampling
season 72 species occurred in the four largest Pilliga Outwash
wetlands compared to 47 species for one sampling season in
five upland wetlands (D. Bell, unpublished data).
The local name for these wetlands is ‘gilgai’, ‘tank gilgai’
or simply ‘tanks’. Gilgais are soil surface undulations in
desert landscapes that result from differential movements
of clay soil blocks (Hallsworth et al. 1955; Beadle 1981).
The distinctive lattice gilgai patterns on the grey cracking
clays under Brigalow to the north and northwest of Pilliga
National Park and Pilliga State Conservation Area can
clearly be distinguished on SPOT5 imagery from the
less patterned and more random ephemeral wetlands of
the Pilliga Outwash; it is unlikely that Pilliga Outwash
wetlands are formed through gilgai processes (Jim Charley
pers. comm.). The geology of Pilliga National Park is sand
plain, with sand predominant, gravel, and clay; the geology
186 Cunninghamia 12(3): 2012 Bell, Hunter & Montgomery, Ephemeral wetlands of the Pilliga
northwest is channel and oodplain alluvium (Atlas of NSW
2011). Outwash wetlands are thought to be depressions
originating from former billabongs or ponds left over from
ancient drainage lines, with the ‘tank’ depressions possibly
from more recent streams and their associated wetlands (Jim
Charley pers. comm.). Similar ponds occur sporadically
today along Coghill Creek.
Multiple levels of variability in the sampling data relate to
the timing of rainfall events, sampling times, salinity and
possibly to metapopulation dynamics. There is a degree
of unpredictability in whole wetland species richness not
apparently related to wetland size. There was no obvious
explanation for some small wetlands (and some large)
having many species and others not. Some wetlands may
have more sodic soils limiting them to more salt tolerant
species or the discrepancies may be due solely to chance.
Opportunistic colonization or extinction theoretically could
result in smaller population sizes, since filling events are
highly stochastic and localized. Some wetlands were no
doubt sampled at an early establishment phase since filling;
others at a later stage when herbfields were well established.
These are common methodological issues for sampling in
aseasonal ephemeral wetlands. The isolation in space of
some of the wetland populations may also limit dispersal of
some species and result in their limitation to certain wetlands.
Further exploration of the elements of this variability could
involve further sampling in both wet and dry phases and soil
and water testing.
Wetting/drying regime
Details of the depth, frequency, duration, extent and
variability of filling of these wetlands are as yet unknown,
and likely to be unpredictably stochastic. We presume that
the wetlands only fill from overland flow after extraordinary
rainfall events or series of events, but partially fill or remain
damp for some time after any reasonably large rainfall event.
Seed banks of ruderal species are no doubt replenished as a
result of these smaller events but true aquatics (deep water
floating-leaved, submerged and emergents) rely on long-
term persistence of seeds, tubers (Triglochin multifructa) or
rhizomes (Juncus, Cyperus gunnii subsp. gunnii) in the soil.
Rainfall is not only sporadic but usually highly localized so that
some wetlands fill while others may remain dry. That fraction
that fills allow species to complete life cycles and contribute to
persistence of these wetland communities in the landscape.
Similarities to other wetlands
These small but discrete lentic wetlands are found only
within that relatively small area of the Pilliga Scrub
towards the northwestern edge of the Pilliga Outwash and
are generally associated with closely patterned ephemeral
creeks and waterways (Figure 1). In the area searched on
SPOT 5 imagery (between Pilliga township, the Namoi
River and Narrabri in the north and the Pilliga sandstone
escarpment in the south), the only other lentic wetlands
detected were occasional dams, the much larger Yarrie Lake
and the distinctly patterned lattice gilgae on heavy clays.
Shallow ephemeral wetlands with sporadic wetting and
drying cycles are however not unique to the Pilliga. Although
mostly undescribed (but see McGann et al. 2001), ephemeral
wetlands are known to occur in other semiarid to arid parts
of NSW (see Porter et al. 2007). But we are unaware of any
that are numerous enough to form aggregations in such a
relatively small area and on such distinctive geomorphology.
Growth form types
Growth form types encountered in these wetlands are similar
to those of ephemeral wetlands worldwide: dwarf annuals
or short-lived species such as Eleocharis pusilla, Crassula
sieberiana, Eriocaulon australasicum, Centrolepis eremica,
Fig. 5. Typical Community 2 changes in dominant species along a water depth gradient in two large shallow basin wetlands. The black line
indicates changes in water depth; the green line distributional changes in dominant species with depth and distance from wetland margins.
Cunninghamia 12(3): 2012 Bell, Hunter & Montgomery, Ephemeral wetlands of the Pilliga 187
Callitriche sonderi, Ranunculus sessiliflorus and geophytic
perennials (species with persistent bases) such as Isoetes
muelleri and Ophioglossum lusitanicum (Deil 2005). Many
more species are ruderal or short-lived rather than perennial
and of those species establishing on damp soil few are clonal
(e.g. Eleocharis pusilla), in contrast to the strictly clonal
aquatic species of the deeper water. Not all species in the
ephemeral herbfield component are wetland specialists but
belong to those taxa encountered on damp soils in many other
situations such as in riparian areas and drainage depressions
(e.g. Epaltes australis).
Former land-use
The wetlands, especially the ‘tank’ wetlands, appear to have
been of use as a bare (i.e. tree-free) area by pastoralists. The
remains of a small stockyard was seen in one wetland; others
have remnants of fencing around them and were apparently
used with a rough one-way gate to trap and herd cattle. One
or two others provided an open area for cutting and stacking
Species significance
Three species currently listed on the NSW Threatened
Species Conservation Act 1995 were found within the
wetlands and six others were considered regionally
significant. The small annual herb Eriocaulon australasicum
(Family Eriocaulaceae) was occasional to common in plots
in four of the wetlands surveyed; this species is listed as
Endangered, both federally (EPBC Act) and statewide (TSC
Act), and in ROTAP (3V). There was a very early collection
along the Murray River in New South Wales (OE&H 2011a;
PlantNet 2011). Eriocaulon australasicum is known from a
few populations in Victoria and adjoining South Australia.
The annual herb Lepidium monoplocoides (Family
Brassicaceae), found scattered at wetland margins, is listed as
Endangered both federally (EPBC Act) and statewide (TSC Act)
and in ROTAP (3ECi) and is known from semi-arid regions of
New South Wales, Victoria and possibly South Australia.
Myriophyllum implicatum (Family Haloragaceae), a strictly
dioecious creeping herb (Orchard 1985) that forms discrete
mats on damp mud and can tolerate shallow water, was found
in four localized shallow basin wetlands, in one of which it
was the dominant species in an extensive band near the water’s
edge. Myriophyllum implicatum is usually confined to coastal
areas in south-eastern Queensland with an undated record
from the Hastings River in north-eastern New South Wales
(OE&H 2011b) and was considered extinct in New South
Wales until collected in 2008 by John Benson during surveys
in the Pilliga Region (Benson et al. 2010; PlantNet 2011).
Six species are considered regionally significant since they
are disjunct or thought to be at or near their geographic limits.
These taxa are: Centrolepis eremica, Drosera burmanni,
Hydrocotyle tripartita, Isoetes muelleri, Peplidium
foecundum and Philydrum lanuginosum. Of interest also
are the Nymphoides geminata populations. Nymphoides
geminata is usually homostylous but populations in the
Pilliga Outwash are consistently heterostylous.
Soil disturbance
Soil disturbance risks both disruption of the seed bank by
deeper burial of seeds and encouragement of weedy species.
Minor to extensive digging by wild pigs was seen in almost all
wetlands in 2010; pig wallows in deep holes were also seen
in September 2011. In addition, the soil surface of the more
accessible wetlands shows evidence of deep wheel tracks
of recreational vehicles (Fig. 6). Trampling and grazing by
stray cattle, feral goats and horses are also potential threats
to soil stability.
A plume of deposited soil from the erosion of a gully and
scald close to the northern boundary has the potential to
enlarge and to ultimately fill one of the ‘tank’ wetlands. Road
construction in or near wetlands is also a potential threat.
Road construction and hydrological change
A road has been constructed through the middle of one
of the mapped shallow basin wetlands with associated
roadside drains and additional drains elsewhere in the basin.
During a drought in late 2010 this drained wetland was
described as an ephemeral herbfield but with almost none
of the ephemeral wetland flora described for Community
2 (Hunter 2010). Hunter (2010) described this community
as a derived herbfield dominated by Tripogon loliiformis
and Enteropogon acicularis, floristically distinct from the
Bulbine semibarbataCalandrinia eremaea herbfield in
an intact wetland sampled during the same survey. Some
wetlands on private property to the north and northwest
appear to have been made more permanent by impoundment.
Fig. 6. Soil disturbance by recreational vehicles in a shallow basin
wetland, Pilliga NP, September 2011 (Wetland 98, 30˚30’15”S,
188 Cunninghamia 12(3): 2012 Bell, Hunter & Montgomery, Ephemeral wetlands of the Pilliga
Only 11% of taxa sampled during this survey were exotic.
Of these the small sedge Schoenoplectus erectus is known
to cause problems elsewhere (Benson et al. 2010), but is not
as yet a common component of these wetland communities.
We recommend that these ephemeral wetland communities
be considered endangered in New South Wales. Benson et
al. (2010) states that they are inadequately protected and
gives them the threat category Endangered (E/3c threat
criteria 2,4). These wetlands are relatively rare and localized
in the Pilliga Outwash landscape and are morphologically
distinct from and should not be confused with the more
common lattice gilgai depressions on grey cracking clays
under Brigalow on lands to the north and northwest. Only
one third of the mapped wetlands occur in reserves. Further
addition of lands to reserves or voluntary conservation
agreements would be beneficial to conservation, as well as
population studies of threatened species and monitoring of
weed invasion. Protection from recreational vehicles, pig
control and sedimentation is urgently required. Revisiting
and sampling the permanently marked sites in both wet
and dry phases would provide additional knowledge on the
vegetation dynamics of these communities.
The NSW Office for Environment and Heritage at Baradine
is thanked for providing vehicles and staff to assist the
survey. Sincere thanks are also due to Shane Edmonstone
who assisted the third author in quad bike ground-truthing
of wetlands, and to Kate Smiley, Daniel Bailey, and Jon
Burne for assistance with fieldwork. Ian Telford of the
N. C. W. Beadle Herbarium, University of New England
and John Hosking are thanked for assistance with species
nomenclature and identification.
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Manuscript accepted 2 April 2012
Cunninghamia 12(3): 2012 Bell, Hunter & Montgomery, Ephemeral wetlands of the Pilliga 189
C1 C2 C3 Other
Chara fibrosa 1
Chara sp.1
Nitella sonderi 1
Nitella sp.1
Isoetes muelleri 1
Marsilea costulifera 1
Marsilea drummondii a
Marsilea hirsuta 1
Ophioglossum lusitanicum 1
Bulbine semibarbata 1
Centrolepis eremica 1
Centrolepis strigosa subsp. strigosa 1
Commelina cyanea 1 1
Murdannia graminea 1
Carex inversa s. lat. 1
Cyperus betchei subsp. betchei 1 1
Cyperus difformis 1 1
Cyperus flaccidus 1
Cyperus gunnii subsp. gunnii 1 1
Cyperus gymnocaulos 1
Cyperus rigidellus 1
Cyperus sanguinolentus 1
Cyperus squarrosus 1
Eleocharis macbarronii 1
Eleocharis pallens 1
Eleocharis plana 1 1
Eleocharis pusilla 1 1
Fimbristylis dichotoma 1 1
Fuirena incrassata 1 1
Isolepis hookeriana 1
Lipocarpha microcephala 1 1
*Schoenoplectus erectus 1
Schoenus apogon 1
Eriocaulon australasicum 1
Ottelia ovalifolia subsp. ovalifolia 1
Vallisneria australis 1
*Sisyrinchium sp. A 1
Juncus aridicola 1
Juncus bufonius 1
Juncus continuus a
Juncus flavidus 1
Juncus ochrocoleus 1
Juncus psammophilus 1 1
Juncus subsecundus 1 1
Triglochin calcitrapa 1
Triglochin multifructa o
Najas tenuifolia 1
Philydrum lanuginosum 1 1
Dianella revoluta subsp. revoluta 1
Amphibromus nervosus 1
Chloris truncata 1 1
Cynodon dactylon 1 1
Dichelachne micrantha 1
Diplachne fusca 1 1 1
Eragrostis elongata 1 1
Eragrostis parviflora 1
Eragrostis speciosa o
Lachnagrostis filiformis 1
Panicum decompositum a
Pseudoraphis spinescens 1
Sporobolus caroli
*Vulpia bromoides 1
Walwhalleya subxerophila 1
Potamogeton sulcatus 1
Glinus oppositifolius 1
Damasonium minus 1
Alternanthera denticulata 1 1
*Gomphrena celosioides 1 1
Eryngium paludosum 1
Hydrocotyle tripartita 1
*Bidens pilosa 1
Brachyscome ciliaris var. subintegrifolia 1
Brachyscome goniocarpa 1
Brachyscome heterodonta b
Appendix 1. Vascular species and charophytes of Pilliga Outwash ephemeral wetlands. Community 1 is sedgeland/herbfield
of ‘tank’ wetlands; 2: herbfield/sedgeland with an ephemeral component in shallow basin wetlands; 3. Diplachne fusca
grassland. Exotic taxa are prefixed with an asterisk. Small letters indicate species named in other surveys or recorded
opportunistically: a: Benson (2010), b: Hunter (2010), o: opportunistic.
190 Cunninghamia 12(3): 2012 Bell, Hunter & Montgomery, Ephemeral wetlands of the Pilliga
Brachysome multifida var. multifida 1
Brachyscome nodosa a
Calotis hispidula 1
Calotis sp.1
*Centaurea melitensis 1
Centipeda cunninghamia b
Centipeda minima subsp. minima 1
Centipeda thespidioides 1
*Conyza bonariensis 1
Epaltes australis 1 1 1
Euchiton sphaericus 1
*Gamochaeta calviceps 1
*Gamochaeta coarctata 1
Helichrysum luteoalbum 1
Lemooria burkittii b
Myriocephalus pluriflorus 1
Myriocephalus rhizocephalus 1
Senecio glossanthus 1
*Soliva anthemifolia 1
*Sonchus oleraceus 1
Triptilodiscus pygmaeus 1
*Xanthium occidentale 1 1
Lepidium monoplocoides 1 1
Rorippa laciniata 1
Callitrichaceae 1
Callitriche sonderi 1
Wahlenbergia gracilenta b
Wahlenbergia gracilis 1
Wahlenbergia tumidifructa 1
*Sagina apetala 1
*Spergularia rubra 1 1 1
Allocasuarina luehmannii 1
Chenopodium pumilio 1
Dysphania glomulifera subsp. glomulifera o
Hypericum gramineum 1 1
*Cuscuta campestris 1
Crassula sieberiana 1
Drosera burmannii 1
Drosera indica 1
Drosera peltata 1
Elatine gratioloides 1
Chamaesyce drummondii 1
*Centaurium tenuiflorum 1
Goodenia gracilis 1
Goodenia sp.
Myriophyllum implicatum 1
Myriophyllum simulans 1 1
Myriophyllum striatum a
Myriophyllum verrucosum 1
Utricularia dichotoma 1
Isotoma fluviatilis subsp. borealis 1
Mitrasacme paludosa 1 1
Lythrum hyssopifolia 1
Nymphoides crenata 1 1
Nymphoides geminata 1
Eucalyptus chloroclada 1
Plantago turrifera 1
Polygonum plebeium 1
Rumex tenax 1
Calandrinia eremaea 1 1
Calandrinia pumila 1
Portulaca bicolor var. rosea
Portulaca filifolia 1 1
Portulaca oleracea 1
Primulaceae 1
*Anagallis arvensis 1
Myosurus minimus var. australis 1
Ranunculus sessiliflorus var. pilulifer 1
Glossostigma diandrum 1
Gratiola pedunculata 1
Mimulus gracilis 1
Peplidium foecundum 1
*Veronica peregrina 1
... Additionally, defining boundaries depends on conceptualisation and even if precise criteria are used, subjectivity is always unavoidable (Canny 1981;Winning 1991;Post et al. 2007). This is further exacerbated in many parts of the world and particularly within Australia due to unpredictable rainfall and long-term cycles leading to ephemerality (Bell et al. 2012;Schael et al. 2015;Lechner et al. 2016;Hunter and Lechner 2017;Hunter and Hunter 2020). Ephemeral wetlands may wet seasonally, episodically or intermittently causing inundation from months to years during wet cycles or in short flush events over days or weeks leading to significant changes in species dominance over short periods of time (Schael et al. 2015). ...
... Ephemeral wetlands may wet seasonally, episodically or intermittently causing inundation from months to years during wet cycles or in short flush events over days or weeks leading to significant changes in species dominance over short periods of time (Schael et al. 2015). Many Australian wetlands are impermanent in nature and may inundate rarely and are more often dry causing major changes in which life form types are promoted effecting vegetation classification (Paijmans et al. 1985;Bell et al. 2008Bell et al. , 2012. Even when more complex indicators are used to define wetlands and their component vegetation many of these may not be evident in ephemeral phases (Schael et al. 2015). ...
... In terms of sampling, wetlands are often small and lack connectedness (Bell et al. 2008(Bell et al. , 2012Cohen et al. 2016), which can lead to under-sampling within general stratified plot-based methods . Plot-based sampling methodologies designed for zonal vegetation may not be appropriate for the scale of assemblage variation within wetlands masking important changes (De Cáceres et al. 2015;Gellie et al. 2018). ...
The vegetation communities within semi-permanent or ephemeral montane marshes colloquially known as lagoons are an under investigated wetland type of the New England Tablelands Bioregion (NETB) yet they are listed (Upland Wetlands) on both state and federal acts as endangered. Lack of survey and analysis of plot data has meant that the variation in vegetation due to zonation, seasonality and unpredictable wetting and drying cycles are poorly understood. Here, 317 full floristic 2 × 2-m plots were placed across 13 lagoons. The plot data were classified to allow description of native and novel vegetation types using the hierarchical EcoVeg schema. The updated classification includes one Division and Macrogroup with 15 Alliances and 47 Associations. Permanent 50-m transects with a 1 × 1-m plot at every 5m (10 per transect) were placed within lagoons. Five lagoons were resurveyed annually for 3years. Within transects, each plot was assigned an Association after each survey period. Approximately one third of transect plots changed in vegetation type each year, often at the Alliance level. Over the 3-year period the number of Associations reduced by ~30% across transects associated with increasing drought and drying out of the wetlands. Transitional environments with the greatest level of hydrological periodicity had the greatest variety of Associations recorded. Highly dynamic systems with increased temporal turnover are likely to require increased sampling effort both spatially and temporally than more stable vegetated systems. The constant changing nature of these communities poses significant issues for management and conservation planning, including benchmarking and offsetting, which may require novel solutions.
... There is now a consensus that the formalisation of vegetation nomenclature and units is best done through the use of plot data sampled using appropriate protocols, standardised sampling techniques (e.g. plot size, scoring system) and with the use of appropriate statistics (Faber-Langendoen associations (Bell et al. 2012) defined as the Pilliga Outwash Ephemeral Wetlands in the Brigalow Belt South Bioregion (http:// aspx?id=20299, accessed 20 January 2017) and Halosarcia lylei low, open-shrubland in the Murray-Darling Depression Bioregion (, accessed 20 January 2017) on the NSW Threatened Species Conservation Act 1995. ...
... At larger extents, current classifications that include examples of ephemeral wetlands in arid and semi-arid areas of NSW are largely supervised approaches, relying on expert opinion (Fox 1991;Scott 1992;Porteners 1993;Pickard and Norris 1994;Westbrooke et al. 1998;Keith 2004;Benson et al. 2006). At smaller extents and specific locales, such as parks and reserves, many examples of unsupervised classifications exist (Westbrooke and Miller 1995;Porteners et al. 1997;McGann et al. 2001;Westbrooke et al. 2003;Hunter 2005;Bell et al. 2012;Smith and Smith 2014;. Keith (2004), using a type-based supervised classification, produced a set of higher-order hierarchical vegetation types for NSW termed 'formations' and 'classes'. ...
Describing, classifying and quantifying vegetation communities is fundamental for understanding their current distribution, rarity, interrelationships, and ecosystem functions. In this study, we apply a consistent objective classification system for ephemeral wetlands of arid and semi-arid areas of New South Wales (NSW), Australia. Our approach uses a two-step statistically-based, hierarchical, multi-scale classification of environmental data at broad-scales and floristics data at intermediate-scales. At broad-scales ecoregionalization methods were used to describe three wetland macrogroups. Within these groups, we performed unsupervised analyses of 640 floristic survey plots using the Bray-Curtis algorithm, clustering via group averaging and testing of clusters using SIMPROF. From this we delineated 18 vegetation groups with class definition based on a combination of diagnostic and non-diagnostic SIMPER outputs and dominant taxa. We show that a consistent classification system can be effectively created for subsets of vegetation that have adequate plot data within a general matrix that is poorly sampled if outputs are restricted to appropriate scales of resolution. We suggest that our approach provides a stable and robust classification system that can be added to as more data becomes available.
... A total of 94 mapped wetlands were visited, of these seven where found not to be ephemeral wetlands for various reasons (92.5% accuracy) (Figures 3 & 4). Wetlands visited included the four wetlands found to be dominated by this Myriophyllum implicatum by Bell et al. (2012) in September and November of 2010 and J.S. Benson in February of 2008. 87 wetlands were visited during this current survey period none of which were found to currently contain Myriophyllum implicatum and this included the four wetlands previously known to contain this species. ...
... Schoenoplectus erectus was found by J.S. Benson and considered to be a threat to Myriophyllum implicatum. The species was found within five sites (PT05, PT06, PT09, PT11 & PT25) by Bell et al. (2012). Sites PT09 and PT11 both contained Myriophyllum implicatum and it is suggested that an eradication program be implemented. ...
Technical Report
Full-text available
The Office of Environment and Heritage under funding from the Saving Our Species program requested Hewlett Hunter Pty Ltd to conduct a survey of the current extant populations of Myriophyllum implicatum Orch. (Haloragaceae) within the Pilliga reserve network within north west New South Wales.
... Australia is a dry continent, and thus, the more common and widely distributed wetlands are those that are impermanent in nature; that is, they may 'wet-up' once a year, multiple times a year or once within several decades, often not associated with seasonal patterns, but are dry more often than they are wet (Paijmans et al. 1985;Bell et al. 2008;Bell et al. 2012;Hunter and Lechner 2017). Such wetlands may contain shallow water less than 2 m depth, but more commonly only have saturated soils or seasonally standing water a few centimetres depth. ...
Full-text available
Aims : To use unsupervised techniques to produce a hierarchical classification of montane mires of the study region. Study area : New England Tablelands Bioregion (NETB) of eastern Australia. Methods : A dataset of 280 vascular floristic survey plots placed across the variation in montane mires of the NETB was collated. Vegetation types were identified with the aid of a clustering method based on group averaging and tested using similarity profile analysis (SIMPROF) and through ordinations using Bray-Curtis similarity and non-metric multidimensional scaling (NMDS). A hierarchical schema was developed based on EcoVeg hierarchy and was circumscribed using positive and negative diagnostic taxa via similarity percentage analysis (SIMPER) and importance based on summed cover scores and frequency. Results : We defined one macrogroup to include all montane mire vegetation of the NETB and within these two groups and twelve alliances. Conclusions : Our study re-enforced the separation of bogs from other montane mire systems and confirmed the separation of fens and wet meadows, a distinction that previously had not been independently tested. Based on our results many existing montane mire communities of the NETB have been ill-defined at multiple hierarchical levels, leading to confusion in threat status and mapping. Additionally, nearly half of the alliances we recognise were found to have no correlates within current classification systems, which necessarily has implications for the effectiveness of current conservation planning. Taxonomic reference : PlantNET (, accessed June 2016). Abbreviations : BC Act = Biodiversity Conservation Act; EPBC Act = Environmental Protection and Biodiversity Act; NETB = New England Tablelands Bioregion; NMDS = non-metric multidimensional scaling; PCT = plant community type; RE = regional ecosystem; SIMPER = similarity percentage analysis; SIMPROF = similarity profile analysis.
... Currently there are no known occurrences in conservation reserves. The Pilliga State Conservation Area is situated within 10 km of known sites and may have suitable habitat, although surveys of its ephemeral wetlands by Bell et al. (2012) Etymology: Rather than the commoner interpretation of 'claviflora' -clubbed flowers -the epithet is from the Latin clavus, a purple stripe or band decorating the tunic worn by persons of state in Ancient Rome and -flora, flower; referring to the deep purple bands visible on the ventral side of throat of the corolla tube that extend into the tube. ...
Full-text available
Lobelia claviflora Albr. & R.W.Jobson sp. nov. is described and illustrated, with notes on distribution, habitat, conservation status and features distinguishing it from closely related species of Lobelia and Isotoma.
... Because of temporal and within wetland variation, vegetation description in these, as in other dynamic systems, is problematic (Bell 2000;Bell et al. 2012). Although vegetation at the regional or whole wetland scale is appropriate for large-scale mapping (Benson & Jacobs 1994;Benson & Ashby 2000), broad descriptions ignore, of necessity, a wealth of detail that occurs at finer grains. ...
Technical Report
Full-text available
The Northern Tablelands Local Land Services requested Hewlett Hunter Pty Ltd to initiate a survey and monitoring program for Montane Lagoons within the New England Bioregion. Actions to be carried out included: a. Direct engagement with landholders known to have lagoons on their lands, b. Develop a rapid survey and monitoring technique appropriate for the dynamic nature of the lagoon environment and easily used by non-experts, c. Conduct survey and where applicable place markers for long term monitoring, d. Presentation at one open field day on lagoons, e. Evaluate lagoon condition. Though much research has been conducted specifically on the Lagoons within the Northern Tablelands of New South Wales there is still little understanding of the broader aspects of how best to manage these systems. Each lagoon is unique in how much they may wet or dry and what occurs within their small catchments. This variability leads to difficulties in condensing knowledge that may be broadly applicable to the lagoons as a whole or what may constitute a functioning system. The term lagoon itself maybe misleading to many as it conjures up beliefs that these systems should be always or primarily wet. This may lead to an over emphasis of the importance of characteristics that are attributed to the wet phase of these systems and the flora and fauna associated with this phase. This current report, while gathering a large amount of primary site data, should be seen as a background document providing largely anecdotal and sometimes speculative observations that may assist in highlighting areas of knowledge gap or where best efforts may be placed in order to obtain the better understanding. Only with further education, data collection and cross agency effort can we get beyond expert opinion to expert driven facts.
... The history of classification and mapping from the 1940s onwards in NSW is summarised in Keith (2004) and Benson (2006). A number of surveys (including Benson 1994;Hunter & Clarke 1998;Keith & Bedward 1999;Benson & Ashby 2000;Gellie 2005;Tozer et al. 2010;Bell et al. 2012;Hunter & Lechner 2017) have used similar analytical techniques to delineate fine hierarchical level vegetation types. Keith (2004) produced a mainly qualitative vegetation class classification which transformed best available vegetation mapping into a State-wide vegetation map largely by reassigning existing vegetation map polygons rather than using vegetation plot data. ...
Full-text available
We review vascular plant plot survey data, plot-based terrestrial vegetation classification protocols and schema by state and bioregions across Australia, discussing recent regional approaches in States and bioregions. A high degree of inconsistency exists in vegetation classification methods and management of plot data across jurisdictions and Australia currently lacks a unified national vegetation plot database, vegetation plot-recording protocols and agreed thematic outputs for classification. Broad-scale classifications were developed largely to support vegetation mapping based on remote sensing of image patterns. Since the 1970s, plot datasets from well-sampled regions have been subjected to a range of analyses (sometimes numerical) producing finer-scaled but idiosyncratic classifications. There are robust numerical classifications for less than 5% of the Australian continent. In poorly sampled and plot-free regions, vegetation classification has focussed on expert description or hybrid approaches using patchy quantitative outputs where they exist. A rigorous quantitative continental regional to local scale approach to classification will not be possible until major data gaps are filled. Additionally, the impact of Australia’s inconsistent rainfall on species composition and abundance in analyses of combined datasets requires careful consideration. Given that vegetation classification is integral to Australian biodiversity laws and regulations, there would be benefits in extending quantitative plot coverage to data-poor areas, encouraging cross jurisdictional co-operation of classification procedures, promoting the use of comparable methodologies and sampling under different disturbance and climatic regimes. The development of a consistent vegetation classification across Australia will also require inter-state co-operation, higher standards of plot data curation and plant taxa nomenclature, agreed nation-wide classification protocols and a scientifically defensible hierarchical classification that should integrate with the International Vegetation Classification (IVC).
... We used the number of Red List species as an indicator of the conservation value of the plant communities emerging from the soil samples. Other studies have shown that the conservation value of temporarily flooded depressions can be very high (Bell et al. 2012;Casanova and Brock 1990;Lukacs et al. 2013). Indeed, we also found endangered species in most of the soil samples. ...
Full-text available
Temporarily flooded depressions in arable fields support populations of specialised plant species that are affected by flooding and agricultural management. Depending on the degree of flooding, different proportions of wetland and arable species contribute to the seed bank. This is reflected by high inter-annual variations in plant communities with a high conservation value. Due to ongoing agricultural intensification, the biodiversity of temporarily flooded depressions has declined, and several plant species have become regionally extinct. Because seed banks harbour persistent seeds over long periods, they play a crucial role in the conservation and restoration of temporary wetland vegetation. This study focuses on the effects of different flooding regimes on plant species emerging from seed banks of temporarily flooded depressions in arable fields in northeast Germany. We cultivated soil samples from upper and lower wetland zones under short, intermediate and long-term flooding (5, 15 and 40 cm above soil surface) in a common garden experiment over 2 years. We observed significant changes in species composition depending on the flooding duration. Species richness declined and evenness increased with increasing flooding duration. Upper and lower zones showed similar species richness and evenness, but species compositions differed. Red List species emerged from all treatments although the species differed, indicating that all communities emerging under different flooding regimes have a high conservation value. Seed banks under fluctuating site conditions can constitute a series of alternating plant communities. This could be used to develop management strategies that benefit different communities with high conservation values.
... Although Dianella sp. are not species restricted to wetland habitats, some species have been observed in ombrotrophic bogs, swamps and other mires (e.g. Wardle 1991;Bell et al. 2012). These wetlands are characterized by being fed only by precipitation and by commonly being nutrient-poor and acidic, which may be similar to the past conditions of the Raraku palaeo-mire. ...
Full-text available
Easter Island, a remote island in the Pacific Ocean, is currently primarily covered by grasslands, but palaeoecological studies have shown the former presence of different vegetation. Much of its original biota has been removed during the last two millennia, most likely by human activities, and little is known about the native flora. Macrofossil and pollen analyses of a sediment core from the Raraku crater lake have revealed the occurrence of a plant that is currently extinct from the island: Dianella cf. intermedia/adenanthera (Xanthorrhoeaceae), which grew and disappeared at the Raraku site long before human arrival. The occurrence of Dianella within the Raraku sedimentary sequence (between 9.4 and 5.4 cal. kyr B.P.) could have been linked to the existence of favorable palaeoenvironmental conditions (peatland rather than the present-day lacustrine environment) during the early to mid Holocene. This finding contributes new knowledge about indigenous plant diversity on Easter Island and reinforces the usefulness of further macrofossil and pollen analyses to identify native species on Easter Island and elsewhere.
Full-text available
The vegetation of Narran Lake Nature Reserve (4527 ha) in the central north of New South Wales approximately 30 km west of Cumborah (29°43', 147°29') in the Walgett Shire on the North Western Plains and the Darling River Plains Bioregion is described. Seven communities are defined based on flexible UPGMA analysis of cover-abundance scores of all vascular plant taxa. These communities are mapped based on ground truthing, air photo interpretation and geological substrate. All communities are simple in structure being primarily woodlands, shrublands and herbfields. Communities are: 1) Mixed Low Woodlands, 2) Mulga Low Woodlands, 3) Triodia Hummock Grasslands, 4) Chenopod Low Open Shrublands, 5) Ephemeral Herbfields, 6) Riparian Open Forests, and 7) Lignum Shrubby Thickets. A total of 325 taxa were recorded including two species listed under the NSW Threatened Species Conservation Act (1995), Lepidium monoplocoides and Goodenia macbarroni. An additional 11 species are considered to be at their geographic limit or disjunct in their distribution; 11% are exotic in origin.
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The floristic composition and extent of Carex-dominated fens in the New South Wales New England Tablelands Bioregion and Barrington Tops area (lat 28° 41' S–31° 55' S; long 151° 23' E–152° 05' E) together with outliers from the central west (Coonabarabran) are described from 81 full floristic survey sites. These fens contained 234 vascular plant taxa of which 27% were exotic. The fens were dominated by herbaceous vegetation (96% of taxa). Cluster analysis of cover-abundance scores of vascular plant taxa from 81 plots placed within 71 separate Carex fens revealed three alliances: 1) Carex appressa, 2) Scirpus polystachyus – Carex tereticaulis and 3) Carex gaudichaudiana and seven communities: (1) Carex appressa – Stellaria angustifolia Fen (2) Carex appressa Fen (3) Scirpus polystachyus – Carex appressa Fen (4) Carex tereticaulis Fen (5) Carex gaudichaudiana – Isachne globosa Fen (6) Carex sp. Bendemeer – Carex gaudichaudiana Fen (7) Carex gaudichaudiana – Glyceria australis Fen The distribution of alliances showed a pattern of east-west separation. The most easterly alliance shares many features with the Carex gaudichaudiana Alliance of the Monaro Region of southern NSW while the other alliances have no counterparts within the current literature. We estimate that up to 5 000 ha of fen vegetation survive in the New England Bioregion of which 90% is on grazed land and only 0.2% is within conservation reserves. Seven outstanding examples of fens remain; most are examples of Community 5, with one representing Community 6 and none representing the other five communities. Many of these are not secured, and none of those within reserves are in their 'natural' state. We therefore strongly encourage measures to allow closure of drains, the opening of dams, and the rehabilitation of important fens such as Bishops, Racecourse and New Country Swamps. Cunninghamia (2009) 11(1): 49–64
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Abstract: For the Western Plains of New South Wales, 213 plant communities are classified and described and their protected area and threat status assessed. The communities are listed on the NSW Vegetation Classification and Assessment database (NSWVCA). The full description of the communities is placed on an accompanying CD together with a read-only version of the NSWVCA database. The NSW Western Plains is 45.5 million hectares in size and covers 57% of NSW. The vegetation descriptions are based on over 250 published and unpublished vegetation surveys and maps produced over the last 50 years (listed in a bibliography), rapid field checks and the expert knowledge on the vegetation. The 213 communities occur over eight Australian bioregions and eight NSW Catchment Management Authority areas. As of December 2005, 3.7% of the Western Plains was protected in 83 protected areas comprising 62 public conservation reserves and 21 secure property agreements. Only one of the eight bioregions has greater than 10% of its area represented in protected areas. 31 or 15% of the communities are not recorded from protected areas. 136 or 64% have less than 5% of their pre-European extent in protected areas. Only 52 or 24% of the communities have greater than 10% of their original extent protected, thus meeting international guidelines for representation in protected areas. 71 or 33% of the plant communities are threatened, that is, judged as being ‘critically endangered’, ‘endangered’ or ‘vulnerable’. While 80 communities are recorded as being of ‘least concern’ most of these are degraded by lack of regeneration of key species due to grazing pressure and loss of top soil and some may be reassessed as being threatened in the future. Threatening processes include vegetation clearing on higher nutrient soils in wetter regions, altered hydrological regimes due to draw-off of water from river systems and aquifers, high continuous grazing pressure by domestic stock, feral goats and rabbits, and in some places native herbivores — preventing regeneration of key plant species, exotic weed invasion along rivers and in fragmented vegetation, increased salinity, and over the long term, climate change. To address these threats, more public reserves and secure property agreements are required, vegetation clearing should cease, re-vegetation is required to increase habitat corridors and improve the condition of native vegetation, environmental flows to regulated river systems are required to protect inland wetlands, over-grazing by domestic stock should be avoided and goat and rabbit numbers should be controlled and reduced. Conservation action should concentrate on protecting plant communities that are threatened or are poorly represented in protected areas.
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The vegetation of montane lagoons of the New England Tablelands Bioregion, New South Wales is examined using flexible UPGMA analysis of frequency scores on all vascular plant taxa, charophytes and one liverworts. Seven communities are described- 1. Hydrocotyle tripartita - Isotoma fluviatilis - Ranunculus inundatus - Lilaeopsis polyantha herbfield 2. Eleocharis sphacelata - Potamogeton tricarinatus sedgeland 3. Eleocharis sphacelata - Utricularia australis - Isolepis fluitans, herbfield 4. Utricularia australis - Nitella sonderi herbfield 5. Eleocharis sphacelata - Utricularia australis - Ricciocarpus natans sedgeland 6. Carex gaudichaudiana - Holcus lanatus - Stellaria angustifolia sedgeland 7. Cyperus sphaeroides - Eleocharis gracilis - Schoenus apogon - Carex gaudichaudiana sedgeland. 58 lagoons were located and identified, only 28% of which are considered to be intact and in good condition. Two threatened species (Aldovandra vesiculosa and Arthaxon hispidus) and three RoTAP-listed taxa were encountered during the survey. Cunninghamia (2008) 10(3): 475-492
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This fourth paper in the NSW Vegetation Classification and Assessment series covers the Brigalow Belt South (BBS) and Nandewar (NAN) Bioregions and the western half of the New England Bioregion (NET), an area of 9.3 million hectares being 11.6% of NSW. It completes the NSWVCA coverage for the Border Rivers-Gwydir and Namoi CMA areas and records plant communities in the Central West and Hunter–Central Rivers CMA areas. In total, 585 plant communities are now classified in the NSWVCA covering 11.5 of the 18 Bioregions in NSW (78% of the State). Of these 226 communities are in the NSW Western Plains and 416 are in the NSW Western Slopes. 315 plant communities are classified in the BBS, NAN and west-NET Bioregions including 267 new descriptions since Version 2 was published in 2008. Descriptions of the 315 communities are provided in a 919 page report on the DVD accompanying this paper along with updated reports on other inland NSW bioregions and nine Catchment Management Authority areas fully or partly classified in the NSWVCA to date. A read-only version of Version 3 of the NSWVCA database is on the DVD for use on personal computers. A feature of the BBS and NAN Bioregions is the array of ironbark and bloodwood Eucalyptusdominated shrubby woodlands on sandstone and acid volcanic substrates extending from Dubbo to Queensland. This includes iconic natural areas such as Warrumbungle and Mount Kaputar National Parks and the 500,000 ha Pilliga Scrub forests. Large expanses of basalt-derived soils support grassy box woodland and native grasslands including those on the Liverpool Plains; near Moree; and around Inverell, most of which are cleared and threatened. Wetlands occur on sodic soils near Yetman and in large clay gilgais in the Pilliga region. Sedgelands are rare but occupy impeded creeks. Aeolian lunettes occur at Narran Lake and near Gilgandra. Areas of deep sand contain Allocasuarina, eucalypt mallee and Melaleuca uncinata heath. Tall grassy or ferny open forests occur on mountain ranges above 1000m elevation in the New England Bioregion and on the Liverpool Range while grassy box woodlands occupy lower elevations with lower rainfall and higher temperatures. The vegetation classification and assessment is based on over 100 published and unpublished vegetation surveys and map unit descriptions, expert advice, extra plot sampling and data analysis and over 25 000 km of road traverse with field checking at 805 sites. Key sources of data included floristic analyses produced in western regional forest assessments in the BBS and NAN Bioregions, floristic analyses in over 60 surveys of conservation reserves and analysis of plot data in the western NET Bioregion and covering parts of the Namoi and Border Rivers-Gwydir CMA areas. Approximately 60% of the woody native vegetation in the study area has been cleared resulting in large areas of “derived” native grasslands. As of June 2010, 7% of the area was in 136 protected areas and 127 of the 315 plant communities were assessed to be adequately protected in reserves. Using the NSWVCA database threat criteria, 15 plant communities were assessed as being Critically Endangered, 59 Endangered, 60 Vulnerable, 99 Near Threatened and 82 Least Concern. 61 of these communities are assessed as part of NSW or Commonwealth-listed Threatened Ecological Communities. Current threats include expanding dryland and irrigated cropping on alluvial plains, floodplains and gently undulating topography at lower elevations; over-grazing of steep hills; altered water tables and flooding regimes; localised mining; and the spread of exotic species, notably Coolatai Grass (Hyparrhenia hirta).
The 36 species of Myriophyllum found in Australia are keyed, described and illustrated. Fifteen species (M. alpinum, M. austropygmaeum, M. balladoniensis, M. costatum, M. crispatum, M. decussatum, M. echinatum, M. im- plicatum, M. limnophilum, M. lophatum, M. muricatum, M. papillosum, M. petraeum, M. simulans, M. striatum), one subspecies (M. callitrichoides ssp. striatum) and two varieties (M. gracile var. lineare and var. laeve) are newly recognized, and one new com- bination (M. pedunculatum ssp. longibracteolatum) is proposed. The grouping of the Australian species into 'alliances' is discussed, and their relationships with some extra- Australian species are explored.
Based upon a world-wide literature review and a database, which refers to 250 publications and documents about 8500 phytosociological relevés, the following questions are discussed: What are the common ecological parameters for temporary wetlands and which environmental conditions offer a niche for dwarf ephemerals? Which taxa have evolved and speciated within ephemeral wetland habitats? How do the relations between relief features, local hydrology and climatic conditions change in different parts of the world? Which global patterns in flora and vegetation do occur?The review is restricted to ephemeral freshwater ecosystems with the following two properties: Above-ground plant cover is seasonal, and the habitats are water-saturated or submerged only part of the year. For a better understanding of large-scale patterns, the results of studies about small-scale zonation, variability in time (phenology and year-to-year dynamics), ecophysiology and life strategies are briefly reported. Finally, conservation aspects and trends of floristic globalization are considered.Three habitat types can be distinguished according to relief, hydrology and climate:1. Seasonal pools: They occur in semi-arid and subhumid climates at both sides of the Tropic of Cancer. The catchment areas are local or the ponds are purely rainwater systems.2. Amphibic shorelines of permanent ponds, lakes and rivers: They concentrate in perhumid extratropical temperate zones and in orotropical climates. Along allochthonous rivers with extended catchments and with seasonal flood pulse, large temporary floodplains also occur in semi-arid regions.3. Ephemeral flush habitats: In the perhumid tropics and in the subhumid subtropics, ephemeral wetlands are linked to runoff-habitats like the slopes of inselbergs and rock outcrops and to interflow habitats along intermittent streams.The distribution of some keystone taxa reflects the present climatic differentiation of the globe and to some extent also historical events (palaeogeography, speciation processes). Myosurus for example is linked to extratropical regions, Lilaeopsis to the New World and the Southern Hemisphere, Limnophila and Rhamphicarpa to the Palaeotropical region. Vicariance patterns are a common phenomenon. Examples can be seen in Isoetes, Marsilea, Ophioglossum, Juncus (sections Tenageia, Ozophyllum and Caespitosi), Limosella, Crassula (section Helophytum), Bacopa, Hydrocotyle, Eriocaulon and Xyris. These genera speciated within this environment and evolved habitat equivalent species. The reduced size and the spatial isolation of the habitat reduce gene flow and favour allopatric speciation. The variability in time and small-scale ecological gradients stimulate sympatric speciation by temporal separation of the populations. Niche-equivalent taxa replace each other in different parts of the world. The niche of dwarf ephemeroid annuals is occupied by Centrolepidaceae in the Australian region, by Restionaceae in the Capensis, by Eriocaulaceae in the Australian region and East Asia, by Juncaceae in the holarctic kingdom, by Orcuttieae in the Californian phytogeographical sector, and by Cyperaceae, Crassulaceae, Gentianaceae, Elatinaceae and Apiaceae in all floristic kingdoms. Other predominant life forms are herbaceous perennials with the isoetid syndrome, geophytic ferns (Ophioglossum, Marsilea), carnivorous plants from the families Lentibulariaceae and Droseraceae, and poikilohydric vascular plants with the xyroid syndrome. The latter occur in the Tropics, with Xyridaceae (pantropical), Velloziaceae (neotropical region), Afrotrilepis, Craterostigma, Lindernia, Chamaegigas (palaeotropical region), Trilepis (neotropical region) and Borya (Australian region). (to be continued in the full text).