Cunninghamia : A Journal of Plant Ecology for Eastern Australia, Volume 8, Issue 2 (2003)
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Floristic composition and environmental relationships of Sphagnum-dominated communities in Victoria
(2003)
Floristic community types and their environmental correlates are described for Sphagnum-dominated communities throughout Victoria. Current threats to the condition of these communities are outlined, with an assessment of their conservation status. Sites from lowland (350 m) to alpine (1780 m) areas were surveyed and seven floristic groups were recognised using cluster analysis and non-metric multi-dimensional scaling techniques. The strongest floristic gradients corresponded to altitude, temperature, rainfall, geology and current condition. Several of the sites surveyed were degraded, with some sites heavily impacted by cattle grazing or invaded by weeds. While some floristic groups, particularly sub-alpine bogs, are reserved in national parks, others such as montane and lowland bogs occur on forestry and private land tenures. Reservation has not protected some sites from threatening processes, most notably in alpine national parks, where cattle grazing has seriously degraded many of these Sphagnum peatland communities to either disclimax communities or isolated moss beds no longer functioning ecologically as peatlands. Further surveys of Sphagnum-dominated communities elsewhere in Victoria are warranted, especially montane and lowland areas. The results suggest Sphagnum-dominated communities will require conservation planning and management action throughout their geographic range in Victoria.
The vegetation of the Central Division of New South Wales (lat. 31°–33° S, long. 146° 30’–149° E) was classified and mapped (Cobar–Nyngan–Gilgandra, Nymagee–Narromine–Dubbo 1:250 000 mapsheets) as part of the NSW National Parks & Wildlife Service wheat-belt mapping series. The vegetation classification was derived using traditional air photo interpretation and quantitative analysis of data from 428 field sites. Analyses included hierarchical classification in PATN to define floristic groups, then Fidel and ANOSIM to elucidate the characteristic species of the groups and explore the consistency of these relationships at various levels of similarity. Maps and descriptions show the floristic composition and structure, the geographic distribution of assemblages, the current extent, and shape and degree of connectivity of vegetation and changes in native woody vegetation cover over time.
22 vegetation units were defined, 19 were woodlands and forests dominated by eucalypts including Eucalyptus populnea subsp. bimbil — P4 Poplar Box Woodlands and P16 Simple Poplar Box Woodlands; Eucalyptus largiflorens — R3 Black Box Woodlands; Eucalyptus microcarpa — P12 Woodlands on Jurassic Sandstone and P13 Grey Box Woodlands; Eucalyptus camaldulensis — R1 River Red Gum Forests and Woodlands; Eucalyptus intertexta — P14 Red Box, Poplar Box and Pine Woodlands, U1 Red Box, Poplar Box, Pine and Green Mallee Woodlands and U2 Red Box, Poplar Box and Pine Woodlands on Granite Hillslopes; Eucalyptus dwyeri — U3 Dwyer’s Red Gum Low Open Woodland on Granite Crests, H1 Dwyer’s Red Gum, Ironbark and Green Mallee Woodlands and H9 Dwyer’s Red Gum Open Woodlands on Granite Hills; Eucalyptus viridis — H2 Green Mallee Woodlands; Eucalyptus morrisii — H6 Grey Mallee Open Woodlands; Mallee — H7 Mallee Woodlands on Rolling Hills and P1 Mallee Woodlands on Plains; Eucalyptus dealbata — H8 Tumble-down Red Gum Woodlands on Basalt Hills; and Eucalyptus chloroclada — P15 Dirty Red Gum, Pine and Poplar Box Woodlands. These eucalypt woodlands exhibit diversity in structure and associated species composition. Two tall open shrublands of Acacia pendula — R5 Myall Woodlands and Flindersia maculosa — P11 Leopardwood Open Shrublands and a woodland dominated by Callitris glaucophylla — P6 White Cypress Pine Woodlands are included in the mapping.
The current extent of native woody vegetation is 1.2 million ha (29%) of the total 4.1 million ha study area. Over a period of 15 years approximately 130 000 ha or 10% of the extant vegetation was cleared. Only four of the 22 vegetation units are represented in conservation reserves. These reserves are not considered to adequately represent the diversity of the vegetation units they contain nor do they comprehensively represent the diversity of the vegetation. Threatening processes including; continued clearing, changing water regimes, habitat fragmentation, over-grazing by domestic, feral and native animals, nutrient enrichment, compaction of soil, firewood collection and weed invasion operate in this predominantly agricultural landscape, all of which have implications for the long-term persistence of the vegetation of the area.
The vegetation of Arakoola Nature Reserve (3189 ha), 29°17’S, 150°48’E, 100 km north-west of Inverell, in north western New South Wales is described. Seven vegetation 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. They are: Community 1: Eucalyptus albens (White Box) – Eucalyptus melanophloia (Silver-leaved Ironbark) Basalt Woodland, Community 2: Angophora leiocarpa (Smooth-barked Apple) – Corymbia dolichocarpa (Long-fruited Bloodwood) Sandstone Woodland, Community 3: Angophora leiocarpa (Smoothbarked Apple) – Eucalyptus macrorhyncha (Red Stringybark) Woodland, Community 4: Chloris truncata (Windmill Grass) Grassland, Community 5: Herbfield/Sedgeland, Community 6: Eucalyptus camaldulensis (Red Gum) – Eucalyptus melliodora (Yellow Box) Riparian Woodland, Community 7: Angophora floribunda (Rough-barked Apple) – Callistemon viminalis (Weeping Bottlebrush) Riparian Woodland.
There are 23 taxa considered significant within Arakoola Nature Reserve including the twining herb Desmodium campylocaulon and the shrub Pomaderris queenslandica (listed as Endangered under the NSW Threatened Species Conservation Act), and the grasses Dichantheum setosum and Bothriochloa biloba, and the perennial herbs Goodenia macbarroni and Thesium australe (all listed as Vulnerable under the TSC Act). A comprehensive species list of about 450 plant species is given for the Nature Reserve.
Information is provided on the taxonomy and distribution of 40 species of naturalised or naturalising plants newly recorded for New South Wales during the period 1 January 2000 to 31 December 2001. These species are: Abrus precatorius subsp. precatorius, Acacia pulchella var. pulchella, Agave vivipara, Alnus glutinosa, Berberis thunbergii, Bryophyllum daigremontianum x Bryophyllum delagoense, Callisia fragrans, Celtis sinensis, Chamaesyce ophthalmica, Cotoneaster ?horizontalis, Cupressus arizonica, Cylindropuntia arbuscula, Cylindropuntia leptocaulis, Cylindropuntia spinosior, Cylindropuntia tunicata, Cyperus teneristolon, Deutzia crenata, Erica arborea, Erica glandulosa, Geranium robertianum, Hieracium murorum species group, Hippeastrum puniceum hybrid, Hyacinthoides non-scripta, Hypericum kouytchense, Hypericum patulum, Jacaranda mimosifolia, Jasminum polyanthum, Juglans regia, Justicia betonica, Koelreuteria formosana, Myagrum perfoliatum, Oenothera biennis, Pinus durangensis (naturalising), Pinus nigra var. corsicana, Schinus terebinthifolius, Scorpiurus muricatus, Tillandsia usneoides, Triadica sebifera, Viola riviniana and Vitis vinifera s. lat.
Wallum and related vegetation on the NSW North Coast : description and phytosociological analysis
(2003)
Wallum is the regionally distinct vegetation on coastal dunefields, beach ridge plains and sandy backbarrier flats in subtropical northern NSW and southern Queensland (22°S to 33°S). This study examined floristic patterns in the wallum and allied vegetation along 400 km of coastline in north-eastern NSW. Floristic and environmental data were compiled for 494 quadrats allocated on the basis of air photo pattern and latitude. A phytosociological classification displayed strong congruence with an initial classification based upon photo pattern, especially for single stratum vegetation, thereby suggesting that API (air photo interpretation) is a valuable technique for the recognition of floristic assemblages. The utility of API for depicting the spatial distribution of tallest stratum species in multi-stratum vegetation was also confirmed. Nonetheless, photo signatures of the tallest stratum are less satisfactory as surrogates for identifying noda for the full complement of species in multi-stratum vegetation. Ordination supported the numerical classification, and reinforced the value of API for capturing meaningful biological and environmental data. Plant – environment relationships were examined for a range of variables. The consistent trend to emerge was a comparatively strong correlation between floristic composition and topographic position, and in some instances also between floristic composition and geology. Mean species richness at the 25 m2 scale was lower in wetter habitats, although differences were not consistently significant.
The breeding systems of the rainforest shrubs Hicksbeachia pinnatifolia and Triunia youngiana were studied in north-east New South Wales, where the former is listed as a vulnerable species. Hicksbeachia pinnatifolia flowered in winter and spring, and produced an average of 36 inflorescences per plant with 155 flowers per inflorescence (5580 flowers per plant). Inflorescences initiated and matured only a small number of fruits (c. 1–2 per inflorescence) in self-pollinated and open-pollinated treatments. This compared to about 17 fruits initiated and 4 fruits matured per inflorescence when cross-pollinated. Triunia youngiana flowered in spring and produced an average of 3 inflorescences per plant containing 23 flowers per inflorescence (69 flowers per plant). Plants were unable to initiate any fruit in autogamy and self-pollinated treatments. Plants in a cross-pollination treatment produced over three times as many fruit (3.5 matured per plant) compared to a control treatment (0.8 per plant), suggesting that plants were pollen-limited. Both treatments experienced substantial (80%) fruit abortion. These results indicate that Triunia youngiana is self-incompatible whereas Hicksbeachia pinnatifolia appears to be partially self-compatible.