Cunninghamia : A Journal of Plant Ecology for Eastern Australia, Volume 6, Issue 3 (2000)
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Vegetation survey of the Barrington Tops and Mount Royal National Parks for use in fire management
(2000)
This paper reports on a vegetation study undertaken to enable the development of appropriate fire management strategies for the conservation of biodiversity. The approach taken is to relate fire response mechanisms reported for species within the literature to floristic patterns.
Floristic and environmental data were obtained from the National Parks and Wildlife Service. The data set was derived from 262 plots located within and around the study area. Data were analysed using classification, ordination, one way non-parametric analysis of variance, and correlation routines contained within the PATN computer package.
On the basis of this analysis, 14 vegetation communities were delineated including 12 non-rainforest communities. There was a strong relationship between the floristic pattern and a number of environmental variables, including altitude, climatic variables, geographic location, and geology. "Years since logging" and "Years since last fire" were also relatively highly correlated, but much of this data is based on subjective field estimates in relatively few sites, often several years after a fire had occurred and is therefore less reliable.
The relationships between floristic data and known plant fire response mechanisms, were generally weak, though significant. The weakness of the correlation is probably due to the lack of information on fire response for many species. On the basis of the existing data base, preliminary guidelines are provided on the nature of suitable fire regimes. Suggestions are given for further study of the floristic pattern, fire history, and other data required to guide ecological fire management in the future.
This study examined a variety of written, cartographic and pictorial historical materials to document the extent and distribution of inter-tidal wetlands and riparian vegetation along the Parramatta River and its bays from 1788 (first settlement in Port Jackson) to c. 1940 (when documentation by aerial photographs commenced). Although data available do not permit detailed quantitative analysis, and no single source is definitive, in total they yield a more detailed picture has hitherto been available. These historical sources indicate that in the 19th century extensive mudflats and saltmarsh communities dominated the inter-tidal zone, with mangroves more limited to creek fringes and some patches in bays for much of the period. In the upper river from Subiaco Creek to Parramatta, there is no evidence for the presence of mangroves until the 1870s. Following settlement and increased sedimentation, inter-tidal mudflats expanded, mangroves colonised up river and out onto mudflats in bays in the latter part of the 19th century, followed by expansion into saltmarsh in the 20th century.
This study demonstrates that some of the assumptions regarding the former extent of mangroves on which recent studies and foreshore plans are based are inappropriate. The historical data, combined with subsequent aerial photographic data, provides an enlarged database that needs to be taken into account in the formulation of conservation management plans and restoration strategies.
The "Zara" exclosure (approximately 35°10'21''S, 144°41'59''E) is on a source-bordering dune on the Riverine Plain north of Deniliquin. The vegetation of this sandhill closely represents the original vegetation that once covered sandhills of the south-west Riverina prior to European occupation. Three vegetation communities comprising six associated Map Units were defined by cluster analysis within the 60 ha exclosure. These were the Callitris Mixed Woodland (Map Units 1, 2, 3, and 6), the Black Box Woodland (Map Unit 5) and the White-top Grassland (Map Unit 4). Seventy-seven taxa were recorded during the survey, and the vegetation was dominated by species from the families Chenopodiaceae and Poaceae. Three shrubs, the exotic weed Lycium ferocissimum and the natives Rhagodia spinescens and Enchylaena tomentosa occurred at more than 75% of sites. The distribution of vegetation communities was strongly associated with attributes of the soil (e.g. soil texture and organic carbon) and plant and litter cover. Vegetation communities occupying remnant sandhills such as the "Zara" exclosure are some of the most vulnerable communities on the Riverine Plain.
The vegetation of Booti Booti National Park and Yahoo Nature Reserve on the lower North Coast of New South Wales has been classified and mapped from aerial photography at a scale of 1:25,000. The plant communities so identified are described in terms of their composition and distribution within Booti Booti NP and Yahoo NR. The plant communities are also discussed in terms of their distribution elsewhere in south-eastern Australia, with particular emphasis given to the NSW North Coast where compatible vegetation mapping has been undertaken in many additional areas. Floristic relationships are also examined by numerical analysis of full-floristics and foliage cover data for 48 sites. A comprehensive list of vascular plant taxa is presented, and significant taxa are discussed. Management issues relating to the vegetation of the reserves are outlined.
Vegetation in the remote Pooncarie region of south-western New South Wales was surveyed in the springs of 1995 and 1997 following rain. One area of 100 km2 was examined in 1995 and three zones totalling 468 km2 were surveyed in 1997. Sampling in 1997 targeted sites removed from artificial watering points and human habitation. Two of the three areas examined in 1997 were remote from access tracks. These areas were assumed to be relatively free from human impacts, have reduced grazing pressures and hence higher plant species diversity and a greater conservation value than areas which were closer to human disturbance or artificial water supplies.
Both the 1995 and 1997 data were statistically analysed using a hierarchical agglomerative clustering technique. Three broad vegetation groupings were discerned, Mallee dune crests, Lake beds and Mallee with Trioda scariosa.
Species richness for the area was high with 36% of the total species recorded being ephemerals. Exotic species were found in almost all the sampling locations, accounting for approximately 10% of the total species diversity. As exotic species are indicators of disturbance, it can be concluded that disturbance, or its influence, is widespread, but relatively minimal, throughout the area. Scats of native and exotic grazing animals were found throughout the survey areas.
A total of 375 species (328 native and 47 exotic) from 64 families/subfamilies was recorded in both surveys. In the 1995 survey, 263 species (226 native and 37 exotic) from 57 families/subfamilies were recorded. In the 1997 survey, 311 species (277 native and 34 exotic) from 61 families/subfamilies were noted. In terms of species of conservation significance, two species of national, five species of state and 21 species of regional significance were recorded. One new species was recorded for New South Wales and 25 new species were recorded for South Far West Plains botanical division.
The remnant natural vegetation (excluding native grasslands) of the Guyra 1: 100 000 map sheet area was sampled by way of 312 20 m × 20 m plots in which all vascular species were recorded using a modified Braun-Blanquet abundance rating. Sampling was stratified to cover the environmental factors of substrate, topographic position and altitude. Floristic analyses used the Kulczynski coefficient of dissimilarity in an agglomerative hierarchical cluster analysis and multidimensional scaling ordinations. Twenty-one plant communities were selected from the cluster analysis. The contribution of species to these groupings was investigated using a fidelity analysis. Another three communities were distinguished from aerial photographs and field traverse. These 24 plant communities are described and all except riparian vegetation are mapped. Their extent was mapped using aerial photography and ground traverses. The vegetation map was digitised at a scale of 1:25,000 but has been reduced to 1:100,000 for this publication. The minimum area mapped is 1 ha.
Eight hundred and eighty-nine plant taxa are reported for the study area, 681 of which were recorded during the survey. Common families are Poaceae, Asteraceae, Fabaceae, Myrtaceae, Orchidaceae and Cyperaceae. The status of the 28 nationally or State listed rare or threatened plant species, and other regionally rare species recorded in the area, is discussed. Some plant communities, such as those dominated by the stringybarks Eucalyptus caliginosa and Eucalyptus laevopinea, are ubiquitous in the landscape. Other communities are restricted in their geographic extent and contain a distinct suite of species. These included heath swamps, some forests on leucogranite and wetland vegetation in lagoons on basalt plateaux. 74% of the native woody vegetation has been cleared. This has particularly affected plant communities on higher nutrient soils including Eucalyptus viminalis and Eucalyptus dalrympleana subsp. heptantha open forest on basalt plateaux, Eucalyptus nova-anglica woodland in valleys, and Eucalyptus blakelyi and Eucalyptus melliodora woodland on sediments at lower altitudes. Most of the remnants have been grazed by stock thus influencing the understorey structure and species composition. Upright forbs and Acacia would appear to be less common now than prior to European settlement. Dieback of eucalypts over the last two decades has compounded the impacts of clearing. Logging and firewood cutting affects some plant communities. Weeds are most invasive where understorey disturbance is greatest, which is mainly in the small remnants on higher nutrient soil (basalt and sediments). Most of the lagoons in the study area have been drained or impounded, thus depleting wetland vegetation. Changes to fire regimes in the forest remnants may also have altered the populations of fire-dependent species. Most of the plant communities are poorly represented in conservation reserves. Conservation initiatives on private land are required to protect most of the communities. Key sites for conservation are listed.