Publication Server of Goethe University Frankfurt am Main (Goethe University Frankfurt) · 2005 · 27 citations · 6 references
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Natural ResourcesBotanyEcologyForest EcologyForest InventoryPlant EcologyForest CoverForest GeographyForest StructureLandscape ClassificationVegetation Cover AssessmentVegetation StructureAbundance Data AnalysisClassification Of Plant CommunitiesForest RegionsNative Wetland VegetationVegetation Cover MappingVegetation SurveysWetland VegetationWetland Vegetation Surveys
The Southern Forests study area covers an area of about six million hectares of south-eastern New South Wales, south of Oberon and Kiama and east of Albury and Boorowa (latitude 33 02'-37 06' S; longitude 146 56' -147 06' E).The total area of existing vegetation mapped was three million hectares (3 120 400 hectares) or about 50% of the study area.Terrestrial, wetland and estuarine vegetation of the Southern Forests region were classified into 206 vegetation groups and mapped at a scale between 1: 25 000 and 1: 100 000.The classification was based on a cluster analysis of detailed field surveys of vascular plants, as well as field knowledge in the absence of field survey data.The primary classification was based on 3740 vegetation samples with full floristics cover abundance data.Additional classifications of full floristics presence-absence and tree canopy data were carried out to guide mapping in areas with few full floristic samples.The mapping of extant vegetation was carried out by tagging vegetation polygons with vegetation codes, guided by expert knowledge, using field survey data classified into vegetation groups, remote sensing, and other environmental spatial data.The mapping of pre-1750 vegetation involved tagging of soils mapping with vegetation codes at 1: 100 000 scale, guided by spatial modelling of vegetation groups using generalised additive statistical models (GAMS), and expert knowledge.Profiles of each of the vegetation groups on the CD-ROM* provide key indicator species, descriptions, statistics and lists of informative plant species.The 206 vegetation groups cover the full range of natural vegetation, including rainforests, moist eucalypt forests, dry shrub forests, grassy forests, mallee low forests, heathlands, shrublands, grasslands and wetlands.There are 138 groups of Eucalyptus forests or woodlands, 12 rainforest groups, and 46 non-forest groups.Of the 206 groups, 193 were classified and mapped in the study area.Thirteen vegetation groups were not mapped because of their small size and lack of samples, or because they fell outside the study area.Updated regional extant and pre-1750 vegetation maps of southern New South Wales have been produced in 2005, based on those originally prepared in 2000 for the southern Regional Forest Agreement (RFA).Further validation and remapping of extant vegetation over 10% of the study area has subsequently improved the quality of the vegetation map, and removed some of the errors in the original version.The revised map provides a reasonable representation of native vegetation at a scale between 1: 25 000 and 1: 100 000 across the study area.In 2005 native vegetation covers 50% of the study area.Environmental pressures on the remaining vegetation include clearing, habitat degradation from weeds and nutrification, severe droughts, changing fire regimes, and urbanisation.Grassy woodlands and forests, temperate grasslands, and coastal and riparian vegetation have been the most reduced in areal extent.Over 90% of the grassy woodlands and temperate grasslands have been lost.Conservation of the remaining vegetation in these formations is problematic because of the small, discontinuous, and degraded nature of the remaining patches of vegetation. Cunninghamia (2005) 9(2): 219-254*CD-ROM is inside back coverThe northern part of the study area comprises undulating high plateaus of granite and basalt, surrounded by Devonian and Ordovician sandstone, quartz sandstone, siltstones and shales.These plateaus include Oberon, Kanangra-Boyd, and Crookwell-Taralga, and, with elevations from 900 to 1300 m, define the Great Divide.To the east of the northern high plateaus, highly dissected hills 300 to 400 m in elevation, rapidly descend to the Kowmung and Wollondilly Rivers.In the dissected valleys, Devonian quartzites, sandstones, and shales predominate. ClimateMean annual rainfall ranges from 465 mm at Cooma on the Monaro plains to over 2300 mm at Charlottes Pass in the Snowy Mountains.Rainfall is lowest on the Monaro plains, increasing east towards the coast and west to the mountains.Deep valleys or lower plateaus on the leeward side of higher mountain ranges result in areas of lower rainfall, examples of which are found in the rain-shadow valleys of the Araluen Valley, the Monaro plains and the middle Snowy and Murrumbidgee catchments.By contrast, average annual rainfall above 1200 mm is found on the Kanangra-Boyd plateau, and along the South Coast escarpment extending from Kiama down to the Wadbilliga ranges.During winter snowfalls are common above 1000 m on the Australian Alps and the Central and Southern Tablelands.Snow covers the higher parts of the Australian Alps, above 1600 m, for periods up to four months.Heavy frosts are a frequent occurrence over most of the South-East Highlands and Australian Alps during the winter months, becoming more severe in broader deep valleys fringing the mountain ranges, as a result of cold air drainage.Mean annual temperature ranges from 2 C near Mount Kosciuszko, to 16 C along the coastal plains north of Ulladulla.Temperature increases as the elevation falls in both easterly and westerly directions away from the higher mountain ranges and the Great Dividing Range, which splits the region in half from north to south (NPWS 1998).These extremes greatly influence the distribution and pattern of vegetation.Seasonality of rainfall also varies across the study area.The northern coastal escarpment around Kiama shows a strong summer peak in rainfall, while the western side of the Kosciusko ranges shows a strong winter rainfall peak. Land Use HistoryEuropean land use across the study area has been mainly forestry, agriculture, mining and human settlement.On the Central Tablelands and Western Slopes, large areas were opened up to pastoral development from the 1830s onwards.Much of this land was covered in grassy woodlands.The steeper, more infertile and more remote forested land on the Tablelands was either occasionally cleared or left for rough grazing and selective logging.Evidence of these activities is still present in the forest structure on private or public land today.
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