V. J. Neldner

The extent and status of remnant vegetation in Queensland and its implications for statewide vegetation management and legislation

Vegetation classification, survey and mapping provide key information underpinning the implementation of statewide vegetation management legislation and associated policies in Queensland. This paper summarises: (i) the Queensland Herbarium survey and mapping methods and land classification system and its role in vegetation management legislation; and, (ii) the current extent and rate of vegetation clearing by bioregion, sub-region and Broad Vegetation Group; (iii) and the amount of vegetation protected under legislated statewide bioregional and regional ecosystem thresholds. Information also is provided on the pre-clearing and current extent by 18 Broad Vegetation Groups and the area of non-remnant woody vegetation by bioregion. The implications for vegetation management are discussed, along with a comparison of clearing statistics derived from other studies that use different classification and mapping methodologies. The majority of Queensland has relatively continuous native vegetation cover (82% remnant native vegetation remaining in 1999). The productive soils of the southern part of the Brigalow Belt, lowlands in South-east Queensland, New England Tableland and Central Queensland Coast have been, however, extensively cleared with 7–30% of remnant vegetation remaining. Between 1997 and 1999, the annual rate of remnant clearing in Queensland was 4460 km2 of which over 60% occurred in the Brigalow Belt bioregion. A greater proportion of this recent clearing occurred in Broad Vegetation Groups that are associated with less fertile and/or more arid parts of the State compared with pre 1997 clearing. For bioregions and regional ecosystems where past clearing has been extensive, a substantial proportion (50–91%) of the remaining vegetation is protected by bioregional and regional ecosystem thresholds prescribed under statewide legislation and associated policies. For other bioregions and regional ecosystems, other factors such as rainfall, soil and areas of high conservation value are likely to play a larger role in determining the amount of vegetation protected. However, the effectiveness of the Queensland legislation cannot be assessed until regional planning processes have been completed and all criteria addressed.

Using geographic information systems (GIS) to determine the adequacy of sampling in vegetation surveys

Abstract Data from biological surveys are increasingly being used for making land use and management decisions, and as input in predictive models. Biased or inadequately sampled data sets may result in misleading predictions and lead to poor management decisions. Five methods for assessing the adequacy of sampling in vegetation surveys using Geographic Information Systems (GIS) were investigated. The methods were used and assessed on a 1:250,000 scale vegetation survey on Cape York Peninsula, Australia. For surveys in progress, the Intuitive Reliability Assessment (Method 1) and Sampling Intensity Index (Method 2) were found to be very useful at identifying undersampled plant assemblages and areas. Non-stratified Environmental Parameter Analysis (Method 3) and Environmental Domain Analysis (Method 5) gave only general assessment of areas requiring further sampling. For more specific identification of supplementary sampling sites, the complementary use of Methods 1 or 2 was required. However, Methods 3 and 5 together with Gradsect Evaluation using DOMAIN (Method 4), can assist in the planning of comprehensive and efficient sampling strategies for new surveys. The results of this study have application to a wide range of natural resource surveys.

Problems of placing boundaries on ecological continua - options for a workable national rainforest definition in Australia

Options for a new definition of, and key for, rainforest in Australia are provided. The definitions take a national perspective, and are based on the ecological characteristics of rainforest species and some structural and floristic characteristics. Rainforest plant species are defined as those adapted to regenerating under low-light conditions experienced under the closed canopy or in localised gaps caused by recurring disturbances which are part of the natural rainforest ecosystem, and are not dependent on fire for successful regeneration. Three definitions are provided which differ in the extent of inclusion of transitional and seral communities. The first definition recognises communities such as mixed forests as transitional to rainforests and therefore as separate communities. The second definition includes a minimal component of emergent non-rainforest species in rainforest in the recognition that the main floristic component and functioning of the communities cannot be distinguished. The third definition includes the late successional stages of transitional and seral communities in rainforest on the presumption that such communities include non-rainforest species which are close to senescence, and that these communities are essential for the long-term conservation of rainforest in areas where rainforest is vulnerable and subject to major disturbance, particularly by fire. The first definition is concluded to be the least ambiguous and arbitrary, and enables a consistent approach to rainforest management. Recognition of mixed forests as a distinctive and mappable vegetation type should be incorporated in a comprehensive conservation strategy inclusive of all ecosystem developmental stages.

OPTIMUM TIME FOR SAMPLING FLORISTIC DIVERSITY IN TROPICAL EUCALYPT WOODLANDS OF NORTHERN QUEENSLAND

The timing of vegetation sampling in highly seasonal environments is one of the critical factors in determining the proportion of the flora captured in a single sampling. Four sites were located within a 20 km radius of Mareeba, north Queensland and sampled every three months for three years. The sites were located in a variety of eucalypt communities and across an altitudinal range from 380 to 840 m above sea level. In these eucalypt communities experiencing highly seasonal rainfall typical of the tropical savannas, vegetation sampling in the early dry season (May) maximises the diversity of flora recorded. The ANOVA analysis showed a significant effect of month of sampling for the number of ground taxa recorded (P < 0.005). There was significant variation (P < 0.005) in species diversity between the sites but in all four study sites the May sampling recorded greater than 84% of the total recorded flora, whereas the November samplings accounted for between 21% and 56% of the flora. This supports the experience of other researchers that a May sampling is near optimum for sampling the ground layer floristic diversity in tropical eucalypt woodlands. Most vegetation survey and mapping data are of necessity collected at less than ideal times of the year due to access and resource issues. Care must be exercised in using data collected in the dry season, as only a limited proportion of the total ground flora is likely to be recorded. Studies designed to capture the full florisitic inventory of species present in these highly seasonal environments need to budget resources and plan to access these environments in the late wet season.

The lichen flora of tropical Cape York Peninsula, Queensland, Australia

The first account of the lichen flora of the Cape York Peninsula bioregion is provided with 423 lichen taxa from 47 families and 127 genera recorded. The tropical savannas of Cape York Peninsula, which experience annual or biennial ground fires, are generally a harsh environment for lichen establishment and growth. The majority of eucalypts and Melaleuca viridiflora Sol. ex Gaertn. trees that dominate much of Cape York Peninsula vegetation regularly shed their bark and do not generally provide a suitable habitat for lichen establishment and persistence. However, even in these savanna habitats, some tree species provide suitable fire-safe substrates for lichens. The rainforest, riparian and coastal vegetation lichen flora is much more diverse, primarily because of the lack of fire but also because of more mesic conditions and persistent thin bark types. Most of the lichens (413 lichen species) survive on a number of bark types, while there are 51 species on rock substrates (10 exclusively on rocks). The diverse lichen flora is dominated by pantropical species, many of which are shared with New Guinea, Thailand and the Northern Territory. However, eleven lichen species are only known from Cape York Peninsula.

Assessing the invasion threat of non-native plant species in protected areas using Herbarium specimen and ecological survey data. A case study in two rangeland bioregions in Queensland

Naturalised non-native plants that become invasive pose a significant threat to the conservation of biodiversity in protected areas (areas dedicated and managed for long-term conservation of nature), economic productivity of agricultural businesses, and societal impacts including community, culture infrastructure and health. Quantifying the spread, potential dominance and invasion threat of these species is fundamental to effective eradication and development of threat mitigation policy. But this is often hampered by the lack of comprehensive data. This study used existing ecological survey data from 2548 sites and 64 758 Herbarium specimen records to document the status and abundance of non-native plants in two case study bioregions, Cape York Peninsula (CYP) and the Desert Uplands (DEU) in Queensland covering a total area of 186 697 km2. There were 406 non-native species in the CYP, 186 (45.6%) of which are known environmental weeds and 159 non-natives in DEU, of which 69 (43.5%) are environmental weeds. Inside the protected areas, there were 98 species of environmental weeds in CYP, 27 of which are listed as weeds of State significance (Weeds of National Significance (WONS), Queensland declared and non-declared pest plants categories). In DEU, there were 18 environmental weeds inside protected areas and none of them was listed as a weed of State significance. Non-native species that recorded foliage cover dominance in the ecological site data are generally recognised as environmental weeds in Queensland. The threat of weeds from outside of protected areas was serious, with 41 weeds of State significance found in CYP, five of which are WONS, and 25 weeds of State significance found in DEU, 10 of which are WONS.