Low-density koala (Phascolarctos cinereus) populations in the mulgalands of south-west Queensland. IV. Abundance and conservation status

Urban encroachment on dense, coastal koala populations has ensured that their management has received increasing government and public attention. The recently developed National Koala Conservation Strategy calls for maintenance of viable populations in the wild. Yet the success of this, and other, conservation initiatives is hampered by lack of reliable and generally accepted national and regional population estimates. In this paper we address this problem in a potentially large, but poorly studied, regional population in the State that is likely to have the largest wild populations. We draw on findings from previous reports in this series and apply the faecal standing-crop method (FSCM) to derive a regional estimate of more than 59 000 individuals. Validation trials in riverine communities showed that estimates of animal density obtained from the FSCM and direct observation were in close agreement. Bootstrapping and Monte Carlo simulations were used to obtain variance estimates for our population estimates in different vegetation associations across the region. The most favoured habitat was riverine vegetation, which covered only 0.9% of the region but supported 45% of the koalas. We also estimated that between 1969 and 1995 similar to 30% of the native vegetation associations that are considered as potential koala habitat were cleared, leading to a decline of perhaps 10% in koala numbers. Management of this large regional population has significant implications for the national conservation of the species: the continued viability of this population is critically dependent on the retention and management of riverine and residual vegetation communities, and future vegetation-management guidelines should be cognisant of the potential impacts of clearing even small areas of critical habitat. We also highlight eight management implications.

Assessment of relationships between precipitation and satellite derived vegetation condition in South Australia

The normalised difference vegetation index (NDVI) has evolved as a primary tool for monitoring continental-scale vegetation changes and interpreting the impact of short to long-term climatic events on the biosphere. The objective of this research was to assess the nature of relationships between precipitation and vegetation condition, as measured by the satellite-derived NDVI within South Australia. The correlation, timing and magnitude of the NDVI response to precipitation were examined for different vegetation formations within the State (forest, scrubland, shrubland, woodland and grassland). Results from this study indicate that there are strong relationships between precipitation and NDVI both spatially and temporally within South Australia. Differences in the timing of the NDVI response to precipitation were evident among the five vegetation formations. The most significant relationship between rainfall and NDVI was within the forest formation. Negative correlations between NDVI and precipitation events indicated that vegetation green-up is a result of seasonal patterns in precipitation. Spatial patterns in the average NDVI over the study period closely resembled the boundaries of the five classified vegetation formations within South Australia. Spatial variability within the NDVI data set over the study period differed greatly between and within the vegetation formations examined depending on the location within the state. ACRONYMS AVHRR Advanced Very High Resolution Radiometer ENVSAEnvironments of South Australia EOS Terra-Earth Observing System EVIEnhanced Vegetation Index MODIS Moderate Resolution Imaging Spectro-radiometer MVC Maximum Value Composite NDVINormalised Difference Vegetation Index NIRNear Infra-Red NOAANational Oceanic and Atmospheric Administration SPOT Systeme Pour l’Observation de la Terre. [ABSTRACT FROM AUTHOR]

Management effectiveness: Assessing management of protected areas?

To maximise the potential of protected areas, we need to understand the strengths and weaknesses in their management and the threats and stresses that they face. There is increasing pressure on governments and other bodies responsible for protected areas to monitor their effectiveness. The reasons for assessing management effectiveness include the desire by managers to adapt and improve their management strategies, improve planning and priority setting and the increasing demands for reporting and accountability being placed on managers, both nationally and internationally. Despite these differing purposes for assessment, some common themes and information needs can be identified, allowing assessment systems to meet multiple uses. Protected-area management evaluation has a relatively short history. Over the past 20 years a number of systems have been proposed but few have been adopted by management agencies. In response to a recognition of the need for a globally applicable approach to this issue, the IUCN World Commission on Protected Areas developed a framework for assessing management effectiveness of both protected areas and protected area systems. This framework was launched at the World Conservation Congress in Jordan in 2000. The framework provides guidance to managers to develop locally relevant assessment systems while helping to harmonise assessment approaches around the world. The framework is strongly linked to the protected area management process and is adaptable to different types and circumstances of protected areas around the world. Examples from Fraser Island in Australia and the Congo Basin illustrate the use of the framework.

Options for guaranteeing the effective management of the world's protected areas

A rapid increase in the number and size of protected areas has prompted interest in their effectiveness and calls for guarantees that they are providing a good return on investment by maintaining their values. Research reviewed here suggests that many remain under threat and a significant number are already suffering deterioration. One suggestion for encouraging good management is to develop a protected-area certification system: however this idea remains controversial and has created intense debate. We list a typology of options for guaranteeing good protected-area management, and give examples, including: danger lists; self-reporting systems against individual or standardised criteria; and independent assessment including standardised third-party reporting, use of existing certification systems such as those for forestry and farming and certification tailored specifically to protected areas. We review the arguments for and against certification and identify some options, such as: development of an accreditation scheme to ensure that assessment systems meet minimum standards; building up experience from projects that are experimenting with certification in protected areas; and initiating certification schemes for specific users such as private protected areas or institutions like the World Heritage Convention.

How the west was once: vegetation change in south-west Queensland from 1930 to 1995

Conflicting perceptions of past and present rangeland condition and limited historical data have led to debate regarding the management of vegetation in pastoral landscapes both internationally and in Australia. In light of this controversy we have sought to provide empirical evidence to determine the trajectory of vegetational change in a semi-arid rangeland for a significant portion of the 20th century using a suite of proxy measures. Ambathala Station, approximately 780 km west of Brisbane, in the semi-arid rangelands of south-western Queensland, Australia. We excavated stratified deposits of sheep manure which had accumulated beneath a shearing shed between the years 1930 and 1995. Multi-proxy data, including pollen and leaf cuticle analyses and analysis of historical aerial photography were coupled with a fine resolution radiocarbon chronology to generate a near annual history of vegetation on the property and local area. Aerial photography indicates that minor (< 5%) increases in the density of woody vegetation took place between 1951 and 1994 in two thirds of the study area not subjected to clearing. Areas that were selectively or entirely cleared prior to the 1950s (approximately 16% of the study area) had recovered to almost 60% of their original cover by the 1994 photo period. This slight thickening is only partially evident from pollen and leaf cuticle analyses of sheep faeces. Very little change in vegetation is revealed over the nearly 65 years based on the relative abundances of pollen taxonomic groups. Microhistological examination of sheep faeces provides evidence of dramatic changes in sheep diet. The majority of dietary changes are associated with climatic events of sustained above-average rainfall or persistent drought. Most notable in the dietary analysis is the absence of grass during the first two decades of the record. In contrast to prevailing perceptions and limited research into long-term vegetation change in the semi-arid areas of eastern Australia, the record of vegetation change at the Ambathala shearing shed indicates only a minor increase in woody vegetation cover and no decrease in grass cover on the property over the 65 years of pastoral activity covered by the study. However, there are marked changes in the abundance of grass cuticles in sheep faeces. The appearance and persistence of grass in sheep diets from the late 1940s can be attributed to the effects of periods of high rainfall and possibly some clearing and thinning of vegetation. Lower stock numbers may have allowed grass to persist through later drought years. The relative abundances of major groups of plant pollen have not changed significantly over the past 65 years.

Modelling pre-clearing vegetation distribution using GIS-integrated statistical, ecological and data models: A case study from the wet tropics of Northeastern Australia

Traditional vegetation mapping methods use high cost, labour-intensive aerial photography interpretation. This approach can be subjective and is limited by factors such as the extent of remnant vegetation, and the differing scale and quality of aerial photography over time. An alternative approach is proposed which integrates a data model, a statistical model and an ecological model using sophisticated Geographic Information Systems (GIS) techniques and rule-based systems to support fine-scale vegetation community modelling. This approach is based on a more realistic representation of vegetation patterns with transitional gradients from one vegetation community to another. Arbitrary, though often unrealistic, sharp boundaries can be imposed on the model by the application of statistical methods. This GIS-integrated multivariate approach is applied to the problem of vegetation mapping in the complex vegetation communities of the Innisfail Lowlands in the Wet Tropics bioregion of Northeastern Australia. The paper presents the full cycle of this vegetation modelling approach including sampling sites, variable selection, model selection, model implementation, internal model assessment, model prediction assessments, models integration of discrete vegetation community models to generate a composite pre-clearing vegetation map, independent data set model validation and model prediction's scale assessments. An accurate pre-clearing vegetation map of the Innisfail Lowlands was generated (0.83r(2)) through GIS integration of 28 separate statistical models. This modelling approach has good potential for wider application, including provision of. vital information for conservation planning and management; a scientific basis for rehabilitation of disturbed and cleared areas; a viable method for the production of adequate vegetation maps for conservation and forestry planning of poorly-studied areas. (c) 2006 Elsevier B.V. All rights reserved.

Mapping structural parameters and species composition of riparian vegetation using IKONOS and Landsat ETM+ data in Australian tropical savannahs

Government agencies responsible for riparian environments are assessing the utility of remote sensing for mapping and monitoring vegetation structural parameters. The objective of this work was to evaluate Ikonos and Landsat-7 ETM+ imagery for mapping structural parameters and species composition of riparian vegetation in Australian tropical savannahs for a section of Keelbottom Creek, Queensland, Australia. Vegetation indices and image texture from Ikonos data were used for estimating leaf area index (R-2 = 0.13) and canopy percentage foliage cover (R-2 = 0.86). Pan-sharpened Ikonos data were used to map riparian species composition (overall accuracy = 55 percent) and riparian zone width (accuracy within +/- 3 m). Tree crowns could not be automatically delineated due to the lack of contrast between canopies and adjacent grass cover. The ETM+ imagery was suited for mapping the extent of riparian zones. Results presented demonstrate the capabilities of high and moderate spatial resolution imagery for mapping properties of riparian zones.

Linking riparian vegetation spatial structure in Australian tropical savannas to ecosystem health indicators: semi-variogram analysis of high spatial resolution satellite imagery

Government agencies responsible for riparian environments are assessing the combined utility of field survey and remote sensing for mapping and monitoring indicators of riparian zone health. The objective of this work was to determine if the structural attributes of savanna riparian zones in northern Australia can be detected from commercially available remotely sensed image data. Two QuickBird images and coincident field data covering sections of the Daly River and the South Alligator River - Barramundie Creek in the Northern Territory were used. Semi-variograms were calculated to determine the characteristic spatial scales of riparian zone features, both vegetative and landform. Interpretation of semi-variograms showed that structural dimensions of riparian environments could be detected and estimated from the QuickBird image data. The results also show that selecting the correct spatial resolution and spectral bands is essential to maximize the accuracy of mapping spatial characteristics of savanna riparian features. The distribution of foliage projective cover of riparian vegetation affected spectral reflectance variations in individual spectral bands differently. Pan-sharpened image data enabled small-scale information extraction (< 6 m) on riparian zone structural parameters. The semi-variogram analysis results provide the basis for an inversion approach using high spatial resolution satellite image data to map indicators of savanna riparian zone health.

Mapping indicators of riparian vegetation health using IKONOS and Landsat-7 ETM+ image data in Australian tropical savannas

Government agencies responsible for riparian environments are assessing the utility of remote sensing for mapping and monitoring environmental health indicators. The objective of this work was to evaluate IKONOS and Landsat-7 ETM+ imagery for mapping riparian vegetation health indicators in tropical savannas for a section of Keelbottom Creek, Queensland, Australia. Vegetation indices and image texture from IKONOS data were used for estimating percentage canopy cover (r2=0.86). Pan-sharpened IKONOS data were used to map riparian species composition (overall accuracy=55%) and riparian zone width (accuracy within 4 m). Tree crowns could not be automatically delineated due to the lack of contrast between canopies and adjacent grass cover. The ETM+ imagery was suited for mapping the extent of riparian zones. Results presented demonstrate the capabilities of high and moderate spatial resolution imagery for mapping properties of riparian zones, which may be used as riparian environmental health indicators