33 research outputs found
An inventory of wild sandalwood stocks in Vanuatu
Characterizing sandalwood (S. austrocaledonicum) abundance in Vanuatu is challenging due to the broad, discontinuous yet highly modified distribution of sandalwood and the lack of systematic historical inventories or detailed harvest documentation. The preliminary distribution has been estimated from anecdotal ranges provided by the Vanuatu Department of Forests (VDoF), GIS spatial analyses and recorded sandalwood locations collected during the Oil Quality Survey (Page, 2005) and during the 2007 sandalwood inventory survey conducted for this project. Historic densities have been estimated from anecdotal descriptions and harvest data records. Current densities are based on the 2007 field survey of sandalwood populations on
four Vanuatu islands. The surveys were conducted in regions of known sandalwood populations. The low aggregated density (0.4 trees/ha) of commercially sized trees found in these surveyed populations is a cause for concern. Based on the field data, we estimate that the current resource on the four islands surveyed is approximately 210 tonnes, with another 80 tonnes estimated on other islands of Vanuatu. At current harvest rates this resource may be quickly depleted and there will be a shortfall until plantation sandalwood is available in 10-15 years. Consideration should therefore be given to reducing the quota for wild sandalwood harvest to a sustainable level
Monitoring the environmental impact of mining in remote locations through remotely sensed data
Mining is an integral part of the development of many countries in the Asia-Pacific region and is associated with adverse environmental and social impacts. The monitoring of mining in remote locations is problematic due to difficulties of access. Satellite remote sensing is able to provide information on landscape transformation in a cost-effective way around large-scale mines. The PT Freeport Indonesia mine in Papua (Indonesia) is the world's largest copper-gold mine and previous studies have documented a range of impacts. A multi-temporal analysis of Landsat 5 imagery of the Freeport area was undertaken for the years between 1988 and 2004. Anthropogenic land cover changes were quantified by screen digitising polygons from three false colour composite images over this period to determine the area of forested land that had been cleared and the area that had been affected by mine-derived sediment transported by the Ajkwa River system. The results show that both settlement and sediment had radically altered land cover and together had led to a sixfold increase in the area of ultra-diverse lowland tropical rainforest cleared in the study area. The study highlights the utility of this method to monitor elements of the impact of large-scale mining and other extensive forms of resource exploitation such as deforestation in developing countries
Karst in Southeast Asia
[Extract] Flying over the patchwork quilt of land uses that comprise Southeast Asia, one often sees extensive tracts of\ud
rugged topography with plateaux pitted with depressions,\ud
deep gorges, rivers arising at the bases of mountains, and towers arising from alluvia ted plains, These are the karst lands, formed on limestone bedrock and subject to the solutional erosion of that bedrock above and below ground. With a total area of about 400 000 km2, Southeast Asia contains some of the more extensive\ud
karst regions in the world (Figure 10. 1). Many of these karst areas are of high relief with spectacular arrays of tower and cone karst. Many have now been inscribed on the World Heritage list in recognition of their unique geomorphology and biology. They are scattered throughout the islands of the Malay archipelago as well as the adjoining fringe of the Asian mainland. Karst is found in Malaysia, the Philippines, Thailand, Brunei, Indonesia, Cambodia, Viet Nam, Lao PDR, and Papua New Guinea
Coastal geomorphology and historic change in the Pennefather River area, Cape York
[Extract] The Australian coastline is shaped by processes operating over a wide range of time-scales, ranging from post-glacial sea level rise to daily tides. In northern Australia cyclonic waves and winds must be added, as well as the effects of major floods. Geomorphic process records are largely absent over most of the area, while maps and aerial photography rarely predate the 1960s. Thus there may be value in considering the written records of early explorers in combination with historic imagery to evaluate long-term coastal change. Such an opportunity was provided through the Flinders Bicentenary expedition organised by the Royal Geographical Society of Queensland. The specific area was the Pennefather River of western Cape York, some 40 km north of Weipa.\ud
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The Pennefather River (Figure 1, page 202) has a well developed spit at its mouth, backed by extensive mud banks and mangrove swamps. This is a consequence of dominant longshore drift and periodic flood outflows from the river. This spit may well have changed its extent and location in historic times since Flinders visited the area in 1802. To the north and south of the estuary are a set of three well developed transgressive dunes which may correlate with the early to mid-Holocene sequence recorded near Weipa by Lees et al. (1999). These transgressive dunes were probably formed by the reworking of late Pleistocene sand masses following recovery of sea level after the Last Glacial. This mechanism, termed the Cooper-Thom event, relies on the role of large storms in the Gulf of Carpentaria destroying coastal vegetation and thus remobilising stabilised dunes. Do such storms cause similar effects today? Have major cyclones in the historic period reshaped this landscape? What other disturbance processes are at work
Caves: Processes, Development and Management
This book is aimed at students of the natural environment, but it will also appeal to those - cavers, environmental managers and field naturalists - who are curious about the underground world and its inhabitants. it is illustrated throughout with photographs, maps and line diagrams, almost all of which are original to the book
Management of Caves
People have used caves in many ways for tens of thousands of years and only recently recognized their recreational, aesthetic, and scientific value. However, this has not prevented their degradation and some suggest the carrying capacity of a cave is effectively zero. Caving results in a variety of impacts on the physical cave environment, although not equally for all caves or every part of the cave, which is then a challenge for management is to correctly evaluate the relative vulnerability of cave passages. These impacts can arise because tourist caves require physical alteration of natural passages, installation of lighting, pathways, platforms, and associated infrastructure. Cave fauna are impacted by alteration of cave hydrology, temperatures, lighting conditions, and carbon dioxide levels. Resulting invasive plants, desiccation of cave formations, and localized sedimentation highlight the need for effective ongoing monitoring of the cave atmosphere, water quality, and particulate deposition. Even scientific researches have impact; therefore, proposed research projects must minimize damage and maximize benefit for all cave stakeholders. Cave inventories are important for documenting valuable cave features, and they also allow for inter-cave comparisons and help with management classification and/or zoning. More enlightened management regimes consider good relations with park neighbors as essential and parks are run using principles of adaptive management. Cave managers should embrace the new management paradigms whilst conserving what are essentially nonrenewable resources
Learning from the tropics: biological and geomorphological processes
This publication does not have an abstract
Book review of "Creatures from the Depths of Time: the biology of caves and other subterranean habitats" by David C. Culver and Tanja Pipan, Oxford University Press
This publication does not have an abstract.\u