1,721,096 research outputs found
Catchment to reef: water quality and ecosystem health in tropical streams
No full textAround the world agricultural and industrial landscapes have massively affected terrestrial and aquatic habitats as well as the water quality of run-off from entire landscapes, resulting in dramatically altered ecosystem integrity in freshwaters, coastal wetlands, estuaries and coastal marine systems. Although these systems are reasonably well understood in temperate areas, in the tropics there is much less information on such environmental impacts and fewer examples of remediation. In Australia, the export of nutrients, sediments and contaminants into near coastal waters and the Great Barrier Reef (GBR)lagoon, the world's largest reef system, has increased substantially since European settlement, severely impacting on the viability and condition of these ecosystems and the industries that depend on them (Baker 2003). Approximately 200 near-shore reefs are under immediate direct pressure from declining water quality in the Queensland Wet Tropics and Whitsunday areas. Degradation of habitats (e.g. removal of riparian vegetation and invasion by weeds) and run-off of excess nutrients, sediments and agricultural chemicals are also causing substantial impacts on the rivers and wetlands that feed into the GBR lagoon and threaten the biodiversity and ecology of these systems and their important role in the greater GBR environment. Protection and restoration of these ecosystems are critical challenges to managers and policy~makers in Australia and elsewhere in the tropics
Rainforest science and its application
No full text[Extract] The Wet Tropics of Queensland were inscribed on the World Heritage List on 9 December 1988 as a direct consequence of the accumulated scientific research and understanding of the region's rainforests up to that time. In 1992 the Wet Troplcs Management Authority was established as the body responsible for the coordinated management of the World Heritage Area, while the Rainforest CRC (Cooperative Research Centre for Tropical Rainforest Ecology and Management) was established in 1993 as the body responsible for both the coordination and the undertaking of scientific research to assist in the management of the World Heritage Area and associated rainforest landscapes.
Undertaking scientific research in World Heritage areas is more than a legitimate activity, it is also a duty. The importance of such research is explicitly acknowledged in Wet Tropics World Heritage legislation and in international conventions such as the World Heritage Convention and the Convention on Biological Diversity. One of the benefits that World Heritage areas provide for scientific researchers is the provision of protected benchmark and/or control sites where the direct impact of human activities is minimal relative to surrounding landscapes
Impacts of tropical cyclones on forests in the wet tropics of Australia
No full text[Extract] Disturbances both anthropogenic and natural, shape forest ecosystems by controlling their species composition, structure and functional processes (Dale et al.2001), The tropical forests of the Wet Tropics of north-east Australia have been moulded by their land use and disturbance history over many millennia but particularly over the past 100 years (see Pannell, Chapter 4; Turton, Chapter 5; Laurance & Goosem, Chapter 23, this volume). Forests of the Wet Tropics region are subjected to a plethora of natural disturbances, including fire, drought, native pathogen outbreaks, floods, occasional landslides and tropical cyclones. All these natural disturbances interact in complex ways with anthropogenic disturbances across the Wet Tropics landscape, such as land-use change resulting from forest conversion to agricultural systems, earlier logging practices, urban and peri-urban development and expansion of the tourism industry (see Part III this volume).
As in many parts of the non-equatorial tropics (Whitmore 1974; Boose et al. 1994), tropical cyclones (a.k.a. hurricanes and typhoons) are significant disturbance phenomena for forest ecosystems in the Wet Tropics of north-east Australia, especially those near the coast. For this reason, even continuous forests in the region have been described as hyper-disturbed ecosystems with patches of damaged forest constantly recovering from previous cyclonic events, often in concert with floods, droughts and fires (Webb 1958). Cyclones are part of the ecosystem dynamics of these forested landscapes and recovery of canopy cover following such events is often remarkably rapid, although forest structure and composition may take many decades to recover. The same cannot be said for fragmented forests in the Wet Tropics, located within either an agricultural or grassland matrix. These forest fragments are particularly vulnerable to impacts of tropical cyclones and their associated strong winds, largely due to their high forest edge to area ratios (Laurance 1991, 1997). These fragments are also more prone to post-disturbance weed invasion and bush fires than nearby areas of continuous forest
Australian rainforests in a global context
No full text[Extract] Moist tropical rainforests cover approximately 6-7% of the surface of the globe and occur in a band about 15-20° either side of the equator. Typically they receive more than 2000 mm precipitation a year and although they may frequently experience a dry season, this is often punctuated by periods of heavy rainfall. These forests are typified by their evergreen nature, although some species of trees can be deciduous. Longer and drier dry seasons inevitably produce tropical dry forests, with most tree species being deciduous. Throughout this book when authors refer to rainforests they are referring to moist tropical rainforests
Environmental impacts of tourism and recreation in the Wet Tropics
No full text[Extract] Tourists and local residents are continually seeking new recreation and leisure experiences, particularly in biologically complex and pristine environments such as coral reefs and tropical rainforests (Turton & Stork 2006). By the very nature of these complex and sensitive environments, there is a significant risk that over-visitation or inappropriate visitor use of these unique resources, or the inappropriate construction of resort and associated facilities, may lead to their decline and hence threaten their long term sustainability (Buckley 2004). These potential dangers are exacerbated by the rapid expansion of international tourism and the steady growth of domestic tourism and recreation in many tropical countries (Christ et al. 2003)
Lessons for other tropical forest landscapes
No full textIn recent decades, governments and the general public have grown increasingly alarmed at the declining state of the world's environment. These concerns were first highlighted internationally by the Stockholm Conference on the Human Environment (1972). Equally important was the Brundland Report Our Common Futute (Brundtland 1987), produced by the World Commission on Environment and Development, which argued eloquently that, without fundamental changes in practices and innovation, further economic development would continue to exhaust natural resources and severely harm the global environment. This report defined sustainable development as that which 'meets the needs of the present without compromising the ability of future generations to meet their own needs'. This report also highlighted the striking inequity of economic progress and suggested that equity, growth and environmental maintenance are all simultaneously possible through enlightened technological and social change
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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