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The dichotomy between protection and logging of the Endangered and valuable timber species Amburana cearensis in north-west Argentina
- Natalia Politi, Luis Rivera, Leónidas Lizárraga, Malcolm Hunter, Jr, Guillermo E. Defossé
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Amburana cearensis is a commercially valuable timber species, categorized as Endangered on the IUCN Red List. It is distributed throughout the seasonal dry tropical forests of Brazil, Paraguay, Bolivia, Peru and Argentina. In Argentina it is restricted to the provinces of Salta, where legislation sets a minimum cutting diameter of 60 cm, and Jujuy, where logging of this species has been banned since 1972. The effect of these laws on the species’ conservation status has not been assessed. We estimated species density, using distance sampling methodology, and measured the diameter at breast height of each individual encountered at 13 sites in north-west Argentina. Across both provinces we found a density of 1.12 individuals ha−1 (95% CI 0.48–2.63) and there was no significant difference between the density in Salta (5.15 ha−1;; 95% CI 3.14–8.45) and that in Jujuy (3.67 ha−1;; 95% CI 2.59–5.17), although 84% of the individuals encountered in Salta were found at one site. Diameter at breast height was significantly lower in Salta than in Jujuy (23 ± 12 vs 41 ± 18 cm; P < 0.05). These differences in the demography of the species between the provinces may be attributable to the application of different legislation. Our results indicate that it would be prudent to halt logging of this species in Salta until further information is gathered and a sustainable management plan developed.
Preface
- Edited by Malcolm L. Hunter, University of Maine, Orono
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- Book:
- Maintaining Biodiversity in Forest Ecosystems
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- 20 February 2010
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- 10 June 1999, pp xiii-xvi
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Summary
Ecosystem management, sustainable forestry, ecological forestry, and similar terms are waxing stronger and stronger in the language of forest managers, reflecting a growing realization that society wants much more than timber products from forests. Recreation, wildlife, and water often come to mind first. They have been the big three ‘other values’ for many years and they remain a driving force for forest management. However within the last ten years or so, even this list of four values has seemed inadequate; the core ecological or biological values of a forest seem to be missing. For some people the term ‘wildlife’ captures this issue; for most people ‘wildlife’ is too closely associated with a small portion of our biota, especially the birds and mammals. Consequently, a number of terms have developed around this issue – biotic integrity, ecosystem health, and others–but arguably themostprominent is ‘biological diversity’ or ‘biodiversity’. This book is about maintaining biodiversity in forests, a set of ecosystems that occupy only about6%of the earth's total surface area, but which harbors a greatly disproportionate share of the earth's biological diversity.
This book is intended to reach a broad audience with the latest thinking about maintaining forest biodiversity, especially in forests managed for timber production. Among all the people interested in forests, those who are managing forests on a day to day basis and the students who will soon be joining the ranks of professional natural resource managers are our particular focus. The book is global in scope but, with over half of its contributors coming from North America, there is a clear North American bias.
1 - Biological diversity
- Edited by Malcolm L. Hunter, University of Maine, Orono
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- Book:
- Maintaining Biodiversity in Forest Ecosystems
- Published online:
- 20 February 2010
- Print publication:
- 10 June 1999, pp 3-21
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Summary
For over a decade the mail has brought a steady stream of flyers announcing new books and conferences with the terms ‘biological diversity’ or ‘biodiversity’ featured prominently. Apparently ‘biodiversity’ is here to stay, holding an important position in the vocabulary of natural resource management. It arrived just as people were becoming sensitive to the entire spectrum of life with which we share the planet and the myriad threats facing it. Despite this prominence the term still confuses many people. In large part this is because biodiversity seems like something that we should be able to quantify, like biomass or population density, but in practice only limited components of biodiversity can be measured easily. This constraint pushes biodiversity toward being more of a conceptual entity, analogous to aesthetics or ecosystem integrity, than a tangible thing. In this chapter we will first try to sort through the confusion to provide a clear idea of what biodiversity is. In the second part we will summarize the many reasons why it is important to maintain biodiversity. Finally, in the third part we will discuss the relationship between biodiversity and related concepts such as ecosystem integrity and sustainability.
What is biodiversity?
Biodiversity could be defined simply as ‘the diversity of life’, but a fuller definition is generally preferable. A definition such as ‘the diversity of life in all its forms and at all its levels of organization’ (Hunter 1990) reminds us that biodiversity includes the microbes and fungi that are often overshadowed by plants and animals. It also compels us to look beyond species to the genetic and ecosystem components of life on earth (Figure 1.1).
2 - Principles of ecological forestry
- Edited by Malcolm L. Hunter, University of Maine, Orono
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- Book:
- Maintaining Biodiversity in Forest Ecosystems
- Published online:
- 20 February 2010
- Print publication:
- 10 June 1999, pp 22-62
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Summary
Ecologically sound stewardship has long been a cornerstone of the forestry profession. But just what does ‘ecologically sound’ mean in practice? Historically, foresters were often taught that forest ecosystems could be engineered at will for human benefit. Ensuring ecological integrity meant not violating ‘constraints’ associated with soil, water quality, and wildlife (implicitly defined as well-known birds and mammals). Recently, the definition of ecological integrity has expanded; clearly, a primary focus is now on maintaining, and even restoring, native biological diversity. At the same time, a growing worldwide demand for forest products has encouraged foresters to expand traditional high-yield practices, amidst growing evidence that such systems often conflict with biodiversity.
While not discounting the difficulty of these conflicts, we believe there is a vision of ecological forestry that offers hope. To set the stage for the rest of this book, we define ecosystems, stands, and landscapes. Next, we review various incarnations of forestry, with emphasis on North American practice and the strong influence of the U.S. Forest Service. Hopefully, this will help readers to place the current discussion of ecological forestry into an historical, scientific, and professional context. Important principles of ecological forestry are defined and discussed, and related to traditional timber production forestry. Finally, a balanced forestry paradigm, which blends elements of traditional and ecological forestry, is described.
Ecosystems, stands, and landscapes
Asked to define ecosystem, a politician who was espousing the importance of protecting ecosystems hesitated for a long time then finally said, ‘Well … they're kind of like an aquarium … they have plants and animals … and other stuff.’ In fairness to the politician, ecosystems can be rather hard to define.