López Ramón and Michael A. Toman
- Published in print:
- 2006
- Published Online:
- September 2006
- ISBN:
- 9780199298006
- eISBN:
- 9780191603877
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/0199298009.003.0014
- Subject:
- Economics and Finance, Development, Growth, and Environmental
Tropical forest conservation and sustainable natural forest management both imply benefits and invoke considerable costs. The spatial and temporal mismatch of such benefits (which might not ...
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Tropical forest conservation and sustainable natural forest management both imply benefits and invoke considerable costs. The spatial and temporal mismatch of such benefits (which might not materialize until far in the future and could be shared by many parties) and costs (which often occur at a local scale and must be borne in the short term) prevents an efficient forest management at the national level. While the international community has developed a variety of instruments to align global and national incentives, the implementation of such policies needs to take into account national property right regimes and the recent trend towards the devolution of rights and responsibilities to communities and private individuals, which has a significant impact on the relative importance of different types of market failures and policy effects. This paper summarizes existing literature on the causes of deforestation and the magnitude of various forest benefit components, discusses the usefulness of forest valuation exercises for guiding policy choices regarding forest management and conservation, and highlights the key role of market failure in tropical forest conservation. It explores the various policy options that exist for the rest of the world to address market failure, and concludes with conditions necessary for improving current systems.Less
Tropical forest conservation and sustainable natural forest management both imply benefits and invoke considerable costs. The spatial and temporal mismatch of such benefits (which might not materialize until far in the future and could be shared by many parties) and costs (which often occur at a local scale and must be borne in the short term) prevents an efficient forest management at the national level. While the international community has developed a variety of instruments to align global and national incentives, the implementation of such policies needs to take into account national property right regimes and the recent trend towards the devolution of rights and responsibilities to communities and private individuals, which has a significant impact on the relative importance of different types of market failures and policy effects. This paper summarizes existing literature on the causes of deforestation and the magnitude of various forest benefit components, discusses the usefulness of forest valuation exercises for guiding policy choices regarding forest management and conservation, and highlights the key role of market failure in tropical forest conservation. It explores the various policy options that exist for the rest of the world to address market failure, and concludes with conditions necessary for improving current systems.
Adrian C. Newton
- Published in print:
- 2007
- Published Online:
- September 2007
- ISBN:
- 9780198567448
- eISBN:
- 9780191717895
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198567448.003.0001
- Subject:
- Biology, Plant Sciences and Forestry
This introductory chapter focuses on the application of ecological techniques in forest conservation and management. It presents a brief overview of recent developments in international forest ...
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This introductory chapter focuses on the application of ecological techniques in forest conservation and management. It presents a brief overview of recent developments in international forest policy. It also includes a summary of recent initiatives aimed at providing conservation assessments of forests.Less
This introductory chapter focuses on the application of ecological techniques in forest conservation and management. It presents a brief overview of recent developments in international forest policy. It also includes a summary of recent initiatives aimed at providing conservation assessments of forests.
David Wainhouse
- Published in print:
- 2004
- Published Online:
- April 2010
- ISBN:
- 9780198505648
- eISBN:
- 9780191728150
- Item type:
- book
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198505648.001.0001
- Subject:
- Biology, Ecology, Plant Sciences and Forestry
This book aims to provide a critical appraisal of the theory and practice of key methods of forest pest management. The appropriate application of these ‘ecological methods’ in the development of ...
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This book aims to provide a critical appraisal of the theory and practice of key methods of forest pest management. The appropriate application of these ‘ecological methods’ in the development of Integrated Pest Management (IPM) programmes depends on a clear understanding of pest biology and population dynamics, and an appreciation of the ecology and economic importance of both semi-natural and plantation forests. These aspects provide a focus for discussion throughout the book. The main themes of the first four chapters are the influence of forest composition and structure on the nature and severity of pest problems, the threat posed by the introduction of exotic pests in global trade, how risk-rating of forests can provide an early warning of outbreaks, and the role that silviculture can play in both contributing to and helping to reduce the impact of pests. The following four chapters discuss in turn the nature of tree resistance and its exploitation, the principles and practice of biological and microbial control, and the use of semiochemicals in manipulating insect populations. The final chapter on IPM includes a discussion of the economic and environmental impact of pests, with practical examples of IPM illustrated in a series of case studies. The potential impact of climate change is briefly discussed. Many of the examples and case studies relate to insect pests, but the term ‘pest’ is used in its widest sense to include fungal pathogens. Brief reference is also made to mammalian herbivores.Less
This book aims to provide a critical appraisal of the theory and practice of key methods of forest pest management. The appropriate application of these ‘ecological methods’ in the development of Integrated Pest Management (IPM) programmes depends on a clear understanding of pest biology and population dynamics, and an appreciation of the ecology and economic importance of both semi-natural and plantation forests. These aspects provide a focus for discussion throughout the book. The main themes of the first four chapters are the influence of forest composition and structure on the nature and severity of pest problems, the threat posed by the introduction of exotic pests in global trade, how risk-rating of forests can provide an early warning of outbreaks, and the role that silviculture can play in both contributing to and helping to reduce the impact of pests. The following four chapters discuss in turn the nature of tree resistance and its exploitation, the principles and practice of biological and microbial control, and the use of semiochemicals in manipulating insect populations. The final chapter on IPM includes a discussion of the economic and environmental impact of pests, with practical examples of IPM illustrated in a series of case studies. The potential impact of climate change is briefly discussed. Many of the examples and case studies relate to insect pests, but the term ‘pest’ is used in its widest sense to include fungal pathogens. Brief reference is also made to mammalian herbivores.
Oliver L. Phillips, Timothy R. Baker, Luzmila Arroyo, Niro Higuchi, Timothy Killeen, William F. Laurance, Simon L. Lewis, Jon Lloyd, Yadvinder Malhi, Abel Monteagudo, David A. Neill, Percy Nuñez Vargas, J. Natalino N. Silva, Rodolfo Vásquez Martinez, Miguel Alexiades, Samuel Almeida, Sandra Brown, Jerome Chave, James A. Comiskey, Claudia I. Czimczik, Anthony Di Fiore, Terry Erwin, Caroline Kuebler, Susan G. Laurance, Henrique E. M. Nascimento, Jean Olivier, Walter Palacios, Sandra Patiño, Nigel Pitman, Carlos A. Quesada, Mario Saldias, Armando Torres Lezama, and Barbara Vinceti
- Published in print:
- 2005
- Published Online:
- September 2007
- ISBN:
- 9780198567066
- eISBN:
- 9780191717888
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198567066.003.0010
- Subject:
- Biology, Plant Sciences and Forestry
Previous work found that tree turnover, biomass, and large liana densities increased in mature tropical forests in the late 20th century, indicating a concerted shift in forest ecological processes. ...
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Previous work found that tree turnover, biomass, and large liana densities increased in mature tropical forests in the late 20th century, indicating a concerted shift in forest ecological processes. However, the findings have proved controversial. Here, regional-scale patterns of tree turnover are characterized, using improved datasets available for Amazonia that span the last twenty-five years. The main findings include: trees at least 10 cm in diameter recruit and die twice as fast on the richer soils of western Amazonia compared to trees on the poorer soils of eastern Amazonia; turnover rates have increased throughout Amazonia over the last two decades; mortality and recruitment rates have tended to increase in every region and environmental zone; recruitment rates consistently exceed mortality rates; and increases in recruitment and mortality rates are greatest in western Amazonia. These patterns and trends are not caused by obvious artefacts in the data or the analyses, and cannot be directly driven by a mortality driver such as increased drought because the biomass in these forests has simultaneously increased. Apparently, therefore, widespread environmental changes are stimulating the growth and productivity of Amazon forests.Less
Previous work found that tree turnover, biomass, and large liana densities increased in mature tropical forests in the late 20th century, indicating a concerted shift in forest ecological processes. However, the findings have proved controversial. Here, regional-scale patterns of tree turnover are characterized, using improved datasets available for Amazonia that span the last twenty-five years. The main findings include: trees at least 10 cm in diameter recruit and die twice as fast on the richer soils of western Amazonia compared to trees on the poorer soils of eastern Amazonia; turnover rates have increased throughout Amazonia over the last two decades; mortality and recruitment rates have tended to increase in every region and environmental zone; recruitment rates consistently exceed mortality rates; and increases in recruitment and mortality rates are greatest in western Amazonia. These patterns and trends are not caused by obvious artefacts in the data or the analyses, and cannot be directly driven by a mortality driver such as increased drought because the biomass in these forests has simultaneously increased. Apparently, therefore, widespread environmental changes are stimulating the growth and productivity of Amazon forests.
Oliver L. Phillips and Yadvinder Malhi
- Published in print:
- 2005
- Published Online:
- September 2007
- ISBN:
- 9780198567066
- eISBN:
- 9780191717888
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198567066.003.0018
- Subject:
- Biology, Plant Sciences and Forestry
At the start of the 21st century the human race lives in a radically altered biosphere, and in an atmosphere that is shifting rapidly to conditions with no direct analogue in Earth's prehistory. ...
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At the start of the 21st century the human race lives in a radically altered biosphere, and in an atmosphere that is shifting rapidly to conditions with no direct analogue in Earth's prehistory. These atmospheric changes are certain to have impacts on the Earth's ecosystems, but the complexity of these ecosystems and the multiplicity of processes and scales make the exact nature of these impacts difficult to tease out. This book has examined the potential impacts on the most complex of terrestrial ecosystems, the great tropical forests, and addresses the important question: what will (any remaining) mature old-growth tropical forests look like at the end of this century? Answering this question has implications for conservation, global biodiversity, and global biogeochemical cycling, as well as being a test for our understanding of natural- and human-impacted ecosystems.Less
At the start of the 21st century the human race lives in a radically altered biosphere, and in an atmosphere that is shifting rapidly to conditions with no direct analogue in Earth's prehistory. These atmospheric changes are certain to have impacts on the Earth's ecosystems, but the complexity of these ecosystems and the multiplicity of processes and scales make the exact nature of these impacts difficult to tease out. This book has examined the potential impacts on the most complex of terrestrial ecosystems, the great tropical forests, and addresses the important question: what will (any remaining) mature old-growth tropical forests look like at the end of this century? Answering this question has implications for conservation, global biodiversity, and global biogeochemical cycling, as well as being a test for our understanding of natural- and human-impacted ecosystems.
Adrian C. Newton
- Published in print:
- 2007
- Published Online:
- September 2007
- ISBN:
- 9780198567448
- eISBN:
- 9780191717895
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198567448.003.0002
- Subject:
- Biology, Plant Sciences and Forestry
This chapter discusses the use of remote sensing technologies and geographical information systems (GIS), which have revolutionized the ability to map patterns of forest distribution and estimate ...
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This chapter discusses the use of remote sensing technologies and geographical information systems (GIS), which have revolutionized the ability to map patterns of forest distribution and estimate rates of forest loss and recovery. The application of these methods to forest ecology and conservation is described, with reference to practical examples. An introduction to GIS methods is then provided, followed by a description of the methods used to assess the spatial characteristics of forest landscapes.Less
This chapter discusses the use of remote sensing technologies and geographical information systems (GIS), which have revolutionized the ability to map patterns of forest distribution and estimate rates of forest loss and recovery. The application of these methods to forest ecology and conservation is described, with reference to practical examples. An introduction to GIS methods is then provided, followed by a description of the methods used to assess the spatial characteristics of forest landscapes.
Adrian C. Newton
- Published in print:
- 2007
- Published Online:
- September 2007
- ISBN:
- 9780198567448
- eISBN:
- 9780191717895
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198567448.003.0004
- Subject:
- Biology, Plant Sciences and Forestry
This chapter describes methods for studying forest dynamics. Topics covered include characterizing forest disturbance regimes, analysis of forest disturbance history, characterizing forest gaps, ...
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This chapter describes methods for studying forest dynamics. Topics covered include characterizing forest disturbance regimes, analysis of forest disturbance history, characterizing forest gaps, measuring light environments, measuring other aspects of microclimate, assessing the dynamics of tree populations, seed bank studies, and defining functional groups of species.Less
This chapter describes methods for studying forest dynamics. Topics covered include characterizing forest disturbance regimes, analysis of forest disturbance history, characterizing forest gaps, measuring light environments, measuring other aspects of microclimate, assessing the dynamics of tree populations, seed bank studies, and defining functional groups of species.
Patrick Meir and John Grace
- Published in print:
- 2005
- Published Online:
- September 2007
- ISBN:
- 9780198567066
- eISBN:
- 9780191717888
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198567066.003.0007
- Subject:
- Biology, Plant Sciences and Forestry
Drought stress in tropical forests can have a major impact on global carbon, water, and energy cycles. This chapter examines drought-induced responses in the processing of carbon and water by intact ...
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Drought stress in tropical forests can have a major impact on global carbon, water, and energy cycles. This chapter examines drought-induced responses in the processing of carbon and water by intact tropical forest ecosystems over short (physiological) and longer (ecological) timescales. Both levels of understanding should be represented in analyses of climate-forest ecosystem feedback. Although limited spatial information on the diversity of the physical properties of soil constrains estimates of drought vulnerability, tree functional convergence across species based on simple measures such as wood density would simplify how drought responses can be represented and linked to changes in forest composition through mortality indices. While insufficient on their own, satellite-derived measurements of ecosystem properties (e.g. leaf area index) and processes (e.g. mortality and photosynthesis) are expected to provide increasingly detailed information that can be used to test understanding of short- and longer-term responses to drought.Less
Drought stress in tropical forests can have a major impact on global carbon, water, and energy cycles. This chapter examines drought-induced responses in the processing of carbon and water by intact tropical forest ecosystems over short (physiological) and longer (ecological) timescales. Both levels of understanding should be represented in analyses of climate-forest ecosystem feedback. Although limited spatial information on the diversity of the physical properties of soil constrains estimates of drought vulnerability, tree functional convergence across species based on simple measures such as wood density would simplify how drought responses can be represented and linked to changes in forest composition through mortality indices. While insufficient on their own, satellite-derived measurements of ecosystem properties (e.g. leaf area index) and processes (e.g. mortality and photosynthesis) are expected to provide increasingly detailed information that can be used to test understanding of short- and longer-term responses to drought.
Jos Barlow and Carlos A. Peres
- Published in print:
- 2005
- Published Online:
- September 2007
- ISBN:
- 9780198567066
- eISBN:
- 9780191717888
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198567066.003.0008
- Subject:
- Biology, Plant Sciences and Forestry
Over the last twenty years the combined effects of El Niñno-induced droughts and land-use change have greatly increased the frequency of fire incidents in humid tropical forests. Despite the ...
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Over the last twenty years the combined effects of El Niñno-induced droughts and land-use change have greatly increased the frequency of fire incidents in humid tropical forests. Despite the potential for rapid ecosystem alteration and the current prevalence of wildfire disturbance, the consequences of such fires for tropical forest biodiversity remain poorly understood. This chapter provides a pantropical review of the current state of knowledge on these fires, including new data from seasonally dry forests in central Brazilian Amazonia. Tree mortality and changes in forest structure are strongly linked to burn severity. Despite the paucity of data on faunal responses to tropical forest fires, some trends are becoming apparent; for example, large canopy frugivores and understorey insectivorous birds appear to be highly sensitive to changes in forest structure and composition during the first years following fires. Finally, the viability of techniques and legislation for reducing forest flammability and preventing anthropogenic ignition sources from coming into contact with flammable forests is tested.Less
Over the last twenty years the combined effects of El Niñno-induced droughts and land-use change have greatly increased the frequency of fire incidents in humid tropical forests. Despite the potential for rapid ecosystem alteration and the current prevalence of wildfire disturbance, the consequences of such fires for tropical forest biodiversity remain poorly understood. This chapter provides a pantropical review of the current state of knowledge on these fires, including new data from seasonally dry forests in central Brazilian Amazonia. Tree mortality and changes in forest structure are strongly linked to burn severity. Despite the paucity of data on faunal responses to tropical forest fires, some trends are becoming apparent; for example, large canopy frugivores and understorey insectivorous birds appear to be highly sensitive to changes in forest structure and composition during the first years following fires. Finally, the viability of techniques and legislation for reducing forest flammability and preventing anthropogenic ignition sources from coming into contact with flammable forests is tested.
V. Alaric Sample
- Published in print:
- 2008
- Published Online:
- September 2008
- ISBN:
- 9780195309454
- eISBN:
- 9780199871261
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780195309454.003.0023
- Subject:
- Biology, Ecology, Biodiversity / Conservation Biology
This chapter characterizes sustainability as a central and traditional concern within the science and management practices of forestry. It summarizes the historical evolution of sustainability in ...
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This chapter characterizes sustainability as a central and traditional concern within the science and management practices of forestry. It summarizes the historical evolution of sustainability in forest management and the concept of a “regulated forest”. It then examines the means by which natural resource policy developed in the United States, the influence of the European concept of sustained yield, and the promotion of forest conservation practices, and additional possibilities for policy development to achieve sustainable forest management both on local levels and in a global context.Less
This chapter characterizes sustainability as a central and traditional concern within the science and management practices of forestry. It summarizes the historical evolution of sustainability in forest management and the concept of a “regulated forest”. It then examines the means by which natural resource policy developed in the United States, the influence of the European concept of sustained yield, and the promotion of forest conservation practices, and additional possibilities for policy development to achieve sustainable forest management both on local levels and in a global context.
Adrian Newton
- Published in print:
- 2007
- Published Online:
- September 2007
- ISBN:
- 9780198567448
- eISBN:
- 9780191717895
- Item type:
- book
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198567448.001.0001
- Subject:
- Biology, Plant Sciences and Forestry
Forest conservation has become one of the most important environmental issues currently facing humanity, as a result of widespread deforestation and forest degradation. Pressures on remaining natural ...
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Forest conservation has become one of the most important environmental issues currently facing humanity, as a result of widespread deforestation and forest degradation. Pressures on remaining natural forests continue to intensify, leading to high rates of biodiversity loss. Understanding how human activities influence ecological processes within forests is essential for developing effective conservation action. This book describes research methods and techniques relevant to understanding forest ecology, with a particular focus on those that are relevant to practical conservation and sustainable forest management. This information is currently disparate and difficult to locate, and the intention here is to provide a comprehensive synthesis. Methods are presented for assessing forest extent and condition, structure and composition, and forest dynamics at a variety of scales. Techniques for assessing genetic variation and reproductive ecology, and for evaluating the habitat value of forests are also described. Particular emphasis is given to state-of-the-art techniques, such as remote sensing, GIS, computer modelling, and molecular markers. However, traditional methods of forest mensuration and ecological survey are also presented. The methods and techniques described are generally applicable to all forest types, including both temperate and tropical forest ecosystems.Less
Forest conservation has become one of the most important environmental issues currently facing humanity, as a result of widespread deforestation and forest degradation. Pressures on remaining natural forests continue to intensify, leading to high rates of biodiversity loss. Understanding how human activities influence ecological processes within forests is essential for developing effective conservation action. This book describes research methods and techniques relevant to understanding forest ecology, with a particular focus on those that are relevant to practical conservation and sustainable forest management. This information is currently disparate and difficult to locate, and the intention here is to provide a comprehensive synthesis. Methods are presented for assessing forest extent and condition, structure and composition, and forest dynamics at a variety of scales. Techniques for assessing genetic variation and reproductive ecology, and for evaluating the habitat value of forests are also described. Particular emphasis is given to state-of-the-art techniques, such as remote sensing, GIS, computer modelling, and molecular markers. However, traditional methods of forest mensuration and ecological survey are also presented. The methods and techniques described are generally applicable to all forest types, including both temperate and tropical forest ecosystems.
Anthony Scott
- Published in print:
- 2008
- Published Online:
- May 2008
- ISBN:
- 9780198286035
- eISBN:
- 9780191718410
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198286035.003.0012
- Subject:
- Economics and Finance, Development, Growth, and Environmental
Some Norman forests were directly controlled by the landlord, and some were a part of the shared manorial common lands. The latter were held and used for timber or pasture by the tenants and ...
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Some Norman forests were directly controlled by the landlord, and some were a part of the shared manorial common lands. The latter were held and used for timber or pasture by the tenants and freeholders and eventually cleared completely. Modern rights to forested land were formed in the landlord's own woods, for hunting and recreation, fuel supply, and leasing to a timber contractor. The rights of many lords were restricted, tied up in settlements requiring that the timber be left intact. In law the timber stand was attached to and so part of the land. By dealing with a contractor, did an owner thereby also sell his interest in the land, lease the land with a right to remove its timber; license the contractor to enter and remove the timber, or sell the trees only? All disputed cases showed that the answer somehow depended on duration of the right. A leading case in 1957 found that if the trees were still growing, they were part of the land but if they were mature they were chattels merely warehoused on the land, to be dealt in separately. Turning to the exclusivity characteristic, it is shown how nuisance law and government intervention were adapted for forest fires. The chapter turns to two neglected property-right opportunities. One concerns multiple-owner, multiple-use forests: the adaptation of specialized forest rights for price-mechanism selection among competing land uses and products. The second is to broaden the existence of ‘tree tenures’ so that forest landowners can lease out the right for a holder to bring on successive stands of timber.Less
Some Norman forests were directly controlled by the landlord, and some were a part of the shared manorial common lands. The latter were held and used for timber or pasture by the tenants and freeholders and eventually cleared completely. Modern rights to forested land were formed in the landlord's own woods, for hunting and recreation, fuel supply, and leasing to a timber contractor. The rights of many lords were restricted, tied up in settlements requiring that the timber be left intact. In law the timber stand was attached to and so part of the land. By dealing with a contractor, did an owner thereby also sell his interest in the land, lease the land with a right to remove its timber; license the contractor to enter and remove the timber, or sell the trees only? All disputed cases showed that the answer somehow depended on duration of the right. A leading case in 1957 found that if the trees were still growing, they were part of the land but if they were mature they were chattels merely warehoused on the land, to be dealt in separately. Turning to the exclusivity characteristic, it is shown how nuisance law and government intervention were adapted for forest fires. The chapter turns to two neglected property-right opportunities. One concerns multiple-owner, multiple-use forests: the adaptation of specialized forest rights for price-mechanism selection among competing land uses and products. The second is to broaden the existence of ‘tree tenures’ so that forest landowners can lease out the right for a holder to bring on successive stands of timber.
Mark Maslin
- Published in print:
- 2005
- Published Online:
- September 2007
- ISBN:
- 9780198567066
- eISBN:
- 9780191717888
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198567066.003.0014
- Subject:
- Biology, Plant Sciences and Forestry
This chapter highlights and explains the impressive story of the persistence of the Amazonian rainforest throughout the Cenozoic. Palaeoclimate and palaeoecological records suggest that the Amazon ...
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This chapter highlights and explains the impressive story of the persistence of the Amazonian rainforest throughout the Cenozoic. Palaeoclimate and palaeoecological records suggest that the Amazon rainforest originated in the late Cretaceous and has been a permanent feature of South America for at least the last 55 million years. During the late Palaocene the ‘rainforest’ or ‘megathermal moist forest’ (MTMF) may have stretched as far south as 45°S in South America. The main climatic feature of the last 55 million years has been global cooling and the general constriction of the megathermal moist forests to the tropics. However, the Amazon rainforest has survived the high temperatures of the early Eocene climate optimum and the aridity and low carbon dioxide levels of the Quaternary glacial periods. The Amazon rainforest should, therefore, not be viewed as a geologically ephemeral feature of South America, but rather as a constant feature of the global Cenozoic biosphere. The forest is now, however, entering a set of climatic conditions with no past analogue.Less
This chapter highlights and explains the impressive story of the persistence of the Amazonian rainforest throughout the Cenozoic. Palaeoclimate and palaeoecological records suggest that the Amazon rainforest originated in the late Cretaceous and has been a permanent feature of South America for at least the last 55 million years. During the late Palaocene the ‘rainforest’ or ‘megathermal moist forest’ (MTMF) may have stretched as far south as 45°S in South America. The main climatic feature of the last 55 million years has been global cooling and the general constriction of the megathermal moist forests to the tropics. However, the Amazon rainforest has survived the high temperatures of the early Eocene climate optimum and the aridity and low carbon dioxide levels of the Quaternary glacial periods. The Amazon rainforest should, therefore, not be viewed as a geologically ephemeral feature of South America, but rather as a constant feature of the global Cenozoic biosphere. The forest is now, however, entering a set of climatic conditions with no past analogue.
Sharon A. Cowling, Richard A. Betts, Peter M. Cox, Virginia J. Ettwein, Chris D. Jones, Mark A. Maslin, and Steven A. Spall
- Published in print:
- 2005
- Published Online:
- September 2007
- ISBN:
- 9780198567066
- eISBN:
- 9780191717888
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198567066.003.0016
- Subject:
- Biology, Plant Sciences and Forestry
This chapter contrasted HadCM3LC simulations of Amazonian forest at the Last Glacial Maximum (21 kya) and a Younger Dryas-like period (13-12 kya) with predicted responses of future warming to provide ...
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This chapter contrasted HadCM3LC simulations of Amazonian forest at the Last Glacial Maximum (21 kya) and a Younger Dryas-like period (13-12 kya) with predicted responses of future warming to provide estimates of the climatic limits under which the Amazon forest remains relatively stable. Simulations indicate that despite lower atmospheric CO2 concentrations and increased aridity during the LGM, Amazonia remains mostly forested, and that the cooler climate of the Younger Dryas-like period in fact causes a trend towards increased above-ground carbon balance relative to today. The vegetation feedbacks responsible for maintaining forest integrity in past climates (i.e. decreased evapotranspiration and reduced photorespiration) cannot be maintained in the future. Although elevated atmospheric CO2 contributes to a positive enhancement of plant carbon and water balance, decreased stomatal conductance and increased plant and soil respiration cause a positive feedback that amplifies localised drying and climate warming. The Amazonian forest appears to be presently near its critical resiliency threshold, and even minor climate warming may be sufficient to promote deleterious feedbacks on forest integrity.Less
This chapter contrasted HadCM3LC simulations of Amazonian forest at the Last Glacial Maximum (21 kya) and a Younger Dryas-like period (13-12 kya) with predicted responses of future warming to provide estimates of the climatic limits under which the Amazon forest remains relatively stable. Simulations indicate that despite lower atmospheric CO2 concentrations and increased aridity during the LGM, Amazonia remains mostly forested, and that the cooler climate of the Younger Dryas-like period in fact causes a trend towards increased above-ground carbon balance relative to today. The vegetation feedbacks responsible for maintaining forest integrity in past climates (i.e. decreased evapotranspiration and reduced photorespiration) cannot be maintained in the future. Although elevated atmospheric CO2 contributes to a positive enhancement of plant carbon and water balance, decreased stomatal conductance and increased plant and soil respiration cause a positive feedback that amplifies localised drying and climate warming. The Amazonian forest appears to be presently near its critical resiliency threshold, and even minor climate warming may be sufficient to promote deleterious feedbacks on forest integrity.
Christian Körner
- Published in print:
- 2005
- Published Online:
- September 2007
- ISBN:
- 9780198567066
- eISBN:
- 9780191717888
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198567066.003.0006
- Subject:
- Biology, Plant Sciences and Forestry
The fixation and storage of carbon by tropical forests, which contain close to half of the globe's biomass carbon, may be affected by elevated atmospheric CO2 concentration. Classical theoretical ...
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The fixation and storage of carbon by tropical forests, which contain close to half of the globe's biomass carbon, may be affected by elevated atmospheric CO2 concentration. Classical theoretical approaches assume a uniform stimulation of photosynthesis and growth across taxa. Direct assessments of the carbon balance either by flux studies or by repeated forest inventories also suggest a current net uptake, although magnitudes sometimes exceed those missing in the global C-balance. Reasons for such discrepancies may lie in the nature of forest dynamics and in differential responses of taxa or plant functional types. This contribution argues that CO2 enrichment may cause forests to become more dynamic and that faster tree turnover may convert a stimulatory effect of elevated CO2 on photosynthesis and growth into a long-term net biomass carbon loss by favouring shorter lived trees of lower wood density. At the very least, this is a scenario which deserves inclusion into long-term projections in the carbon relations of tropical forests. Species and plant functional type specific responses (‘biodiversity effects’) and forest dynamics need to be accounted for in projections of future carbon-storage in tropical forests.Less
The fixation and storage of carbon by tropical forests, which contain close to half of the globe's biomass carbon, may be affected by elevated atmospheric CO2 concentration. Classical theoretical approaches assume a uniform stimulation of photosynthesis and growth across taxa. Direct assessments of the carbon balance either by flux studies or by repeated forest inventories also suggest a current net uptake, although magnitudes sometimes exceed those missing in the global C-balance. Reasons for such discrepancies may lie in the nature of forest dynamics and in differential responses of taxa or plant functional types. This contribution argues that CO2 enrichment may cause forests to become more dynamic and that faster tree turnover may convert a stimulatory effect of elevated CO2 on photosynthesis and growth into a long-term net biomass carbon loss by favouring shorter lived trees of lower wood density. At the very least, this is a scenario which deserves inclusion into long-term projections in the carbon relations of tropical forests. Species and plant functional type specific responses (‘biodiversity effects’) and forest dynamics need to be accounted for in projections of future carbon-storage in tropical forests.
William F. Laurance, Alexandre A. Oliveira, Susan G. Laurance, Richard Condit, Henrique E. M. Nascimento, Ana Andrade, Christopher W. Dick, Ana C. Sanchez-Thorin, Thomas E. Lovejoy, and José E. L. S. Ribeiro
- Published in print:
- 2005
- Published Online:
- September 2007
- ISBN:
- 9780198567066
- eISBN:
- 9780191717888
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198567066.003.0009
- Subject:
- Biology, Plant Sciences and Forestry
The rainforests of central Amazonia are some of the most species-rich tree communities on earth. In recent decades, forests in the central-Amazonian landscape have experienced highly non-random ...
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The rainforests of central Amazonia are some of the most species-rich tree communities on earth. In recent decades, forests in the central-Amazonian landscape have experienced highly non-random changes in dynamics and composition. These analyses are made on a network of eighteen permanent plots unaffected by any detectable disturbance. Within these plots, tree mortality, recruitment, and growth have increased over time. Of 115 relatively abundant tree genera, twenty-seven changed significantly in density or basal area — a value nearly fourteen times greater than that expected by chance. An independent, eight-year study in nearby forests corroborated these shifts in composition. Despite increasing tree mortality, pioneer trees did not increase in abundance, but genera of faster-growing trees, including many canopy and emergent species, are increasing in dominance or density, whereas genera of slower-growing trees, including many subcanopy species, are declining. Rising atmospheric CO2 concentrations may explain these changes, although the effects of this and other large-scale environmental alterations have not been fully explored. These compositional changes could have important effects on the carbon storage, dynamics, and biota of Amazonian forests.Less
The rainforests of central Amazonia are some of the most species-rich tree communities on earth. In recent decades, forests in the central-Amazonian landscape have experienced highly non-random changes in dynamics and composition. These analyses are made on a network of eighteen permanent plots unaffected by any detectable disturbance. Within these plots, tree mortality, recruitment, and growth have increased over time. Of 115 relatively abundant tree genera, twenty-seven changed significantly in density or basal area — a value nearly fourteen times greater than that expected by chance. An independent, eight-year study in nearby forests corroborated these shifts in composition. Despite increasing tree mortality, pioneer trees did not increase in abundance, but genera of faster-growing trees, including many canopy and emergent species, are increasing in dominance or density, whereas genera of slower-growing trees, including many subcanopy species, are declining. Rising atmospheric CO2 concentrations may explain these changes, although the effects of this and other large-scale environmental alterations have not been fully explored. These compositional changes could have important effects on the carbon storage, dynamics, and biota of Amazonian forests.
Tim McClanahan and George M. Branch (eds)
- Published in print:
- 2008
- Published Online:
- May 2008
- ISBN:
- 9780195319958
- eISBN:
- 9780199869596
- Item type:
- book
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780195319958.001.0001
- Subject:
- Biology, Aquatic Biology
The book summarizes recent developments in the ecology of kelp forests and coral reefs in order to develop an understanding of the general principles of their ecological organization and how they ...
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The book summarizes recent developments in the ecology of kelp forests and coral reefs in order to develop an understanding of the general principles of their ecological organization and how they might be managed from an ecosystem perspective. Ecosystem management has recently become a major focus of efforts to sustain and manage natural resources and this primarily depends on an understanding of the state of the environment, component taxa, and their interactions that compose these food webs. Consequently, this book is an effort to make the desired transition toward ecosystem management by summarizing some of the recent and significant advances in our understanding of the Earth's shallow subtidal marine reefs in the last few decades, specifically coral reefs and kelp forests. The book offers a current review of our understanding of shallow benthic marine reefs and associated fisheries, focusing on food webs and how they have and are currently being altered by human influences. Chapters collectively span the globe and bring together the disparate literature into a synthetic and holistic understanding of these ecosystems. The authors introduce the environments and the food webs, how they vary in space and time, and address human influences. Based on the data and information reviewed, the authors present recommendations that would alleviate potential environmental or biodiversity problems. The main findings of the chapters are summarized in a concluding section synthesizing the organization of shallow marine reefs.Less
The book summarizes recent developments in the ecology of kelp forests and coral reefs in order to develop an understanding of the general principles of their ecological organization and how they might be managed from an ecosystem perspective. Ecosystem management has recently become a major focus of efforts to sustain and manage natural resources and this primarily depends on an understanding of the state of the environment, component taxa, and their interactions that compose these food webs. Consequently, this book is an effort to make the desired transition toward ecosystem management by summarizing some of the recent and significant advances in our understanding of the Earth's shallow subtidal marine reefs in the last few decades, specifically coral reefs and kelp forests. The book offers a current review of our understanding of shallow benthic marine reefs and associated fisheries, focusing on food webs and how they have and are currently being altered by human influences. Chapters collectively span the globe and bring together the disparate literature into a synthetic and holistic understanding of these ecosystems. The authors introduce the environments and the food webs, how they vary in space and time, and address human influences. Based on the data and information reviewed, the authors present recommendations that would alleviate potential environmental or biodiversity problems. The main findings of the chapters are summarized in a concluding section synthesizing the organization of shallow marine reefs.
Adrian C. Newton
- Published in print:
- 2007
- Published Online:
- September 2007
- ISBN:
- 9780198567448
- eISBN:
- 9780191717895
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198567448.003.0003
- Subject:
- Biology, Plant Sciences and Forestry
This chapter describes methods that can be used to characterize communities of tree species based on a field survey, focusing on the methods that are most commonly used today. Information is also ...
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This chapter describes methods that can be used to characterize communities of tree species based on a field survey, focusing on the methods that are most commonly used today. Information is also provided on techniques for estimating the species richness and diversity of forest communities, which has received increasing attention in the wake of the Convention on Biological Diversity.Less
This chapter describes methods that can be used to characterize communities of tree species based on a field survey, focusing on the methods that are most commonly used today. Information is also provided on techniques for estimating the species richness and diversity of forest communities, which has received increasing attention in the wake of the Convention on Biological Diversity.
Adrian C. Newton
- Published in print:
- 2007
- Published Online:
- September 2007
- ISBN:
- 9780198567448
- eISBN:
- 9780191717895
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780198567448.003.0007
- Subject:
- Biology, Plant Sciences and Forestry
This chapter describes methods for assessing a series of habitat variables, including deadwood volume, vertical stand structure, characteristics of forest fragments and edge effects, and the ...
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This chapter describes methods for assessing a series of habitat variables, including deadwood volume, vertical stand structure, characteristics of forest fragments and edge effects, and the characteristics of habitat trees. It also provides an account of modelling procedures that are increasingly being used to produce habitat maps for individual species. Finally, some suggestions are presented on how to undertake an assessment of forest biodiversity.Less
This chapter describes methods for assessing a series of habitat variables, including deadwood volume, vertical stand structure, characteristics of forest fragments and edge effects, and the characteristics of habitat trees. It also provides an account of modelling procedures that are increasingly being used to produce habitat maps for individual species. Finally, some suggestions are presented on how to undertake an assessment of forest biodiversity.
Thomas J. Stohlgren
- Published in print:
- 2006
- Published Online:
- September 2007
- ISBN:
- 9780195172331
- eISBN:
- 9780199790395
- Item type:
- chapter
- Publisher:
- Oxford University Press
- DOI:
- 10.1093/acprof:oso/9780195172331.003.0009
- Subject:
- Biology, Plant Sciences and Forestry
This chapter considers the difficulties in designing the plant diversity component of monitoring programs designed to report the condition and production of the nation's forests, including changes in ...
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This chapter considers the difficulties in designing the plant diversity component of monitoring programs designed to report the condition and production of the nation's forests, including changes in understory plant diversity. The methods were modified to be flexible enough to work equally well in a variety of forest types, yet standardized enough to allow for highly comparable data on plant diversity across the United States. The US Department of Agriculture's Forest Health Monitoring program accomplished this task. It is a national program that makes annual evaluations of the condition, changes, and trends in the health of forest ecosystems in the US. The monitoring program consists of a nationwide, uniform distribution of sample plots providing a large, unbiased sample of the nation's forests (1 plot/63,942 ha).Less
This chapter considers the difficulties in designing the plant diversity component of monitoring programs designed to report the condition and production of the nation's forests, including changes in understory plant diversity. The methods were modified to be flexible enough to work equally well in a variety of forest types, yet standardized enough to allow for highly comparable data on plant diversity across the United States. The US Department of Agriculture's Forest Health Monitoring program accomplished this task. It is a national program that makes annual evaluations of the condition, changes, and trends in the health of forest ecosystems in the US. The monitoring program consists of a nationwide, uniform distribution of sample plots providing a large, unbiased sample of the nation's forests (1 plot/63,942 ha).
