Barbara Zimmerman | University of Toronto (original) (raw)

Papers by Barbara Zimmerman

Research paper thumbnail of Species density and associations in Caribbean reef corals

Journal of Experimental Marine Biology and Ecology, 1976

... 2.17 AfoM<K^-M COtWnc.K! (L.) 2.66 2.82 2.41 ^4. a^arift^M cfOMN (Verrill) 2.11 2.63 1.96 ... more ... 2.17 AfoM<K^-M COtWnc.K! (L.) 2.66 2.82 2.41 ^4. a^arift^M cfOMN (Verrill) 2.11 2.63 1.96 1.89 1.48 1.51 1.73 1.71 1.54 24 MH GOODWIN ^r ^^.. true ... om;y (Lamarck) j.69 ).76 Dtp/orM /a&)TMf/!t/b''y?!M (L.) 0.10 0.36 .S;Wera.!f^M ra^Mn^ (Pallas) 0.13 0.26 Monyo^fyea cacemo ...

Research paper thumbnail of Hunting for Sustainability in Tropical Forests. Edited by John G. Robinson and Elizabeth L. Bennett, Columbia University Press, New York, 2000, pp. xxi, 1–592. ISBN 0-231-10976-8 (alk. paper); 0-231-10977-6 (pbk.: alk. paper); (www.columbia.edu/cu/cup)

Ecological Economics, 2001

Research paper thumbnail of Use of RADARSAT SAR Data for Sustainable Management of Natural Resources: A Test Case in the Kayapó Indigenous Area, Pará, Brazil

Canadian Journal of Remote Sensing, 1998

RESUMEL'utilite des donnees RADARSAT a ouverture synthetique en modes standard et fin a ete t... more RESUMEL'utilite des donnees RADARSAT a ouverture synthetique en modes standard et fin a ete testee dans le cadre d'une recherche sur l'elaboration et la mise en place d'une politique d'utilisation des ressources axee sur le developpement durable dans la zone indigene de Kayapo, dans le sud de l'etat du Para, au Bresil. Le potentiel des donnees RADARSAT s'est revele interessant dans deux tâches precises : 1) l'identification de petites percees dans la canopee resultant des perturbations dues aux operations forestieres ou autres activites humaines et 2) la discrimination entre les principaux types d'ecosysteme de la region, en particulier le cerrado (savane), la foret de plateau et la foret de plaine d'inondation. Ainsi, des scenes RADARSAT ont ete comparees a des cartes geographiques des activites d'extraction de l'acajou dans la region et a une scene Landsat-TM. Les activites d'extraction (qui se sont poursuivies entre 0,5 et 5 annees avant l'acquisition RADARSAT) sont peu evidentes dans les scenes RADARS...

Research paper thumbnail of OBSOLETE: The Natural and Social History of the Indigenous Lands and Protected Areas Corridor of the Xingu River Basin and Prospects for Protection

The 280,000 km 2 of indigenous lands and protected areas (ILPAs) of the Xingu river basin form a ... more The 280,000 km 2 of indigenous lands and protected areas (ILPAs) of the Xingu river basin form a continuous forest corridor inhabited by 25 indigenous peoples and about 185 riverine ( ribeirinho ) families. Spanning one of the world's most intense deforestation zones in Para and Mato Grosso states, the Xingu ILPAs exemplify how Brazilian government policy and indigenous and forest communities’ mobilization have worked to reduce Amazon deforestation rates. We find that projects of nongovernmental organizations (NGOs) and government support for indigenous and traditional communities have developed scalable resource management and income generation projects within the ILPAs. They have supported territorial surveillance and protection in the absence of government enforcement of protected areas including indigenous territories. Most importantly, NGOs have enabled local communities to organize and administer their own institutions—critical to building capacity to manage their territories. We find striking differences in the level of ecological intactness between large areas of forest controlled by indigenous communities that have allied with NGOs compared with the forest of those communities that do not receive NGO investment. Larger-scale sustainable sources of finance will be needed to address current threats and continuing lawlessness in the frontier region. Payment for ecosystem services, including Reducing Emissions from Deforestation and Forest Degradation (REDD +), potentially including both public and private sources, could attain the scale needed.

Research paper thumbnail of An historical interpretation of habitat use by frogs in a Central Amazonian Forest

Research paper thumbnail of Prospects for Sustainable Logging in Tropical Forests

Journal of Biogeography, 1986

A convincing body of evidence shows that as it is presently codified, sustainable forest-manageme... more A convincing body of evidence shows that as it is presently codified, sustainable forest-management (SFM) logging implemented at an industrial scale guarantees commercial and biological depletion of high-value timber species within three harvests in all three major tropical forest regions. The minimum technical standards necessary for approaching ecological sustainability directly contravene the prospects for financial profitability. Therefore, industrial-scale SFM is likely to lead to the degradation and devaluation of primary tropical forests as surely as widespread conventional unmanaged logging does today. Recent studies also show that logging in the tropics, even using SFM techniques, releases significant carbon dioxide and that carbon stocks once stored in logged timber and slash takes decades to rebuild. These results beg for a reevaluation of the United Nations Framework Convention on Climate Change proposals to apply a Reducing Emissions from Deforestation and Forest Degradation subsidy for the widespread implementation of SFM logging in tropical forests. However, encouraging models of the successful sustainable management of tropical forests for timber and nontimber products exist at local-community scales.

Research paper thumbnail of Large Scale Forest Conservation With an Indigenous People in the Highly Threatened Southeastern Amazon of Brazil: The Kayapo

Encyclopedia of the World's Biomes, 2020

This article was originally published in Encyclopedia of the World&#39;s Biomes, published by... more This article was originally published in Encyclopedia of the World&#39;s Biomes, published by Elsevier, and the attached copy is provided by Elsevier for the author&#39;s benefit and for the benefit of the author&#39;s institution, for non-commercial research and educational use including without limitation use in instruction at your institution, sending it to specific colleagues who you know, and providing a copy to your institution&#39;s administrator.

Research paper thumbnail of Wilderness protected areas : management guidelines for IUCN category 1b protected areas

The designation of geographical entities in this book, and the presentation of the material, does... more The designation of geographical entities in this book, and the presentation of the material, does not imply the expression of any opinion whatsoever on the part of IUCN or other participating organizations concerning the legal status of any country, territory, or area, or of its authorities, or concerning the delimitation of its frontiers or boundaries. The views expressed in this publication do not necessarily reflect those of IUCN or other participating organizations.

Research paper thumbnail of Book Review: Maraca: the biodiversity and environment of an Amazonian rainforest

Progress in Physical Geography, 2000

Research paper thumbnail of A comparison of structural features of calls of open and forest habitat frog species in the central Amazon

Research paper thumbnail of Prospects for Sustainable Logging in Tropical Forests

BioScience, 2012

A convincing body of evidence shows that as it is presently codified, sustainable forest-manageme... more A convincing body of evidence shows that as it is presently codified, sustainable forest-management (SFM) logging implemented at an industrial scale guarantees commercial and biological depletion of high-value timber species within three harvests in all three major tropical forest regions. The minimum technical standards necessary for approaching ecological sustainability directly contravene the prospects for financial profitability. Therefore, industrial-scale SFM is likely to lead to the degradation and devaluation of primary tropical forests as surely as widespread conventional unmanaged logging does today. Recent studies also show that logging in the tropics, even using SFM techniques, releases significant carbon dioxide and that carbon stocks once stored in logged timber and slash takes decades to rebuild. These results beg for a reevaluation of the United Nations Framework Convention on Climate Change proposals to apply a Reducing Emissions from Deforestation and Forest Degradation subsidy for the widespread implementation of SFM logging in tropical forests. However, encouraging models of the successful sustainable management of tropical forests for timber and nontimber products exist at local-community scales.

Research paper thumbnail of Large Scale Forest Conservation With an Indigenous People in the Highly Threatened Southeastern Amazon of Brazil: The Kayapo

Encyclopedia of the World's Biomes, 2020

This article was originally published in Encyclopedia of the World's Biomes, published by Elsevie... more This article was originally published in Encyclopedia of the World's Biomes, published by Elsevier, and the attached copy is provided by Elsevier for the author's benefit and for the benefit of the author's institution, for non-commercial research and educational use including without limitation use in instruction at your institution, sending it to specific colleagues who you know, and providing a copy to your institution's administrator.

Research paper thumbnail of Vocalizations of primary forest frog species in the Central Amazon

Acta Amazonica, 1984

The calls of 18 species of Amazonian forest frogs were recorded in 3 localities: the Tapajos Nati... more The calls of 18 species of Amazonian forest frogs were recorded in 3 localities: the Tapajos National Park near Itaituba, the Reserva Ducke near Manaus, and the INPA-WWF reserves near Manaus. Structural and time parameters and sonographs of these calls including previously undescribed vocalization by 10 species are presented. Unlike open habitat species, several forest frong species characteriscally demonstrated one on more of the following temporal parameters: very low call rates, sporadic intervals, infrequent nights of calling and synchronized chorusing. It is hypothesized that predation has influenced the evolution of vocal behaviour in Amazonian forest frogs.

Research paper thumbnail of Mackey et al 2014 Policy Options for World's Primary Forests

Research paper thumbnail of An experimental test of density- and distant-dependent recruitment of mahogany (Swietenia macrophylla) in southeastern Amazonia

Oecologia, 2006

According to the Janzen-Connell model, high mortality of seeds and seedlings in proximity to cons... more According to the Janzen-Connell model, high mortality of seeds and seedlings in proximity to conspecific adults can help maintain species diversity in tropical forests. Using a natural population of big-leaf mahogany (Swietenia macrophylla King), we tested the model&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s mechanism by examining seed predation and juvenile recruitment in the forest understory and in treefall gaps in the vicinity of both isolated and clumped adults. We used tethered seeds placed in three types of exclosure plots: (1) complete access to seeds, (2) semi-access (access by small-sized seed predators) and (3) no access (all mammals excluded). Exclosure treatments were applied within the understory (both near and far from adults) and in gaps at eight fruiting adults in the late dry season (2001) and scored ten months later. Significantly more seeds were removed in canopy gaps near clumped adults than at isolated adults; otherwise, none of the treatment factors significantly influenced seed predation. In contrast, understory juvenile recruitment was significantly enhanced by distance from adults and was twice as high at isolated than clumped adults, providing novel support for the Janzen-Connell mechanism. No-access exclosures protected significantly more seeds than semi- and full-access exclosures, implicating small mammals in seed losses. Across the eight trees, juvenile recruitment in the no-access exclosures decreased significantly with conspecific adult densities, implicating non-mammalian density-responsive factor(s) in mortality following germination; likely a known specialist invertebrate herbivore. When all treatments were combined, conspecific adult basal area and total DBH explained 72 and 90% of variation in overall juvenile recruitment, respectively. Collectively, these results indicate that Janzen-Connell effects can operate in S. macrophylla, especially during the seed-to-seedling transition, and will likely reduce recruitment in areas of high conspecific densities. They also suggest that further research into the causes of density-dependence in tropical trees should investigate mortality agents following germination.

Research paper thumbnail of Juvenile mortality and attacks by a specialist herbivore increase with conspecific adult basal area of Amazonian Swietenia macrophylla (Meliaceae)

Journal of Tropical Ecology, 2006

According to the Janzen–Connell model, host-specific natural enemies can promote species coexiste... more According to the Janzen–Connell model, host-specific natural enemies can promote species coexistence of canopy trees in tropical forests by attacking progeny where they are most concentrated. However, empirical evidence relating negative density-dependent mortality to herbivory and, in particular, attack by specialist herbivores, remains rare. We investigated density dependence in a natural population of Swietenia macrophylla in a south-eastern Amazon forest of Brazil. Across 24 adult trees, we found that initial juvenile densities were positively correlated with basal area of adult conspecifics whereas subsequent survivorship over 1 y for these juveniles declined strongly with increasing basal area of adult conspecifics. For 18 trees with > 5 juveniles surviving for 1 y, further evidence supporting the Janzen–Connell mechanism was obtained in that leaf herbivory and attack by a specialist microlepidopteran moth (Steniscadia poliophaea) increased, and overall foliar condition dec...

Research paper thumbnail of Variation in Small Mammal Species Richness by Trap Height and Trap Type in Southeastern Amazonia

Journal of Mammalogy, 2005

Despite its biological richness, the rodent and marsupial fauna of many parts of the Amazon Basin... more Despite its biological richness, the rodent and marsupial fauna of many parts of the Amazon Basin remains poorly known and the efficacy of different methods in assessing its diversity are poorly understood. We present results of small mammal trapping at a previously unsurveyed site in the Xingú Basin of the southeastern Amazon, Pará, Brazil; provide details on a new method for arboreal trapping; and compare species richness among traps at different heights and between different trap types. Mammals were livetrapped at 3 trap heights: ground, understory (1-3 m above ground), and canopy (mean height ¼ 11.5 m 6 3.2 SD, range ¼ 4.8-16.8 m, n ¼ 76 trap stations). We recorded 1,769 captures of 1,178 individuals of 8 marsupial and 17 rodent species in 38,090 trap-nights (or 19,320 station-nights, where a station-night consisted of 1 Sherman and 1 Tomahawk live trap at 1 height for 1 night). Overall trap success was 6.1 individuals per 100 station-nights; success by trap position was 9.0% for ground (7,850 station-nights), 4.7% for understory (7,850 station-nights), and 2.9% for canopy (3,490 station-nights). Success by trap type was 4.7% for Shermans and 5.9% for Tomahawks, with Tomahawk traps showing a more rapid accumulation of species. Rarefied species accumulation curves showed little improvement with the inclusion of canopy trapping, which we attribute to high variability in the development of vertical structure at the site. We suggest that in areas with low and often-broken canopies, only ground and understory traps need be employed for long-term studies; however, some form of canopy trapping should be used during initial surveys so that the utility of arboreal trapping can be evaluated.

Research paper thumbnail of Amazonian Small Mammal Abundances in Relation to Habitat Structure and Resource Abundance

Journal of Mammalogy, 2006

Previous studies in tropical rain forests suggest that most small mammal species reach their high... more Previous studies in tropical rain forests suggest that most small mammal species reach their highest densities in disturbed habitats; however, only a few sites have been examined. Consequently, habitat and resource use for many species is poorly understood. This is especially true in the Amazon Basin, where no studies of microhabitat associations of small mammals have been undertaken. We studied relationships with habitat variables and resource abundances for 5 species of marsupials and 9 species of rodents at a site in southeastern Amazonia. Small mammals were sampled with traps placed both on the ground and in the understory. Eight habitat variables were measured to quantify habitat structure. Measures of insect biomass were collected by the use of sticky traps, and fruit abundance was quantified. Patterns of habitat use were examined using logistic regression, multiple regression, and ordinations. Many species showed increased abundances with habitat features indicative of edgeaffected or disturbed habitats, showing negative relationships with understory openness, understory woody-stem density, tree density, and tree size; and positive relationships with number of vines per tree, mean log size, number of logs, and volume of downed wood. We obtained support for the hypothesis that the cause of this pattern is increased resource abundances in these areas, because both insect biomass and number of fruiting trees showed similar relationships. However, for many species, measures of resource abundance were not important once habitat features were entered into the models, indicating that the relationship to resources is an indirect one.

Research paper thumbnail of Ecology and Calls of Four Species of Amazonian Forest Frogs

Journal of Herpetology, 1988

JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, a... more JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact

Research paper thumbnail of Canopy cover mediates interactions between a specialist caterpillar and seedlings of a neotropical tree

Journal of Ecology, 2007

1. Light availability may be crucial for understanding dynamics of plant-herbivore interactions i... more 1. Light availability may be crucial for understanding dynamics of plant-herbivore interactions in temperate and tropical forest communities. This is because local light availability can influence both tree seedling tolerance and susceptibility to herbivory-yet how they mediate levels of insect herbivory that vary with the density of host population is virtually unknown. Here we tested predictions of three key, non-mutually exclusive hypotheses of plant-herbivore interactions: the Limiting Resource Model (LRM), the Plant Vigour Hypothesis (PVH), and the Janzen-Connell Mechanism (JCM). 2. In an Amazonian forest, we planted Swietenia macrophylla seedlings (c. 5 months old) into natural canopy gaps and the shaded understorey and simulated the damage patterns of the specialist herbivore moth, Steniscadia poliophaea , by clipping seedling leaves. Over the next 8 months, we monitored seedling performance in terms of growth and survivorship and also quantified herbivory to new young leaves on a seasonal basis. 3. In support of the LRM, severe leaf damage (≥ 50%) was lethal for Swietenia macrophylla seedlings in the understorey, but in gaps only reduced seedling growth. In support of the PVH, gap seedlings suffered greater post-simulated herbivory (up to 100% defoliation) by S. poliophaea caterpillars than their understorey counterparts. 4. Adding a novel dimension to the Janzen-Connell hypothesis, we found that early wet season herbivory of seedlings in gaps increased with conspecific adult density within a 125-m radius; whereas in the understorey only those seedlings within 50 m of a Swietenia tree were attacked by caterpillars. 5. Synthesis. These results suggest lepidopterans that need young leaves for food may forage more widely in forests to find seedlings in light-rich canopy gaps. Moths may achieve this successfully by being first attracted to gaps, and then searching within them for suitable hosts. A conceptual model, integrating conspecific adult tree density with light-driven changes in seedling tolerance/vigour and their susceptibility to herbivory and mortality, is presented. Spatial variation in the light available to tree seedlings often affects their tolerance and vigour, which may have important consequences for leaf-chewing insects and the scale of density-dependent herbivory in forests.

Research paper thumbnail of Species density and associations in Caribbean reef corals

Journal of Experimental Marine Biology and Ecology, 1976

... 2.17 AfoM<K^-M COtWnc.K! (L.) 2.66 2.82 2.41 ^4. a^arift^M cfOMN (Verrill) 2.11 2.63 1.96 ... more ... 2.17 AfoM<K^-M COtWnc.K! (L.) 2.66 2.82 2.41 ^4. a^arift^M cfOMN (Verrill) 2.11 2.63 1.96 1.89 1.48 1.51 1.73 1.71 1.54 24 MH GOODWIN ^r ^^.. true ... om;y (Lamarck) j.69 ).76 Dtp/orM /a&)TMf/!t/b''y?!M (L.) 0.10 0.36 .S;Wera.!f^M ra^Mn^ (Pallas) 0.13 0.26 Monyo^fyea cacemo ...

Research paper thumbnail of Hunting for Sustainability in Tropical Forests. Edited by John G. Robinson and Elizabeth L. Bennett, Columbia University Press, New York, 2000, pp. xxi, 1–592. ISBN 0-231-10976-8 (alk. paper); 0-231-10977-6 (pbk.: alk. paper); (www.columbia.edu/cu/cup)

Ecological Economics, 2001

Research paper thumbnail of Use of RADARSAT SAR Data for Sustainable Management of Natural Resources: A Test Case in the Kayapó Indigenous Area, Pará, Brazil

Canadian Journal of Remote Sensing, 1998

RESUMEL'utilite des donnees RADARSAT a ouverture synthetique en modes standard et fin a ete t... more RESUMEL'utilite des donnees RADARSAT a ouverture synthetique en modes standard et fin a ete testee dans le cadre d'une recherche sur l'elaboration et la mise en place d'une politique d'utilisation des ressources axee sur le developpement durable dans la zone indigene de Kayapo, dans le sud de l'etat du Para, au Bresil. Le potentiel des donnees RADARSAT s'est revele interessant dans deux tâches precises : 1) l'identification de petites percees dans la canopee resultant des perturbations dues aux operations forestieres ou autres activites humaines et 2) la discrimination entre les principaux types d'ecosysteme de la region, en particulier le cerrado (savane), la foret de plateau et la foret de plaine d'inondation. Ainsi, des scenes RADARSAT ont ete comparees a des cartes geographiques des activites d'extraction de l'acajou dans la region et a une scene Landsat-TM. Les activites d'extraction (qui se sont poursuivies entre 0,5 et 5 annees avant l'acquisition RADARSAT) sont peu evidentes dans les scenes RADARS...

Research paper thumbnail of OBSOLETE: The Natural and Social History of the Indigenous Lands and Protected Areas Corridor of the Xingu River Basin and Prospects for Protection

The 280,000 km 2 of indigenous lands and protected areas (ILPAs) of the Xingu river basin form a ... more The 280,000 km 2 of indigenous lands and protected areas (ILPAs) of the Xingu river basin form a continuous forest corridor inhabited by 25 indigenous peoples and about 185 riverine ( ribeirinho ) families. Spanning one of the world's most intense deforestation zones in Para and Mato Grosso states, the Xingu ILPAs exemplify how Brazilian government policy and indigenous and forest communities’ mobilization have worked to reduce Amazon deforestation rates. We find that projects of nongovernmental organizations (NGOs) and government support for indigenous and traditional communities have developed scalable resource management and income generation projects within the ILPAs. They have supported territorial surveillance and protection in the absence of government enforcement of protected areas including indigenous territories. Most importantly, NGOs have enabled local communities to organize and administer their own institutions—critical to building capacity to manage their territories. We find striking differences in the level of ecological intactness between large areas of forest controlled by indigenous communities that have allied with NGOs compared with the forest of those communities that do not receive NGO investment. Larger-scale sustainable sources of finance will be needed to address current threats and continuing lawlessness in the frontier region. Payment for ecosystem services, including Reducing Emissions from Deforestation and Forest Degradation (REDD +), potentially including both public and private sources, could attain the scale needed.

Research paper thumbnail of An historical interpretation of habitat use by frogs in a Central Amazonian Forest

Research paper thumbnail of Prospects for Sustainable Logging in Tropical Forests

Journal of Biogeography, 1986

A convincing body of evidence shows that as it is presently codified, sustainable forest-manageme... more A convincing body of evidence shows that as it is presently codified, sustainable forest-management (SFM) logging implemented at an industrial scale guarantees commercial and biological depletion of high-value timber species within three harvests in all three major tropical forest regions. The minimum technical standards necessary for approaching ecological sustainability directly contravene the prospects for financial profitability. Therefore, industrial-scale SFM is likely to lead to the degradation and devaluation of primary tropical forests as surely as widespread conventional unmanaged logging does today. Recent studies also show that logging in the tropics, even using SFM techniques, releases significant carbon dioxide and that carbon stocks once stored in logged timber and slash takes decades to rebuild. These results beg for a reevaluation of the United Nations Framework Convention on Climate Change proposals to apply a Reducing Emissions from Deforestation and Forest Degradation subsidy for the widespread implementation of SFM logging in tropical forests. However, encouraging models of the successful sustainable management of tropical forests for timber and nontimber products exist at local-community scales.

Research paper thumbnail of Large Scale Forest Conservation With an Indigenous People in the Highly Threatened Southeastern Amazon of Brazil: The Kayapo

Encyclopedia of the World's Biomes, 2020

This article was originally published in Encyclopedia of the World&#39;s Biomes, published by... more This article was originally published in Encyclopedia of the World&#39;s Biomes, published by Elsevier, and the attached copy is provided by Elsevier for the author&#39;s benefit and for the benefit of the author&#39;s institution, for non-commercial research and educational use including without limitation use in instruction at your institution, sending it to specific colleagues who you know, and providing a copy to your institution&#39;s administrator.

Research paper thumbnail of Wilderness protected areas : management guidelines for IUCN category 1b protected areas

The designation of geographical entities in this book, and the presentation of the material, does... more The designation of geographical entities in this book, and the presentation of the material, does not imply the expression of any opinion whatsoever on the part of IUCN or other participating organizations concerning the legal status of any country, territory, or area, or of its authorities, or concerning the delimitation of its frontiers or boundaries. The views expressed in this publication do not necessarily reflect those of IUCN or other participating organizations.

Research paper thumbnail of Book Review: Maraca: the biodiversity and environment of an Amazonian rainforest

Progress in Physical Geography, 2000

Research paper thumbnail of A comparison of structural features of calls of open and forest habitat frog species in the central Amazon

Research paper thumbnail of Prospects for Sustainable Logging in Tropical Forests

BioScience, 2012

A convincing body of evidence shows that as it is presently codified, sustainable forest-manageme... more A convincing body of evidence shows that as it is presently codified, sustainable forest-management (SFM) logging implemented at an industrial scale guarantees commercial and biological depletion of high-value timber species within three harvests in all three major tropical forest regions. The minimum technical standards necessary for approaching ecological sustainability directly contravene the prospects for financial profitability. Therefore, industrial-scale SFM is likely to lead to the degradation and devaluation of primary tropical forests as surely as widespread conventional unmanaged logging does today. Recent studies also show that logging in the tropics, even using SFM techniques, releases significant carbon dioxide and that carbon stocks once stored in logged timber and slash takes decades to rebuild. These results beg for a reevaluation of the United Nations Framework Convention on Climate Change proposals to apply a Reducing Emissions from Deforestation and Forest Degradation subsidy for the widespread implementation of SFM logging in tropical forests. However, encouraging models of the successful sustainable management of tropical forests for timber and nontimber products exist at local-community scales.

Research paper thumbnail of Large Scale Forest Conservation With an Indigenous People in the Highly Threatened Southeastern Amazon of Brazil: The Kayapo

Encyclopedia of the World's Biomes, 2020

This article was originally published in Encyclopedia of the World's Biomes, published by Elsevie... more This article was originally published in Encyclopedia of the World's Biomes, published by Elsevier, and the attached copy is provided by Elsevier for the author's benefit and for the benefit of the author's institution, for non-commercial research and educational use including without limitation use in instruction at your institution, sending it to specific colleagues who you know, and providing a copy to your institution's administrator.

Research paper thumbnail of Vocalizations of primary forest frog species in the Central Amazon

Acta Amazonica, 1984

The calls of 18 species of Amazonian forest frogs were recorded in 3 localities: the Tapajos Nati... more The calls of 18 species of Amazonian forest frogs were recorded in 3 localities: the Tapajos National Park near Itaituba, the Reserva Ducke near Manaus, and the INPA-WWF reserves near Manaus. Structural and time parameters and sonographs of these calls including previously undescribed vocalization by 10 species are presented. Unlike open habitat species, several forest frong species characteriscally demonstrated one on more of the following temporal parameters: very low call rates, sporadic intervals, infrequent nights of calling and synchronized chorusing. It is hypothesized that predation has influenced the evolution of vocal behaviour in Amazonian forest frogs.

Research paper thumbnail of Mackey et al 2014 Policy Options for World's Primary Forests

Research paper thumbnail of An experimental test of density- and distant-dependent recruitment of mahogany (Swietenia macrophylla) in southeastern Amazonia

Oecologia, 2006

According to the Janzen-Connell model, high mortality of seeds and seedlings in proximity to cons... more According to the Janzen-Connell model, high mortality of seeds and seedlings in proximity to conspecific adults can help maintain species diversity in tropical forests. Using a natural population of big-leaf mahogany (Swietenia macrophylla King), we tested the model&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s mechanism by examining seed predation and juvenile recruitment in the forest understory and in treefall gaps in the vicinity of both isolated and clumped adults. We used tethered seeds placed in three types of exclosure plots: (1) complete access to seeds, (2) semi-access (access by small-sized seed predators) and (3) no access (all mammals excluded). Exclosure treatments were applied within the understory (both near and far from adults) and in gaps at eight fruiting adults in the late dry season (2001) and scored ten months later. Significantly more seeds were removed in canopy gaps near clumped adults than at isolated adults; otherwise, none of the treatment factors significantly influenced seed predation. In contrast, understory juvenile recruitment was significantly enhanced by distance from adults and was twice as high at isolated than clumped adults, providing novel support for the Janzen-Connell mechanism. No-access exclosures protected significantly more seeds than semi- and full-access exclosures, implicating small mammals in seed losses. Across the eight trees, juvenile recruitment in the no-access exclosures decreased significantly with conspecific adult densities, implicating non-mammalian density-responsive factor(s) in mortality following germination; likely a known specialist invertebrate herbivore. When all treatments were combined, conspecific adult basal area and total DBH explained 72 and 90% of variation in overall juvenile recruitment, respectively. Collectively, these results indicate that Janzen-Connell effects can operate in S. macrophylla, especially during the seed-to-seedling transition, and will likely reduce recruitment in areas of high conspecific densities. They also suggest that further research into the causes of density-dependence in tropical trees should investigate mortality agents following germination.

Research paper thumbnail of Juvenile mortality and attacks by a specialist herbivore increase with conspecific adult basal area of Amazonian Swietenia macrophylla (Meliaceae)

Journal of Tropical Ecology, 2006

According to the Janzen–Connell model, host-specific natural enemies can promote species coexiste... more According to the Janzen–Connell model, host-specific natural enemies can promote species coexistence of canopy trees in tropical forests by attacking progeny where they are most concentrated. However, empirical evidence relating negative density-dependent mortality to herbivory and, in particular, attack by specialist herbivores, remains rare. We investigated density dependence in a natural population of Swietenia macrophylla in a south-eastern Amazon forest of Brazil. Across 24 adult trees, we found that initial juvenile densities were positively correlated with basal area of adult conspecifics whereas subsequent survivorship over 1 y for these juveniles declined strongly with increasing basal area of adult conspecifics. For 18 trees with > 5 juveniles surviving for 1 y, further evidence supporting the Janzen–Connell mechanism was obtained in that leaf herbivory and attack by a specialist microlepidopteran moth (Steniscadia poliophaea) increased, and overall foliar condition dec...

Research paper thumbnail of Variation in Small Mammal Species Richness by Trap Height and Trap Type in Southeastern Amazonia

Journal of Mammalogy, 2005

Despite its biological richness, the rodent and marsupial fauna of many parts of the Amazon Basin... more Despite its biological richness, the rodent and marsupial fauna of many parts of the Amazon Basin remains poorly known and the efficacy of different methods in assessing its diversity are poorly understood. We present results of small mammal trapping at a previously unsurveyed site in the Xingú Basin of the southeastern Amazon, Pará, Brazil; provide details on a new method for arboreal trapping; and compare species richness among traps at different heights and between different trap types. Mammals were livetrapped at 3 trap heights: ground, understory (1-3 m above ground), and canopy (mean height ¼ 11.5 m 6 3.2 SD, range ¼ 4.8-16.8 m, n ¼ 76 trap stations). We recorded 1,769 captures of 1,178 individuals of 8 marsupial and 17 rodent species in 38,090 trap-nights (or 19,320 station-nights, where a station-night consisted of 1 Sherman and 1 Tomahawk live trap at 1 height for 1 night). Overall trap success was 6.1 individuals per 100 station-nights; success by trap position was 9.0% for ground (7,850 station-nights), 4.7% for understory (7,850 station-nights), and 2.9% for canopy (3,490 station-nights). Success by trap type was 4.7% for Shermans and 5.9% for Tomahawks, with Tomahawk traps showing a more rapid accumulation of species. Rarefied species accumulation curves showed little improvement with the inclusion of canopy trapping, which we attribute to high variability in the development of vertical structure at the site. We suggest that in areas with low and often-broken canopies, only ground and understory traps need be employed for long-term studies; however, some form of canopy trapping should be used during initial surveys so that the utility of arboreal trapping can be evaluated.

Research paper thumbnail of Amazonian Small Mammal Abundances in Relation to Habitat Structure and Resource Abundance

Journal of Mammalogy, 2006

Previous studies in tropical rain forests suggest that most small mammal species reach their high... more Previous studies in tropical rain forests suggest that most small mammal species reach their highest densities in disturbed habitats; however, only a few sites have been examined. Consequently, habitat and resource use for many species is poorly understood. This is especially true in the Amazon Basin, where no studies of microhabitat associations of small mammals have been undertaken. We studied relationships with habitat variables and resource abundances for 5 species of marsupials and 9 species of rodents at a site in southeastern Amazonia. Small mammals were sampled with traps placed both on the ground and in the understory. Eight habitat variables were measured to quantify habitat structure. Measures of insect biomass were collected by the use of sticky traps, and fruit abundance was quantified. Patterns of habitat use were examined using logistic regression, multiple regression, and ordinations. Many species showed increased abundances with habitat features indicative of edgeaffected or disturbed habitats, showing negative relationships with understory openness, understory woody-stem density, tree density, and tree size; and positive relationships with number of vines per tree, mean log size, number of logs, and volume of downed wood. We obtained support for the hypothesis that the cause of this pattern is increased resource abundances in these areas, because both insect biomass and number of fruiting trees showed similar relationships. However, for many species, measures of resource abundance were not important once habitat features were entered into the models, indicating that the relationship to resources is an indirect one.

Research paper thumbnail of Ecology and Calls of Four Species of Amazonian Forest Frogs

Journal of Herpetology, 1988

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Research paper thumbnail of Canopy cover mediates interactions between a specialist caterpillar and seedlings of a neotropical tree

Journal of Ecology, 2007

1. Light availability may be crucial for understanding dynamics of plant-herbivore interactions i... more 1. Light availability may be crucial for understanding dynamics of plant-herbivore interactions in temperate and tropical forest communities. This is because local light availability can influence both tree seedling tolerance and susceptibility to herbivory-yet how they mediate levels of insect herbivory that vary with the density of host population is virtually unknown. Here we tested predictions of three key, non-mutually exclusive hypotheses of plant-herbivore interactions: the Limiting Resource Model (LRM), the Plant Vigour Hypothesis (PVH), and the Janzen-Connell Mechanism (JCM). 2. In an Amazonian forest, we planted Swietenia macrophylla seedlings (c. 5 months old) into natural canopy gaps and the shaded understorey and simulated the damage patterns of the specialist herbivore moth, Steniscadia poliophaea , by clipping seedling leaves. Over the next 8 months, we monitored seedling performance in terms of growth and survivorship and also quantified herbivory to new young leaves on a seasonal basis. 3. In support of the LRM, severe leaf damage (≥ 50%) was lethal for Swietenia macrophylla seedlings in the understorey, but in gaps only reduced seedling growth. In support of the PVH, gap seedlings suffered greater post-simulated herbivory (up to 100% defoliation) by S. poliophaea caterpillars than their understorey counterparts. 4. Adding a novel dimension to the Janzen-Connell hypothesis, we found that early wet season herbivory of seedlings in gaps increased with conspecific adult density within a 125-m radius; whereas in the understorey only those seedlings within 50 m of a Swietenia tree were attacked by caterpillars. 5. Synthesis. These results suggest lepidopterans that need young leaves for food may forage more widely in forests to find seedlings in light-rich canopy gaps. Moths may achieve this successfully by being first attracted to gaps, and then searching within them for suitable hosts. A conceptual model, integrating conspecific adult tree density with light-driven changes in seedling tolerance/vigour and their susceptibility to herbivory and mortality, is presented. Spatial variation in the light available to tree seedlings often affects their tolerance and vigour, which may have important consequences for leaf-chewing insects and the scale of density-dependent herbivory in forests.