Abstract We compared the demography of the palm Euterpe edulis in a large forest fragment that is... more Abstract We compared the demography of the palm Euterpe edulis in a large forest fragment that is protected from palm harvesting with that in three smaller fragments where harvesting has occurred. Palms were censused from 2005 to 2007 in nine 30 mx 30 m plots in each forest fragment. Each individual was assigned to one of five stage classes: seedling, infant, juvenile, immature, and reproductive.
Summary 1 Fragmentation severely alters physical conditions in forest understories, but few studi... more Summary 1 Fragmentation severely alters physical conditions in forest understories, but few studies have connected these changes to demographic impacts on forest species using detailed experimental examination at the individual and population levels.
Abstract Ecologists commonly use matrix models to study the population dynamics of plants. Most s... more Abstract Ecologists commonly use matrix models to study the population dynamics of plants. Most studies of plant demography use plot-based methods to collect data, in part, because mapped individuals are easier to relocate in subsequent surveys and survey methods can be standardized among sites. However, there is tremendous variation among studies, both in terms of plot arrangement and the total area sampled.
The Andes range and the Amazon basin represent the most diverse biological community on earth and... more The Andes range and the Amazon basin represent the most diverse biological community on earth and the largest tropical forest on earth, respectively, but they are historically understudied by biologists. In this paper we provide the first quantitative description of the volume and geographical distribution of ecological research in these regions. We compiled a dataset of all articles based on the Andes and Amazon regions published in two prominent international tropical ecology journals between 1995 and 2008.
Studies simultaneously evaluating the importance of safe-site and seed limitation for plant estab... more Studies simultaneously evaluating the importance of safe-site and seed limitation for plant establishment are rare, particularly in human-modified landscapes.
Abstract Tolerance is the ability of a plant to regrow or reproduce following damage. While exper... more Abstract Tolerance is the ability of a plant to regrow or reproduce following damage. While experimental studies typically measure tolerance in response to the intensity of herbivory (ie, the amount of leaf tissue removed in one attack), the impact of how many times plants are attacked during a growing season (ie, the frequency of damage) is virtually unexplored.
ABSTRACT Participatory research among the Kaiabi people at Xingu Indigenous Park in the southern ... more ABSTRACT Participatory research among the Kaiabi people at Xingu Indigenous Park in the southern Brazilian Amazon was conducted to support sound natural resource management. We studied aspects of the ethnoecology of an understory herbaceous plant, arumã (Ischnosiphon gracilis, Marantaceae), used in basketry weaving by Kaiabi men.
The Association for Tropical Biology and Conservation and the Editorial Board of Biotropica proud... more The Association for Tropical Biology and Conservation and the Editorial Board of Biotropica proudly announce the winner of the 2007 Biotropica Award for Excellence in Tropical Biology and Conservation, presented to the author of a paper published in Biotropica during 2006. We recognize an outstanding contribution based on original research conducted in tropical regions.
Background The organization of networks of interacting species, such as plants and animals engage... more Background The organization of networks of interacting species, such as plants and animals engaged in mutualisms, strongly influences the ecology and evolution of partner communities. Habitat fragmentation is a globally pervasive form of spatial heterogeneity that could profoundly impact the structure of mutualist networks.
Facilitative interactions between neighboring plants can influence community composition, especia... more Facilitative interactions between neighboring plants can influence community composition, especially in locations where environmental stress is a factor limiting competitive effects. The longleaf pine savanna of the southeastern United States is a threatened and diverse system where seedling recruitment success and understory species richness levels are regulated by the availability of moist microsites.
Background Matrix models are widely used to study the dynamics and demography of populations. An ... more Background Matrix models are widely used to study the dynamics and demography of populations. An important but overlooked issue is how the number of individuals sampled influences estimates of the population growth rate (λ) calculated with matrix models. Even unbiased estimates of vital rates do not ensure unbiased estimates of λ–Jensen's Inequality implies that even when the estimates of the vital rates are accurate, small sample sizes lead to biased estimates of λ due to increased sampling variance.
Habitat loss and fragmentation remain the greatest threats to the world's biodiversity1. The loca... more Habitat loss and fragmentation remain the greatest threats to the world's biodiversity1. The local extinction of plant species from habitat fragments is common2, although the reasons for this are not fully understood. Fragmentation is known to influence both birth-and death-related processes3, but the disruption of plant reproduction, especially pollination and seed production, is thought to be particularly important4, 5.
ABSTRACT Arthropods are the most diverse and abundant group of animals found in tropical lowland ... more ABSTRACT Arthropods are the most diverse and abundant group of animals found in tropical lowland forests, and in light of ongoing global change phenomena, it is essential to better understand their responses to anthropogenic disturbances. Here we present a review of arthropod responses to forest deforestation and fragmentation based on studies conducted at the Biological Dynamics of Forest Fragments Project (BDFFP), located in central Amazonia. These studies involved a wide range of arthropod groups.
Abstract Despite research demonstrating that water and nutrient availability exert strong effects... more Abstract Despite research demonstrating that water and nutrient availability exert strong effects on multiple ecosystem processes in tropical forests, little is known about the effect of these factors on the demography and population dynamics of tropical trees. Over the course of 5 years, we monitored two common Amazonian secondary forest species—Lacistema pubescens and Myrcia sylvatica—in dry-season irrigation, litter-removal and control plots.
Background The dispersal ability of queens is central to understanding ant life-history evolution... more Background The dispersal ability of queens is central to understanding ant life-history evolution, and plays a fundamental role in ant population and community dynamics, the maintenance of genetic diversity, and the spread of invasive ants. In tropical ecosystems, species from over 40 genera of ants establish colonies in the stems, hollow thorns, or leaf pouches of specialized plants. However, little is known about the relative dispersal ability of queens competing for access to the same host plants.
RESUMO Nos trópicos, muitas espécies de formigas nidificam obrigatoriamente em bolsas foliares ou... more RESUMO Nos trópicos, muitas espécies de formigas nidificam obrigatoriamente em bolsas foliares ou outras estruturas especializadas de plantas mirmecófitas. Contudo, os sinais que as rainhas de formigas usam para encontrar plantas hospedeiras disponíveis permanecem pouco conhecidos. Neste estudo testamos a hipótese de que as rainhas de Pheidole minutula usam voláteis para encontrar sua planta hospedeira Maieta guianensis (Melastomataceae).
Abstract The herbaceous ground cover of the longleaf pine ecosystem harbors the highest plant spe... more Abstract The herbaceous ground cover of the longleaf pine ecosystem harbors the highest plant species richness in North America, with up to 50 species per square meter, but the mechanisms that regulate this diversity are not well understood. In this system, variability in seedling recruitment events may best explain the extremely high small-scale species richness and its relationship to soil moisture and system net primary productivity.
Abstract• Premise: After deforestation, environmental changes in the remaining forest fragments a... more Abstract• Premise: After deforestation, environmental changes in the remaining forest fragments are often most intense near the forest edge, but few studies have evaluated plant growth or plasticity of plant growth in response to edge effects.• Methods: In a 2-year common garden experiment, we compared biomass allocation and growth of Heliconia acuminata with identical genotypes grown in 50× 35 m common gardens on a 25-year-old edge and in a forest interior site.
Abstract: Increased temporal variance in life-history traits is generally predicted to decrease i... more Abstract: Increased temporal variance in life-history traits is generally predicted to decrease individual fitness and population growth. We show that a widely used result of stochastic sensitivity analysis that bolsters this generality is flawed because it ignores the effects of correlations between vital rates. Considering the effects of these correlations (although ignoring autocorrelations), we show that the apparently simple relationship between vital rate variance and fitness can be considerably more complex than previously thought.
Abstract We compared the demography of the palm Euterpe edulis in a large forest fragment that is... more Abstract We compared the demography of the palm Euterpe edulis in a large forest fragment that is protected from palm harvesting with that in three smaller fragments where harvesting has occurred. Palms were censused from 2005 to 2007 in nine 30 mx 30 m plots in each forest fragment. Each individual was assigned to one of five stage classes: seedling, infant, juvenile, immature, and reproductive.
Summary 1 Fragmentation severely alters physical conditions in forest understories, but few studi... more Summary 1 Fragmentation severely alters physical conditions in forest understories, but few studies have connected these changes to demographic impacts on forest species using detailed experimental examination at the individual and population levels.
Abstract Ecologists commonly use matrix models to study the population dynamics of plants. Most s... more Abstract Ecologists commonly use matrix models to study the population dynamics of plants. Most studies of plant demography use plot-based methods to collect data, in part, because mapped individuals are easier to relocate in subsequent surveys and survey methods can be standardized among sites. However, there is tremendous variation among studies, both in terms of plot arrangement and the total area sampled.
The Andes range and the Amazon basin represent the most diverse biological community on earth and... more The Andes range and the Amazon basin represent the most diverse biological community on earth and the largest tropical forest on earth, respectively, but they are historically understudied by biologists. In this paper we provide the first quantitative description of the volume and geographical distribution of ecological research in these regions. We compiled a dataset of all articles based on the Andes and Amazon regions published in two prominent international tropical ecology journals between 1995 and 2008.
Studies simultaneously evaluating the importance of safe-site and seed limitation for plant estab... more Studies simultaneously evaluating the importance of safe-site and seed limitation for plant establishment are rare, particularly in human-modified landscapes.
Abstract Tolerance is the ability of a plant to regrow or reproduce following damage. While exper... more Abstract Tolerance is the ability of a plant to regrow or reproduce following damage. While experimental studies typically measure tolerance in response to the intensity of herbivory (ie, the amount of leaf tissue removed in one attack), the impact of how many times plants are attacked during a growing season (ie, the frequency of damage) is virtually unexplored.
ABSTRACT Participatory research among the Kaiabi people at Xingu Indigenous Park in the southern ... more ABSTRACT Participatory research among the Kaiabi people at Xingu Indigenous Park in the southern Brazilian Amazon was conducted to support sound natural resource management. We studied aspects of the ethnoecology of an understory herbaceous plant, arumã (Ischnosiphon gracilis, Marantaceae), used in basketry weaving by Kaiabi men.
The Association for Tropical Biology and Conservation and the Editorial Board of Biotropica proud... more The Association for Tropical Biology and Conservation and the Editorial Board of Biotropica proudly announce the winner of the 2007 Biotropica Award for Excellence in Tropical Biology and Conservation, presented to the author of a paper published in Biotropica during 2006. We recognize an outstanding contribution based on original research conducted in tropical regions.
Background The organization of networks of interacting species, such as plants and animals engage... more Background The organization of networks of interacting species, such as plants and animals engaged in mutualisms, strongly influences the ecology and evolution of partner communities. Habitat fragmentation is a globally pervasive form of spatial heterogeneity that could profoundly impact the structure of mutualist networks.
Facilitative interactions between neighboring plants can influence community composition, especia... more Facilitative interactions between neighboring plants can influence community composition, especially in locations where environmental stress is a factor limiting competitive effects. The longleaf pine savanna of the southeastern United States is a threatened and diverse system where seedling recruitment success and understory species richness levels are regulated by the availability of moist microsites.
Background Matrix models are widely used to study the dynamics and demography of populations. An ... more Background Matrix models are widely used to study the dynamics and demography of populations. An important but overlooked issue is how the number of individuals sampled influences estimates of the population growth rate (λ) calculated with matrix models. Even unbiased estimates of vital rates do not ensure unbiased estimates of λ–Jensen's Inequality implies that even when the estimates of the vital rates are accurate, small sample sizes lead to biased estimates of λ due to increased sampling variance.
Habitat loss and fragmentation remain the greatest threats to the world's biodiversity1. The loca... more Habitat loss and fragmentation remain the greatest threats to the world's biodiversity1. The local extinction of plant species from habitat fragments is common2, although the reasons for this are not fully understood. Fragmentation is known to influence both birth-and death-related processes3, but the disruption of plant reproduction, especially pollination and seed production, is thought to be particularly important4, 5.
ABSTRACT Arthropods are the most diverse and abundant group of animals found in tropical lowland ... more ABSTRACT Arthropods are the most diverse and abundant group of animals found in tropical lowland forests, and in light of ongoing global change phenomena, it is essential to better understand their responses to anthropogenic disturbances. Here we present a review of arthropod responses to forest deforestation and fragmentation based on studies conducted at the Biological Dynamics of Forest Fragments Project (BDFFP), located in central Amazonia. These studies involved a wide range of arthropod groups.
Abstract Despite research demonstrating that water and nutrient availability exert strong effects... more Abstract Despite research demonstrating that water and nutrient availability exert strong effects on multiple ecosystem processes in tropical forests, little is known about the effect of these factors on the demography and population dynamics of tropical trees. Over the course of 5 years, we monitored two common Amazonian secondary forest species—Lacistema pubescens and Myrcia sylvatica—in dry-season irrigation, litter-removal and control plots.
Background The dispersal ability of queens is central to understanding ant life-history evolution... more Background The dispersal ability of queens is central to understanding ant life-history evolution, and plays a fundamental role in ant population and community dynamics, the maintenance of genetic diversity, and the spread of invasive ants. In tropical ecosystems, species from over 40 genera of ants establish colonies in the stems, hollow thorns, or leaf pouches of specialized plants. However, little is known about the relative dispersal ability of queens competing for access to the same host plants.
RESUMO Nos trópicos, muitas espécies de formigas nidificam obrigatoriamente em bolsas foliares ou... more RESUMO Nos trópicos, muitas espécies de formigas nidificam obrigatoriamente em bolsas foliares ou outras estruturas especializadas de plantas mirmecófitas. Contudo, os sinais que as rainhas de formigas usam para encontrar plantas hospedeiras disponíveis permanecem pouco conhecidos. Neste estudo testamos a hipótese de que as rainhas de Pheidole minutula usam voláteis para encontrar sua planta hospedeira Maieta guianensis (Melastomataceae).
Abstract The herbaceous ground cover of the longleaf pine ecosystem harbors the highest plant spe... more Abstract The herbaceous ground cover of the longleaf pine ecosystem harbors the highest plant species richness in North America, with up to 50 species per square meter, but the mechanisms that regulate this diversity are not well understood. In this system, variability in seedling recruitment events may best explain the extremely high small-scale species richness and its relationship to soil moisture and system net primary productivity.
Abstract• Premise: After deforestation, environmental changes in the remaining forest fragments a... more Abstract• Premise: After deforestation, environmental changes in the remaining forest fragments are often most intense near the forest edge, but few studies have evaluated plant growth or plasticity of plant growth in response to edge effects.• Methods: In a 2-year common garden experiment, we compared biomass allocation and growth of Heliconia acuminata with identical genotypes grown in 50× 35 m common gardens on a 25-year-old edge and in a forest interior site.
Abstract: Increased temporal variance in life-history traits is generally predicted to decrease i... more Abstract: Increased temporal variance in life-history traits is generally predicted to decrease individual fitness and population growth. We show that a widely used result of stochastic sensitivity analysis that bolsters this generality is flawed because it ignores the effects of correlations between vital rates. Considering the effects of these correlations (although ignoring autocorrelations), we show that the apparently simple relationship between vital rate variance and fitness can be considerably more complex than previously thought.
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Papers by Emilio Bruna