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Paulo R. Guimarães - One of the best experts on this subject based on the ideXlab platform.
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pleistocene megafaunal extinctions and the functional loss of long distance Seed Dispersal services
Ecography, 2018Co-Authors: Mathias M. Pires, Mauro Galetti, Paulo R. Guimarães, Pedro JordanoAbstract:Pleistocene extinctions affected mainly large-bodied animals, determining the loss or changes in numerous ecological functions. Evidence points to a central role of many extinct megafauna herbivores as Seed dispersers. An important step in understanding the legacy of extinct mutualistic interactions is to evaluate the roles and effectiveness of megafauna herbivores in Seed Dispersal. Here we use morphological and ecophysiological allometries to estimate both quantitative and qualitative aspects of Seed-Dispersal services likely provided by extinct megafauna. We developed a mechanistic model that encompasses four stages of Seed Dispersal – Seed ingestion, gut retention, animal movement, and Seed deposition. We estimate Seed-Dispersal kernels through simulations to infer the role of Pleistocene megafauna in promoting long-distance Dispersal and examine how Seed Dispersal was affected by extinctions. Simulations suggest extinct large-bodied frugivores would frequently disperse large Seeds over a thousand meters, whereas smaller-bodied frugivores are more likely to deposit the Seeds over a few hundred meters. Moreover, events of long-distance Seed Dispersal by the extinct megafauna would be up to ten times longer than long-distance Dispersal by smaller-sized extant mammals. By estimating the combined distribution of Seed Dispersal distances considering all large-bodied mammalian frugivores in specific South American Pleistocene assemblages we found that long-distance Dispersal contracted by at least two thirds after the megafauna died out. The disruption of long-distance Dispersal is expected to have consequences for recruitment, spatial and genetic structure of plant populations, population persistence and community composition. Promoting long-distance Seed Dispersal was one among other salient features of extinct Pleistocene megafauna that reveal their influence on natural ecosystems. Modeling the consequences of megafaunal extinctions can offer quantitative predictions on the consequences of ongoing defaunation to plant populations and ecological communities. This article is protected by copyright. All rights reserved.
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Pleistocene megafaunal extinctions and the functional loss of long‐distance Seed‐Dispersal services
Ecography, 2017Co-Authors: Mathias M. Pires, Mauro Galetti, Paulo R. Guimarães, Pedro JordanoAbstract:Pleistocene extinctions affected mainly large-bodied animals, determining the loss or changes in numerous ecological functions. Evidence points to a central role of many extinct megafauna herbivores as Seed dispersers. An important step in understanding the legacy of extinct mutualistic interactions is to evaluate the roles and effectiveness of megafauna herbivores in Seed Dispersal. Here we use morphological and ecophysiological allometries to estimate both quantitative and qualitative aspects of Seed-Dispersal services likely provided by extinct megafauna. We developed a mechanistic model that encompasses four stages of Seed Dispersal – Seed ingestion, gut retention, animal movement, and Seed deposition. We estimate Seed-Dispersal kernels through simulations to infer the role of Pleistocene megafauna in promoting long-distance Dispersal and examine how Seed Dispersal was affected by extinctions. Simulations suggest extinct large-bodied frugivores would frequently disperse large Seeds over a thousand meters, whereas smaller-bodied frugivores are more likely to deposit the Seeds over a few hundred meters. Moreover, events of long-distance Seed Dispersal by the extinct megafauna would be up to ten times longer than long-distance Dispersal by smaller-sized extant mammals. By estimating the combined distribution of Seed Dispersal distances considering all large-bodied mammalian frugivores in specific South American Pleistocene assemblages we found that long-distance Dispersal contracted by at least two thirds after the megafauna died out. The disruption of long-distance Dispersal is expected to have consequences for recruitment, spatial and genetic structure of plant populations, population persistence and community composition. Promoting long-distance Seed Dispersal was one among other salient features of extinct Pleistocene megafauna that reveal their influence on natural ecosystems. Modeling the consequences of megafaunal extinctions can offer quantitative predictions on the consequences of ongoing defaunation to plant populations and ecological communities. This article is protected by copyright. All rights reserved.
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reconstructing past ecological networks the reconfiguration of Seed Dispersal interactions after megafaunal extinction
Oecologia, 2014Co-Authors: Mathias M. Pires, Mauro Galetti, Marco Aurélio Pizo, Camila I Donatti, Rodolfo Dirzo, Paulo R. GuimarãesAbstract:The late Quaternary megafaunal extinction impacted ecological communities worldwide, and affected key ecological processes such as Seed Dispersal. The traits of several species of large-Seeded plants are thought to have evolved in response to interactions with extinct megafauna, but how these extinctions affected the organization of interactions in Seed-Dispersal systems is poorly understood. Here, we combined ecological and paleontological data and network analyses to investigate how the structure of a species-rich Seed-Dispersal network could have changed from the Pleistocene to the present and examine the possible consequences of such changes. Our results indicate that the Seed-Dispersal network was organized into modules across the different time periods but has been reconfigured in different ways over time. The episode of megafaunal extinction and the arrival of humans changed how Seed dispersers were distributed among network modules. However, the recent introduction of livestock into the Seed-Dispersal system partially restored the original network organization by strengthening the modular configuration. Moreover, after megafaunal extinctions, introduced species and some smaller native mammals became key components for the structure of the Seed-Dispersal network. We hypothesize that such changes in network structure affected both animal and plant assemblages, potentially contributing to the shaping of modern ecological communities. The ongoing extinction of key large vertebrates will lead to a variety of context-dependent rearranged ecological networks, most certainly affecting ecological and evolutionary processes.
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Large vertebrates as the missing components of Seed-Dispersal networks
Biological Conservation, 2013Co-Authors: Mariana Morais Vidal, Mathias M. Pires, Paulo R. GuimarãesAbstract:Abstract Large-bodied frugivores may play a key role in the networks of plants and their Seed dispersers. These species, however, are often threatened by human impacts that lead to defaunation. In this paper, we discuss the potential implications of the loss of large frugivores for Seed-Dispersal networks. First, we review the role of large vertebrates as Seed dispersers in different tropical ecosystems to show that these species are likely to be important components of Seed-Dispersal networks. Second, we showed that, despite their importance, large vertebrates are absent from most of the Seed-Dispersal networks described in the available literature. We identified three main reasons for this absence: (1) large vertebrates have already died out in the studied areas; (2) studies focus on particular taxonomic groups that consist mostly of small birds; and (3) it is inherently difficult to describe the interactions of naturally rare and secretive species such as large vertebrates. We argue that a proper evaluation of the importance of large frugivores within Seed-Dispersal networks would benefit from considering aspects other than the frequency of interactions. We suggest weighting pairwise interactions by their ecological consequences to quantify the contribution of large frugivores to outcomes of Seed Dispersal, such as landscape connectivity.
Laurence Culot - One of the best experts on this subject based on the ideXlab platform.
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Advances and Frontiers in Primate Seed Dispersal
International Journal of Primatology, 2018Co-Authors: Onja H Razafindratsima, Yamato Tsuji, Hiroki Sato, Laurence CulotAbstract:Primates play important roles as Seed dispersers in many tropical ecosystems, such that studies of their Seed Dispersal services and impacts have gained interests among primatologists and ecologists in the past few decades. In this article, we first report that the number of scientific publications on primate Seed Dispersal has increased rapidly over the past 20 years, based on an extensive literature review. These publications encompass diverse primate taxa from the four geographic regions where they naturally occur. We then summarize the contributions to this Special Issue, which reflect on these progresses. Finally, we provide new directions for the next decade.
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Long-term consistency in spatial patterns of primate Seed Dispersal.
Ecology and evolution, 2017Co-Authors: Eckhard W. Heymann, Laurence Culot, Christoph Knogge, Tony Enrique Noriega Piña, Emérita R. Tirado Herrera, Matthias Klapproth, Dietmar ZinnerAbstract:Seed Dispersal is a key ecological process in tropical forests, with effects on various levels ranging from plant reproductive success to the carbon storage potential of tropical rainforests. On a local and landscape scale, spatial patterns of Seed Dispersal create the template for the recruitment process and thus influence the population dynamics of plant species. The strength of this influence will depend on the long-term consistency of spatial patterns of Seed Dispersal. We examined the long-term consistency of spatial patterns of Seed Dispersal with spatially explicit data on Seed Dispersal by two neotropical primate species, Leontocebus nigrifrons and Saguinus mystax (Callitrichidae), collected during four independent studies between 1994 and 2013. Using distributions of Dispersal probability over distances independent of plant species, cumulative Dispersal distances, and kernel density estimates, we show that spatial patterns of Seed Dispersal are highly consistent over time. For a specific plant species, the legume Parkia panurensis, the convergence of cumulative distributions at a distance of 300 m, and the high probability of Dispersal within 100 m from source trees coincide with the dimension of the spatial-genetic structure on the embryo/juvenile (300 m) and adult stage (100 m), respectively, of this plant species. Our results are the first demonstration of long-term consistency of spatial patterns of Seed Dispersal created by tropical frugivores. Such consistency may translate into idiosyncratic patterns of regeneration.
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Partitioning the relative contribution of one-phase and two-phase Seed Dispersal when evaluating Seed Dispersal effectiveness
Methods in Ecology and Evolution, 2014Co-Authors: Laurence Culot, Marie-claude Huynen, Eckhard W. HeymannAbstract:Summary Seed Dispersal effectiveness (SDE) is a conceptual framework that aims at quantifying the contribution of Seed Dispersal vectors to plant fitness. While it is well recognized that diplochorous Dispersal systems, characterized by two successive Dispersal steps performed by two different vectors (Phase I = primary Seed Dispersal and Phase II = secondary Seed Dispersal) which are common in temperate and tropical regions, little attention has been given to distinguishing the relative contribution of one-phase and two-phase Dispersal to overall SDE. This conceptual gap probably results from the lack of a clear methodology to include Phase II Dispersal into the calculation of SDE and to quantify its relative contribution. We propose a method to evaluate the relative contribution of one-phase and two-phase Dispersal to SDE and determine whether two Seed dispersers are better than one. To do so, we used the SDE landscape and an extension of the SDE landscape, the Phase II effect landscape, which measures the direction and magnitude of the Phase II Dispersal effect on overall SDE. We used simulated and empirical data from a diplochorous Dispersal system in the Peruvian Amazon to illustrate this new approach. Our approach provides the relative contribution of one-phase SDE (SDE1) and two-phase SDE (SDE2) to overall SDE and quantifies how much SDE changes with the addition of Phase II Dispersal. Considering that the Seed Dispersal process is context dependent so that Phase II depends on Phase I, we predict the possible range of variation of SDE according to the variation of the probability of Phase II Dispersal. In our specific study system composed of two primate species as primary Dispersal vectors and different species of dung beetles as secondary Dispersal vectors, the relative contribution of SDE1 and SDE2 to overall SDE varied between plant species. We discuss the context dependency of the Phase II Dispersal and the potential applications of our approach. This extension to the conceptual framework of SDE enables quantitative evaluation of the effect of Phase II Dispersal on plant fitness and can be easily adapted to other biotic and/or abiotic diplochorous Dispersal systems.
Mathias M. Pires - One of the best experts on this subject based on the ideXlab platform.
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pleistocene megafaunal extinctions and the functional loss of long distance Seed Dispersal services
Ecography, 2018Co-Authors: Mathias M. Pires, Mauro Galetti, Paulo R. Guimarães, Pedro JordanoAbstract:Pleistocene extinctions affected mainly large-bodied animals, determining the loss or changes in numerous ecological functions. Evidence points to a central role of many extinct megafauna herbivores as Seed dispersers. An important step in understanding the legacy of extinct mutualistic interactions is to evaluate the roles and effectiveness of megafauna herbivores in Seed Dispersal. Here we use morphological and ecophysiological allometries to estimate both quantitative and qualitative aspects of Seed-Dispersal services likely provided by extinct megafauna. We developed a mechanistic model that encompasses four stages of Seed Dispersal – Seed ingestion, gut retention, animal movement, and Seed deposition. We estimate Seed-Dispersal kernels through simulations to infer the role of Pleistocene megafauna in promoting long-distance Dispersal and examine how Seed Dispersal was affected by extinctions. Simulations suggest extinct large-bodied frugivores would frequently disperse large Seeds over a thousand meters, whereas smaller-bodied frugivores are more likely to deposit the Seeds over a few hundred meters. Moreover, events of long-distance Seed Dispersal by the extinct megafauna would be up to ten times longer than long-distance Dispersal by smaller-sized extant mammals. By estimating the combined distribution of Seed Dispersal distances considering all large-bodied mammalian frugivores in specific South American Pleistocene assemblages we found that long-distance Dispersal contracted by at least two thirds after the megafauna died out. The disruption of long-distance Dispersal is expected to have consequences for recruitment, spatial and genetic structure of plant populations, population persistence and community composition. Promoting long-distance Seed Dispersal was one among other salient features of extinct Pleistocene megafauna that reveal their influence on natural ecosystems. Modeling the consequences of megafaunal extinctions can offer quantitative predictions on the consequences of ongoing defaunation to plant populations and ecological communities. This article is protected by copyright. All rights reserved.
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Pleistocene megafaunal extinctions and the functional loss of long‐distance Seed‐Dispersal services
Ecography, 2017Co-Authors: Mathias M. Pires, Mauro Galetti, Paulo R. Guimarães, Pedro JordanoAbstract:Pleistocene extinctions affected mainly large-bodied animals, determining the loss or changes in numerous ecological functions. Evidence points to a central role of many extinct megafauna herbivores as Seed dispersers. An important step in understanding the legacy of extinct mutualistic interactions is to evaluate the roles and effectiveness of megafauna herbivores in Seed Dispersal. Here we use morphological and ecophysiological allometries to estimate both quantitative and qualitative aspects of Seed-Dispersal services likely provided by extinct megafauna. We developed a mechanistic model that encompasses four stages of Seed Dispersal – Seed ingestion, gut retention, animal movement, and Seed deposition. We estimate Seed-Dispersal kernels through simulations to infer the role of Pleistocene megafauna in promoting long-distance Dispersal and examine how Seed Dispersal was affected by extinctions. Simulations suggest extinct large-bodied frugivores would frequently disperse large Seeds over a thousand meters, whereas smaller-bodied frugivores are more likely to deposit the Seeds over a few hundred meters. Moreover, events of long-distance Seed Dispersal by the extinct megafauna would be up to ten times longer than long-distance Dispersal by smaller-sized extant mammals. By estimating the combined distribution of Seed Dispersal distances considering all large-bodied mammalian frugivores in specific South American Pleistocene assemblages we found that long-distance Dispersal contracted by at least two thirds after the megafauna died out. The disruption of long-distance Dispersal is expected to have consequences for recruitment, spatial and genetic structure of plant populations, population persistence and community composition. Promoting long-distance Seed Dispersal was one among other salient features of extinct Pleistocene megafauna that reveal their influence on natural ecosystems. Modeling the consequences of megafaunal extinctions can offer quantitative predictions on the consequences of ongoing defaunation to plant populations and ecological communities. This article is protected by copyright. All rights reserved.
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reconstructing past ecological networks the reconfiguration of Seed Dispersal interactions after megafaunal extinction
Oecologia, 2014Co-Authors: Mathias M. Pires, Mauro Galetti, Marco Aurélio Pizo, Camila I Donatti, Rodolfo Dirzo, Paulo R. GuimarãesAbstract:The late Quaternary megafaunal extinction impacted ecological communities worldwide, and affected key ecological processes such as Seed Dispersal. The traits of several species of large-Seeded plants are thought to have evolved in response to interactions with extinct megafauna, but how these extinctions affected the organization of interactions in Seed-Dispersal systems is poorly understood. Here, we combined ecological and paleontological data and network analyses to investigate how the structure of a species-rich Seed-Dispersal network could have changed from the Pleistocene to the present and examine the possible consequences of such changes. Our results indicate that the Seed-Dispersal network was organized into modules across the different time periods but has been reconfigured in different ways over time. The episode of megafaunal extinction and the arrival of humans changed how Seed dispersers were distributed among network modules. However, the recent introduction of livestock into the Seed-Dispersal system partially restored the original network organization by strengthening the modular configuration. Moreover, after megafaunal extinctions, introduced species and some smaller native mammals became key components for the structure of the Seed-Dispersal network. We hypothesize that such changes in network structure affected both animal and plant assemblages, potentially contributing to the shaping of modern ecological communities. The ongoing extinction of key large vertebrates will lead to a variety of context-dependent rearranged ecological networks, most certainly affecting ecological and evolutionary processes.
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Large vertebrates as the missing components of Seed-Dispersal networks
Biological Conservation, 2013Co-Authors: Mariana Morais Vidal, Mathias M. Pires, Paulo R. GuimarãesAbstract:Abstract Large-bodied frugivores may play a key role in the networks of plants and their Seed dispersers. These species, however, are often threatened by human impacts that lead to defaunation. In this paper, we discuss the potential implications of the loss of large frugivores for Seed-Dispersal networks. First, we review the role of large vertebrates as Seed dispersers in different tropical ecosystems to show that these species are likely to be important components of Seed-Dispersal networks. Second, we showed that, despite their importance, large vertebrates are absent from most of the Seed-Dispersal networks described in the available literature. We identified three main reasons for this absence: (1) large vertebrates have already died out in the studied areas; (2) studies focus on particular taxonomic groups that consist mostly of small birds; and (3) it is inherently difficult to describe the interactions of naturally rare and secretive species such as large vertebrates. We argue that a proper evaluation of the importance of large frugivores within Seed-Dispersal networks would benefit from considering aspects other than the frequency of interactions. We suggest weighting pairwise interactions by their ecological consequences to quantify the contribution of large frugivores to outcomes of Seed Dispersal, such as landscape connectivity.
Pedro Jordano - One of the best experts on this subject based on the ideXlab platform.
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pleistocene megafaunal extinctions and the functional loss of long distance Seed Dispersal services
Ecography, 2018Co-Authors: Mathias M. Pires, Mauro Galetti, Paulo R. Guimarães, Pedro JordanoAbstract:Pleistocene extinctions affected mainly large-bodied animals, determining the loss or changes in numerous ecological functions. Evidence points to a central role of many extinct megafauna herbivores as Seed dispersers. An important step in understanding the legacy of extinct mutualistic interactions is to evaluate the roles and effectiveness of megafauna herbivores in Seed Dispersal. Here we use morphological and ecophysiological allometries to estimate both quantitative and qualitative aspects of Seed-Dispersal services likely provided by extinct megafauna. We developed a mechanistic model that encompasses four stages of Seed Dispersal – Seed ingestion, gut retention, animal movement, and Seed deposition. We estimate Seed-Dispersal kernels through simulations to infer the role of Pleistocene megafauna in promoting long-distance Dispersal and examine how Seed Dispersal was affected by extinctions. Simulations suggest extinct large-bodied frugivores would frequently disperse large Seeds over a thousand meters, whereas smaller-bodied frugivores are more likely to deposit the Seeds over a few hundred meters. Moreover, events of long-distance Seed Dispersal by the extinct megafauna would be up to ten times longer than long-distance Dispersal by smaller-sized extant mammals. By estimating the combined distribution of Seed Dispersal distances considering all large-bodied mammalian frugivores in specific South American Pleistocene assemblages we found that long-distance Dispersal contracted by at least two thirds after the megafauna died out. The disruption of long-distance Dispersal is expected to have consequences for recruitment, spatial and genetic structure of plant populations, population persistence and community composition. Promoting long-distance Seed Dispersal was one among other salient features of extinct Pleistocene megafauna that reveal their influence on natural ecosystems. Modeling the consequences of megafaunal extinctions can offer quantitative predictions on the consequences of ongoing defaunation to plant populations and ecological communities. This article is protected by copyright. All rights reserved.
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Pleistocene megafaunal extinctions and the functional loss of long‐distance Seed‐Dispersal services
Ecography, 2017Co-Authors: Mathias M. Pires, Mauro Galetti, Paulo R. Guimarães, Pedro JordanoAbstract:Pleistocene extinctions affected mainly large-bodied animals, determining the loss or changes in numerous ecological functions. Evidence points to a central role of many extinct megafauna herbivores as Seed dispersers. An important step in understanding the legacy of extinct mutualistic interactions is to evaluate the roles and effectiveness of megafauna herbivores in Seed Dispersal. Here we use morphological and ecophysiological allometries to estimate both quantitative and qualitative aspects of Seed-Dispersal services likely provided by extinct megafauna. We developed a mechanistic model that encompasses four stages of Seed Dispersal – Seed ingestion, gut retention, animal movement, and Seed deposition. We estimate Seed-Dispersal kernels through simulations to infer the role of Pleistocene megafauna in promoting long-distance Dispersal and examine how Seed Dispersal was affected by extinctions. Simulations suggest extinct large-bodied frugivores would frequently disperse large Seeds over a thousand meters, whereas smaller-bodied frugivores are more likely to deposit the Seeds over a few hundred meters. Moreover, events of long-distance Seed Dispersal by the extinct megafauna would be up to ten times longer than long-distance Dispersal by smaller-sized extant mammals. By estimating the combined distribution of Seed Dispersal distances considering all large-bodied mammalian frugivores in specific South American Pleistocene assemblages we found that long-distance Dispersal contracted by at least two thirds after the megafauna died out. The disruption of long-distance Dispersal is expected to have consequences for recruitment, spatial and genetic structure of plant populations, population persistence and community composition. Promoting long-distance Seed Dispersal was one among other salient features of extinct Pleistocene megafauna that reveal their influence on natural ecosystems. Modeling the consequences of megafaunal extinctions can offer quantitative predictions on the consequences of ongoing defaunation to plant populations and ecological communities. This article is protected by copyright. All rights reserved.
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The signatures of Anthropocene defaunation: cascading effects of the Seed Dispersal collapse.
Scientific reports, 2016Co-Authors: Néstor Pérez-méndez, Pedro Jordano, Cristina García, Alfredo ValidoAbstract:Anthropogenic activity is driving population declines and extinctions of large-bodied, fruit-eating animals worldwide. Loss of these frugivores is expected to trigger negative cascading effects on plant populations if remnant species fail to replace the Seed Dispersal services provided by the extinct frugivores. A collapse of Seed Dispersal may not only affect plant demography (i.e., lack of recruitment), but should also supress gene flow via Seed Dispersal. Yet little empirical data still exist demonstrating the genetic consequences of defaunation for animal-dispersed plant species. Here, we first document a significant reduction of Seed Dispersal distances along a gradient of human-driven defaunation, with increasing loss of large- and medium-bodied frugivores. We then show that local plant neighbourhoods have higher genetic similarity, and smaller effective population sizes when large Seed dispersers become extinct (i.e., only small frugivores remain) or are even partially downgraded (i.e., medium-sized frugivores providing less efficient Seed Dispersal). Our results demonstrate that preservation of large frugivores is crucial to maintain functional Seed Dispersal services and their associated genetic imprints, a central conservation target. Early signals of reduced Dispersal distances that accompany the Anthropogenic defaunation forecast multiple, cascading effects on plant populations.
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Meta-Analysis of the Effects of Human Disturbance on Seed Dispersal by Animals
Conservation biology : the journal of the Society for Conservation Biology, 2012Co-Authors: Julia S. Markl, Anna Traveset, Pedro Jordano, S. Joseph Wright, Matthias Schleuning, Pierre-michel Forget, Joanna E. Lambert, Katrin Böhning-gaeseAbstract:Animal-mediated Seed Dispersal is important for sustaining biological diversity in forest ecosys- tems, particularly in the tropics. Forest fragmentation, hunting, and selective logging modify forests in myriad ways and their effects on animal-mediated Seed Dispersal have been examined in many case studies. How- ever, the overall effects of different types of human disturbance on animal-mediated Seed Dispersal are still unknown. We identified 35 articles that provided 83 comparisons of animal-mediated Seed Dispersal between disturbed and undisturbed forests; all comparisons except one were conducted in tropical or subtropical ecosystems. We assessed the effects of forest fragmentation, hunting, and selective logging on Seed Dispersal of fleshy-fruited tree species. We carried out a meta-analysis to test whether forest fragmentation, hunting, and selective logging affected 3 components of animal-mediated Seed Dispersal: frugivore visitation rate, number of Seeds removed, and distance of Seed Dispersal. Forest fragmentation, hunting, and selective logging did not affect visitation rate and were marginally associated with a reduction in Seed-Dispersal distance. Hunting and selective logging, but not fragmentation, were associated with a large reduction in the number of Seeds removed. Fewer Seeds of large-Seeded than of small-Seeded tree species were removed in hunted or selectively logged forests. A plausible explanation for the consistently negative effects of hunting and selective logging on large-Seeded plant species is that large frugivores, as the predominant Seed dispersers for large-Seeded plant species, are the first animals to be extirpated from hunted or logged forests. The reduction in forest area after fragmentation appeared to have weaker effects on frugivore communities and animal-mediated Seed Dispersal than hunting and selective logging. The differential effects of hunting and selective logging on large- and small-Seeded tree species underpinned case studies that showed disrupted plant-frugivore interactions could trigger a homogenization of Seed traits in tree communities in hunted or logged tropical forests.
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Seed Dispersal effectiveness revisited: a conceptual review
The New phytologist, 2010Co-Authors: Eugene W. Schupp, Pedro Jordano, José M. GómezAbstract:Summary Growth in Seed Dispersal studies has been fast-paced since the Seed disperser effectiveness (SDE) framework was developed 17 yr ago. Thus, the time is ripe to revisit the framework in light of accumulated new insight. Here, we first present an overview of the framework, how it has been applied, and what we know and do not know. We then introduce the SDE landscape as the two-dimensional representation of the possible combinations of the quantity and the quality of Dispersal and with elevational contours representing isoclines of SDE. We discuss the structure of disperser assemblages on such landscapes. Following this we discuss recent advances and ideas in Seed Dispersal in the context of their impacts on SDE. Finally, we highlight a number of emerging issues that provide insight into SDE. Overall, the SDE framework successfully captures the complexities of Seed Dispersal. We advocate an expanded use of the term Dispersal encompassing the multiple recruitment stages from fruit to adult. While this entails difficulties in estimating SDE, it is a necessary expansion if we are to understand the central relevance of Seed Dispersal in plant ecology and evolution. Contents Summary 1
Eckhard W. Heymann - One of the best experts on this subject based on the ideXlab platform.
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Long-term consistency in spatial patterns of primate Seed Dispersal.
Ecology and evolution, 2017Co-Authors: Eckhard W. Heymann, Laurence Culot, Christoph Knogge, Tony Enrique Noriega Piña, Emérita R. Tirado Herrera, Matthias Klapproth, Dietmar ZinnerAbstract:Seed Dispersal is a key ecological process in tropical forests, with effects on various levels ranging from plant reproductive success to the carbon storage potential of tropical rainforests. On a local and landscape scale, spatial patterns of Seed Dispersal create the template for the recruitment process and thus influence the population dynamics of plant species. The strength of this influence will depend on the long-term consistency of spatial patterns of Seed Dispersal. We examined the long-term consistency of spatial patterns of Seed Dispersal with spatially explicit data on Seed Dispersal by two neotropical primate species, Leontocebus nigrifrons and Saguinus mystax (Callitrichidae), collected during four independent studies between 1994 and 2013. Using distributions of Dispersal probability over distances independent of plant species, cumulative Dispersal distances, and kernel density estimates, we show that spatial patterns of Seed Dispersal are highly consistent over time. For a specific plant species, the legume Parkia panurensis, the convergence of cumulative distributions at a distance of 300 m, and the high probability of Dispersal within 100 m from source trees coincide with the dimension of the spatial-genetic structure on the embryo/juvenile (300 m) and adult stage (100 m), respectively, of this plant species. Our results are the first demonstration of long-term consistency of spatial patterns of Seed Dispersal created by tropical frugivores. Such consistency may translate into idiosyncratic patterns of regeneration.
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Partitioning the relative contribution of one-phase and two-phase Seed Dispersal when evaluating Seed Dispersal effectiveness
Methods in Ecology and Evolution, 2014Co-Authors: Laurence Culot, Marie-claude Huynen, Eckhard W. HeymannAbstract:Summary Seed Dispersal effectiveness (SDE) is a conceptual framework that aims at quantifying the contribution of Seed Dispersal vectors to plant fitness. While it is well recognized that diplochorous Dispersal systems, characterized by two successive Dispersal steps performed by two different vectors (Phase I = primary Seed Dispersal and Phase II = secondary Seed Dispersal) which are common in temperate and tropical regions, little attention has been given to distinguishing the relative contribution of one-phase and two-phase Dispersal to overall SDE. This conceptual gap probably results from the lack of a clear methodology to include Phase II Dispersal into the calculation of SDE and to quantify its relative contribution. We propose a method to evaluate the relative contribution of one-phase and two-phase Dispersal to SDE and determine whether two Seed dispersers are better than one. To do so, we used the SDE landscape and an extension of the SDE landscape, the Phase II effect landscape, which measures the direction and magnitude of the Phase II Dispersal effect on overall SDE. We used simulated and empirical data from a diplochorous Dispersal system in the Peruvian Amazon to illustrate this new approach. Our approach provides the relative contribution of one-phase SDE (SDE1) and two-phase SDE (SDE2) to overall SDE and quantifies how much SDE changes with the addition of Phase II Dispersal. Considering that the Seed Dispersal process is context dependent so that Phase II depends on Phase I, we predict the possible range of variation of SDE according to the variation of the probability of Phase II Dispersal. In our specific study system composed of two primate species as primary Dispersal vectors and different species of dung beetles as secondary Dispersal vectors, the relative contribution of SDE1 and SDE2 to overall SDE varied between plant species. We discuss the context dependency of the Phase II Dispersal and the potential applications of our approach. This extension to the conceptual framework of SDE enables quantitative evaluation of the effect of Phase II Dispersal on plant fitness and can be easily adapted to other biotic and/or abiotic diplochorous Dispersal systems.
