Biodiversity loss is one of the main challenges of our time and attempts to address it require a ... more Biodiversity loss is one of the main challenges of our time and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space. While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes vast areas of the tropics remain understudied. In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity, but it remains among the least known forests in America and is often underrepresented in biodiversity databases. To worsen this situation, human-induced modifications may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost.
Forests that regrow naturally on abandoned fields are important for restoring biodiversity and ec... more Forests that regrow naturally on abandoned fields are important for restoring biodiversity and ecosystem services, but can they also preserve the distinct regional tree floras? Using the floristic composition of 1215 early successional forests (≤20 years) in 75 human-modified landscapes across the Neotropic realm, we identified 14 distinct floristic groups, with a between-group dissimilarity of 0.97. Floristic groups were associated with location, bioregions, soil pH, temperature seasonality, and water availability. Hence, there is large continental-scale variation in the species composition of early successional forests, which is mainly associated with biogeographic and environmental factors but not with human disturbance indicators. This floristic distinctiveness is partially driven by regionally restricted species belonging to widespread genera. Early secondary forests contribute therefore to restoring and conserving the distinctiveness of bioregions across the Neotropical realm,...
Boletim do Museu Paraense Emílio Goeldi - Ciências Naturais
O histórico de uso do solo é fator determinante da sucessão secundária na Amazônia central, levan... more O histórico de uso do solo é fator determinante da sucessão secundária na Amazônia central, levando ao estabelecimento de comunidades de plantas com estrutura, composição florística, biomassa e dinâmica distintas. A utilização do fogo para renovação de pastagens compromete o potencial regenerativo dessas áreas, que, quando abandonadas, são dominadas pelo gênero Vismia e colonizadas por poucas espécies, resultando em florestas secundárias pouco diversificadas nas quais a sucessão permanece estagnada. Uma vegetação mais rica e dominada pelo gênero Cecropia coloniza áreas com histórico de uso menos intensivo, permitindo o rápido desenvolvimento da sucessão. Embasado nos conhecimentos adquiridos ao longo de duas décadas de estudo, discutimos aspectos práticos relacionados ao potencial e aos custos do manejo da sucessão secundária para a restauração dos serviços ambientais e como forma de aliar a geração de renda à redução do desmatamento na região. O manejo do dossel e os plantios de en...
The seed bank is directly related to forest resilience because it contributes to the greatest num... more The seed bank is directly related to forest resilience because it contributes to the greatest number of regenerants after the occurrence of disturbances. Changes in seed density, floristic composition, and life forms completely alter the successional trajectory of forest environments. These changes are directly related to land use. For example, suppression of the seed bank can occur in pastures, that experience frequent fires with increase of density of seeds and predominance of herbs are typical of highly degraded areas, such as Poaceae, Rubiaceae, Asteraceae, and Cyperaceae. Melastomataceae seedlings are an important component of the seed bank in the Amazon rainforest. On the other hand, Urticaceae has greater representation in forests that exhibit low-impact land use. Any change in seed bank functionality is bound to compromise the diversity, regeneration potential and overall maintenance of tropical forests. Therefore, it is necessary to expand studies that investigate seed bank...
This database is the product of the 2ndFOR collaborative research network on secondary forests. T... more This database is the product of the 2ndFOR collaborative research network on secondary forests. The database contains aboveground biomass data (in Mg/ha) for 1334 secondary forest plots differing in time since abandonment. The plots belong to different chonosequence studies in the Neotropics. For a description of the database, see Poorter et al. 2016. Biomass resilience of Neotropical secondary forests. Nature doi:10.1038/nature16512
Land-use change occurs nowhere more rapidly than in the tropics, where the imbalance between defo... more Land-use change occurs nowhere more rapidly than in the tropics, where the imbalance between deforestation and forest regrowth has large consequences for the global carbon cycle1. However, considerable uncertainty remains about the rate of biomass recovery in secondary forests, and how these rates are influenced by climate, landscape, and prior land use2, 3, 4. Here we analyse aboveground biomass recovery during secondary succession in 45 forest sites and about 1,500 forest plots covering the major environmental gradients in the Neotropics. The studied secondary forests are highly productive and resilient. Aboveground biomass recovery after 20 years was on average 122 megagrams per hectare (Mg ha−1), corresponding to a net carbon uptake of 3.05 Mg C ha−1 yr−1, 11 times the uptake rate of old-growth forests. Aboveground biomass stocks took a median time of 66 years to recover to 90% of old-growth values. Aboveground biomass recovery after 20 years varied 11.3-fold (from 20 to 225 Mg ha−1) across sites, and this recovery increased with water availability (higher local rainfall and lower climatic water deficit). We present a biomass recovery map of Latin America, which illustrates geographical and climatic variation in carbon sequestration potential during forest regrowth. The map will support policies to minimize forest loss in areas where biomass resilience is naturally low (such as seasonally dry forest regions) and promote forest regeneration and restoration in humid tropical lowland areas with high biomass resilience
Este estudo teve como objetivos principais: (1) Avaliar a relacao entre peso de sementes, numero ... more Este estudo teve como objetivos principais: (1) Avaliar a relacao entre peso de sementes, numero de sementes, peso de frutos, numero de frutos e numero de sementes por fruto baseando-se na premissa de um modelo conceitual denominado de seed packaging ; (2) Avaliar as relacoes das variaveis de sementes e frutos (peso e numero), duracao da frutificacao e porcentagem de germinacao com a densidade de plântulas e individuos adultos; e (3) Avaliar os efeitos da topografia e das condicoes de micro-sitio sobre o banco de semente e o sucesso no estabelecimento de especies arboreas. O local de estudo e a area experimental do Projeto Dinâmica Biologica de Fragmento de Florestais, localizado a 80 km ao norte da cidade de Manaus, Amazonas. Para os objetivos 1 e 2, durante cerca de tres anos, o acompanhamento fenologico foi realizado para 12 especies pioneiras, para as quais a floracao e frutificacao foram monitoradas mensalmente. O peso de sementes e frutos, numero de sementes e frutos e a taxa ...
Enrichment plantings into secondary forest are an important option in restoring species diversity... more Enrichment plantings into secondary forest are an important option in restoring species diversity and ecosystem services. However, little attention has been given to environmental requirements for species performance. This study evaluated the effects of lightgaps and topographic position on the growth and survival of four native tree species (Pouteria caimito, Garcinia macrophylla, Dipteryx odorata and Cynometra bauhiniaefolia) planted into a 26-year old secondary forest originating from abandoned pastures in the central Amazon Basin. Artificial lightgaps and control plots under closed canopy were uniformly distributed on plateaus and bottomlands near water bodies. Seedlings were planted randomly into the plots and monitored for 28 months. Seedling survival rate was high (93%) and did not differ among species. Overall, lightgaps produced a 38% increase in seedling height relative to the controls. Although the four species naturally occur in mature forest, two of the four grew signif...
Tropical secondary forests recover quickly (decades) in tree species richness but slowly (centuri... more Tropical secondary forests recover quickly (decades) in tree species richness but slowly (centuries) in species composition.
This study characterizes the flowering and fruiting phenology of the 13 most common pioneer tree ... more This study characterizes the flowering and fruiting phenology of the 13 most common pioneer tree species in early successional forests of the Central Amazon. For each species, 30 individuals, 10 each in three secondary forests, were monitored monthly for four years at the Biological Dynamics of Forest Fragments Project, north of Manaus. Five species showed nearly continuous flowering and fruiting throughout the study, indicating that resources were available to pollinators and dispersers on a regular basis. The other eight species showed stronger seasonality in reproduction, seven of them annually, and one supra-annually. Overall, flowering was concentrated in the transition from the dry to the rainy season and fruiting was concentrated in the rainy season. There was no relationship between reproductive phenology and tree pollinator type or dispersal mode. Reproductive phenology was remarkably consistent year to year. The pioneer community showed a variety of phenological patterns b...
Succession in the Brazilian Amazon depends on prior land-use history. Abandoned clearcuts become ... more Succession in the Brazilian Amazon depends on prior land-use history. Abandoned clearcuts become dominated by Cecropia trees and exhibit species replacements characteristic of natural succession in forest lightgaps. In contrast, abandoned pastures are dominated by Vismia trees that inhibit natural succession for a decade or more. Here we explore how advance regeneration and limited seed dispersal may contribute to the arrested succession in Vismia-dominated stands. Vegetation surveys showed that every Vismia stem in 3–8 year old Vismia stands originated as a re-sprout. In Cecropia stands, all tree species, including Vismia, originated mostly from seeds, after deforestation and abandonment. The 100% re-sprouts of Vismia in the abandoned pastures confirms that Vismia dominance results from re-sprouting following pasture fires. Seed rain in both Vismia and Cecropia dominated stands was limited almost exclusively to second growth species already reproducing in those stands, suggesting t...
Land-use change occurs nowhere more rapidly than in the tropics, where the imbalance between defo... more Land-use change occurs nowhere more rapidly than in the tropics, where the imbalance between deforestation and forest regrowth has large consequences for the global carbon cycle. However, considerable uncertainty remains about the rate of biomass recovery in secondary forests, and how these rates are influenced by climate, landscape, and prior land use. Here we analyse aboveground biomass recovery during secondary succession in 45 forest sites and about 1,500 forest plots covering the major environmental gradients in the Neotropics. The studied secondary forests are highly productive and resilient. Aboveground biomass recovery after 20 years was on average 122 megagrams per hectare (Mg ha(-1)), corresponding to a net carbon uptake of 3.05 Mg C ha(-1) yr(-1), 11 times the uptake rate of old-growth forests. Aboveground biomass stocks took a median time of 66 years to recover to 90% of old-growth values. Aboveground biomass recovery after 20 years varied 11.3-fold (from 20 to 225 Mg ha...
Secondary forests or " capoeiras " accounted for 20% of the total deforested area in th... more Secondary forests or " capoeiras " accounted for 20% of the total deforested area in the Brazilian Amazon in 2006. This study relates land use history and biomass accumulation in a chronosequence of secondary forests in the Apuí municipality, one of the deforestation hotspots in the Amazon. Aboveground live biomass (ABGB) was estimated for trees in 16 secondary forests with ages ranging from 3-23 years of abandonment, and subjected to two previous land uses: eight areas were clearcut and used only once for small farm agriculture and then abandoned (low intensity); eight areas were maintained mainly as pasture experiencing several prescribed fires until abandonment (high intensity). Satellite imagery data between 1985 and 2010 was supplemented with landowner interviews in order to define the secondary forests age and their previous land use history. The point-centered quarter method was used for sampling trees in four diametric classes (1<5 cm, 5<10 cm, 10<20 cm, ≥...
Biodiversity loss is one of the main challenges of our time and attempts to address it require a ... more Biodiversity loss is one of the main challenges of our time and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space. While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes vast areas of the tropics remain understudied. In the American tropics, Amazonia stands out as the world&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s most diverse rainforest and the primary source of Neotropical biodiversity, but it remains among the least known forests in America and is often underrepresented in biodiversity databases. To worsen this situation, human-induced modifications may eliminate pieces of the Amazon&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost.
Forests that regrow naturally on abandoned fields are important for restoring biodiversity and ec... more Forests that regrow naturally on abandoned fields are important for restoring biodiversity and ecosystem services, but can they also preserve the distinct regional tree floras? Using the floristic composition of 1215 early successional forests (≤20 years) in 75 human-modified landscapes across the Neotropic realm, we identified 14 distinct floristic groups, with a between-group dissimilarity of 0.97. Floristic groups were associated with location, bioregions, soil pH, temperature seasonality, and water availability. Hence, there is large continental-scale variation in the species composition of early successional forests, which is mainly associated with biogeographic and environmental factors but not with human disturbance indicators. This floristic distinctiveness is partially driven by regionally restricted species belonging to widespread genera. Early secondary forests contribute therefore to restoring and conserving the distinctiveness of bioregions across the Neotropical realm,...
Boletim do Museu Paraense Emílio Goeldi - Ciências Naturais
O histórico de uso do solo é fator determinante da sucessão secundária na Amazônia central, levan... more O histórico de uso do solo é fator determinante da sucessão secundária na Amazônia central, levando ao estabelecimento de comunidades de plantas com estrutura, composição florística, biomassa e dinâmica distintas. A utilização do fogo para renovação de pastagens compromete o potencial regenerativo dessas áreas, que, quando abandonadas, são dominadas pelo gênero Vismia e colonizadas por poucas espécies, resultando em florestas secundárias pouco diversificadas nas quais a sucessão permanece estagnada. Uma vegetação mais rica e dominada pelo gênero Cecropia coloniza áreas com histórico de uso menos intensivo, permitindo o rápido desenvolvimento da sucessão. Embasado nos conhecimentos adquiridos ao longo de duas décadas de estudo, discutimos aspectos práticos relacionados ao potencial e aos custos do manejo da sucessão secundária para a restauração dos serviços ambientais e como forma de aliar a geração de renda à redução do desmatamento na região. O manejo do dossel e os plantios de en...
The seed bank is directly related to forest resilience because it contributes to the greatest num... more The seed bank is directly related to forest resilience because it contributes to the greatest number of regenerants after the occurrence of disturbances. Changes in seed density, floristic composition, and life forms completely alter the successional trajectory of forest environments. These changes are directly related to land use. For example, suppression of the seed bank can occur in pastures, that experience frequent fires with increase of density of seeds and predominance of herbs are typical of highly degraded areas, such as Poaceae, Rubiaceae, Asteraceae, and Cyperaceae. Melastomataceae seedlings are an important component of the seed bank in the Amazon rainforest. On the other hand, Urticaceae has greater representation in forests that exhibit low-impact land use. Any change in seed bank functionality is bound to compromise the diversity, regeneration potential and overall maintenance of tropical forests. Therefore, it is necessary to expand studies that investigate seed bank...
This database is the product of the 2ndFOR collaborative research network on secondary forests. T... more This database is the product of the 2ndFOR collaborative research network on secondary forests. The database contains aboveground biomass data (in Mg/ha) for 1334 secondary forest plots differing in time since abandonment. The plots belong to different chonosequence studies in the Neotropics. For a description of the database, see Poorter et al. 2016. Biomass resilience of Neotropical secondary forests. Nature doi:10.1038/nature16512
Land-use change occurs nowhere more rapidly than in the tropics, where the imbalance between defo... more Land-use change occurs nowhere more rapidly than in the tropics, where the imbalance between deforestation and forest regrowth has large consequences for the global carbon cycle1. However, considerable uncertainty remains about the rate of biomass recovery in secondary forests, and how these rates are influenced by climate, landscape, and prior land use2, 3, 4. Here we analyse aboveground biomass recovery during secondary succession in 45 forest sites and about 1,500 forest plots covering the major environmental gradients in the Neotropics. The studied secondary forests are highly productive and resilient. Aboveground biomass recovery after 20 years was on average 122 megagrams per hectare (Mg ha−1), corresponding to a net carbon uptake of 3.05 Mg C ha−1 yr−1, 11 times the uptake rate of old-growth forests. Aboveground biomass stocks took a median time of 66 years to recover to 90% of old-growth values. Aboveground biomass recovery after 20 years varied 11.3-fold (from 20 to 225 Mg ha−1) across sites, and this recovery increased with water availability (higher local rainfall and lower climatic water deficit). We present a biomass recovery map of Latin America, which illustrates geographical and climatic variation in carbon sequestration potential during forest regrowth. The map will support policies to minimize forest loss in areas where biomass resilience is naturally low (such as seasonally dry forest regions) and promote forest regeneration and restoration in humid tropical lowland areas with high biomass resilience
Este estudo teve como objetivos principais: (1) Avaliar a relacao entre peso de sementes, numero ... more Este estudo teve como objetivos principais: (1) Avaliar a relacao entre peso de sementes, numero de sementes, peso de frutos, numero de frutos e numero de sementes por fruto baseando-se na premissa de um modelo conceitual denominado de seed packaging ; (2) Avaliar as relacoes das variaveis de sementes e frutos (peso e numero), duracao da frutificacao e porcentagem de germinacao com a densidade de plântulas e individuos adultos; e (3) Avaliar os efeitos da topografia e das condicoes de micro-sitio sobre o banco de semente e o sucesso no estabelecimento de especies arboreas. O local de estudo e a area experimental do Projeto Dinâmica Biologica de Fragmento de Florestais, localizado a 80 km ao norte da cidade de Manaus, Amazonas. Para os objetivos 1 e 2, durante cerca de tres anos, o acompanhamento fenologico foi realizado para 12 especies pioneiras, para as quais a floracao e frutificacao foram monitoradas mensalmente. O peso de sementes e frutos, numero de sementes e frutos e a taxa ...
Enrichment plantings into secondary forest are an important option in restoring species diversity... more Enrichment plantings into secondary forest are an important option in restoring species diversity and ecosystem services. However, little attention has been given to environmental requirements for species performance. This study evaluated the effects of lightgaps and topographic position on the growth and survival of four native tree species (Pouteria caimito, Garcinia macrophylla, Dipteryx odorata and Cynometra bauhiniaefolia) planted into a 26-year old secondary forest originating from abandoned pastures in the central Amazon Basin. Artificial lightgaps and control plots under closed canopy were uniformly distributed on plateaus and bottomlands near water bodies. Seedlings were planted randomly into the plots and monitored for 28 months. Seedling survival rate was high (93%) and did not differ among species. Overall, lightgaps produced a 38% increase in seedling height relative to the controls. Although the four species naturally occur in mature forest, two of the four grew signif...
Tropical secondary forests recover quickly (decades) in tree species richness but slowly (centuri... more Tropical secondary forests recover quickly (decades) in tree species richness but slowly (centuries) in species composition.
This study characterizes the flowering and fruiting phenology of the 13 most common pioneer tree ... more This study characterizes the flowering and fruiting phenology of the 13 most common pioneer tree species in early successional forests of the Central Amazon. For each species, 30 individuals, 10 each in three secondary forests, were monitored monthly for four years at the Biological Dynamics of Forest Fragments Project, north of Manaus. Five species showed nearly continuous flowering and fruiting throughout the study, indicating that resources were available to pollinators and dispersers on a regular basis. The other eight species showed stronger seasonality in reproduction, seven of them annually, and one supra-annually. Overall, flowering was concentrated in the transition from the dry to the rainy season and fruiting was concentrated in the rainy season. There was no relationship between reproductive phenology and tree pollinator type or dispersal mode. Reproductive phenology was remarkably consistent year to year. The pioneer community showed a variety of phenological patterns b...
Succession in the Brazilian Amazon depends on prior land-use history. Abandoned clearcuts become ... more Succession in the Brazilian Amazon depends on prior land-use history. Abandoned clearcuts become dominated by Cecropia trees and exhibit species replacements characteristic of natural succession in forest lightgaps. In contrast, abandoned pastures are dominated by Vismia trees that inhibit natural succession for a decade or more. Here we explore how advance regeneration and limited seed dispersal may contribute to the arrested succession in Vismia-dominated stands. Vegetation surveys showed that every Vismia stem in 3–8 year old Vismia stands originated as a re-sprout. In Cecropia stands, all tree species, including Vismia, originated mostly from seeds, after deforestation and abandonment. The 100% re-sprouts of Vismia in the abandoned pastures confirms that Vismia dominance results from re-sprouting following pasture fires. Seed rain in both Vismia and Cecropia dominated stands was limited almost exclusively to second growth species already reproducing in those stands, suggesting t...
Land-use change occurs nowhere more rapidly than in the tropics, where the imbalance between defo... more Land-use change occurs nowhere more rapidly than in the tropics, where the imbalance between deforestation and forest regrowth has large consequences for the global carbon cycle. However, considerable uncertainty remains about the rate of biomass recovery in secondary forests, and how these rates are influenced by climate, landscape, and prior land use. Here we analyse aboveground biomass recovery during secondary succession in 45 forest sites and about 1,500 forest plots covering the major environmental gradients in the Neotropics. The studied secondary forests are highly productive and resilient. Aboveground biomass recovery after 20 years was on average 122 megagrams per hectare (Mg ha(-1)), corresponding to a net carbon uptake of 3.05 Mg C ha(-1) yr(-1), 11 times the uptake rate of old-growth forests. Aboveground biomass stocks took a median time of 66 years to recover to 90% of old-growth values. Aboveground biomass recovery after 20 years varied 11.3-fold (from 20 to 225 Mg ha...
Secondary forests or " capoeiras " accounted for 20% of the total deforested area in th... more Secondary forests or " capoeiras " accounted for 20% of the total deforested area in the Brazilian Amazon in 2006. This study relates land use history and biomass accumulation in a chronosequence of secondary forests in the Apuí municipality, one of the deforestation hotspots in the Amazon. Aboveground live biomass (ABGB) was estimated for trees in 16 secondary forests with ages ranging from 3-23 years of abandonment, and subjected to two previous land uses: eight areas were clearcut and used only once for small farm agriculture and then abandoned (low intensity); eight areas were maintained mainly as pasture experiencing several prescribed fires until abandonment (high intensity). Satellite imagery data between 1985 and 2010 was supplemented with landowner interviews in order to define the secondary forests age and their previous land use history. The point-centered quarter method was used for sampling trees in four diametric classes (1<5 cm, 5<10 cm, 10<20 cm, ≥...
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