The Experts below are selected from a list of 5130 Experts worldwide ranked by ideXlab platform
Karen A Kainer - One of the best experts on this subject based on the ideXlab platform.
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swidden fallow management to increase landscape level Brazil Nut productivity
Forest Ecology and Management, 2020Co-Authors: Eduardo Bongiolo, Karen A Kainer, Christina L Staudhammer, Wendell P Cropper, Lucia Helena De Oliveira WadtAbstract:Abstract Brazil Nut (Bertholletia excelsa Bonpl.) is considered the cornerstone non-timber species of Amazonian conservation. Nuts (or seeds) of this massive tree are harvested by local people living in and near old growth forests, supporting local livelihoods and regional economies. Secondary forests, however, particularly plots previously used for agriculture (swidden fallows), present better B. excelsa seedling and sapling recruitment than mature forest. This study examines the extent to which forest residents could increase Nut productivity by allowing their fallows to grow into Brazil Nut rich forests. We conducted B. excelsa inventories in the Brazilian state of Acre in abandoned swidden fallows of different ages. We also conducted interviews to determine landowner perspectives on the fallow potential for increasing Nut production. An individual-based model, based on in-situ inventories and primary and secondary datasets from prior fieldwork, simulated growth, survivorship and production from the 250 inventoried trees in 18 fallows of varying sizes (from 0.41 to 4.18 ha) and different regrowth stages (12 to 60 years old). These simulation model predictions showed that after 10 years, 2.4% of existing trees would be productive, with an average of 68.6 ± 21.5 fruits per reproductively mature tree in the four fallows that most quickly yielded productive trees. By the final projected time interval (40 years), predictions suggest all fallows will produce fruits with cumulative production averaging 1475 ± 359 fruits ha−1, suggesting an increase in landowner income of US$55.1 ± 13.4 per hectare of fallow. Our simulation model is the first to explore fruit productivity of Brazil Nut in secondary forest. It likely underpredicts B. excelsa growth and Nut production, considering that swidden fallows provide better resource availability than the forest-derived datasets we used to construct the model equations. In conclusion, our findings support previous research that suggests that higher B. excelsa recruitment rates observed in abandoned swidden fallows could indeed translate into greater adult densities and thus potentially, higher Nut production – a conclusion mirrored by most participant landowners.
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are Brazil Nut populations threatened by fruit harvest
Biotropica, 2018Co-Authors: Todd D Bertwell, Karen A Kainer, Christina L Staudhammer, Wendell P Cropper, Lucia Helena De Oliveira WadtAbstract:Harvest of Brazil Nuts from the large, iconic tree Bertholletia excelsa generates substantial income for smallholders, providing a strong incentive to conserve the mature forests where it grows. Although much previous work has focused on the impact of Nut harvest on new seedling recruits into B. excelsa populations, the connection between harvest rates and long-term population stability is still unclear. Moreover, there is additional uncertainty for Brazil Nut management in terms of population response to climate change and other anthropogenic influences. We drew on 14 years of research in two sites in Acre, Brazil with different B. excelsa Nut harvest intensities (39% and 81%), to produce stochastic and deterministic matrix population models which incorporated parameter uncertainty in vital rates. Adult abundance was projected to remain close to the current observed abundance or higher through the next 50 years. Elasticity analyses revealed that the asymptotic population growth rate (λ) was most sensitive to stasis vital rates in sapling, juvenile, and adult stages. Deterministic transition matrices calculated using diameter growth rates dependent on rainfall yielded average λ values around 1.0 under extreme high, extreme low, and average annual rainfall. While sustained high rates of Brazil Nut harvest and climate change could potentially negatively impact B. excelsa populations, changes in human use of the forested landscape are more immediate concern. To reduce the risk of population decline, smallholders and managers of B. excelsa rich forests should focus on conservation of pre-mature and mature individuals.
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testing a silvicultural recommendation Brazil Nut responses 10 years after liana cutting
Journal of Applied Ecology, 2014Co-Authors: Karen A Kainer, Lucia Helena De Oliveira Wadt, Christina L StaudhammerAbstract:Summary 1. Lianas or woody vines can be detrimental to the trees that support them. Research on liana cutting for tropical timber management has demonstrated positive yet costly benefits, but liana cutting to enhance commercial outputs of nontimber forest products has not been examined. We implemented a controlled experiment to quantify the effects of cutting lianas on Brazil Nut Bertholletia excelsa Bonpl. fecundity. 2. We conducted our 10-year experiment in a Brazilian extractive reserve where local harvesters collect fruits from this Amazonian canopy-emergent species as part of their forest-based livelihood system. We cut 454 lianas with a total basal area of 241 m 2 from 78 of 138 host trees ≥50 cm diameter at breast height. 3. Treated trees were significantly better producers 3 ½ years after liana cutting, and these differences increased dramatically in subsequent years, with consistent proportionally higher production in treated versus untreated individuals. 4. The number of lianas rooted within 5 m of the host tree significantly explained production levels, suggesting both above- and below-ground liana–host tree competition. Once host crowns were liana-free, branch regrowth was highly visible, particularly in heavily infested trees, and crown reassessments suggested that liana cutting improved crown form. Additionally, liana cutting may induce some nonproducing trees to become producers and may circumvent mortality of trees heavily infested with lianas (> 75% crown covered). 5. Liana removal can be implemented easily when harvesting Brazil Nut fruits. Only lianas associated with B. excelsa trees should be cut to conserve liana ecosystem functions. 6. Synthesis and applications. We quantified effects of liana cutting on Brazil Nut host tree fecundity and provided estimates of increased commercial yields. Our long-term (10-year) study permits understanding of biological variation and informs related management decisions. Findings suggest that liana cutting reduces above- and below-ground competition with individual trees, ultimately allowing mature host crowns to recover such that 9–10 years after liana cutting, treated trees produced on average three times more fruits than untreated trees. Application of liana cutting to other tropical species would likely boost fruit and seed production, increase host tree fecundity and potentially enhance future recruitment.
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shifting cultivation effects on Brazil Nut bertholletia excelsa regeneration
Forest Ecology and Management, 2008Co-Authors: Jamie N Cotta, Karen A Kainer, Lucia Helena De Oliveira Wadt, Christina L StaudhammerAbstract:Abstract Brazil Nut ( Bertholletia excelsa ), has emerged as the cornerstone of the extractive economy in much of the Amazon, but the debate continues as to whether or not current harvest levels have a detrimental effect on Brazil Nut seedling recruitment. While regeneration studies to date have been conducted solely within mature forest, our study provides further insight into current Brazil Nut regeneration dynamics, with a unique first look at regeneration in swidden fallows within two multiple-use areas in Acre, Brazil. Recruitment of individuals ≤10 cm diameter at breast height (dbh) was evaluated within three 9 ha mature forest plots and six fallows of 0.5–1.0 ha each. Higher mean densities of B. excelsa seedlings (individuals −1 , respectively). A generalized linear mixed model analysis revealed that in addition to forest type, proximity to seed sources also explained seedling densities. Height and diameter growth of young B. excelsa individuals was positively related to light availability. Photosynthetic photon flux density levels were over three times higher in fallows versus mature forest during peak sunlight hours. Results suggest that fallow environments may provide favorable conditions for B. excelsa regeneration. Not only can anthropogenic disturbance in the form of shifting cultivation play a positive role in B. excelsa regeneration, its historic presence on the landscape could explain current Brazil Nut densities and distributions. Finally, swidden fallows could potentially be managed for enhanced Brazil Nut densities, which may provide an opportunity for greater income for extractive families while contributing to the sustainability of Brazil Nut extraction and forest conservation in the long term.
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sustainable forest use in Brazilian extractive reserves natural regeneration of Brazil Nut in exploited populations
Biological Conservation, 2008Co-Authors: Lucia Helena De Oliveira Wadt, Karen A Kainer, Christina L Staudhammer, R O P SerranoAbstract:Abstract The emergence of Brazilian extractive reserves reinforced the notion that sustainable forest use could play a central role in conservation. Brazil Nut is considered a model non-timber product for promoting conservation through use. Demographic studies, however, have demonstrated differential impacts of Nut harvest on Brazil Nut population structure. Comparing three populations with different forest use histories, degrees of road access, and recent levels of Nut harvest, we asked: (1) Are they exhibiting regeneration failure? and (2) Are seedling/sapling densities explained by adult Brazil Nut structure, fruit fate and/or overall forest structure? We installed four 9-ha plots in each site to census Brazil Nut trees ⩾10 cm dbh, and within each plot, 36 subplots (25 × 25 m each) to quantify regeneration, overall forest structure, and open and closed fruit counts. Approximately 29–55% of fruits was unharvested, and more than 90% of these was opened by scatterhoarding dispersers. Population structure approximated a reverse-J size class distribution, with seedling densities varying from 3.2 to 5.8 individuals ha −1 . We conclude that within the current harvest context, regeneration is sufficient for population persistence in our sites, at least over the medium term. The socioeconomics of sustainably managing Brazil Nut is the greater challenge, involving interlinked competitive land uses, Nut quality, and substantial increases in local income from harvest. Some of these challenges are being addressed in Brazil, Bolivia and Peru, providing hope that this cornerstone extractive species will continue to play a prominent role in the ecological and economic landscape of Amazonia.
Christina L Staudhammer - One of the best experts on this subject based on the ideXlab platform.
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swidden fallow management to increase landscape level Brazil Nut productivity
Forest Ecology and Management, 2020Co-Authors: Eduardo Bongiolo, Karen A Kainer, Christina L Staudhammer, Wendell P Cropper, Lucia Helena De Oliveira WadtAbstract:Abstract Brazil Nut (Bertholletia excelsa Bonpl.) is considered the cornerstone non-timber species of Amazonian conservation. Nuts (or seeds) of this massive tree are harvested by local people living in and near old growth forests, supporting local livelihoods and regional economies. Secondary forests, however, particularly plots previously used for agriculture (swidden fallows), present better B. excelsa seedling and sapling recruitment than mature forest. This study examines the extent to which forest residents could increase Nut productivity by allowing their fallows to grow into Brazil Nut rich forests. We conducted B. excelsa inventories in the Brazilian state of Acre in abandoned swidden fallows of different ages. We also conducted interviews to determine landowner perspectives on the fallow potential for increasing Nut production. An individual-based model, based on in-situ inventories and primary and secondary datasets from prior fieldwork, simulated growth, survivorship and production from the 250 inventoried trees in 18 fallows of varying sizes (from 0.41 to 4.18 ha) and different regrowth stages (12 to 60 years old). These simulation model predictions showed that after 10 years, 2.4% of existing trees would be productive, with an average of 68.6 ± 21.5 fruits per reproductively mature tree in the four fallows that most quickly yielded productive trees. By the final projected time interval (40 years), predictions suggest all fallows will produce fruits with cumulative production averaging 1475 ± 359 fruits ha−1, suggesting an increase in landowner income of US$55.1 ± 13.4 per hectare of fallow. Our simulation model is the first to explore fruit productivity of Brazil Nut in secondary forest. It likely underpredicts B. excelsa growth and Nut production, considering that swidden fallows provide better resource availability than the forest-derived datasets we used to construct the model equations. In conclusion, our findings support previous research that suggests that higher B. excelsa recruitment rates observed in abandoned swidden fallows could indeed translate into greater adult densities and thus potentially, higher Nut production – a conclusion mirrored by most participant landowners.
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are Brazil Nut populations threatened by fruit harvest
Biotropica, 2018Co-Authors: Todd D Bertwell, Karen A Kainer, Christina L Staudhammer, Wendell P Cropper, Lucia Helena De Oliveira WadtAbstract:Harvest of Brazil Nuts from the large, iconic tree Bertholletia excelsa generates substantial income for smallholders, providing a strong incentive to conserve the mature forests where it grows. Although much previous work has focused on the impact of Nut harvest on new seedling recruits into B. excelsa populations, the connection between harvest rates and long-term population stability is still unclear. Moreover, there is additional uncertainty for Brazil Nut management in terms of population response to climate change and other anthropogenic influences. We drew on 14 years of research in two sites in Acre, Brazil with different B. excelsa Nut harvest intensities (39% and 81%), to produce stochastic and deterministic matrix population models which incorporated parameter uncertainty in vital rates. Adult abundance was projected to remain close to the current observed abundance or higher through the next 50 years. Elasticity analyses revealed that the asymptotic population growth rate (λ) was most sensitive to stasis vital rates in sapling, juvenile, and adult stages. Deterministic transition matrices calculated using diameter growth rates dependent on rainfall yielded average λ values around 1.0 under extreme high, extreme low, and average annual rainfall. While sustained high rates of Brazil Nut harvest and climate change could potentially negatively impact B. excelsa populations, changes in human use of the forested landscape are more immediate concern. To reduce the risk of population decline, smallholders and managers of B. excelsa rich forests should focus on conservation of pre-mature and mature individuals.
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testing a silvicultural recommendation Brazil Nut responses 10 years after liana cutting
Journal of Applied Ecology, 2014Co-Authors: Karen A Kainer, Lucia Helena De Oliveira Wadt, Christina L StaudhammerAbstract:Summary 1. Lianas or woody vines can be detrimental to the trees that support them. Research on liana cutting for tropical timber management has demonstrated positive yet costly benefits, but liana cutting to enhance commercial outputs of nontimber forest products has not been examined. We implemented a controlled experiment to quantify the effects of cutting lianas on Brazil Nut Bertholletia excelsa Bonpl. fecundity. 2. We conducted our 10-year experiment in a Brazilian extractive reserve where local harvesters collect fruits from this Amazonian canopy-emergent species as part of their forest-based livelihood system. We cut 454 lianas with a total basal area of 241 m 2 from 78 of 138 host trees ≥50 cm diameter at breast height. 3. Treated trees were significantly better producers 3 ½ years after liana cutting, and these differences increased dramatically in subsequent years, with consistent proportionally higher production in treated versus untreated individuals. 4. The number of lianas rooted within 5 m of the host tree significantly explained production levels, suggesting both above- and below-ground liana–host tree competition. Once host crowns were liana-free, branch regrowth was highly visible, particularly in heavily infested trees, and crown reassessments suggested that liana cutting improved crown form. Additionally, liana cutting may induce some nonproducing trees to become producers and may circumvent mortality of trees heavily infested with lianas (> 75% crown covered). 5. Liana removal can be implemented easily when harvesting Brazil Nut fruits. Only lianas associated with B. excelsa trees should be cut to conserve liana ecosystem functions. 6. Synthesis and applications. We quantified effects of liana cutting on Brazil Nut host tree fecundity and provided estimates of increased commercial yields. Our long-term (10-year) study permits understanding of biological variation and informs related management decisions. Findings suggest that liana cutting reduces above- and below-ground competition with individual trees, ultimately allowing mature host crowns to recover such that 9–10 years after liana cutting, treated trees produced on average three times more fruits than untreated trees. Application of liana cutting to other tropical species would likely boost fruit and seed production, increase host tree fecundity and potentially enhance future recruitment.
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shifting cultivation effects on Brazil Nut bertholletia excelsa regeneration
Forest Ecology and Management, 2008Co-Authors: Jamie N Cotta, Karen A Kainer, Lucia Helena De Oliveira Wadt, Christina L StaudhammerAbstract:Abstract Brazil Nut ( Bertholletia excelsa ), has emerged as the cornerstone of the extractive economy in much of the Amazon, but the debate continues as to whether or not current harvest levels have a detrimental effect on Brazil Nut seedling recruitment. While regeneration studies to date have been conducted solely within mature forest, our study provides further insight into current Brazil Nut regeneration dynamics, with a unique first look at regeneration in swidden fallows within two multiple-use areas in Acre, Brazil. Recruitment of individuals ≤10 cm diameter at breast height (dbh) was evaluated within three 9 ha mature forest plots and six fallows of 0.5–1.0 ha each. Higher mean densities of B. excelsa seedlings (individuals −1 , respectively). A generalized linear mixed model analysis revealed that in addition to forest type, proximity to seed sources also explained seedling densities. Height and diameter growth of young B. excelsa individuals was positively related to light availability. Photosynthetic photon flux density levels were over three times higher in fallows versus mature forest during peak sunlight hours. Results suggest that fallow environments may provide favorable conditions for B. excelsa regeneration. Not only can anthropogenic disturbance in the form of shifting cultivation play a positive role in B. excelsa regeneration, its historic presence on the landscape could explain current Brazil Nut densities and distributions. Finally, swidden fallows could potentially be managed for enhanced Brazil Nut densities, which may provide an opportunity for greater income for extractive families while contributing to the sustainability of Brazil Nut extraction and forest conservation in the long term.
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sustainable forest use in Brazilian extractive reserves natural regeneration of Brazil Nut in exploited populations
Biological Conservation, 2008Co-Authors: Lucia Helena De Oliveira Wadt, Karen A Kainer, Christina L Staudhammer, R O P SerranoAbstract:Abstract The emergence of Brazilian extractive reserves reinforced the notion that sustainable forest use could play a central role in conservation. Brazil Nut is considered a model non-timber product for promoting conservation through use. Demographic studies, however, have demonstrated differential impacts of Nut harvest on Brazil Nut population structure. Comparing three populations with different forest use histories, degrees of road access, and recent levels of Nut harvest, we asked: (1) Are they exhibiting regeneration failure? and (2) Are seedling/sapling densities explained by adult Brazil Nut structure, fruit fate and/or overall forest structure? We installed four 9-ha plots in each site to census Brazil Nut trees ⩾10 cm dbh, and within each plot, 36 subplots (25 × 25 m each) to quantify regeneration, overall forest structure, and open and closed fruit counts. Approximately 29–55% of fruits was unharvested, and more than 90% of these was opened by scatterhoarding dispersers. Population structure approximated a reverse-J size class distribution, with seedling densities varying from 3.2 to 5.8 individuals ha −1 . We conclude that within the current harvest context, regeneration is sufficient for population persistence in our sites, at least over the medium term. The socioeconomics of sustainably managing Brazil Nut is the greater challenge, involving interlinked competitive land uses, Nut quality, and substantial increases in local income from harvest. Some of these challenges are being addressed in Brazil, Bolivia and Peru, providing hope that this cornerstone extractive species will continue to play a prominent role in the ecological and economic landscape of Amazonia.
Lucia Helena De Oliveira Wadt - One of the best experts on this subject based on the ideXlab platform.
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strong el nino reduces fruit production of Brazil Nut trees in the eastern amazon
Acta Amazonica, 2021Co-Authors: Dayane Nathalia Barbosa Pastana, Lucia Helena De Oliveira Wadt, Erica De Souza Modena, Ezaquiel De Souza Neves, Lucieta Guerreiro Martorano, A C Liraguedes, Rafael Lucas Figueiredo De Souza, Felipe Felix Costa, Anderson Pedro Bernardina Batista, Marcelino Carneiro GuedesAbstract:ABSTRACT The Brazil-Nut tree (Bertholletia excelsa) is native to the Amazon rainforest, and its fruit production varies naturally with climatic conditions. Our aim was to evaluate the temporal variation in Brazil-Nut production associated with climatic variables, including the strong El Nino of 2015/2016. The study was carried out in two 9-ha permanent plots in the northeastern Brazilian Amazon from 2007 to 2018: one in forest (12-year monitoring) and the other in savannah/forest transition (eight years). Overall, we monitored fruit production of 205 trees with diameter at breast height ≥ 50 cm. Annual fruit production was related to temporal series (2005-2018) of climatic data (the Oceanic Nino Index; and precipitation and air temperature from two local meteorological stations). Average fruit production per tree in 2017 was eight times lower than in 2015 and two times lower than the general average for both sites, and was significantly associated to the El Nino of 2015/2016, that increased average maximum monthly temperature and reduced the precipitation in the region, extending the dry season from three to six months. Years with higher and lower fruit production per tree coincided in both sites. Annual fruit production was significantly and negatively correlated with thermal anomalies that occurred in the third semester prior to harvest monitoring. Years with higher production were related with predominance of neutrality or the La Nina phenomenon at the global scale, and higher rainfall at the local scale. The relationship of fruit production with climate was independent of the local habitat.
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swidden fallow management to increase landscape level Brazil Nut productivity
Forest Ecology and Management, 2020Co-Authors: Eduardo Bongiolo, Karen A Kainer, Christina L Staudhammer, Wendell P Cropper, Lucia Helena De Oliveira WadtAbstract:Abstract Brazil Nut (Bertholletia excelsa Bonpl.) is considered the cornerstone non-timber species of Amazonian conservation. Nuts (or seeds) of this massive tree are harvested by local people living in and near old growth forests, supporting local livelihoods and regional economies. Secondary forests, however, particularly plots previously used for agriculture (swidden fallows), present better B. excelsa seedling and sapling recruitment than mature forest. This study examines the extent to which forest residents could increase Nut productivity by allowing their fallows to grow into Brazil Nut rich forests. We conducted B. excelsa inventories in the Brazilian state of Acre in abandoned swidden fallows of different ages. We also conducted interviews to determine landowner perspectives on the fallow potential for increasing Nut production. An individual-based model, based on in-situ inventories and primary and secondary datasets from prior fieldwork, simulated growth, survivorship and production from the 250 inventoried trees in 18 fallows of varying sizes (from 0.41 to 4.18 ha) and different regrowth stages (12 to 60 years old). These simulation model predictions showed that after 10 years, 2.4% of existing trees would be productive, with an average of 68.6 ± 21.5 fruits per reproductively mature tree in the four fallows that most quickly yielded productive trees. By the final projected time interval (40 years), predictions suggest all fallows will produce fruits with cumulative production averaging 1475 ± 359 fruits ha−1, suggesting an increase in landowner income of US$55.1 ± 13.4 per hectare of fallow. Our simulation model is the first to explore fruit productivity of Brazil Nut in secondary forest. It likely underpredicts B. excelsa growth and Nut production, considering that swidden fallows provide better resource availability than the forest-derived datasets we used to construct the model equations. In conclusion, our findings support previous research that suggests that higher B. excelsa recruitment rates observed in abandoned swidden fallows could indeed translate into greater adult densities and thus potentially, higher Nut production – a conclusion mirrored by most participant landowners.
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are Brazil Nut populations threatened by fruit harvest
Biotropica, 2018Co-Authors: Todd D Bertwell, Karen A Kainer, Christina L Staudhammer, Wendell P Cropper, Lucia Helena De Oliveira WadtAbstract:Harvest of Brazil Nuts from the large, iconic tree Bertholletia excelsa generates substantial income for smallholders, providing a strong incentive to conserve the mature forests where it grows. Although much previous work has focused on the impact of Nut harvest on new seedling recruits into B. excelsa populations, the connection between harvest rates and long-term population stability is still unclear. Moreover, there is additional uncertainty for Brazil Nut management in terms of population response to climate change and other anthropogenic influences. We drew on 14 years of research in two sites in Acre, Brazil with different B. excelsa Nut harvest intensities (39% and 81%), to produce stochastic and deterministic matrix population models which incorporated parameter uncertainty in vital rates. Adult abundance was projected to remain close to the current observed abundance or higher through the next 50 years. Elasticity analyses revealed that the asymptotic population growth rate (λ) was most sensitive to stasis vital rates in sapling, juvenile, and adult stages. Deterministic transition matrices calculated using diameter growth rates dependent on rainfall yielded average λ values around 1.0 under extreme high, extreme low, and average annual rainfall. While sustained high rates of Brazil Nut harvest and climate change could potentially negatively impact B. excelsa populations, changes in human use of the forested landscape are more immediate concern. To reduce the risk of population decline, smallholders and managers of B. excelsa rich forests should focus on conservation of pre-mature and mature individuals.
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testing a silvicultural recommendation Brazil Nut responses 10 years after liana cutting
Journal of Applied Ecology, 2014Co-Authors: Karen A Kainer, Lucia Helena De Oliveira Wadt, Christina L StaudhammerAbstract:Summary 1. Lianas or woody vines can be detrimental to the trees that support them. Research on liana cutting for tropical timber management has demonstrated positive yet costly benefits, but liana cutting to enhance commercial outputs of nontimber forest products has not been examined. We implemented a controlled experiment to quantify the effects of cutting lianas on Brazil Nut Bertholletia excelsa Bonpl. fecundity. 2. We conducted our 10-year experiment in a Brazilian extractive reserve where local harvesters collect fruits from this Amazonian canopy-emergent species as part of their forest-based livelihood system. We cut 454 lianas with a total basal area of 241 m 2 from 78 of 138 host trees ≥50 cm diameter at breast height. 3. Treated trees were significantly better producers 3 ½ years after liana cutting, and these differences increased dramatically in subsequent years, with consistent proportionally higher production in treated versus untreated individuals. 4. The number of lianas rooted within 5 m of the host tree significantly explained production levels, suggesting both above- and below-ground liana–host tree competition. Once host crowns were liana-free, branch regrowth was highly visible, particularly in heavily infested trees, and crown reassessments suggested that liana cutting improved crown form. Additionally, liana cutting may induce some nonproducing trees to become producers and may circumvent mortality of trees heavily infested with lianas (> 75% crown covered). 5. Liana removal can be implemented easily when harvesting Brazil Nut fruits. Only lianas associated with B. excelsa trees should be cut to conserve liana ecosystem functions. 6. Synthesis and applications. We quantified effects of liana cutting on Brazil Nut host tree fecundity and provided estimates of increased commercial yields. Our long-term (10-year) study permits understanding of biological variation and informs related management decisions. Findings suggest that liana cutting reduces above- and below-ground competition with individual trees, ultimately allowing mature host crowns to recover such that 9–10 years after liana cutting, treated trees produced on average three times more fruits than untreated trees. Application of liana cutting to other tropical species would likely boost fruit and seed production, increase host tree fecundity and potentially enhance future recruitment.
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shifting cultivation effects on Brazil Nut bertholletia excelsa regeneration
Forest Ecology and Management, 2008Co-Authors: Jamie N Cotta, Karen A Kainer, Lucia Helena De Oliveira Wadt, Christina L StaudhammerAbstract:Abstract Brazil Nut ( Bertholletia excelsa ), has emerged as the cornerstone of the extractive economy in much of the Amazon, but the debate continues as to whether or not current harvest levels have a detrimental effect on Brazil Nut seedling recruitment. While regeneration studies to date have been conducted solely within mature forest, our study provides further insight into current Brazil Nut regeneration dynamics, with a unique first look at regeneration in swidden fallows within two multiple-use areas in Acre, Brazil. Recruitment of individuals ≤10 cm diameter at breast height (dbh) was evaluated within three 9 ha mature forest plots and six fallows of 0.5–1.0 ha each. Higher mean densities of B. excelsa seedlings (individuals −1 , respectively). A generalized linear mixed model analysis revealed that in addition to forest type, proximity to seed sources also explained seedling densities. Height and diameter growth of young B. excelsa individuals was positively related to light availability. Photosynthetic photon flux density levels were over three times higher in fallows versus mature forest during peak sunlight hours. Results suggest that fallow environments may provide favorable conditions for B. excelsa regeneration. Not only can anthropogenic disturbance in the form of shifting cultivation play a positive role in B. excelsa regeneration, its historic presence on the landscape could explain current Brazil Nut densities and distributions. Finally, swidden fallows could potentially be managed for enhanced Brazil Nut densities, which may provide an opportunity for greater income for extractive families while contributing to the sustainability of Brazil Nut extraction and forest conservation in the long term.
Marcos J C Alcocer - One of the best experts on this subject based on the ideXlab platform.
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selection of recombinant antibodies by phage display technology and application for detection of allergenic Brazil Nut bertholletia excelsa in processed foods
Journal of Agricultural and Food Chemistry, 2013Co-Authors: Silvia De La Cruz, Marcos J C Alcocer, Ines Lopezcalleja, Isabel Gonzalez, Rosario Martin, Teresa GarciaAbstract:Current immunological methods for detection of Brazil Nut allergens in foods are based on polyclonal antibodies raised in animals. Phage display technology allows the procurement of high-affinity antibodies avoiding animal immunization steps and therefore attaining the principle of replacement supported by animal welfare guidelines. In this study, we screened Tomlinson I and J libraries for specific binders against Brazil Nut by employing a Brazil Nut protein extract and a purified Brazil Nut 2S globulin, and we successfully isolated a phage single chain variable fragment (named BE95) that specifically recognizes Brazil Nut proteins. The selected phage scFv was further used as affinity probe to develop an indirect phage-ELISA for detection of Brazil Nut in experimental binary mixtures and in commercial food products, with a limit of detection of 5 mg g(-1). This study describes for the first time the isolation of recombinant antibody fragments specific for an allergenic tree Nut protein from a naive library and paves the way to develop new immunoassays for food analysis based on probes that can be produced in vitro when required and do not rely on animal immunization.
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taqman real time pcr assay for detection of traces of Brazil Nut bertholletia excelsa in food products
Food Control, 2013Co-Authors: Silvia De La Cruz, Marcos J C Alcocer, Ines Lopezcalleja, Isabel Gonzalez, Rosario Martin, Teresa GarciaAbstract:Mislabeling of food products containing Brazil Nut may represent a serious thread for allergic consumers. In order to protect sensitized individuals, reliable methods to detect trace amounts of Brazil Nut must be accessible to food industry as well as Food Safety authorities. According to this, a TaqMan real-time polymerase chain reaction (PCR) method has been developed for specific detection of Brazil Nut in foodstuffs. The method employs Brazil Nut specific primers and probe, targeting 2S albumin gene (Ber e 1), and a positive amplification control based on 18S rRNA gene. Results obtained on sensitivity with wheat flour spiked with different concentrations of raw and heat treated Brazil Nut showed that the limit of detection (LOD) for the technique was 2.5 mg/kg. Applicability of the Brazil Nut specific system was assessed through analysis of 66 different commercial food samples. The reported real-time PCR assay provides a useful tool for detection of Brazil Nut DNA, and it can be used as a routine analysis to assert accuracy on food labeling.
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lipids are required for the development of Brazil Nut allergy the role of mouse and human inkt cells
Allergy, 2013Co-Authors: Luciana Mirotti, Esther Florsheim, Louise Rundqvist, Goran Larsson, Fabrizio Spinozzi, Maria Leitedemoraes, Momtchilo Russo, Marcos J C AlcocerAbstract:Background Lipids are required for mice sensitization to Ber e 1, Brazil Nut major allergen. Here, we characterized different lipid fractions extracted from Brazil Nuts and the lipid-binding abilit ...
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the major human structural ige epitope of the Brazil Nut allergen ber e 1 a chimaeric and protein microarray approach
Journal of Molecular Biology, 2004Co-Authors: Marcos J C Alcocer, G J Murtagh, P B Wilson, Pavlos Progias, Jing Lin, David B ArcherAbstract:A protein microarray system containing different dilutions of 77 related and non-related proteins was used to show that IgE from subjects allergic to Brazil Nut specifically recognise the seed 2S albumin protein (Ber e 1). Further, correctly folded chimaeric 2S albumin proteins containing structural epitope replacement were constructed and directed to the secretion pathway of the methylotropic yeast Pichia pastoris. Through the use of a chimaeric protein microarray system together with sera from a panel of 18 well-characterised Brazil Nut allergic subjects, a structural IgE epitope of Ber e 1 was mapped to a helix-loop-helix region. The same structural region has been previously reported as the immunodominant region in related food allergens by different techniques. In conclusion, the combination of chimaeric proteins and protein microarrays will greatly facilitate the screening of a large number of individuals for a particular structural epitope and help to further our understanding of how proteins are recognised by the adaptive immune system.
Rogerio Gribel - One of the best experts on this subject based on the ideXlab platform.
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growth and survival over ten years of Brazil Nut trees planted in three anthropogenic habitats in northern amazonia
Acta Amazonica, 2021Co-Authors: Ricardo Scoles, Rogerio GribelAbstract:ABSTRACT We examined the growth and survival of Brazil-Nut trees, Bertholletia excelsa (Lecythidaceae) under different environmental conditions and levels of canopy openness within experimental plantations in the Trombetas River valley, in northern Brazil. We planted 144 seedlings in three anthropogenic habitats with different levels of sunlight exposition: crop field (100% canopy opening), shrub fallow (20-80% canopy opening) and Brazil-Nut forest (< 10% canopy opening). We measured plant height and diameter annually and recorded mortality and resprouting over ten years. The performance of B. excelsa differed significantly among habitats, with the highest growth rate observed at the highest level of canopy openness (crop field). Survival was highest in crop field (85%) and shrub fallow (63%) and lowest in Brazil-Nut forest (17%). Resprouting capacity was higher in the crop field, as Brazil-Nut plants recovered after fire episodes, with most plants resprouting more than one shoot. Some trees in the crop field began to produce flowers and fruits at 9-10 years. We showed that B. excelsa juveniles are light-demanding, with higher survival and growth under conditions of high light exposure. We suggest the use of Brazil-Nut trees for reforestation, restoration of degraded lands and enrichment of secondary vegetation, as long as an adequate management is adopted (e.g., maintaining plants exposed to direct sunlight and control of competing pioneer species).
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Human Influence on the Regeneration of the Brazil Nut Tree (Bertholletia excelsa Bonpl., Lecythidaceae) at Capanã Grande Lake, Manicoré, Amazonas, Brazil
Human Ecology, 2015Co-Authors: Ricardo Scoles, Rogerio GribelAbstract:This study examines the population structure and regeneration of Brazil Nut tree ( Bertholletia excelsa ) populations at sites subjected to extractive activities in the Capanã Grande Lake Extractive Reserve (Rio Madeira, Amazonas, Brazil). We analyze correlations between three regeneration levels (seedling, sapling and juvenile density) and seven possible explicatory variables related to vegetation structure and human action. The tested vegetation structure variables include adult tree density, crown area, basal area, canopy openness, and fruits opened by agoutis. We also test the time of human use and distance from residences as possible explicatory variables. The density values of the Brazil Nut stands in the region are high (12.5 tree/ha), with 60 % of trees having a diameter at breast height (DBH) > 80 cm. The mean potential regeneration (24.8 seedlings/ha), pre-established regeneration (4.4 saplings/ha) and established regeneration (3.2 juveniles/ha) values are high compared to other Brazil Nut tree populations and tend to be greater in the “intensively used” stands, defined as sites where human presence during the year is more frequent. The time of human use and the density of adult Brazil Nut trees are the variables that best correlate with established regeneration (density of juveniles). The number of juveniles/adult Brazil Nut trees is five times higher in intensively used stands than in those moderately used. These results suggest that extractive activities and disturbances in the understory caused by human presence may favor (intentionally or not) regeneration of Brazil Nut trees in more-frequently used stands. The data support the concept, frequently suggested in the literature, that aggregations of Brazil Nut trees could be a consequence of the activities of Amerindian populations.
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the regeneration of Brazil Nut trees in relation to Nut harvest intensity in the trombetas river valley of northern amazonia Brazil
Forest Ecology and Management, 2012Co-Authors: Ricardo Scoles, Rogerio GribelAbstract:Abstract This study examined the harvest of Nuts from Brazil Nut trees (Bertholletia excelsa) in the valley of the Trombetas River, a 760-km tributary on the northern bank of the Amazon River in Para state, Brazil. The region is characterised by old-growth forests dominated by Brazil Nut trees. Demographic data were obtained from twenty-five 50-m × 1000-m transects with different harvest intensities (total area = 125 ha) established approximately along the trails used by Brazil Nut harvesters. For each transect, correlations were calculated between regeneration indicators (seedling, sapling, and juvenile densities) and potential ecological and demographic variables. The Brazil Nut populations in the region were characterised by a low proportion of juveniles (7.8% of trees had a 10 cm 100 cm), and a tendency towards old growth (25.5% of trees had a DBH > 160 cm). There were no seedlings in 52% of the transects, and 80% of the transects had no saplings. The low regeneration levels observed were independent of both harvest intensity and the dispersive activity of agoutis. An analysis of the regeneration indicators and the possible explanatory variables showed that harvests were not responsible for the low regeneration levels observed in the region. Furthermore, in areas with shorter distances between the points of harvest and first transport, the densities of saplings and juveniles were greater. We conclude that the restrictions on Brazil Nut harvesting that are intended to improve the regeneration of Brazil Nut trees are of little or no value. We propose the implementation of compensatory measures involving local communities and the promotion of seedling enrichment in gaps, forest edges, and disturbed areas, with the goal of promoting the growth of new generations of Brazil Nut trees in the region.
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Population Structure of Brazil Nut (Bertholletia excelsa, Lecythidaceae) Stands in Two Areas with Different Occupation Histories in the Brazilian Amazon
Human Ecology, 2011Co-Authors: Ricardo Scoles, Rogerio GribelAbstract:Here we hypothesize that the intensity of disturbances caused by human activities in Brazil Nut stands (castanhais) is positively related with the regeneration of Brazil Nut trees (Bertholletia excelsa H.B.K., Lecythidaceae) and consequently with a younger population structure of this species. In order to test this hypothesis we compared the population structure of Brazil Nut trees in two areas of the Brazilian Amazon with different histories of land usage by humans. Archeological and historical data suggest that the region surrounding the Trombetas River was densely occupied in pre-Columbian times and experienced depopulation after European contact with Amerindian populations, especially in the 16th century. The 25 Brazil Nut stands sampled in this region were dominated by old B. excelsa trees and had scarce recruitment in the understory. These very mature stands likely owe their origins to the interval between the depopulation of the indigenous peoples in the 16th-17th centuries and the establishment of quilombos at the beginning of the 19th century. The second study area was in the vicinity of the Madeira River (Capana Grande Lake), where the castanhais were more accessible and disturbed. In this site, a younger population structure and abundant regeneration of B. excelsa were observed in the 10 sampled stands. Historical data from this region indicate that indigenous populations were replaced gradually beginning in the 18th century, with no evidence of severe depopulation. We suggest that the different historical and contemporary land use patterns contributed to the current contrasting population structures of the castanhais at the two locations. The data also support the idea that the castanhais, even the ones considered to be pristine and “native” forests, result from anthropogenic influences. We found no evidence to support restrictions on seed harvesting as a means to improve regeneration rates of Brazil Nut stands.
