Population structure and nut yield of a Bertholletia excelsa stand in Southwestern Amazonia

Wadt, L. H. de O.; Kainer, Karen A.; Gomes-Silva, D. A. P.

doi:10.1016/j.foreco.2005.02.061

Cited by 139 publications

(244 citation statements)

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“…The average yield of Brazil nut seeds obtained in the ITA population was lower than that obtained in a study conducted at the Chico Mendes Extractive Reserve (RESEX) in Acre (WADT et al, 2005) and similar to that obtained at São João da Baliza in Roraima (TONINI et al, 2008). These authors obtained 10.28 and 4.07 kg of seed/plant, respectively.…”

Section: Discussionsupporting

confidence: 67%

“…Repeatability of fruits and seeds production and... Each population was delimited by a permanent plot of nine hectares (300 m x 300 m), considering in the study all Brazil nut trees with diameter at breast height > 50 cm, which are considered adults according to Wadt et al (2005). Thus, the ITA and CUJ populations consisted of 85 and 51 trees, respectively.…”

Section: Methodsmentioning

confidence: 99%

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Repeatability of Fruits and Seeds Production and Selection of Brazil Nut Genotypes in Native Populations in Roraima1

Pedrozo¹,

Tonini

Resende

et al. 2015

Rev. Árvore

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-This study estimates the repeatability coefficients of two production traits in two native populations of Brazil nut trees. It determines the number of years of suitable evaluations for an efficient selection process, determines the permanent phenotypic correlation between production traits and also the selection of promising trees in these populations. Populations, located in the Itã region (ITA) and in the in the Cujubim region (CUJ), are both belonging to the municipality of Caracaraí, state of Roraima -Brazil, and consist of 85 and 51 adult trees, respectively. Each tree was evaluated regarding the number of fruits per plant (NFP) and fresh seed weight per plant (SWP), for eight (ITA) and five consecutive years (CUJ). Statistical analyses were performed according to the mixed model methodology, using Software Selegen-REML/BLUP (RESENDE, 2007). The repeatability coefficients were low for NFP (0.3145 and 0.3269 for ITA and CUJ, respectively) and also for SWP (0.2957 and 0.3436 for ITA and CUJ, respectively). It on average takes nine evaluation years to reach coefficients of determination higher than 80%. Permanent phenotypic correlation values higher than 0.95 were obtained for NFP and SWP in both populations. Although trees with a high number of fruits and seed weight were identified, more evaluation years are needed to perform the selection process more efficiently.Keywords: Bertholletia excelsa; Genetic improvement; Forest resources. REPETIBILIDADE DE PRODUÇÃO DE FRUTOS E SEMENTES E SELEÇÃO DE GENÓTIPOS DE CASTANHA-DO-BRASIL EM POPULAÇÕES NATIVAS EM RORAIMARESUMO -Os objetivos deste estudo foram estimar coeficientes de repetibilidade de dois caracteres de produção em duas populações nativas de castanheira-do-brasil, determinar o número de anos de avaliações adequado para um eficiente processo de seleção, determinar a correlação fenotípica permanente entre os caracteres de produção e selecionar árvores promissoras nessas populações. As populações, localizadas na região do Itã (ITA) e na região do Cujubim (CUJ), ambas pertencentes ao Município de Caracaraí, Estado de Roraima -Brasil, foram constituídas por 85 e 51 árvores adultas, respectivamente. Cada árvore foi avaliada quanto ao número de frutos por planta (NFP) e peso fresco de sementes por planta (SWP), por oito (ITA) e cinco anos consecutivos (CUJ). As análises estatísticas foram realizadas segundo a metodologia de modelos mistos, utilizando-se o Software Selegen-REML/BLUP (RESENDE, 2007 864Revista Árvore, Viçosa-MG, v.39, n.5, p.863-871, 2015 PEDROZO, C.A. et. al fenotípica permanente entre NFP e SWP acima de 0,95 foram obtidos nas duas populações. Apesar de ter sido possível identificar árvores com elevado número de frutos e peso de sementes, número maior de anos de avaliação é necessário para que o processo seletivo seja realizado de forma mais eficiente.

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Section: Discussionsupporting

confidence: 67%

Section: Methodsmentioning

confidence: 99%

Repeatability of Fruits and Seeds Production and Selection of Brazil Nut Genotypes in Native Populations in Roraima1

Pedrozo¹,

Tonini

Resende

et al. 2015

Rev. Árvore

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“…En este estudio, la densidad total registrada (0,446 individuos ha -1 ) fue mayor que la estimada por Salomão (2009), en la meseta Aviso, al oeste de Pará, e inferior a la obtenida por Peres y Baider (1997), Peres et al (2003), Wadt et al (2005) y Scoles y Gribel (2011), que informaron variaciones desde 1,3 a 23,0 individuos ha -1 en la densidad de B. excelsa en diferentes lugares de la Amazonia. Esta amplia variación se debe a la gran variedad de diseños de muestra, los tamaños de las superficies de la muestra y la selección de las áreas investigadas, de B. excelsa o aleatoriamente (Wadt et al 2005). Además, los efectos del cambio climático y edáfico, son también factores que influyen en esta variación en la densidad de las especies entre los distintos lugares de estudio.…”

Section: Discussionunclassified

“…Peres y Baider (1997), Wadt et al (2005) y Salomão (2009) encontraron a través del índice con base en unidades muestreadas, patrones predominantemente agregados en los individuos de B. excelsa. Esto ocurrió porque, normalmente, estos sín-dromes limitan la distribución de plántulas resultando en altas tasas de germinación y reclutamiento en zonas cer-canas al árbol origen, mientras que en otros lugares estos procesos son más pequeños y aleatorios.…”

Section: Discussionunclassified

“…Como criterio de rareza numérica, se consideró que si la especie posee un individuo por hectárea sería considerada una especie rara (Soares et al 2009). Para definir el patrón espacial fue seleccionada la función K(s) de Ripley (1979), aplicada a la población, y dos subgrupos demográficos: los adultos reproductivamente maduros (dap ≥ 50 cm) y los jóvenes (dap < 50 cm) (Wadt et al 2005). De una manera simplificada, se define el radio de un círculo de 5 m centrado en cada árbol, donde se contó el número de vecinos presentes en el área de este círculo.…”

Section: Metodosunclassified

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Patrón espacial y métodos de muestreo para Bertholletia excelsa (castaña de Pará) en la Mesorregión del Bajo Amazonas, estado de Pará, Brasil

et al. 2017

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SUMMARYThe aim of this study was to analyze the spatial pattern and sampling methods for Bertholletia excelsa. The inventory of exploration, by mapping Cartesian coordinates of all trees with dbh ≥ 20 cm, was carried out in an area of 1,000.31 ha. For the definition of the diametric structure, multivariate techniques were used: cluster and discriminant analysis. To analyze the spatial patterns, individuals were grouped into three levels: population, young individuals and adults; being the random deviation defined by the Ripley's K function. The forest inventories were simulated with a simple random sampling, systematic and adaptive, taking into account plots of 2,500 m², with a sampling intensity of 15 % and an error range of 10 %. Comparisons between sampling methods were performed for the accuracy and precision. Four hundred and forty six trees were registered, of which 59 were young individuals and 387 were adults. A low number of trees in the early stages and a high number of individuals in the intermediate classes characterize the diametric structure. The spatial pattern of the adult population was aggregated, while the young individuals were randomly distributed. Systematic sampling is the best procedure to estimate the total number of individuals of B. excelsa; however, there is a need to investigate the effect of aggregation and size of the largest plots of 0.25 hectares on the estimates of adaptive cluster sampling.

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Strategies to optimize modeling habitat suitability of Bertholletia excelsa in the Pan‐Amazonia

Tourne

Ballester

James

et al. 2019

Ecology and Evolution

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AimAmazon‐nut (Bertholletia excelsa) is a hyperdominant and protected tree species, playing a keystone role in nutrient cycling and ecosystem service provision in Amazonia. Our main goal was to develop a robust habitat suitability model of Amazon‐nut and to identify the most important predictor variables to support conservation and tree planting decisions.LocalizationAmazon region, South America.MethodsWe collected 3,325 unique Amazon‐nut records and assembled >100 spatial predictor variables organized across climatic, edaphic, and geophysical categories. We compared suitability models using variables (a) selected through statistical techniques; (b) recommended by experts; and (c) integrating both approaches (a and b). We applied different spatial filtering scenarios to reduce overfitting. We additionally fine‐tuned MAXENT settings to our data. The best model was selected through quantitative and qualitative assessments.ResultsPrincipal component analysis based on expert recommendations was the most appropriate method for predictor selection. Elevation, coarse soil fragments, clay, slope, and annual potential evapotranspiration were the most important predictors. Their relative contribution to the best model amounted to 75%. Filtering of the presences within a radius of 10 km displayed lowest overfitting, a satisfactory omission rate and the most symmetric distribution curve. Our findings suggest that under current environmental conditions, suitable habitat for Amazon‐nut is found across 2.3 million km2, that is, 32% of the Amazon Biome.Main conclusionThe combination of statistical techniques with expert knowledge improved the quality of our suitability model. Topographic and soil variables were the most important predictors. The combination of predictor variable selection, fine‐tuning of model parameters and spatial filtering was critical for the construction of a reliable habitat suitability model.

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Population structure and nut yield of a Bertholletia excelsa stand in Southwestern Amazonia

Cited by 139 publications

References 19 publications

Repeatability of Fruits and Seeds Production and Selection of Brazil Nut Genotypes in Native Populations in Roraima1

Repeatability of Fruits and Seeds Production and Selection of Brazil Nut Genotypes in Native Populations in Roraima1

Patrón espacial y métodos de muestreo para Bertholletia excelsa (castaña de Pará) en la Mesorregión del Bajo Amazonas, estado de Pará, Brasil

Strategies to optimize modeling habitat suitability of Bertholletia excelsa in the Pan‐Amazonia

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