COMPARISON OF DIFFERENT METHODS OF MEASURING TREE VOLUMES IN THE MUNICIPALITY OF ANAPU, PARÁ, BRAZIL

The objective of this study was to compare three methods of measuring the volume of individual trees used extensively as a basis for adjusting volumetric functions in areas under forest management in the Brazilian Amazon, and verify the influence of species and diameter classes in obtaining the volume of individual trees.   A total of 53 sample trees belonging to five species were analyzed and separated into three diametric classes.  The real volume (VR) was obtained using Smalian’s method on fixed sections of 2 meters intervals along the stem; the geometric volume (VG) was also obtained by Smalian’s method, but with the lengths of the various sections along the stem.  Volume loss (VP) was subtracted from the VR to obtain the usable volume (VA).  An ANOVA in a factorial design (5 x 3 x 3) was performed to verify the effect of 5 species, 3 diameter classes, and 3 volume measurement methods (VR, VG, and VA) on the different volumes obtained.  The 3 factors did affect the outcome of the analysis, but there were no interactions found between these variables.  The volumes obtained by cubic scaling with different lengths (VG) presented a lower mean volume than VR.  Although there was no difference between the means of VA and VR, wood loss was 6.5% of the total volume. There is a relationship between section length and volume loss, according to the presence of hollows, twists and cracks in the logs in the largest diameter classes

Fitossociologia em sistemas agroflorestais com diferentes idades de implantação no município de Medicilândia, PA

Os sistemas agroflorestais surgem como alternativa à degradação dos recursos naturais, pois possibilitam a harmonia entre agricultura e espécies florestais, garantindo a sustentabilidade ambiental. Objetivou-se com o presente trabalho avaliar a composição florística e comparar a estrutura de três sistemas agroflorestais com idades de 20, 30 e 40 anos no Município de Medicilândia, PA. Para análise florística e estrutural, realizou-se o censo florestal nos três sistemas agroflorestais, inventariando todos os indivíduos arbóreos com diâmetro a altura do peito > 10 cm. Para a análise da estrutura horizontal, foram considerados os parâmetros fitossociológicos absolutos e relativos de densidade e dominância. Os parâmetros absolutos e relativos da posição sociológica e regeneração natural foram calculados para a análise estrutural vertical dos sistemas. Para análise do Índice de Valor de Importância Ampliado (IVIA), foram somados todos os parâmetros verticais e horizontais relativos. Os sistemas agroflorestais apresentaram distribuição diamétrica em forma de “J invertido”. Por serem espécies chaves no plantio agroflorestal, Swietenia macrophylla e Tabebuia impetignosa foram as espécies mais importantes em todos os sistemas agroflorestais. A condução da regeneração natural favoreceu o estabelecimento de espécies de valor comercial que não fizeram parte do arranjo inicial dos SAFs, tais como Bagassa guianenses, Tabebuia serratifolia, Schizolobium amazonicum e Dipteryx odorata, denotando sustentabilidade econômica e ecológica nestes sistemas

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 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 or ganism 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 ne glected 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 lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 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,18,19 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

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 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,18,19 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

Fitossociologia em sistemas agroflorestais com diferentes idades de implantação no município de Medicilândia, PA

Os sistemas agroflorestais surgem como alternativa à degradação dos recursos naturais, pois possibilitam a harmonia entre agricultura e espécies florestais, garantindo a sustentabilidade ambiental. Objetivou-se com o presente trabalho avaliar a composição florística e comparar a estrutura de três sistemas agroflorestais com idades de 20, 30 e 40 anos no Município de Medicilândia, PA. Para análise florística e estrutural, realizou-se o censo florestal nos três sistemas agroflorestais, inventariando todos os indivíduos arbóreos com diâmetro a altura do peito > 10 cm. Para a análise da estrutura horizontal, foram considerados os parâmetros fitossociológicos absolutos e relativos de densidade e dominância. Os parâmetros absolutos e relativos da posição sociológica e regeneração natural foram calculados para a análise estrutural vertical dos sistemas. Para análise do Índice de Valor de Importância Ampliado (IVIA), foram somados todos os parâmetros verticais e horizontais relativos. Os sistemas agroflorestais apresentaram distribuição diamétrica em forma de “J invertido”. Por serem espécies chaves no plantio agroflorestal, Swietenia macrophylla e Tabebuia impetignosa foram as espécies mais importantes em todos os sistemas agroflorestais. A condução da regeneração natural favoreceu o estabelecimento de espécies de valor comercial que não fizeram parte do arranjo inicial dos SAFs, tais como Bagassa guianenses, Tabebuia serratifolia, Schizolobium amazonicum e Dipteryx odorata, denotando sustentabilidade econômica e ecológica nestes sistemas

Sample intensity in ombrophilous open forest at Verde Para Sempre Extractive Reserve, Porto de Moz, PA = Intensidade amostral em Floresta Ombrófila Aberta na Resex Verde Para Sempre, Porto de Moz, PA

Determining the ideal sampling intensity is important to guarantee data closer to reality with less cost and time in the forest inventory. The objective of this paper was to evaluate the influence of different sample intensities to estimate the floristic composition, species diversity and the timber volume, beyond compare the results with their respective parameters obtained in the census of an ombrophilous open forest area in Verde Para Sempre Extractive Reserve. Was simulated a random sampling with sampling units of 1 ha and several sample intensities: 5%, 10%, 15% and 20% in an area of 200 ha that it was submitted to a forest census. It was evaluated the phytosociological parameters such as structure and diversity, and the estimated errors in the sampling intensities for the volume. The forest has a structure with high diversity and species of high economic value, indicating the existence of an aptitude for sustainable forest management. The treatment with 5% and 10% sample intensity were not enough to contemplate all the species in the area and estimate the volume inside to the required accuracy limit, maximum of 10% sampling error. The treatments of 15% and 20% resembled the parametric value regarding floristic composition, species diversity and volumetry of the forest census of the area, showing no significant difference between them. The analysis of the phytosociological structure showed the importance of using sample inventories to evaluate the economic potential of an area and its suitability for forest management. = Determinar a intensidade amostral ideal é importante para garantir dados mais próximos da realidade com menor custo e tempo na realização do inventário florestal. Assim, objetivou-se avaliar a influência de diferentes intensidades amostrais para estimar a composição florística, a diversidade de espécies e o volume de madeira, bem como comparar esses resultados com seus respectivos parâmetros obtidos pelo censo de uma área de Floresta Ombrófila Aberta na Resex Verde Para Sempre. Foi simulada uma amostragem aleatória, com unidades amostrais de 1 ha e diversas intensidades amostrais: 5, 10, 15 e 20% em uma área de 200 ha, que foi submetida a um censo florestal. Foram avaliados os parâmetros fitossociológicos, como estrutura e diversidade, e os erros estimados pelas intensidades amostrais para o volume. A floresta apresenta uma estrutura com alta diversidade e espécies de alto valor econômico, indicando aptidão ao manejo florestal sustentável. Os tratamentos 5 e 10% de intensidade amostral não foram suficientes para contemplar todas as espécies existentes na área e estimar o volume dentro do limite de precisão exigido, o máximo de 10% de erro amostral. Os tratamentos de 15 e 20% se assemelharam ao valor paramétrico no que tange a composição florística, a diversidade de espécies e volumetria do censo florestal da área, não apresentando diferença significativa entre eles. A análise da estrutura fitossociológica mostrou a importância de se utilizar inventários amostrais para se avaliar o potencial econômico de uma área e sua aptidão ao manejo florestal