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

Structural and compositional changes in eucalyptus wood chips subjected to dry torrefaction

The aim of this study was to evaluate the structural and compositional changes in eucalyptus wood chips subjected to dry torrefaction. The experiment was conducted in a semi-continuous screw reactor with indirect heating system. Wood chips samples of three initial moisture contents (0, 15 and 30% dry basis) were torrefied up to three final temperatures (220, 260 and 300 °C) and at three heating times (10, 15 and 20 min). The effect of these variables was evaluated through the analysis of chemical composition, thermogravimetry and mechanical durability of the torrefied wood chips. The increase at temperature and time of torrefaction, as well as the drop in the initial moisture content, promoted significant structural and compositional changes in the wood chips. The torrefied samples present a higher resistance to thermal degradation, more friable structure, higher lignin and lower polysaccharides contents than the untreated samples. These changes made it possible to increase the quality of the eucalyptus wood chips to be use as a solid fuel

Propriedades de chapas de flocos fabricadas com adesivo de uréia-formaldeído e de taninos da casca de Eucalyptus grandis W. Hill ex Maiden ou de Eucalyptus pellita F. Muell. Properties of flakeboards made from urea-formaldehyde and bark tannins adhesives of Eucalyptus grandis or Eucalyptus pellita

Os taninos foram extraídos da casca de Eucalyptus grandis e Eucalyptus pellita, com água quente, à qual se adicionaram 4,5% de sulfito de sódio, durante três horas. As temperaturas da solução foram iguais a 70 e 100 ºC para Eucalyptus grandis e Eucalyptus pellita, respectivamente. Para a produção dos adesivos e com o intuito de reduzir a sua viscosidade, os taninos foram sulfitados com sulfito de sódio e ácido acético. Formulações adesivas foram preparadas adicionando-se 0, 25, 50, 75 ou 100% de adesivos tânicos ao adesivo comercial de uréia-formaldeído. Foram fabricadas chapas de flocos de Pinus elliottii Engelm. e Eucalyptus grandis, utilizando-se 8% da formulação adesiva. As propriedades das chapas foram determinadas segundo a norma ASTM D-1037, de 1993. Observou-se que as propriedades das chapas foram superiores ao mínimo estabelecido pela norma ANSI/A 280.1-93, exceto no caso da resistência à umidade. Verificou-se, ainda, que o emprego de uma formulação adesiva contendo resina à base de uréia-formaldeído e tanino-formaldeído pode melhorar algumas propriedades.<br>Bark tannins of Eucalyptus grandis and Eucalyptus pellita were extracted with 4,5% sodium sulfite in hot water solution for a period of three hours. Solution temperatures were 70 and 100ºC, for Eucalyptus grandis and Eucalyptus pellita bark respectively. Tannins were reacted with acetic acid and sodium sulfite to reduce adhesive viscosity. Adhesive formulations were prepared adding 0, 25, 50, 75 or 100% of tannin adhesives to the commercial urea-formaldehyde adhesive. Flakeboards were fabricated with 8% resin content. Board properties were determined according to ASTM D-1037 standards. Except for humidity, all board properties were superior to the values established by ANSI.A 208.1-93 commercial standard. Addition of tannins to the urea-formaldehyde adhesive improved some properties

Air-drying of eucalypts logs: Genetic variations along time and stem profile

Knowledge of wood drying potential is relevant in forestry and biomaterials technology field, being directly related with timber transport, lumber properties, charcoal yield and pulping process. Using mixed models approach by REML-BLUP procedure, we aimed to evaluate the moisture content loss potential among different eucalypt genotypes, by means of genetic correlations, heritabilities, coefficients of variation and determination of wood air-drying over 154 drying days and in five tree stem heights. Moreover, we tested three possible auxiliary traits (Heartwood/Sapwood ratio, Log Circumference, and Basic Wood Density) for indirect selection on wood air-drying rate. The highest air-drying heritabilities occurred at the two most basal stem heights and only after the 98th day. However, genetic correlations across the drying measurements were considerably high from day 42. The three auxiliary traits demonstrated potential for indirect selection, suggesting the possibility of integrating wood air-drying to future Eucalyptus sp. breeding programs. There is no need to wait for industrial moisture content to carry out genetic evaluation. Besides, perform selection at trees basal region is the safest way to improve the air-drying rate of genotypes