Aim Tropical forests store 25% of global carbon and harbour 96% of the world's tree species, but it is not clear whether this high biodiversity matters for carbon storage. Few studies have teased apart the relative importance of forest attributes and environmental drivers for ecosystem functioning, and no such study exists for the tropics. Location Neotropics. Methods We relate aboveground biomass (AGB) to forest attributes (diversity and structure) and environmental drivers (annual rainfall and soil fertility) using data from 144,000 trees, 2050 forest plots and 59 forest sites. The sites span the complete latitudinal and climatic gradients in the lowland Neotropics, with rainfall ranging from 750 to 4350 mm year−1. Relationships were analysed within forest sites at scales of 0.1 and 1 ha and across forest sites along large‐scale environmental gradients. We used a structural equation model to test the hypothesis that species richness, forest structural attributes and environmental drivers have independent, positive effects on AGB. Results Across sites, AGB was most strongly driven by rainfall, followed by average tree stem diameter and rarefied species richness, which all had positive effects on AGB. Our indicator of soil fertility (cation exchange capacity) had a negligible effect on AGB, perhaps because we used a global soil database. Taxonomic forest attributes (i.e. species richness, rarefied richness and Shannon diversity) had the strongest relationships with AGB at small spatial scales, where an additional species can still make a difference in terms of niche complementarity, while structural forest attributes (i.e. tree density and tree size) had strong relationships with AGB at all spatial scales. Main conclusions Biodiversity has an independent, positive effect on AGB and ecosystem functioning, not only in relatively simple temperate systems but also in structurally complex hyperdiverse tropical forests. Biodiversity conservation should therefore be a key component of the UN Reducing Emissions from Deforestation and Degradation strategy.

Assessment of surface temperatures of buffalo bulls (Bubalus bubalis) raised under tropical conditions using infrared thermography ABSTRACTThis paper aimed to evaluate the surface temperatures of buffalo bulls using infrared thermography, considering four distinct anatomical parts over time, and to correlate surface temperatures and thermal comfort indexes. The humid tropical climate (Köppen's Afi) was predominant in the research station where the experiment was performed and the trial lasted from April to August. Ten bulls (n=10) were evaluated every 25 days (morning: 6:00-9:00; afternoon: 12:00-15:00) and the parameters assessed were respiratory rate (RR), rectal temperature (RT), and the thermograms of surface temperature for orbital area (ORB), right flank (RF), left flank (LF) and scrotum (SCR). Climatological data was continuously monitored and the Temperature and Humidity Index (THI) and the Index of Comfort of Benezra (ICB) were calculated. The average values of THI were ≥78, and significant differences between shifts were observed (P<0.05). The ICB ranged from 1.96 to 2.25 and significant differences were observed for shifts and throughout the months (P<0.05). The averages of surface temperatures were RT=38.2±0.5°C, ORB=36.1±0.8°C, LF=33.5±2.5°C, RF=35.4±1.7ºC and SCR=33.3±1.1°C, which exhibited significant differences for shifts and throughout the months (P<0.05). Positive correlations were obtained between THI and ORB (0.72), RF (0.77), LF (0.75) and SCR (0.41) (P<0.0001). The maximum temperature of ORB showed the highest correlation with RT (0.58, P<0.0001). Therefore, the surface temperatures are subject to climatic variations and increase throughout the day, due to the variation in thermal comfort indexes, and the maximum ORB temperature was the parameter most related to rectal temperature. Lastly, the results indicate that IRT may be a useful non-invasive and accurate tool to detect the variations in ORB, LF, RF and SCR temperature in buffalo bulls.Keywords: animal welfare, water buffalo, infrared imaging, core temperature, body surface temperature TR=38,2±0,5ºC, ORB=36,1±0,8ºC, FLd=33,5±2,5ºC, RESUMO O presente trabalho visou avaliar as temperaturas superficiais de diferentes regiões anatômicas de búfalos ao longo do tempo, por meio da termografia infravermelha, e correlacioná-las a índices bioclimatológicos de conforto térmico. O ensaio foi realizado em região de clima tropical úmido (Afi de Köppen), de abril a agosto. Dez touros (n=10) foram avaliados a cada 25 dias (manhã: seis-nove horas; tarde: 12-15h), quanto à frequência respiratória (FR), temperatura retal (TR) e imagens termográficas da órbita ocular (ORB), flanco direito (FLd), flanco esquerdo (FLe) e escroto (ESC). Os dados climatológicos foram ininterruptamente monitorados, e calculados o índice de temperatura e umidade (ITU) e o índice de conforto de Benezra (ICB). O ITU foi ≥78, com diferença entre turnos (P<0,05). Já o ICB variou de 1,96 a 2,25 e apresentou diferenças ao longo dos meses e entre turnos (P<0,05). As temperaturas...

This study evaluated the capacity of thermoregulation and its consequences on the scrotal surface temperature patterns and semen quality of buffalo bulls raised in a wet tropical climate. Eleven water buffaloes were evaluated in the rainiest, in the transitional and in the less rainy season. Air temperature and humidity were consistently high, but the animals did not show thermal stress in any season. The scrotal temperature gradient of buffalo bulls using infrared thermography was described, and three parallel and decreasing thermal bands were characterised. Sperm quality (n = 176 ejaculates) was maintained in normal parameters over the periods. Pearson's coefficients showed that sperm volume and progressive motility were negatively correlated with ocular globe, epididymal tail and minimum scrotal temperatures (p < .01). Sperm membrane integrity was negatively influenced by increases in epididymal tail and minimum scrotal temperatures (p < .01). Ocular globe temperature also showed positive correlation with rectal, spermatic cord, and epididymal tail temperatures (p < .01). Therefore, even under high temperature and humidity, the thermoregulatory system was effective in preventing heat stress and the normality of scrotal surface temperatures, spermatogenesis and sperm maturation were maintained.

BACKGROUND: The increasing demand in Brazil and the world for products derived from the açaí palm (Euterpe oleracea Mart) has generated changes in its production process, principally due to the necessity of maintaining yield in situations of seasonality and climate fluctuation. The objective of this study was to estimate açaí fruit yield in irrigated system (IRRS) and rainfed system or unirrigated (RAINF) using agrometeorological models in response to climate conditions in the eastern Amazon. Modeling was done using multiple linear regression using the 'stepwise forward' method of variable selection. Monthly air temperature (T) values, solar radiation (SR), vapor pressure deficit (VPD), precipitation + irrigation (P + I), and potential evapotranspiration (PET) in six phenological phases were correlated with yield. The thermal necessity value was calculated through the sum of accumulated degree days (ADD) up to the formation of fruit bunch, as well as the time necessary for initial leaf development, using a base temperature of 10 ∘ C. RESULTS:The most important meteorological variables were T, SR, and VPD for IRRS, and for RAINF water stress had the greatest effect. The accuracy of the agrometeorological models, using maximum values for mean absolute percent error (MAPE), was 0.01 in the IRRS and 1.12 in the RAINF. CONCLUSION: Using these models yield was predicted approximately 6 to 9 months before the harvest,

Abstract. The Amazon basin is the world's largest rainforest and the most biologically diverse place on Earth. Despite the critical importance of this region, Amazon forests continue inexorably to be degraded and deforested for various reasons, mainly a consequence of agricultural expansion. The development of novel policy strategies that provide balanced solutions, associating economic growth with environmental protection, is still challenging, largely because the perspective of those most affected – local stakeholders – is often ignored. Participatory fuzzy cognitive mapping (FCM) was implemented to examine stakeholder perceptions towards the sustainable development of two agricultural-forest frontier areas in the Bolivian and Brazilian Amazon. A series of development scenarios were explored and applied to stakeholder-derived FCM, with climate change also analysed. Stakeholders in both regions perceived landscapes of socio-economic impoverishment and environmental degradation driven by governmental and institutional deficiencies. Under such abject conditions, governance and well-integrated social and technological strategies offered socio-economic development, environmental conservation, and resilience to climatic changes. The results suggest there are benefits of a new type of thinking for development strategies in the Amazon basin and that continued application of traditional development policies reduces the resilience of the Amazon to climate change, whilst limiting socio-economic development and environmental conservation.

The plants' answer to the top-bioclimate conditions is important for mapping occurrences and indications of preferential areas for the development of the forest species. This study aimed to georeference the natural occurrence of Taxibranco (Sclerolobium paniculatum Vogel) and Parica (Schizolobium parahyba var. amazonicum (Huber ex Ducke) Barneby) integrated with top-bioclimate information to indicate plantations for rehabilitation of degraded landscape. The data regarding natural occurrence of species was investigated in the literature, the herbaria of Embrapa Eastern Amazon and the Paraense Emilio Goeldi Museum and demonstrative units in the Eastern Amazon. Normal climates from thirty year series with spatial resolution 3 km x 3 km were specialized in Arcgis 9.3 and exported to TerraView 3.2, to create the cellular space for integration of variables in TerraME and to generate top-climate maps and species' natural occurrence. As the Taxi-branco occurs in upland and lowland it was observed that the species prefers areas of predominantly top bioclimate with water deficit between 150 to 250 mm, and elevations below 200 m altitude, next to the river, and the Parica in about 300 m altitude, and water deficit below 180 mm. The knowledge of these zones should enhance the degree of confidence on the areas indicated to the development of strategies for the genetic resources conservation and sustainable management of threatened tree species.

RESUMO Na Amazônia, o principal potencial de contribuição para os Objetivos de Desenvolvimento Sustentável (ODS), está no aproveitamento de resíduos da agroindústria para uso na construção civil, como alternativa de novos materiais sustentáveis. Neste contexto, objetivou-se com este trabalho avaliar o potencial uso de partículas de resíduos de açaí (Euterpe oleracea e Euterpe precatoria) caracterizando-as física, química, térmica e morfologicamente. Foram realizados ensaios de densidade por picnometria, verificação de teor de umidade, e dos teores de lignina, celulose e extrativos, de acordo com os parâmetros normativos da TAPPI 204, 211 e 222. O resultado da densidade média das partículas é de 1,49 g.cm-3, com teor de umidade variando de 2 a 6%. Em relação à composição química, observou-se maiores teores de lignina e extrativos, e redução de celulose em relação à outras fibras vegetais. Através da Microscopia Eletrônica de Varredura (MEV), observou-se a presença somente do endocarpo do caroço de açaí nas partículas de 8 e 14 Tyler, e maior predominância de fibras nas partículas de 48, 100 e 200 Tyler. O conhecimento das características físico-químicas das partículas de resíduo de açaí faz-se necessário para subsidiar etapas de processamento de compósitos com uso destes materiais. Além disso, a utilização de um resíduo como o caroço do açaí potencializa a redução dos impactos ambientais, fornecendo, principalmente para a construção civil, a possibilidade de produção de novos materiais mais ecológicos, gerando indicadores de sustentabilidade nas edificações da Amazônia.

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.