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.

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.

No abstract

Neste estudo foram avaliadas as mudanças estruturais dos fragmentos florestais superiores a 1km2 localizados na porção norte da área do Centro de Endemismo Belém (CEB). Os dados foram obtidos de imagens orbitais do satélite Landsat 5 e 8, dos anos de 1985 e 2018, e se aplicaram sete índices de análise da paisagem no sistema computacional FRAGSTATS v. 4.2. Foram considerados tamanho, forma e proximidade dos fragmentos. O resultado da análise temporal evidenciou que, nesse período, houve um aumento do número (quantidade) de fragmentos, redução do tamanho médio da área total dos mesmos, além da redução significativa da agregação, promovendo o aumento no nível de fragmentação que pode afetar a manutenção da biodiversidade local, pois se refere à diminuição da quantidade de área total de habitat na paisagem da área de estudo.

No abstract

This study presented relevant aspects about the Amazonian environment and how it impacts the thermal comfort of domestic buffaloes (Bubalus bubalis) raised in the Eastern Amazon. Furthermore, strategies for monitoring and mitigating animal heat stress are presented, based on research results with the species. Although domestic buffaloes are considered adaptable animals, exposure to intense solar radiation causes thermal discomfort. This condition is expressed in biophysical indicators, in metabolic, endocrine, behavioral responses, and in body thermographic patterns. Therefore, the biometeorological monitoring of production is crucial to support decision-making regarding environmental management strategies, genetic selection of thermotolerant individuals, and increase in animal welfare. Lastly, the use of silvopastoral systems can help to provide higher thermal comfort, which is a condition that directly impacts the productivity of milk and meat buffaloes when they are raised in tropical regions, such as in the Eastern Amazon.

The objective of this study was to evaluate the regimes of temperature and rainfall in Belém, PA, Brazil, with emphasis on the start of the dry season in order to provide planning support for agricultural activities during years of climatic anomolies in the region. An initial analysis was done of the metropolitan region of Belém comparing it to the typology of Amazonian climates using rainfall data from 1971 to 2014 and creating an annual index of precipitation anomolies (AIPA). The temperature regime was described using a homogeneous rainfall dataset from 1990 to 2014. The hydrological balance was estimated for the period 1990 to 2014 using an index of capacity of soil water availability equal to 100 mm to identify the months with deficit or excess of soil water. Box plots were analyzed by decade and maximums of daily rainfall for the month of August were used. The Pareto principle was applied to 9 indices to assess the effects of rainfall quantity in relation to anomalous years. Although the metropolitan region of Belém is for the most part categorized by the Af2 climate type it is possible to have prolonged soil water deficit from August through November, an effect that is intensified by the El Niño phenomenon. Furthermore, in the month of August there were years with extreme rainfall events, such as that of August 7th, 2010 where 72.4 mm of rainfall occurred representing 53% of total monthly rainfall. This event can be explained by the intense waves of humidity coming from the East that amplified local rainfall. During the last two decades extreme daily rainfall events have become more frequent, and rainfall reductions in the region have tended to intensify in areas that historically receive less rainfall such as the transition between the Amazonian and Savannah biomes. Therefore, in La Niña or El Niño years, the month of August can be considered to be the signal for meso-and large-scale atmospheric mechanisms that influence precipitation regimes and that can have a negative effect of the region's agricultural productivity.

The Brazilian Amazon has a large bovine herd and is an important exporter of meat from cattle and is also one of the most competitive regions for exportation of animal protein. Conventional extensive cattle ranching management has been a strategy promoted by public policies and has contributed to the processes of occupation of the region through modification of public lands with native forests. The objective of this study was to analyze the fundamental elements that have sustained conventional extensive cattle ranching in the Amazon and to demonstrate new strategies to change this paradigm, with a focus on western Pará. Data from the Brazilian Institute of Geography and Statistics (IBGE) on cattle ranching production between 1990 and 2019 were analyzed and separated into two periods, 1990-2000, and 2001-2019. Meteorological data from western Pará were analyzed to describe the agrometeorological conditions (1989 -2012) with respect to the hydrological regime and its controls on the soil-plant-atmosphere system. Results show that the largest greenhouse gas emissions (GGE) from ruminants occurs during the dry season due to pasture forage grasses that are highly lignified. In contrast, lower emissions occur from diets rich in proteins and lipids, with subsequent gains in productivity, thus indicating the benefits of pastures with well-managed grasses. It is believed that cattle ranchers will adopt integrated systems such as integration of crop-livestock-forest (ICLF) when they are able to understand that climate conditions can be allied with sustainability indicators of the production chain. This paradigm shift in production systems applies not only to environmental and economic aspects, but especially to social ones such as opportunities to hire qualified workers coming from regional agrarian science schools