The objective of this study was to evaluate the effect of lipid sources on voluntary intake, digestibility, performance, and CH4 emission of Nellore steers grazing Brachiaria brizantha cv. Xaraés forage in the dry season. Forty-five Nellore steers with average weight of 442±34 kg were alloted into one of the five treatments: without additional fat; with palm oil; with linseed oil; with protected fat; and with whole soybeans. The supplements were provided daily and quantities were adjusted to 1% of body weight and diets were formulated in accordance with the Cornell Net Carbohydrate and Protein System. The experimental design was completely randomized with five treatments and two replications. There were no effects on dry matter, organic matter, and neutral detergent fiber intake with the inclusion of lipids in the diet. The neutral detergent fiber showed decreased digestibility in animals receiving linseed oil and palm oil treatments compared with animals receiving the diet without additional fat. The linseed oil treatment reduced CH4 emissions by 38% when expressed in mg/d/kg BW and tended to reduce the emission in g/d/kg BW0.75. Lipid sources did not affect the weight gain of the animals. The intake and performance of grazing Nellore steers supplemented at 1% body weight with lipid sources were not modified. However, fiber digestibility was reduced with palm or linseed oil addition. Linseed oil reduced enteric CH4 emissions. Linseed oil has the potential to reduce enteric CH4 emissions in continuous tropical grazing systems based on B. brizantha grass.

The Rural Sustentável project aims to decrease greenhouse gas emissions, reduce poverty, and promote sustainable rural development in the Brazilian Amazon and Atlantic Forest biomes: by restoring deforested and degraded land, and by facilitating and promoting the uptake of low carbon agricultural technologies. The project offers farmers a) access to information, through demonstration units and field days; b) access to technical assistance, through in-person and online training and capacity-building; c) access to rural credit, through collaborative farmer-technician partnerships, and d) financial incentives, in the form of results based financing to successful farmer-technician teams. The project is still in its implementation stage, but the innovative design and theory of change of this project offer insights into possible mechanisms for promoting forest restoration on private lands in the tropics.

In Brazil’s central savanna region, government policy is to encourage the conversion of conventional plough tillage (PT) agriculture to no-till (NT) and raise the productivity of under-utilized pastures, including their conversion to integrated crop-livestock (ICL) systems, with the objective of increasing soil organic carbon (SOC) at the expense of atmospheric carbon dioxide. An experiment was established in 1991 by liming and fertilizing at two levels an area of native vegetation (NV). The treatments, replicated in randomized plots, included pastures, continuous cropping and ICL systems under PT or NT. The aim of this study was to quantify the SOC accumulation to 100 cm depth under these treatments over time. The high C:N ratios suggested that there was a high proportion of charcoal present in the soil. Increasing fertilizer inputs had no overall significant effect on SOC stocks. Stocks of SOC changed little under pastures. Analyses of ¹³C abundance showed that higher fertilizer inputs increased the decomposition rate of C derived from NV under pure grass pastures. Continuous cropping under NT preserved SOC and under PT there were significant losses. The highest SOC stocks were found under ILP treatments, but not all ILP treatments accumulated SOC even under NT. These results indicate that government initiatives to substitute PT with NT and to intensify beef cattle production will have only modest short-term gains in SOC accumulation.

Human-induced climate change is considered a conspicuous threat to biodiversity in the 21st century. Species’ response to climate change depends on their exposition, sensitivity and ability to adapt to novel climates. Exposure to climate change is however uneven within species’ range, so that some populations may be more at risk than others. Identifying the regions most exposed to climate change is therefore a first and pivotal step on determining species’ vulnerability across their geographic ranges. Here, we aimed at quantifying mammal local exposure to climate change across species’ ranges. We identified areas in the Brazilian Amazon where mammals will be critically exposed to non-analogue climates in the future with different variables predicted by 15 global circulation climate forecasts. We also built a null model to assess the effectiveness of the Amazon protected areas in buffering the effects of climate change on mammals, using an innovative and more realistic approach. We found that 85% of species are likely to be exposed to non-analogue climatic conditions in more than 80% of their ranges by 2070. That percentage is even higher for endemic mammals; almost all endemic species are predicted to be exposed in more than 80% of their range. Exposure patterns also varied with different climatic variables and seem to be geographically structured. Western and northern Amazon species are more likely to experience temperature anomalies while northeastern species will be more affected by rainfall abnormality. We also observed an increase in the number of critically-exposed species from 2050 to 2070. Overall, our results indicate that mammals might face high exposure to climate change and that protected areas will probably not be efficient enough to avert those impacts.

Human-induced climate change is considered a conspicuous threat to biodiversity in the 21^stcentury. Species’ response to climate change depends on their exposition, sensitivity and ability to adapt to novel climates. Exposure to climate change is however uneven within species’ range, so that some populations may be more at risk than others. Identifying the regions most exposed to climate change is therefore a first and pivotal step on determining species’ vulnerability across their geographic ranges. Here, we aimed at quantifying mammal local exposure to climate change across species’ ranges. We identified areas in the Brazilian Amazon where mammals will be critically exposed to non-analogue climates in the future with different variables predicted by 15 global circulation climate forecasts. We also built a null model to assess the effectiveness of the Amazon protected areas in buffering the effects of climate change on mammals, using an innovative and more realistic approach. We found that 85% of species are likely to be exposed to non-analogue climatic conditions in more than 80% of their ranges by 2070. That percentage is even higher for endemic mammals; almost all endemic species are predicted to be exposed in more than 80% of their range. Exposure patterns also varied with different climatic variables and seem to be geographically structured. Western and northern Amazon species are more likely to experience temperature anomalies while northeastern species will be more affected by rainfall abnormality. We also observed an increase in the number of critically-exposed species from 2050 to 2070. Overall, our results indicate that mammals might face high exposure to climate change and that protected areas will probably not be efficient enough to avert those impacts.

O objetivo deste trabalho foi avaliar o potencial de mitigação de óxido nitroso (N2O) em sistema de integração lavoura-pecuária-floresta (ILPF), em comparação ao monocultivo, e identificar os principais fatores que regulam as emissões deste gás. O experimento foi realizado em Sinop, MT, entre as safras 2012/2013 e 2013/2014, e avaliou os seguintes tratamentos: floresta, lavoura e pastagem, além do ILPF. Durante a realização do experimento, não houve presença de bovinos nas áreas com pastagem. Amostras de óxido nitroso foram coletadas semanalmente, com uso de câmaras estáticas, modelo topo-base. As concentrações do gás foram determinadas por meio de cromatografia gasosa. A precipitação pluvial e a disponibilidade de N foram os principais fatores reguladores das emissões de N2O. O sistema de ILPF apresenta potencial promissor para mitigar as emissões de N2O, com emissão acumulada de 0,367 kg ha-1 de N, em comparação a de 1,401 kg ha-1 emitidas pela lavoura; de 0,298 kg ha-1, pela pastagem; e de 0,165 kg ha-1, pela floresta.

Despite environmental damage of cow meet production residues, specific methods to evaluate its spatial impact on soil contamination are sparse and time consuming. This study aimed to evaluate the potential of spectroscopy (400–2500 nm) to detected soil contaminated with organic compounds. It was conducted two experiments: (1) Three soils were incubated with pure and diluted blood from slaughterhouse in a greenhouse, and spectral data were obtained in laboratory with a FieldSpec sensor. (2) Field experiment was conducted to prove its approach. Soil spectral responses were evaluated by qualitative and quantitative methods, and chemical analyses were carried out. The addition of residues increased levels mostly of Na (92.9 %), Ca (80.9 %) and K (82.7 %). N and C increased 52.7 %. This high significant addition resulted on a decrease in soil reflectance intensity in all spectral ranges. These changed slightly at 650, 1450, 1550, 1900 and 2100 nm indicating alteration due to cation on the CEC of minerals. Principal components and soil line analyses corroborated the discrimination of samples quantification of Na, K, Ca and Mg, where R² vary from 0.68 until 0.85. In field areas with and without the waste also showed different spectra. Spectra were also able to analyze samples located downhill from the area with waste, indicating the presence of the waste close to streams, which came by leaching. The results indicate that it is possible to identify areas with organic residue by a quick method as compared with traditional soil analysis, helping man power inspection.

Changes in the distribution of rainfall and the occurrence of extreme rain events will alter the size and persistence of aquatic ecosystems. Such alterations may affect the structure of local aquatic communities in terms of species composition, and by altering species interactions. In many aquatic ecosystems, leaf litter sustains detrital food webs and could regulate the responses of communities to changes in rainfall. Few empirical studies have focused on how rainfall changes will affect aquatic communities and none have evaluated if basal resource diversity can increase resistance to such rainfall effects. In this study, we used water-holding terrestrial bromeliads, a tropical aquatic ecosystem, to test how predicted rainfall changes and litter diversity may affect community composition and trophic interactions. We used structural equation modeling to investigate the combined effects of rainfall changes and litter diversity on trophic interactions. We demonstrated that changes in rainfall disrupted trophic relationships, even though there were only minor direct effects on species abundance, richness, and community composition. Litter diversity was not able to reduce the impact of changes in rainfall on trophic interactions. We suggest that changes in rainfall can alter the way in which species interact with each other, decreasing the linkages among trophic groups. Such reductions in biotic interactions under climate change will have critical consequences for the functioning of tropical aquatic ecosystems.

A total of 70 Nellore bulls (18 ± 3 months of age) were used to determine the effects of crude glycerine (CG) replacing starch- v. fibre-based energy ingredients in low (LC; 0·40 concentrate) or high concentrate (HC; 0·60 concentrate) – on a dry matter (DM) basis – on DM intake (DMI), methane emissions and growth. Ten bulls were slaughtered (reference group) to obtain the carcass gain (CrG). The 60 remaining bulls (374 ± 24·5 kg) were allocated to a 2 × 3 factorial arrangement (two concentrate levels, LC or HC; and three feeding regimes, FR). The FR were: CO – without CG and maize as an ingredient of concentrate; CGM – inclusion of CG (0·10 of DM) replacing maize in the concentrate; and CGSH – inclusion of CG (0·10 of DM) replacing soybean hulls (SH) in the concentrate. Bulls fed LC or HC had similar DMI (kg/d) and growth. The DMI and average daily gain (ADG) were similar among FR. Concentrate level and FR tended to interact for methane emissions (g) per kg DMI. Bulls fed CGM had a greater G : F (g CrG/kg DMI) than those fed CO or CGSH diets. Increasing dietary concentrate (0·40–0·60) did not affect intake, methane emissions, or growth. Inclusion of CG in diets to replace SH in LC diets tended to decrease methane emissions from animals. When CG replaces SH in the diets, CrG and G:F (g CrG/kg DMI) are decreased compared with bulls fed CGM.

Amazon forest stocks large quantities of carbon both in plant biomass and in soil. Deforestation has accelerated the process of forest fragmentation in the Brazilian Amazon, resulting in changes in carbon stocks in both biomass and soil. Logging, including that under legal forest management, can create edge-like conditions inside the forest. We investigated the relationship between changes in carbon stocks in the soil and the distance to the nearest edge in forest remnants after about 30 years of isolation. We assessed the effect of edges using geographically weighted regression (GWR), which considers the non-stationary character of soil carbon stocks and assigns relative weights to the observations according to the distance between them. Data from 265 georeferenced plots distributed over 28 ha of forest fragments in the Manaus region were included in these analyses. Soil-carbon stocks were estimated for areas before (1984–1986) and after (2012–2013) isolation of the fragments. The GWR model indicated an apparent relationship between change in carbon stocks and distance from the edge (R2 = 0.79). The largest changes occurred in plots located closest to the edges. In 202 plots ⩽100 m from an edge, soil-carbon stock increased significantly (p = 0.01) by a mean of 1.34 Mg ha−1 over the ∼30-year period. Such changes in soil carbon stocks appear to be associated with higher rates of tree mortality caused by microclimatic changes in these areas. Increased necromass inputs combined with changes in composition and structure of vegetation may result in increased rates of decomposition of organic matter, transferring carbon to the soil compartment and increasing soil carbon stocks. Considering both “hard” edges adjacent to deforestation and “soft” edges in logging areas, the soil-carbon increase we measured implies an absorption of 6 × 106 MgC in Brazilian Amazonia. In hard edges maintained for ∼30 years, the soil-carbon increase offsets 8.3% of the carbon losses from “biomass collapse” in the first 100 m from a clearing. Soil carbon did not change significantly in 63 forest-interior plots, suggesting that global climate change has not yet had a detectible effect on this forest carbon compartment.

Fatty acid profile of crossbred beef cattle fed either a diet with corn gluten and protected fat (A) or a control diet (B) was evaluated. Animal’s gender and diet had greater influence on fatty acid profile than genotype. Diet A increased polyunsaturated fatty acids/saturated fatty acids ratio and decreased t11/t10-18:1 ratio and n-6 content.

Este artigo mostra os resultados de pesquisa para o semiárido pernambucano utilizando séries temporais diárias de temperatura e de precipitação com mais de 40 anos, com cenários futuros de mudanças do clima para o período de 2010 a 2050. Para determinar as tendências de mudanças do clima, presente e futuro, foram utilizadas tendências de mudanças climáticas, resultados de balanço hídrico e saídas do modelo atmosférico regional aninhado ETA, em cenário global do modelo climático aninhado em dois modelos climáticos globais, HadCM3 e BESM. Os resultados indicaram tendência de aumento das temperaturas máximas, redução das temperaturas mínimas, redução da pluviosidade, média anual, indicando tendência à aridização na região.