Agriculture and forest: A sustainable strategy in the Brazilian Amazon.

Large-scale agriculture is increasing in anthropogenically modified areas in the Amazon Basin. Crops such as soybean, maize, oil palm, and others are being introduced to supply the world demand for food and energy. However, the current challenge is to enhance the sustainability of these areas by increasing efficiency of production chains and to improve environmental services. The Amazon Basin has experienced a paradigm shift away from the traditional slash-and-burn agricultural practices, which offers decision makers the opportunity to make innovative interventions to enhance the productivity in previously degraded areas by using trees to ecological advantage. This study describes a successful experiment integrating the production of soybean and paricá (Glycine max L. and Schizolobium amazonicum) based on previous research that indicated potential topoclimatic zones for planting paricá in the Brazilian state of Pará. This paper shows that a no-tillage system reduces the effects of drought compared to conventional tillage still used by many farmers in the region. The integrated system was implemented during the 2014/2015 season in 234.6 ha in the high-potential zone in the municipality of Ulianópolis, Pará. Both soybean and paricá were planted simultaneously. Paricá was planted in 5 m x 2 m inter-tree spacing totaling 228x103 trees per hectare and soybean, in 4 m x 100 m spacing, distributed in nine rows with a 0.45 m inter-row distance, occupying 80% of the area. The harvested soybean production was 3.4 t ha-1, higher than other soybean monocultures in eastern Pará. Paricá benefited from soybean fertilization in the first year: It exhibited rapid development in height (3.26 m) and average diameter (3.85 cm). Trees and crop rotation over the following years is six years for forest species and one year for each crop. Our results confirm there are alternatives to the current production systems able to diminish negative impacts resulting from monoculture. In addition, the system provided environmental services such as reduced soil erosion and increased carbon stock by soil cover with no-tillage soybean cultivation. The soybean cover contributes to increased paricá thermal regulation and lower forestry costs. We concluded that innovative interventions are important to show local farmers that it is possible to adapt an agroforest system to large-scale production, thus changing the Amazon.

Lessons from the Terra Preta de Índios of the Amazon region for the utilisation of charcoal for soil amendment.

Neste trabalho faz-se a divulgação do potencial de carvões e resíduos orgânicos parcialmente carbonizados visando obter materiais que mimetizam a matéria orgânica do solo das Terras Pretas de Índio da Amazônia, e que sirvam como condicionadores de solo e seqüestrem carbono de forma recalcitrante e reativa. Pesquisas desenvolvidas por grupos brasileiros e estrangeiros têm contribuído para o entendimento do surgimento e utilização das Terras Pretas de Índio da Amazônia. Aqui são divulgados resultados de estudos químicos no sentido do desenvolvimento do conhecimento científico e tecnológico e de inovação no aproveitamento de subprodutos orgânicos, principalmente de indústrias de biocombustíveis, carvão vegetal metalúrgico e outros, buscando imitar a excelente performance da chamada Terras Pretas de Índio da Amazônia.

Modeling and Mapping Agroforestry Aboveground Biomass in the Brazilian Amazon Using Airborne Lidar Data.

Agroforestry has large potential for carbon (C) sequestration while providing many economical, social, and ecological benefits via its diversified products. Airborne lidar is considered as the most accurate technology for mapping aboveground biomass (AGB) over landscape levels. However, little research in the past has been done to study AGB of agroforestry systems using airborne lidar data. Focusing on an agroforestry system in the Brazilian Amazon, this study first predicted plot-level AGB using fixed-effects regression models that assumed the regression coefficients to be constants. The model prediction errors were then analyzed from the perspectives of tree DBH (diameter at breast height)?height relationships and plot-level wood density, which suggested the need for stratifying agroforestry fields to improve plot-level AGB modeling. We separated teak plantations from other agroforestry types and predicted AGB using mixed-effects models that can incorporate the variation of AGB-height relationship across agroforestry types. We found that, at the plot scale, mixed-effects models led to better model prediction performance (based on leave-one-out cross-validation) than the fixed-effects models, with the coefficient of determination (R2) increasing from 0.38 to 0.64. At the landscape level, the difference between AGB densities from the two types of models was ~10% on average and up to ~30% at the pixel level. This study suggested the importance of stratification based on tree AGB allometry and the utility of mixed-effects models in modeling and mapping AGB of agroforestry systems.

Molecular characterization of accessions of a rare genetic resource: sugary cassava (Manihot esculenta Crantz) from Brazilian Amazon

2016

Parasite communities of the predatory fish, Acestrorhynchus falcatus and Acestrorhynchus falcirostris, living in sympatry in Brazilian Amazon.

This study investigated the parasite communities of wild Acestrorhynchus falcatus and Acestrorhynchus falcirostris populations living in sympatry in Brazilian Amazon. In these two hosts, a total of 12 parasite species e 1-9 parasite species were found per fish, and 10 of these species are metazoans. Eight species of parasites were common to both host species and four of them exhibited differences in abundance and/or prevalence. Parasite communities of the hosts were taxonomically similar (83%) and composed of both ectoparasites and endoparasites, and characterized by high prevalence and high abundance of endoparasites and an aggregated dispersion pattern. For A. falcirostris, the dominant parasite was Ichthyophthirius multifiliis, and for A. falcatus, it was Piscinoodinium pillulare. Shannon diversity and Berger-Parker dominance were similar for both hosts, while the parasites species richness and evenness showed differences influenced by the ectoparasites species. These two populations of hosts that inhabited the same geographical area had different sizes, but were exposed to the same infective stages, and acquired qualitatively and quantitatively similar endoparasites community, thus indicating that the amounts and types of prey congeneric that they were eating were similar. Therefore, the overlap in the same occurrence area play an important role in the parasite communities to these phylogenetically related hosts.

Host-parasite interaction between crustaceans of six fish species from the Brazilian Amazon.

Host-parasite interactions between crustaceans and six fish species (Psectrogaster falcata, Ageneiosus ucayalensis, Acestrorhynchus falcirostris, Hemiodus unimaculatus, Serrasalmus gibbus and Geophagus proximus) from a reservoir in eastern Amazon, northern Brazil, were investigated. Eight hundred and seventy-eight parasites belonging to three crustacean species, Excorallana berbicensis, Argulus chicomendesi and Ergasilus turucuyus, which parasitized the hosts? mouth, gills and tegument, were collected from 295 fish and examined. High infestation levels were caused by E. berbicensis on the body surface of the hosts. Excorallana berbicensis showed aggregate dispersion, except in S. gibbus, while E. turucuyus showed random dispersion in A. falcirostris. The host?s sex did not influence infestation by E. berbicensis, and high parasitism failed to affect the body conditions of the fish. In the case of some hosts, rainfall rates, temperature, dissolved oxygen levels and water pH affected the prevalence and abundance of E. berbicensis, the dominant parasite species. Results revealed that the environment and life-style of the hosts were determining factors in infestations by parasites. Current assay is the first report on E. berbicensis for the six hosts, as well as on A. chicomendesi for G. proximus and P. falcata.

Agroforestry systems and food security among smallholder farmers of the Brazilian Amazon: A strategy for environmental global crisis.

2008

Sustainable forest management for smallholder farmers in the Brazilian Amazon.

The paper describes a forest management system to be applied on smallholder farms, particularly on settlement projects in the Brazilian Amazon. The proposed forest management system was designed to generate a new source of family income and to maintain forest structure and biodiversity. The system is new in three main characteristics: the use of short cycles in the management of tropical forests, the low harvesting intensity and environmental impact, and the direct involvement of the local population in ali forest management activities. It is based on a minimum felling cycle of ten years and an annual timber harvest of 5-10 m3 ha-1.

A study on monogenean parasites from the gills of some cichlids(Pisces: Cichlidae) from the Brazilian Amazon.

The aim of this study was to investigate monogenean fauna in gills of Geophagus camopiensis, Pterophyllum scalare, Satanoperca jurupari,and Satanoperca acuticeps in a tributary from the Amazon River system in Brazil. A total of 2,148 monogenean specimens were collected from140 fish examined from March 2012 to March 2013, and 84.3% of these fish were parasitized by 1 or more species. Such monogeneans were:Sciadicleithrum geophagi, Sciadicleithrum juruparii, Gussevia spiralocirra and Gyrodactylus sp. However, only G. camopiensis was parasitizedby more than 1 species of monogenean, while S. jurupari and S. acuticeps were parasitized by the same species. Prevalence, mean intensity andmean abundance varied among host species and the highest levels of infection were by G. spiralocirra followed by S. geophagi, both parasiteswith aggregated dispersion. Abundance of monogeneans was not influenced by the size of the host. In G. camopiensis, the infection levels byS. geophagi did not vary during the rainy or drainage seasons. This is the first study on monogenean infections for G. camopiensis and S. acuticeps.

Calibration of the maximum carboxylation velocity (Vcmax) using data mining techniques and ecophysiological data from the Brazilian Semiarid region, for use in Dynamic Global Vegetation Models.

The semiarid region of northeastern Brazil, the Caatinga, is extremely important due to its biodiversity and endemism. Measurements of plant physiology are crucial to the calibration of Dynamic Global Vegetation Models (DGVMs) that are currently used to simulate the responses of vegetation in face of global changes. In a field work realized in an area of preserved Caatinga forest located in Petrolina, Pernambuco, measurements of carbon assimilation (in response to light and CO2) were performed on 11 individuals of Poincianella microphylla, a native species that is abundant in this region. These data were used to calibrate the maximum carboxylation velocity (Vcmax) used in the INLAND model. The calibration techniques used were Multiple Linear Regression (MLR), and data mining techniques as the Classification And Regression Tree (CART) and K-MEANS. The results were compared to the UNCALIBRATED model. It was found that simulated Gross Primary Productivity (GPP) reached 72% of observed GPP when using the calibrated Vcmax values, whereas the UNCALIBRATED approach accounted for 42% of observed GPP. Thus, this work shows the benefits of calibrating DGVMs using field ecophysiological measurements, especially in areas where field data is scarce or non-existent, such as in the Caatinga

Soil carbon sequestration in grass and grass-legume pastures in the western Brazilian Amazon.

Land use change from native forests to pastures in the tropics have impact on global carbon (C) cycle through increased rates of C emissions to the atmosphere and the loss of above- and belowground C accumulation and storage capacity (SILVER et al., 2000). This study was conducted to determine the carbon stock in a Ultisol under a pure Brachiaria humidicola (Rendle) Scheick pasture and a mixed pasture of B. humidicola and Arachis pintoi Krapov. & W. C. Greg cv. BRS Mandobi, both without fertilization.

Modeling nitrous oxide emissions in grass and grass-legume pastures in the western Brazilian Amazon.

Mineral nitrogen (N) dynamics in soil and the exchange of N gaseous in the interface soil-atmosphere are intimately associated with animal manure in pastures. According to soil inorganic-N pools and the site studied, forest or pasture, and pastures age the soil inorganic-N pools of ammonium and nitrate can be similar in the forest or ammonium dominated in the pasture. Also annual average net nitrification rates at soil surface in forest can be higher than in pasture suggesting a higher potential for nitrate-N losses either through leaching or gaseous emissions from intact forests compared with established pastures (NEILL et al., 1995).

Creolo beans production systems in Juruá valley, Acre, Brazilian Amazon.

The Juruá valley mesoregion is recognized for its diversity of cultivars of common beans and cowpea and is an important center for on farm bean conservation in Brazil. However, there is little information about production systems of Creoles cultivars and, in this approach, the study aimed to identify the production centers and to gather information about beans production systems. Thirty eight farmers and five merchants were interviewed using semi-structured questionnaries. Juruá valley farmers use three beans production systems: "beach farming", "slash burn system" and "stuffy farming". The systems use family labor with low dependence on external inputs, two classified as itinerant. The study identified two beans production centers: Alto Juruá extractive reserve and Santa Luzia directed settlement project.

Frugivorous flies (Diptera: Tephritidae, Lonchaeidae) associated with fruit production on Ilha de Santana, Brazilian Amazon.

Este trabalho teve por objetivo identificar as espécies de moscas frugívoras (Tephritidae e Lonchaeidae), seus hospedeiros e parasitoides na Ilha de Santana, Estado do Amapá, Amazônia brasileira. Adicionalmente, objetivou estudar a exploração hospedeira por Bactrocera carambolae Drew & Hancock. Foram realizadas coletas de frutos de diversas espécies vegetais, a cada 30 dias, no período de janeiro a julho de 2015. Foram coletadas 149 amostras de frutos (3.142 frutos, 76,3 Kg), pertencentes a 20 espécies vegetais (9 nativas e 11 introduzidas) de 13 famílias botânicas. Houve infestação por moscas frugívoras em 86 amostras (11 espécies de 8 famílias botânicas). Foram obtidos espécimes de cinco espécies de Tephritidae, quatro de Lonchaeidae e três de parasitoides Braconidae. As espécies de moscas frugívoras mais importantes na Ilha de Santana são: B. carambolae, devido sua expressão quarentenária; e Anastrepha obliqua (Macquart) e Anastrepha striata Schiner, pelo fato de infestarem espécies vegetais de importância socioeconômica local. Os hospedeiros Averrhoa carambola (Oxalidaceae), Eugenia uniflora (Myrtaceae), Malpighia emarginata (Malpighiaceae) e Psidium guajava (Myrtaceae) são responsáveis pela manutenção da população de B. carambolae.

Investigating genetic diversity in sapucaia using inter simple sequence repeat markers.

Sapucaia is a tree species originating from the Brazilian Amazon and is widely distributed in Brazil, especially in the mid-north region (Piauí and Maranhão states). Its seeds are rich in calories and proteins, and possess great potential for commercialization. Little is known about the genetic variability in the germplasm of most Lecythis species.