Eastern Amazon Research Articles

PRODUCTIVE FOREST RECOVERY IN LEGAL RESERVE AREA: A CASE STUDY IN EASTERN AMAZON

This study aimed to evaluate a model for Legal Reserve (LR) recovery based on a mixed timber production system (planting + natural regeneration) in the eastern Amazon, state of Pará. For data collection, seven plots of 50 m x 20 m were established, and all individuals with DBH (diameter at breast height) ≥ 5 cm were inventoried. Species diversity, horizontal structure, and commercial wood production were assessed at 13 years of age. A total of 103 species were found, distributed among 69 genera and 33 families. The population density was 1,425 individuals per hectare, and dominance corresponded to 19.45 m².ha-1. The total wood volume was 121.4 m³.ha-1, with 63.3 m³.ha-1 coming from the planted species (S. parahyba var. amazonicum) and 58.1 m³.ha-1 from natural regeneration. Among the regenerating species, Cecropia distachya showed the highest values for the evaluated parameters. The adopted model showed potential for use in LR environmental recovery, reconciling this action with revenue generation through silvicultural interventions that can be applied to the stand, aiming for wood production. To achieve this, adjustments to the regulations governing the forest management of recovering areas are necessary.

ANOMALIES IN THREE FROG SPECIES FROM EASTERN AMAZONIA

We reported anomalies in three anuran species belonging to two families: Craugastoridae (Pristimantis gutturalis and P. chiastonotus), and Bufonidae (Rhinella castaneotica). All records were found in two conservation units, a well-preserved and protected area of the Amazonian rainforest in the state of Amapa, eastern Amazon. The anomalies detected were anophthalmia (characterized by the absence of one or both eyes) in P. gutturalis and P. chiastonotus, and brachydactyly (digit shortened) in R. castaneotica. Further ecotoxicological studies of anurans populations in protected areas are needed to investigate the causes of anomalies.

Prevalence and circulant genotypes of Chlamydia trachomatis in university women from cities in the Brazilian Amazon.

Approximately 80% of infected women infected by Chlamydia trachomatis are asymptomatic, although this infection can lead to serious complications in the female reproductive tract. Few data on Chlamydia infection and genotypes are available in Amazonian communities. To describe the prevalence of and associated factors and to identify the genotypes of sexual C. trachomatis infection in female university students in different urban centers (capital and interiors) in the Brazilian state of Pará, in the eastern Amazon region. A cross-sectional study was performed among young women attending public universities in four different urban centers in the eastern Amazon region. They were invited to participate in the studt and cervical secretions were collected for molecular diagnosis of C. trachomatis. We utilized amplification of the ompA gene by nested PCR. Positive samples were genotyped by nucleotide sequencing. Study participants completed a questionnaire on social, epidemiological, and reproductive health variables. A Qui-square and Binominal regression test were used to evaluate the degree of association of these variables with the infection. A total of 686 female students was included in the study. The overall prevalence of C. trachomatis was 11.2% (77/686). The prevalence of this infection was higher in interiors (15.2% vs 9.5%/ p: 0.0443). Female university students who do not have a sexual partner (11.8%/p <0.008), who do not use a condom in their sexual relations (17.8%/p <0.0001) and who reported having suffered a miscarriage (32%/p <0.0001) have high chances of acquiring this sexual infection. The ompA gene was sequenced in only 33 (42.8%) samples, revealing the genotype J was the most frequent (27.2% [9/33]), followed by genotypes D (24.2% [8/33]), and then genotypes F (18.2% [6/33]), E (15.1% [5/33]) K (6.1% [2/33]), Ia (6.1% [2/33]), and G (3.1% [1/33]). The high prevalence of sexual infection by C. trachomatis in the female university students from the interior of the state of Pará, individuals with no fixed sexual partner, those that had had a miscarriage, the students that do not use condoms in their sexual relations. The genotype J of C. trachomatis genotypes was the most frequent. These data are important to help defining the epidemiological effects of chlamydial infections in Amazonian populations.

Stream fish assemblages in the Eastern Amazon: the role of small tetras (Characidae) in alpha diversity and taxonomic structure

Abstract Wallacean shortfalls in knowledge about biodiversity, especially in the Amazon biome, can only be addressed by increasing sampling efforts in focal areas. The objective of this study was to describe the fish fauna of streams associated with four protected areas in the Eastern Amazon. These areas include the Tapajós (Parque Nacional da Amazônia, Parque Nacional do Jamanxim) and Trombetas drainages (Floresta Nacional Saracá-Taquera), and Tapajós/Xingu interfluve (Reserva Biológica Nascentes da Serra do Cachimbo), state of Pará, Brazil. In the 99 stream reaches surveyed, 176 fish species were recorded. Almost a third of the species and specimens belong to the Characidae family, predominantly represented by small tetras (known as piabasor lambaris). One threatened species (Harttia dissidens) was registered. Of the total richness, 24 species were singletons and associated with specific habitats. The highest taxonomic distinctness was observed for Floresta Nacional Saracá-Taquera, while streams within the Parque Nacional da Amazônia exhibited the greatest taxonomic distinctness variation. Compared to existing records in scientific collections covering stream fish fauna in watersheds of up to 4,300 hectares in Pará, our study added the record of eight other genera and identified relevant areas for additional surveys.

Produtividade da água em coqueiro irrigado nas condições de clima tropical úmido na Amazônia Oriental

ABSTRACT: The growing demand for coconut water has led to the expansion of irrigated green dwarf coconut cultivation; however, the inefficient use of water has contributed to the degradation and waste of water resources, making fundamental studies aiming to optimize the use of water. The objective of this study was to determine the physical productivity and water productivity of green dwarf coconut palms under the climatic conditions of Santa Izabel do Pará, eastern Amazonia, Brazil. The experiment was carried out from 2020 to 2021, in a green dwarf coconut plantation spaced 7.5 m x 7.5 m in a triangle, at Fazenda Reunidas Sococo, with an area of approximately 7 ha. Water productivity (WP) was determined both in terms of fruit production (WPf) and coconut water production (WPca), through the relationship of fruit productivity (fruit biomass and water volume) with accumulated evapotranspiration. The dwarf coconut tree presented a total production of 105 and 186 fruits plant-1 and 37 and 62 L plant-1 of coconut water in the years 2020 and 2021. The largest volumes of water and the highest weights occurred during the wettest season. WPf was of 1.87 fruits m-3 (2020) and 2.94 fruits m-3 (2021) and WPca 0.66 L m-3 (2020) and 0.98 L m-3 (2021).

Impacts of Land Use and Land Cover Change on Ecosystem Service Values in the Eastern Amazon

Impacts of Land Use and Land Cover Change on Ecosystem Service Values in the Eastern Amazon

Philcoxia cachimboensis (Plantaginaceae): uma nova espécie carnívora da Serra do Cachimbo, Amazônia oriental, Brasil

ABSTRACT A new species of Philcoxia (Plantaginaceae) from Serra do Cachimbo, eastern Amazon, Brazil, is described and discussed. Philcoxia cachimboensis sp. nov. is mainly characterized by the corolla with asymmetrically obovate (liver-shaped) lateral lobes, with truncate to sub-emarginate apex. This is the first record of the genus in the Brazilian Amazon. A morphological description, illustration and photographs, conservation status assessment, an updated identification key for the recognized species of Philcoxia, and comparative taxonomic comments are provided.

A ictiofauna da bacia do Rio Potiritá: avaliando o status de conservação em uma área de mineração na Amazônia Oriental

Abstract Aim Considering the importance of knowing the organisms that make up the environments impacted by human activities, we aimed to create an inventory of the ichthyofauna of a bauxite mining area in the Eastern Amazon in this work. Methods Specimens were collected with sieves, trawls, and gill nets at 37 points in rivers and streams during two expeditions (July 2017 and September and October 2017). After euthanasia and laboratory processes, we identified each individual to the lowest possible taxonomic level, and samples were deposited in scientific collections. We analyzed the conservation status of the species on state, national, and international lists. Results A total of 109 species were identified, belonging to 28 families and six orders, emphasizing the Characiformes order (57 species) and the Characidae family (22 species). We identified two new species, and none are threatened with extinction. Conclusions The high species richness recorded in the Potiritá River basin is noteworthy, considering its relatively small area. This diversity should be considered in future environmental impact studies and in monitoring the ichthyofauna in areas affected by human activities.

Macrófitas da microbacia do rio Capitão Poço, Amazônia Oriental, Brasil: composição florística e chave de identificação para as espécies

ABSTRACT We aimed to characterize the floristic composition, detect the life forms, and provide an identification key for the macrophyte species of the Capitão Poço river micro-basin in the State of Pará, located in the Eastern Amazon. The collected specimens were identified and deposited in the HCP herbarium. We found 23 species distributed in 19 genera and 14 families of macrophytes. The families with the highest species richness were Cyperaceae (six spp.), Poaceae (three spp.), Onagraceae and Plantaginaceae (two spp. each). We present here the first record of Dichanthelium aequivaginatum from the Brazilian Amazon and the Northern region of Brazil. We suggest that floristic-taxonomic studies of macrophytes in the hydrographic basins of the northeastern region of Pará should be intensified in order to better understand the regional flora of this group.

Infecção natural por Anaplasma marginale durante as primeiras semanas de vida de bezerros de uma propriedade leiteira da Amazônia Oriental

ABSTRACT: This study detected Anaplasma marginale in calvesusing blood smears and nested PCR (nPCR) and to compare the results with the clinical signs presented by calves on a dairy farm in the municipality of Castanhal, located northeast of the state Pará (1°07’19.1”S and 47°53’53.0”W), eastern Amazon. To this end, 192 blood samples were collected from 24 animals at 1-20, 21-41 and 42-60 days of age. Blood smears and nPCR with primers for the msp5 gene were performed. The prevalence of A. marginale was 61.5% (118/192) for the blood smear technique and nPCR (msp5). The manifestation of clinical signs of anaplasmosis also increased significantly over the course of the study (P &lt; 0.0001), being lower in animals aged 1-20 days, but increasing among those aged 21-41 and 42-60 days. These signs were characterized by apathy, fever, weight loss, diarrhea, dehydration, and hypochromic mucous membranes. Regarding the evaluation of the diagnostic techniques, no significant difference was observed in the detection of A. marginale between the blood smear and nPCR (P = 0.995), but the agent’s rickets increased on Day 47 (P &lt; 0.01) in both tests, thereby demonstrating a near-linear pattern of increase in rickets over the 60 days, with a consequent decrease in globular volume. This shows that of the 24 animals studied, 21 were infected at some point during the study period. Additionally, there was no significant difference between blood smears and nPCR, probably due to medium and high parasitemia, which were directly related to the clinical signs and decrease in globular volume.

Indicators to quantify biodiversity gains for compensation and mineland rehabilitation in the Eastern Amazon.

To connect the protection of natural resources to economic development, environmental rehabilitation is a promising way to repair and compensate for impacts on biodiversity and ecosystem services. Here, we aimed to compare and select potential indicators for the success of different rehabilitating ecosystems to quantify gains in biodiversity and ecosystem services within the Impact Mitigation Hierarchy. We sampled nine environmental variables along rehabilitation chronosequences from rehabilitating (i) iron mining waste piles, (ii) sand quarries, and (iii) compensation areas in the Carajás National Forest. From that, we computed the rehabilitation status, i.e., the proportion of environmental enhancements compared to the overall rehabilitation trajectory, and statistically validated the indicators that best described the status. With a mean rehabilitation status for the oldest rehabilitation stages from waste piles, sand quarries, and compensation areas of 52, 71, and 74%, respectively, we confirmed that rehabilitation activities were able to generate considerable gains in biodiversity. In all the cases, the Shannon diversity, phylogenetic diversity and Leaf Area Index performed better than did the other indices, encouraging the increased use of these indices for upscale monitoring activities. Consistent indicators across distinct projects highlight the importance of maximizing tree diversity and canopy closure in rehabilitation projects to increase biodiversity gains within Impact Mitigation Hierarchy.

Occurrence of Myxobolus spp. (Myxozoa) in the blood of Metynnis lippincottianus (Osteichthyes: Serrasalmidae) from eastern Amazon, Brazil.

Myxozoans are obligatory parasites and can be found in various organs and bloodstreams of fish, thus, the objective of this work was to describe the occurrence of Myxobolus spp. in the circulating blood of Metynnis lippincottianus from River Curiaú, Macapá City, eastern Amazon, Brazil. The samples of M. lippincottianus (11) were caught using cast net and gillnets. The fish blood was collected by puncturing the caudal vessel, using needles and syringes containing 10% of EDTA solution. Blood smear were prepared and panchromatic stained with a combination of May Grunwald-Giemsa-Wright, for observation and examination of the parasitic structures in optical microscope. Tissues from the kidney was examined using specific stereoscopic binoculars to check for the presence of cysts, lesions and parasites. The prevalence of Myxobolus spp. infecting the circulating blood of the fish was 36.36% (4/11) and 15 spores of mixosporyds were visualized. Myxobolus spp. had a prevalence of 54.55% (6/11) in host's kidney tissue and the morphometric spores data converge with observed in the blood. The morphological characteristics of the spores in the blood samples revealed two morphotypes of Myxobolus spp. This is the sixth occurrence recorded of Myxobolus spp. infecting fish blood in Brazil.

First study on the metazoan parasite community of Crenicichla strigata (Cichliformes: Cichlidae).

This study provides the first report of metazoan parasites in Crenicichla strigata. From 31 hosts caught in the Jari River basin, in the eastern Amazon region of Brazil, a total of 1454 parasites were collected: Sciadicleithrum araguariensis, Sciadicleithrum joanae, Sciadicleithrum satanopercae, Posthodiplostomum sp., Genarchella genarchella, Contracaecum sp., Spirocamallanus peraccuratus, Acarina gen. sp. and Dolops geayi. However, the community was dominated by the three species of Sciadicleithrum (Monogenea) and there was similar presence of parasites in the larval and adult stages. The total prevalence was 100% and each of the hosts was parasitized by two or three species, which presented random dispersion. Brillouin diversity, parasite species richness, Berger-Parker dominance index and evenness were low. There was positive correlation between the abundance of Posthodiplostomum sp. the hosts' length, while the abundance of S. peraccuratus showed negative correlation with the body weight of fish. The abundance of S. araguariensis, S. joanae and S. satanopercae showed negative correlation with the hosts' length. The parasite community of C. strigata was characterized by low diversity, low richness, low intensity and low abundance of species.

The South American Tropopause Aerosol Layer (SATAL)

Abstract The presence of an aerosol layer in the upper troposphere/lower stratosphere (UT/LS) in South America was identified with the Modern-Era Retrospective Analysis for Research and Applications version 2 (MERRA-2). This layer, which we shall refer to as the South American tropopause aerosol layer (SATAL), was identified over the Amazon basin at altitudes between 11 and 14 km. It exhibits a seasonal behavior similar to the Asian tropopause aerosol layer (ATAL) and the North American tropopause aerosol layer (NATAL). The SATAL is observed from October to March, coinciding with the presence of the South American monsoon. It forms first in the eastern Amazon basin in October, then moves to the southern Amazon, where it weakens in December–January and finally dissipates in February–March. We hypothesize that two main factors influence the SATAL formation in the UT/LS: 1) the source of aerosols from Africa and 2) the updraft mass flux from deep convective systems during the active phase of the South American monsoon system that transports aerosols to the UT/LS. Further satellite observations of aerosols and field campaigns are needed to provide useful information to find the origin and composition of the aerosols in the UT/LS during the South American monsoon.

TENDÊNCIAS RECENTES DA LINHA DE COSTA NA MARGEM LESTE DO ESTUÁRIO MÉDIO DO RIO PARÁ

The main objective of this article is to quantify the erosion and accretion rates on the eastern margin of the middle Pará Estuary within 32 years (1987, 1993, 1999, 2004, 2008, 2013, and 2019) with the use of remote sensing and data Digital Shoreline Analysis System (DSAS) extension. These methodological procedures recently applied in the Amazon region are effective in the search for intended results. To calculate with significant accuracy the rates of CL changes, select the parameters Net Shoreline Movement (NSM), Linear Regression Rate (LRR), and End Point Rate (EPR) to obtain the variations. In the middle estuary, the rates showed a tendency towards CL retreat in the onshore direction, with an average rate of -38 m and an average accretion rate of 22.97 m prevailing on Mosqueiro Island, related to average rates of variation of -0.58 m/ year (EPR) and -0.54 m/year (LRR) and in Santo Antônio do Tauá with LRR and EPR parameters identifying average rates of variation of -1.67 m/year (LRR) and -1.55 m/year (EPR). Only on Colares island, there was a tendency to accretion, with an average erosion rate of -96.29 m and an average accretion rate of 116.49 m, where the maximum accretion and erosion rates are 405.61 m and -396.87 m, respectively. Keywords: Eastern Amazon, Coastal Dynamics, Estuarine Environment, LANDSAT.

Agronomic efficiency of fertilizers with aggregate technology in the Brazilian Eastern Amazon

Agronomic efficiency of fertilizers with aggregate technology in the Brazilian Eastern Amazon

Evaluation of arsenic contamination from mining exploration in the eastern Amazon

A exposição ambiental ao Arsênio (As) vem aumentando ao longo do tempo, seja naturalmente ou por ação antrópica, este processo causa preocupação na população quanto aos riscos à saúde. Assim, o presente estudo teve como objetivo elencar as informações científicas sobre a contaminação por arsênio na cidade de Santana-AP, por meio de revisão da literatura no Portal de Periódicos da Capes, Scielo, Google Acadêmico e base de dados PubMed. Foram identificados e analisados 10 trabalhos, sendo os únicos publicados na referida região com objeto de estudo a concentração de As. Após análise dos resultados, a concentração de As na água que a comunidade do Elesbão consome, apresentaram-se dentro dos parâmetros estabelecidos &lt;10 µg/L-1. No entanto, a concentração no solo (50 mg.kg-1) e em cabelos (1,0 mg/kg) da referida população estavam acima do valor de referência. Isso é justificado pelo nível de As total identificado em peixes e camarões, ocasionando um possível processo de biomagnificação. Portanto, são necessários estudos que envolvam todas as variáveis possíveis de rota de contaminação pelo As na região foco do presente trabalho, uma vez que, as divergências de resultados geram dúvidas sobre o nível de contaminação. Assim, a presente revisão servirá como pressuposto para avaliação de publicações de outras regiões que sofreram ou sofrem ações antrópicas.

The links between wood traits and species demography change during tree development in a lowland tropical rainforest.

One foundational assumption of trait-based ecology is that traits can predict species demography. However, the links between traits and demographic rates are, in general, not as strong as expected. These weak associations may be due to the use of traits that are distantly related to performance, and/or the lack of consideration of size-related variations in both traits and demographic rates. Here, we examined how wood traits were related to demographic rates in 19 tree species from a lowland forest in eastern Amazonia. We measured 11 wood traits (i.e. structural, anatomical and chemical traits) in sapling, juvenile and adult wood; and related them to growth and mortality rates (MR) at different ontogenetic stages. The links between wood traits and demographic rates changed during tree development. At the sapling stage, relative growth rates (RGR) were negatively related to wood specific gravity (WSG) and total parenchyma fractions, while MR decreased with radial parenchyma fractions, but increased with vessel lumen area (VA). Juvenile RGR were unrelated to wood traits, whereas juvenile MR were negatively related to WSG and axial parenchyma fractions. At the adult stage, RGR scaled with VA and wood potassium concentrations. Adult MR were not predicted by any trait. Overall, the strength of the trait-demography associations decreased at later ontogenetic stages. Our results indicate that the associations between traits and demographic rates can change as trees age. Also, wood chemical or anatomical traits may be better predictors of growth and MR than WSG. Our findings are important to expand our knowledge on tree life-history variations and community dynamics in tropical forests, by broadening our understanding on the links between wood traits and demography during tree development.

Effects of Climatic Conditions and Supplementation with Palm Cake on the Thermoregulation of Crossbred Buffaloes Raised in a Rotational Grazing System and with Natural Shade in Humid Tropical Regions.

In ruminants, diet composition has a positive correlation with heat production, which can influence thermoregulation, energy expenditure and, consequently, animal performance. The objective of this work was to evaluate the effects of climatic conditions and supplementation based on palm kernel cake, on the thermoregulation of crossbred buffaloes in the eastern Amazon. The research was carried out at Embrapa Amazônia Oriental (01°26' S and 48°24' W), Belém, Pará, and lasted 12 months (representing the entire year). Twenty-four buffaloes, females, with initial age and an average weight of 54 ± 7 months and 503.1 ± 23 kg, respectively, non-pregnant, non-lactating and clinically healthy were used, divided into four treatments based on the supplementation content of the palm cake (%DM) in relation to their body weight (%): 0, 0.25, 0.50 and 1.0. The animals were kept in paddocks with Brachiaria brizantha (cv. Marandu), in a rotating system, with water to drink and mineral salt ad libitum. Equipment was installed to record environmental data (temperature and relative humidity, dew point temperature, wet bulb and black globe) and physiological data: rectal temperature (RT); respiratory rate (RR); and body surface temperature (BST), recorded twice a day, always in the morning (6:00 a.m. to 7:00 a.m.) and afternoon (12:00 p.m. to 1:00 p.m.) shifts, and were used to calculate the Globe Temperature and Humidity Index (GTHI). Supplementation did not influence the physiological variables of thermoregulation (p > 0.05). However, there were differences in the GTHI between the shifts, with higher means in the afternoon shift, especially in the less rainy period of the year, where the GTHI reached 92.06 ± 2.74 (p < 0.05). In all periods of the year, the mean values of RT, RR and BST were higher in the afternoon shift (p > 0.05). The respiratory rate (RR) is associated with the annual seasonality of the thermal waters, with higher averages in the afternoons of the rainy season. The positive correlation for rectal temperature, respiratory rate and body surface temperature indicated that buffaloes respond to thermal elevations in the atmosphere (afternoon period) and, consequently, reflect on the GTHI. Supplementation does not influence thermoregulation; the changes observed occurred in response to the region's thermal and rainfall conditions (mainly in the afternoon shift), with higher GTHI values.

Ba theory applied in clay pot irrigation for smallholder farmers in brazilian Eastern Amazon

The objective of this work was to apply the theoretical “Ba” of knowledge management in the “Ba” space, having as its place of evolution the Technological Reference Unit (TRU) with clay pots that reuse rainwater to keep crops irrigated with clay pots on rural properties, in the Eastern Brazilian Amazon. Installed in 2016 in the community of Lavras in Santarém, being a place frequently visited by those interested in learning about the technology. The irrigation has low energy consumption, as the rainwater is distributed to the pots by gravitational force and it is possible to diversify agricultural crops, types of arrangements and different strategies to provide new financial gains for rural producers, due to the possibility of production in dry periods. The TRU is a space where research, teaching, extension and rural producers work in evolutionary partnership. The analysis of main components showed that farmers significantly expanded their knowledge, adding quality of life and improving family income, after installing IrrigaPote. The location is typical of a “Ba” space with sustainable collective learning, pointing out indicators in the social, environmental and economic scope, which can be replicated by rural family-based farmers interested in the efficient use of water, in irrigated crops anywhere in the world terrestrial.