Semiarid Region Of Brazilian Northeast Research Articles

Moisture, temperature and respiration of two soil classes under pasture and tropical dry forest in the semiarid Brazilian region

Soil respiration (Rs), or soil CO2 efflux, is the largest carbon flux from ecosystems to the atmosphere; it is an order of magnitude greater than that released by human activity, and is a key process in CO2 atmospheric accumulation and climate change. Due to its importance, many studies have investigated respiration in different ecosystems, with studies in tropical dry areas being more scarce. We measured the effects of soil temperature and moisture on respiration from Regosols and Luvisols under pasture and native deciduous forests in the Brazilian Northeast semiarid region. Respiration had a direct relationship with soil moisture and an inverse relationship with temperature in both soil classes and land covers. Respiration was higher under the forest than under the pasture (9.0 and 4.8 Mg C ha−1 y−1) in both wet and dry seasons, probably due to higher biomass incorporation and higher root respiration, but it did not differ between soil classes. These respirations corresponded to high proportions of the soil C contents in the 0–10 cm superficial layer (46.2% in Caatinga and 36.7% in pasture). In the Brazilian semiarid region, soil respiration was controlled by soil moisture (positively) and temperature (negatively), both of which were affected by land-use changes.

Dung beetle communities of altitudinal Atlantic forest remnants: diversity and composition

The Altitudinal Atlantic Forest is comprised of humid forest enclaves on top of the mountains surrounded by the Caatinga's xeric shrubland vegetation. It is considered a humidity refuge of endemism in semi-arid regions, and it is under intense anthropogenic pressure. Dung beetle communities are widely used as an ecological indicator of environmental conservation. However, dung beetle communities of the Altitudinal Atlantic Forest are poorly studied, and their value for biodiversity conservation in semi-arid regions is unknown. We describe and compare dung beetle communities of Altitudinal Atlantic Forest remnants located in the Brazilian Northeast semi-arid region to evaluate whether diversity patterns and species composition differ among the remnants. We captured 1,333 beetles belonging to 24 species. Only one remnant showed a statistically significant difference in diversity based on species richness and abundance, and beta diversity showed a high dissimilarity among remnants. The remnants had in common only one species, and the dominant species were distinct among them. Species composition was 16% similar among the sampled remnants, and we registered species commonly found in the Atlantic Forest, the Caatinga, and Amazonia. The structure of the dung beetle community in each remnant could be related to the historical origin and maintenance of the Altitudinal Atlantic Forest. Species compositions changed as a result of geographic location and surrounding environments, which act as filters to dung beetle species flow and establishment. We highlight the importance of the Altitudinal Atlantic Forest for the conservation and maintenance of biodiversity in the semi-arid region.

Mesquite (Prosopis juliflora) extract as a phytogenic additive for sheep finished on pasture in the semiarid region

Phytogenic additives are organic molecules that also improve ruminal fermentation, turning the supplemented individuals into more productive animals, without damage the population welfare. The objective of this study was to evaluate the effects of mesquite (Prosopis juliflora [Sw.] DC.) extract as phytogenic additive for sheep finished on pasture in the Brazilian Northeast semiarid region. Twenty-four intact lambs (Santa Ines × Dorper F1 crossbred) were used, with an initial body weight of 23.00 ± 1.83 kg. The experiment was carried out in a complete randomized design with four treatments and six replicates. Treatments consisted of four diets: Pasture and no supplementation; grazing pasture and phytogenic additive; pasture, supplementation with Tifton 85 hay, and concentrate; and pasture, phytogenic additive, and supplementation with Tifton 85 hay and concentrate. Prior to supplementation, animals received the phytogenic additive according to treatment. There were nonsignificant differences for nutrient intake and behavior patterns (P > 0.05). However, additive intake derived from mesquite provided an increase (P < 0.05) in digestibility (14.40% total digestible nutrients), N balance (27.12% retained N:ingested N) and performance (8.82% final body weight, 21.81% total weight gain, and 30.81% average daily gain) compared to animals consuming only pasture in rainy period. Thus, the use of mesquite extract as phytogenic additive is recommended for sheep finished on pasture in the Brazilian semiarid region.

Population history of the Blue-backed Manakin (Chiroxiphia pareola) supports Plio-Pleistocene diversification in the Amazon and shows a recent connection with the Atlantic Forest

It has been hypothesised that rivers serve as biogeographic barriers and Pleistocene forest refuges may explain the rich species diversity observed within Neotropical rainforests. The lack of correspondence between Amazonian and Atlantic forest species in South America is a good model for testing such hypotheses. We used molecular, ancestral area reconstruction, and potential paleodistribution analyses of Chiroxiphia pareola to test above hypotheses and examine the diversification and/or geographical expansion of populations. Six genes, two mitochondrial and four nuclear, were analysed. All population splits were estimated to have occurred in the Pliocene–Pleistocene period, and the occurrence of an Amazon population split was supported by historical river dynamics. Amazonian populations were not monophyletic, and the eastern Amazonian cluster was a sister of the Atlantic Forest population. Molecular divergence occurring between the Amazonian and Atlantic forest populations was low when compared to splits between the lineages separated by Amazonian rivers. During the early to middle Pleistocene era, regions associated with mountain slopes and riverbanks connected the Amazonian and Atlantic Forest populations near the interior of the Brazilian Northeast semiarid region, which might have facilitated species dispersal from Amazonia into the Atlantic Forest. After this point, the populations were separated, and the Atlantic Forest population remained stable until the end of the Pleistocene and Holocene eras when short-range expansion and demographic growth occurred. Our results provide evidence that highlights the role of rivers and historical climate change in the diversification of Amazonian and Atlantic Forest bird species through the Plio-Pleistocene era.

Application of the watershed sustainability index in the Piranhas-Açu watershed

AbstractThe current worldwide water resources issue is one of the crucial matters to overcome obstacles to sustainable development. This problem, formerly tackled in a sectored manner, is now pointing towards an analysis directed to treating the watershed as a management unit, with regards to all dimensions of knowledge and, especially, to the public participation in the decision-making processes. As an alternative to measure its performance, it has been sought out to develop indexes aimed to measure its sustainability, but there is still a lack of the use of composed efficient methodologies that also enable public participation in decision-making. This research presents a methodology comprising 15 indexes for the calculation of the Watershed Sustainability Index (WSI), followed by the application of the PROMETHEE multi-criteria analysis method and the COPELAND multi-decision-maker method. The methodology was applied to evaluate the performance of subwatersheds of the Piranhas-Açu watershed, located in the Brazilian northeast semi-arid region. The performance ordering, obtained through the application of the methods, emphasizes that subwatersheds' performances are uneven. It can be noticed that the subwatersheds' performances are still far from ideal in relation to water resources management, even in the ones that displayed satisfactory index levels.

São Francisco river Integration Project, Eastern Axis: losses analysis and performance indicators

ABSTRACT Water scarcity is an old problem in the brazilian Northeast semiarid region and limits the economic and social development of the region. To mitigate negative impacts of this situation, the National Integration Ministry elaborated the São Francisco River Integration Project (PISF). The State of Paraíba will benefit from this project through the East Axis and West Axis water transposition systems’ from the São Francisco river. The Paraíba riverbasin will receive the waters of the São Francisco river through the Eastern Axis, since the project foresees that, from the city of Monteiro-PB, the water will be transported through the bed of the Paraíba river. This type of transport will cause high water losses. The present work analyzes water distribution scenarios in terms of water losses, which were simulated with the Acquanet model. The first scenario simulates the current situation, without water transposition of PISF, and the other ones evaluate different ways of distributing the waters of the East Axis among the Paraíba river bed and different pipelines construction scenarios. The results have shown that the construction of pipelines will reduce water losses and increase social gain, through the increase of the benefited population.

Indicators to assess goat welfare on-farm in the semiarid region of Brazilian Northeast

ABSTRACT: In 2015, AWIN Goat Protocol was published in Europe, with indicators that identify welfare level of lactating dairy goats; however, there are no welfare protocols for meat goat. Therefore, the objective of this study was to select animal and resource-based indicators to assess welfare in meat goat in different types of grazing systems in Brazilian semiarid Northeast. Eighteen indicators were selected to evaluate the welfare of meat goat. The knowledge of the welfare degree of these animals is the best way to make improvements and promote a better quality of life to meat goat.

Anthelmintic activity of Cratyliamollis leaves against gastrointestinal nematodes in goats

SUMMARY The present study assessed the in vivo anthelmintic activity of the C. mollis leaf decoction extract when administered orally to naturally infected goats with gastrointestinal nematodes. To this, animals were randomized into three groups:non-treated, control (treated with doramectin 1mL/50 kg b.w.) and C. mollis extract treated groups (2.5mg/kg b.w.). Blood and faecal samples were collected from each animal at day 0, and 30th day posttreatment to monitor immunological and parasitological parameters. A significant faecal egg reduction (61.1%) and an increase in IgA and eosinophils levels were observed in the C. mollis extract treated group, in comparison to the untreated and doramectin groups. Considering that gastrointestinal nematode infections in small ruminants are serious problems in the world, causing economic losses worldwide, associated to high anthelmintic cost, resistance to available anthelmintics and residue problems in meat and milk for human consumption, the plant extract use is an area of interest to search new anthelmintic agents. Thus, Cratyliamollis Mart. Ex Benth, an important medicinal plant from Brazilian Northeast semiarid region, is used to treat different types of diseases, and as forage supplementation. Therefore, the data indicated the potential anthelmintic activity of C. mollis extract; further research is thereby warranted to assess its value for therapeutic purposes.

Cloud condensation nuclei (CCN) concentration in the Brazilian northeast semi-arid region: the influence of local circulation

Ground-based aerosol instrumentation covering particle size diameters from 25 nm to 32 µm was deployed to determine aerosol concentration and cloud condensation nuclei (CCN)-activation properties at water vapor supersaturations in the range of S = 0.20–1.50 % in the remote Brazilian northeast semi-arid region (NEB) in coastal (maritime) and continental (inland) regimes. The instruments measured aerosol number concentration and activation spectra for CCN and revealed that aerosol properties are sensitive with respect to the sources as a function of the local wind circulation system. The observations show that coastal aerosol total number concentrations are above 3,000 cm−3 on average, exhibiting concentration peaks depending on the time of the day in a consistent daily pattern. The variation on aerosol concentration has also influences on the fraction of particles active as CCN. At 1.0 % water vapor supersaturation, the fraction can reach as high as 80 %. Inland aerosol total concentrations were about 1,800–1,900 cm−3 and did not show much diurnal variation. The fraction of particles active as CCN observed inland depend on the history of the air masses, and was much higher when air masses were originated over the sea. It was found that (NH4)2SO4 and NaCl are the major soluble inorganic fraction of the aerosols at the coast. The major fraction of NaCl was present in the coarse mode, while ammonium sulfate dominates the inorganic fraction at the submicron range, with about 10 % of the total aerosol mass at 0.32 µm. Inorganic compounds are almost absent in particles with sizes around 0.1 μm. The study suggests that the air masses with high concentration of CCN originate at the sea. The feasible explanation lies in the fact that the NEB’s beaches have a particular morphology that produces a wide surf zone and creates a large load of aerosols when combined with strong and permanent winds of the region.

Estimation of alluvial recharge in the semiarid

In areas where there is irrigated agriculture, the recuperation of water reserves in alluvial aquifers may occur preferentially due to precipitation. Recharging can be evaluated from variation information of water depth measured in piezometers or observation wells. Thus, the aim of this research is to study the recharge in the alluvial aquifer formed by the Mimoso temporary stream in the semiarid region of Pernambuco (PE), Brazil, using the method of the fluctuation of the water level. This system is typical on the Brazilian Northeast semiarid region, using groundwater for domestic supply and for irrigation on small scale agriculture. Monthly potentiometric levels and rainfall data were used. The selected period for the study, from January 2002 to October 2009, involved extreme events of flooding and droughts as well as regular years, providing a better understanding of the behavior of the alluvial recharge. It was found that the system responds significantly to precipitation events. It was also observed that even with different soil textures in the study area, recharge factors were not significantly different. The study provided a better understanding of the behavior of aquifer recharge and its relationship with the soil and the rainfall events in the region.

Degradation and detoxification of three textile Azo dyes by mixed fungal cultures from semi-arid region of Brazilian Northeast

The aim of this work was to study the degradation and detoxification of three textile azo dyes (Reactive Red 198, Reactive Red 141 and Reactive Blue 214) by mixed fungal cultures from semi-arid region of Brazilian Northeast. Sediment samples of twenty water reservoirs in the surroundings of Serra da Capivara National Park, area of environmental preservation in the caatinga in the State of Piauí, with semi-arid climate, were evaluated in order to select the consortia of fungi capable to degrade and detoxify these dyes. The mixed fungal culture from Caldeirão Escuridão (CE) reservoir was the most efficient in the degradation and detoxification of the dyes tested.

Floristic diversity of two crystalline rocky outcrops in the Brazilian northeast semi-arid region

Floristic composition and structure of vegetation were studied in two rocky outcrop areas in the semi-arid region of northeastern Brazil. From April 2007 to September 2008, 18 monthly field trips were carried out. Vascular plants were randomly collected throughout the outcrop areas. For structural analysis, 30 plots of 1 × 1 m were set in the vegetation islands. The checklist presented combines 211 species (69 families and 168 genera), although only 56 species were collected in the plots. Fabaceae (18 spp.; 8.5%), Asteraceae (17 spp.; 8%), Orchidaceae (13 spp.; 6.1%), Euphorbiaceae (13 spp.; 6.1%), Bromeliaceae (10 spp.; 4.7%), and Poaceae (eight spp.; 3.8%) are the richest families. Overall, 1,792 shrub and herbaceous specimens were counted in the plots. The Shannon-Wiener (H) diversity index values were 2.572 and 2.547 nats individual-1. The species that presented the highest absolute abundance values (number of plants) had low frequencies in the plots and vice-versa. The biological spectrum had a high proportion of phanerophytes and therophytes, followed by cryptophytes, chamaephytes, and hemicryptophytes. The studied flora shares floristic components similar to other rocky outcrop areas of the semi-arid region in northeastern Brazil, including in relation to dominant groups in the vegetation structure.