Brazilian Semiarid Research Articles

Weathering of gneiss saprolites and formation of Planosols under semiarid climate (NE Brazil)

The Brazilian semiarid is one of the most populous regions in the world. The main income for populations in this region is agricultural production, which in turn is limited by climatic and soil conditions. This region has environmental and economic correlations with underdeveloped regions in northwestern Africa, displaying soil surface with monotonous landscapes of smooth undulating relief with large extensions of Planosols. Climatic conditions that lead to the formation of poorly developed soils and to losses of surface layers make these soils susceptible to degradation. In the Brazilian semiarid, lithology shows that felsic rocks are the main factor in pedogenesis of Planosols, conferring the main physical, chemical, and mineralogical attributes to the soil. In this study, we evaluated the pedogenesis by weathering of gneisses (felsic rocks) in two profiles of Planosols in the Cabrobó Desertification Nucleus, Pernambuco State, northeast Brazil, highlighting the role of the parent material in the soil intrinsic characteristics in the pedogenetic processes. The primary assemblage and pedological features were determined by optical microscopy in thin sections of the A, B, and C horizons from the two soil profiles. The secondary assemblage was identified by X-ray diffractometry using the technique: SEM-scanning electron microscopy. Clay formation in situ, colluvial contribution, and elutriation process contributed to the formation of the gradient textural in both Planosols, with no evidence of argilluviation. For total regolith profile, acidic metamorphic rocks present high structural variability directly influencing the evolution of saprolites, the alteration of primary minerals, and the formation routes of secondary minerals. The secondary assemblage was rather similar and comprised illite, smectite, and kaolinite in both regoliths. The saprolite inclination in P1 favors water movement in relation to P2. The regolith in P1 shows greater mineral alteration with increased pedogenic development.

THE CONSTRUCTION OF THE HISTORY OF GEOGRAPHICAL THOUGHT IN/OF THE BRAZILIAN SEMIARID: A PROEMIC CONCEPTUAL DISCUSSION

The construction of the History of Geographic Thought (HPGeo) of the Semi-arid Northeast is a necessary and important study for understanding its consolidation in the scientific and (inter)national aspects. The objective is to analyze the construction of the History of Geographic Thought of the Semiarid Northeast of Brazil. The methodology is based on bibliographic research, seeking the theoretical-methodological support of the theme investigated and enabling the analytical interpretation of historical studies of geography and its scores with regard to the philosophical condition of the Brazilian Semiarid. The results are that its occupation, exploration and domain was based on hegemonic geographical perspectives, according to its historical epoch in chronological course at its level: (inter)national. Another important result was that the main predominant concepts were: geographic determinism, rationalism-systematic and mercantile-commercial capitalism at the Northeast level. Under the analysis in the regional section in the semi-arid region, two primary aspects were analyzed: the Conceptual and the Institutional one. The first focused on three relevant conceptual perspectives: Man, Nature and Economics (N-H-E). The second focused on the institutional, due to the systematic (organized) framework and the framework as a collective: the Farm, the Catholic Church and the Patriarchal Family. With this, geography is founded not only on resisting, but also existing, of transforming determinants into certain and possibilities in the feasibility of building, in today, the future in/your belonging to tomorrow.

Microbial enzymatic stoichiometry and the acquisition of C, N, and P in soils under different land-use types in Brazilian semiarid

This study hypothesized that different land-use affect the microbial enzymatic stoichiometry and C-, N-, and P-acquisition in Brazilian semiarid soils. Thus, the enzymes β-glucosidase (C-acquiring enzyme), urease (N-acquiring enzyme), and acid phosphatase (P-acquiring enzyme) were assessed in soil samples collected at 0–5 and 5–10 cm depth from a tropical dry forest, a protected area with Angico, a protected area with Ipê, scrub area, and an agricultural area with maize. The values of C-, N-, and P-acquiring enzymes were used to calculate the enzymatic C:N, C:P, and N:P ratios. The values of C:P and N:P ratios were higher at 0–5 cm depth, while no significant variation, between soil depth, was observed for C:N ratio. The values of C- and N-acquiring enzymes were higher at 0–5 cm in tropical dry forest areas and Angico forest, respectively. In all land use types, the values of vectors L and A were higher than 1° and 45°, respectively. This study showed that both land-use and soil depth influence the enzymatic stoichiometry, showing higher values of C- and N-acquiring enzymes in native and protected forests at soil surface.

Flash Flood Reconstruction and Analysis—A Case Study Using Social Data

This work proposes a methodology for post-flood analysis in ungauged basins with low data availability located in semi-arid regions. The methodology combines social perception with recorded data. Social perception can be a useful tool to enhance the modeling process in cases where official records are nonexistent or unsatisfactory. For this aim, we structured a four-step methodology. First, we create a repository with the information that reconstructs the analyzed event. Photos and news of the flood event are collected from social media platforms. The next step is to consult official government agencies to obtain documented information about the disaster. Then, semi-structured interviews are carried out with residents to obtain the extension and depth of the flooded spot. This social information creates an overview of the flood event that can be used to evaluate the hydraulic/hydrological modeling of the flood event and the quality of the recorded data. We analyzed a flood event in a city in semi-arid Brazil. The event caused several damages such as the breaking of dams and about 40% of the population was somehow impacted although the official rain data pointed to non-extreme precipitation.

Brazilian semiarid soils formed during the last glacial maximum

Soils formed on pisoliths and sandstones in the Brazilian semiarid were investigated using a high-resolution depth approach to give pedosedimentary and paleoenvironmental reconstructions of the Late Glacial/Holocene pedosequence. Differential erosion favored dissection of an erosion surface that formed isolated plateaus in the Brazilian semiarid. Hyperdystric Ferralsols and Plinthosols occur in flat tops and steep slopes of isolated plateaus. Pedogenesis and erosion/sedimentation-driven pedogenesis influenced the formation of deep, dystrophic, and well-developed soils in plateaus due to environmental conditions from the Late Glacial Maximum throughout the Holocene. Wavy extinction of coarse fraction and Fe-rich nodules, described in thin sections of diagnostic horizons, indicated a similar parent material of soils in plateaus. The TiO2/ZrO2 content ratio of the sand fraction, determined by X-ray fluorescence, indicated horizons buried at 18 kyr, whose strong formation corresponds to a dense paleovegetation and a humid palaeo-climate. The Last Glacial Maximum enabled the formation of Ferralsols by pisoliths and sandstones weathering in plateaus, and semi-deciduous forests persisted on plateaus despite a dry climate since the Late Holocene. Hypereutric Luvisols and Regosols are derived from gneiss in lowlands associated with the modern semiarid climate.

Decision Support System for the Integrated Management of Multiple Supply Systems in the Brazilian Semiarid Region

To alleviate the impacts of water shortages and ensure the effective allocation of water resources, the integration of multiple sources has been a viable but challenging alternative for water resource managers. A robust decision support system (DSS) reduces the complexity of decision making and allows the user to define operational strategies that reduce costs and address system limitations. Through the Particle Swarm Optimization (PSO) collective intelligence algorithm and the operational zoning of reservoirs, it was possible to identify the monthly flow allocation for the Agreste of Pernambuco in Brazil. The analysis of unit costs allowed us to conclude that high local energy tariffs guide the DSS in the exploration of water-transfer works between basins, such as the Agreste pipeline, which had full use of approximately 2 m3/s in the analyzed scenarios. The study also sought to investigate the influence of rainy and dry periods, with the higher flows into local reservoirs in rainy periods leading the system to operate at a cost 2.6% higher compared to the dry period. The use of DSS was able to provide support and parameters that facilitate decision making, ensuring that the system operates efficiently and sustainably.

Ichthyofauna on the move: fish colonization and spread through the São Francisco Interbasin Water Transfer Project

Abstract Projects on river basin integration are keen social-economical drivers in dry regions like the Brazilian semiarid, however, there are concerning ecological impacts implied in those projects. In a long-term analysis, ichthyofauna colonization and spread through the East Axis of the São Francisco River Integration Project (SFIP) was monitored to assess possible impacts on the receiving Paraíba River basin. The fish were collected semiannually (2012 to 2021) from 19 sites in the São Francisco (SF) and Paraíba (PB) basins. A total of 69 fish species were recorded, with distinct fish assemblages between SF (n = 50), PB (n = 35), and the SFIP artificial reservoirs (n = 25). The SFIP reservoirs were colonized by species from the donor basin (SF). In a pioneer finding, Anchoviella vaillanti was recorded for the first time in the receiving basin and it is in the process of establishment. The two SF species that reached PB through the SFIP canals (A. vaillanti and Moenkhausia costae) may be using their year-round reproduction and wide diet to successful spread and colonize the new environment. Since we detected species with potential to reach the receiving basin and became invasives, the implementation of barriers to contain their spread are recommended.

Estratégias de fertilização para reduzir a formação de frutos estenoespermo-cárpicos de manga na região semiárida

Abstract The mango cultivation has shown considerable losses, due to the intense occurrence of physiological disorders in its fruits, and stenospermocarpy is the main disorder under tropical semiarid conditions. So, the experiment was carried out to evaluate the potential loss of yield of mango cv. Palmer by stenospermocarpy, its relation with the nutritional state of the plant and yield as a function of fertilization strategies. The study was conducted in two experimental areas in the Brazilian semiarid. There is evidence that the leaf contents of phosphorus (P), iron (Fe) and zinc (Zn) influenced the development of stenospermocarpy fruits, associated with high temperature and low relative humidity in the flowering period of the crop. The incidence of fruits affected by stenospermocarpy reaches 90%, with an estimated yield loss of 28.81 Mg ha-1 for the mango cv. Palmer.

Does the carnauba-palm riverine vegetation constitute a different type of plant community in the Brazilian semiarid? An analysis of the floristic composition

Abstract Floristic surveys are the main source of information about species composition of different vegetation types and a fundamental input of information for biogeographical studies. Within the Caatinga Domain, there are many vegetation types, of which the most conspicuous is the deciduous caatinga s.s. vegetation. However, along the watercourses of this region, one can find a type of riparian forest called Carnaubais, characterized by a larger presence of evergreen species with access to underground water and a conspicuous occurrence of the endemic “carnauba” palm (Copernicia prunifera). The present study aimed at making a floristic survey on a Carnaubal riverine habitat and a nearby caatinga s.s. site in Ceará, and perform a biogeographical comparison with other sites within the Caatinga Domain. In our study site, we identified 186 species, distributed in 135 genera and 52 families. Of the 186 species recorded, we found 123 species uniquely in the caatinga s.s. phytophysiognomy, 40 uniquely in Carnaubal and 23 in both phytophysiognomies. The most representative families were Fabaceae (31 spp.), Poaceae (15 spp.), and Euphorbiaceae (13 spp.). The UPGMA and NMDS analyses supported the idea that the Carnaubal is a habitat with distinct flora within the Caatinga Domain.

Granitic Inselberg Erosion Controlled by Dike Swarm Array in Semiarid Brazil

Granitic Inselberg Erosion Controlled by Dike Swarm Array in Semiarid Brazil

Deep learning no levantamento aéreo de hotspots para pecuária extensiva no Semiárido Brasileiro

ABSTRACT In the Brazilian Semi-arid Region, extensive livestock farming with ecoproductive management is the most efficient way to maintain and increase the production of goat products (e.g., meat) with of not depleting environmental resources. This set of actions (induced goat migration and pasture closure) is part of Livestock 4.0, in which Industry 4.0 feed areas are efficiently managed using artificial intelligence and deep learning properly monitored by the producer and the consumer. The objective of this work was to identify pasture areas with Opuntia ficus-indica (Mill, Cactaceae) forage palm species for breeding and production of Capra aegagrus-hircus goats (Lineu, Bovidae) using aerial survey images captured by drones classified using deep learning techniques. The methodological steps of the Industry Architecture Reference Model 4.0 were adapted to the field situation (Semi-arid Region) including (A) study area delimitation, (B) image collection (by drones), (C) deep learning training, convolutional neural network (CNN) training, (D) training accuracy analysis, and (E) automatic goat production evaluation and validation. The area classification based on the forage palm density allowed us to measure the environmental degradation caused by livestock. Stimulated goat migration reduced this degradation as well as increased goat biomass and volume production.

Ácido salicílico e prolina modulam tolerância ao estresse hídrico em variedade tradicional de feijão-caupi

ABSTRACT Exogenous applications of chemical compounds stimulate changes in plant metabolism and promote tolerance to different environmental stresses, including water deficit. This study aimed to evaluate the ability of salicylic acid (SA) and proline (PRO) to reduce water stress in a traditional variety of cowpea in a typical Brazilian semiarid climate. A completely randomized design was used in a 2 × 4 factorial scheme, with five replicates. Two irrigation regimes were evaluated corresponding to 100% (W100) and 50% of daily evapotranspiration (W50), respectively, with the addition of the following four attenuators: control (distilled water), SA (550 mg L-1), PRO (690 mg L-1), and 690 mg L-1 PRO + 550 mg L-1 SA. The treatments promoted changes in osmotic and antioxidant metabolism, which may contribute to the tolerance mechanisms of cowpea plants to water stress. The application of SA increased osmoregulator synthesis and protein concentrations, and modulated antioxidant enzyme activity in the cowpea plants under water stress. PRO concentrations increased synergistically in plants treated with PRO and SA, particularly in 50% of water replacement.

Carbon stock and sequestration as a form of payment for environmental services in a sedimentary basin humid forest refuge in brazilian semiarid

Forests function as carbon reservoirs since they act in its sequestration and storage, playing a fundamental role in global climate change mitigation. Payments for this kind of environmental service have emerged as an important means for combating deforestation. This study evaluated the potential of a Sedimentary Basin Humid Forest refuge in a Semiarid Brazilian region (Chapada do Araripe, southern Ceará state) to receive payments for environmental services (PES) for carbon (C) assimilation and storage. The biomass quantification was performed by the non-destructive method and the determination of the C content was carried out using a LECO carbon analyzer to correlate carbon production in different litter components with climate variables. The carbon, carbon increment and stored carbon values were obtained by information collected from a continuous forest inventory. The average carbon content of each litter component and the volume of wood stored in the forest indicated that the fragment has 27.78 t ha−1 of carbon stored in its living biomass and an annual increment of 1.26 t ha−1 year. The carbon sequestered annually totaled 3.99 t ha−1 [carbon incorporated in the litter (2.73 t ha−1) + average annual increment of carbon in the commercial volume (1.26 t ha−1)] indicating that the area sequesters an average of 102.02 t ha−1 CO2e. Of the three studied compartments, only the leaves component showed a significant correlation with any climatic variable (rainfall). Based on amounts paid per ton of carbon sequestered, it is estimated that the area can earn € 2583.79.ha−1 should it participate in a program of PES for carbon sequestration and storage. This value serves as an incentive for the conservation of biodiversity, promoting environmental benefits and financial advantages compared to other forms of land use.

INDICES DE SEVERIDADE DA SECA NO SEMIÁRIDO, PARAÍBA

The occurrence of annual and multiannual droughts in the Brazilian semiarid is a recurrent phenomenon that triggers a series of consequences, impacting the environment and the quality of life of the population inhabiting this region. Due to its location in the drought polygon, the Immediate Geographical Region of Monteiro – PB (REGIM does not diverge from this reality. Given the above, this research aims to correlate the DM, PNI, and RAI Severity Indices of Drought Events in the REGIM, through the historical rainfall series data, to classify the quantitative data on a monthly and annual scale and identify these cycles' Severity of Events (SDE) and consequently evaluate the variation of precipitation over time, identifying the dry and rainy periods. The research sourced monthly rainfall data from the Northeast Development Superintendence (SUDENE), National Institute of Meteorology (INMET), and Executive Agency of Water Management of Paraíba (AESA) to compose the spatial and temporal precipitation variability, which was calculated through the Normal Percentage Index – NPI (CUNHA, 2008), Decision Method – DM (GIBBS; MAHER, 1967) and Rainfall Anomaly Index – RAI (ROOY, 1965). Keywords: Rainfall Standardization Indices – Ipp; Severity of Events – SDE; Water Resources.

GOVERNANÇA ADAPTATIVA E SEGURANÇA HÍDRICA EM CONTEXTO DE MUDANÇAS CLIMÁTICAS NO SEMIÁRIDO

The aim of this paper is to analyze whether the management of water resources in the state of RN meets the requirements of adaptive governance in order to enable adaptation processes to the possible impacts of climate change in semi-arid regions. To do so, the work follows the guidelines of a qualitative, exploratory and descriptive approach using a set of research instruments: bibliographic survey, case study, structured interviews and content analysis. The results show that the management of water resources in RN presents a series of challenges and obstacles to configure itself in a climate adaptive governance perspective. In summary, it is concluded that the management of water resources in the state of RN still does not meet the requirements of a robust adaptive governance capable of operating responses to the risks of climate change and ensuring water security. Keywords: Climate Change. Adaptation. Management of Water Resources. Sustainability. Brazilian Semi-arid.

Response of foliage- and ground-dwelling arthropods to insecticide application: Early step for cotton IPM in the Brazilian semiarid

Foliage- and ground-dwelling arthropods provide ecosystem services, including decomposition and biological control of agricultural pests. Despite this, there is little information on the ground-dwelling arthropod community associated with cotton crops and about their role under pest control practices. Identifying these communities and their preservation would assist smallholder cotton growers in considering an Integrated Pest Management (IPM) approach to pest control. In this context, the strategy of using selective- or broad-spectrum insecticides (both applied only once the pests reached an economic threshold) was assessed using field plots set up within non-Bt cotton structured refuge of a grower field measuring the response of both foliage- and ground-dwelling arthropods and yield. The abundance, species richness, dominance indices, and foliage-dwelling predators and pest species and ground-dwelling predators and decomposers were compared between untreated and insecticide treatments, as was the crop yield. In response to pest monitoring, insecticides were applied 5 and 3 times during the 2018 and 2020 growing seasons, respectively. In 2018 and 2020, 16 and 12 foliage-dwelling predator arthropods and 43 and 47 ground-dwelling predator and decomposer arthropods were collected, respectively. During the 2018 season, broad-spectrum insecticide applications reduced the abundance of foliage-dwelling predators, but had no significant impact on the ground-dwelling community. Principal response curves (PRC) indicated a negative impact of broad-spectrum insecticides only on the foliage-dwelling community, particularly among the Formicidae and Araneae species. Insecticide applications in the 2020 season were only required at the end of the crop season and did not significantly influence the foliage- or ground-dwelling communities. The selective insecticide regime yielded as well as the broad-spectrum insecticide regimes higher yielded than untreated plots. These results demonstrated to the small landholders engaging conservation biological control for the first time, the advantages of an IPM approach to pest management.

Jeans Processing and Water Reuse Systems in a Brazilian Semiarid Region

Purpose: This study aims to analyze the water reuse and technological innovation employed in industrial jeans processing activities in a dry region. Toritama in the Brazilian state of Pernambuco is a part of a ten-city agglomeration involved in garment production and processing. Laundries in Toritama carry out dyeing, wear, fading, and other interventions that add value to the jeans items. This activity uses large quantities of water, which is scarce in this region. Due to rising environmental concerns, the public control agencies passed legislation to ensure the laundries install a water treatment system to treat the effluents. Laundries view the requirement as a disadvantage as small non-formalized laundries are not obliged to implement reuse technology. Method/design/approach: This study used a combined quantitative and qualitative approach to understand the complexity of the social phenomenon. The research was carried out over 2018 and 2019 in formalized laundries. The use of water in the improvement processes and the stages involved were investigated, in addition to determining the cost impact of water reuse. Results and conclusion: the implementing an innovative water treatment system and reusing water plays a critical role in reducing environmental damage caused by industrial activities while also bringing down production costs. Research implications: thus, the study highlights that it is possible for enterprises to gain a competitive advantage while being mindful of the environment. Originality/value: our research fulfills the important role of clarifying the reality of organizations located in regions of peripheral economy that, despite suffering with their specificities, still have space for environmentally and socially sustainable actions.

Sediment yield in a basin in Brazilian Semiarid Regions: A discussion on positive allometry

Sedimentological analyses are essential to understand the system that dictates the sediment yield processes of a basin. Basins have their own characteristics according to climatic, geological, geomorphological, pedological, and phytogeographic influences, on the sediment yield at different scales. This study evaluated the hydrosedimentological aspects of the Rio Seridó hydrographic basin to understand the sediment yield behaviour in the drainage area at different scales. Primary and secondary data, such as imagery (remote sensing), geostatistical methods, hydrosedimentological modelling, and calculations, were used to produce thematic maps, to implement theoretical–methodological revisions of the objects, and determine the specific sediment yield. The sediment delivery ratio was utilized to model the sediment yield at the basin scale, which was calculated using Maner’s Equation and the Universal Soil Loss Equation from 1992 to 2015. The measured data comprised sediment collection, a bathymetric survey of reservoirs, and erosion pins in the drainage basin on a timescaleof up to 82 years. The modelled sediment yield of the basin (2.5 t ha−1 y−1) was comparable to the measurements performed in the semiarid regions for basins of the same scale. The average sediment yield in the reservoirs (2.15 t ha−1 y−1) was very close to the modelled value. Positive allometry was identified for areas of up to 400 km2 in the upper, middle, and lower reaches. Positive allometry was observed with an increase in sediment yield in the drainage area. Globally, this pattern is rare in regions that have not experienced glaciation and this identification is tan important contribution of this research.

Dehydration response in Stylosanthes scabra: Transcriptional, biochemical, and physiological modulations.

Stylosanthes scabra, popularly known as stylo, is native to the Brazilian Caatinga semiarid region and stands out as a drought-tolerant shrub forage crop. This work provides information about the plant response during the first 48 h of water deficit, followed by a rehydration treatment. Besides root transcriptomics data, 13 physiological or biochemical parameters were scrutinized. Additionally, RNA-Seq annotated transcripts not associated with the "Viridiplantae" clade were taxonomically categorized. It was found that S. scabra quickly perceives and recovers from the oscillations of the imposed water regime. Physiologically, mechanisms that minimize evapotranspiration or protect the photosynthetic apparatus stood out. Biochemically, it was found that the root tissue invests in synthesizing compounds that can act as osmolytes (proline and sugars), emphasizing the importance of osmoregulation to water deficit acclimation. Consistently, transcriptome and qPCR analyses showed that a set of enriched biological processes with upregulated (UR) transcripts were involved in protective functions against reactive oxygen species or encoding enzymes of important metabolic pathways, which might contribute to S. scabra response to water deficit. Additionally, several UR kinases and transcription factors were identified. Finally, in an innovative approach, some naturally occurring microbial groups (such as Schizosaccharomyces, Bradyrhizobium, etc.) were identified in the S. scabra roots. This study reveals insights into the physiological, biochemical, and molecular mechanisms underlying the S. scabra response to water deficit and provides candidate genes that may be useful in developing drought-tolerant crop varieties through biotechnological applications.

Bioprospecting Proteolytic Enzymes from Soil Actinobacteria of Brazilian Semiarid Zones

Bioprospecting Proteolytic Enzymes from Soil Actinobacteria of Brazilian Semiarid Zones