Diamantina Region Research Articles

Expanding the knowledge of the bat fauna of the Brazilian Caatinga: new geographical records of molossid bats (Chiroptera, Molossidae) for the Chapada Diamantina region, with taxonomic notes.

The Caatinga, an exclusive biome in Brazil, is the largest tropical dry forest area in the Americas. It is characterized by a semi-arid climate and various soils that harbor a great diversity of flora and fauna. Novel records of aerial insectivorous bat species in the family Molossidae in the Chapada Diamantina, northeastern Brazil are presented. The study is based on field sampling of 115 molossid bat specimens from six genera and 12 taxonomically confirmed species, along with four taxa requiring further evaluation for definitive species identification. All specimens were obtained using mist nets around a small freshwater lagoon surrounded by semideciduous dry forest. The verified genera were Cynomops, Eumops, Molossops, Molossus, Neoplatymops, and Nyctinomops. Our findings enhance the understanding of bat diversity in the Brazilian Caatinga, with the first records of Eumopsdelticus, E.bonariensis, and Molossuscurrentium. The most abundant species were Molossusrufus, Eumopsglaucinus, Cynomopsplanirostris, Nyctinomopslaticaudatus, and Molossusmolossus. Previously unreported morphological and morphometric variations for these Caatinga taxa were examined. Additionally, information on sexual dimorphism in craniodental characteristics of Molossopstemminckii and variations in the presence of the sagittal crest in Neoplatymopsmattogrossensis are provided. Based on the voucher specimens from this study, the recognized number of species of Molossidae known from the Caatinga has increased to 21. Our results offer new insights into the taxonomy and biogeography of Neotropical molossids, highlighting their importance as members of bat communities in dry forest ecosystems from northeastern South America.

Revealing a new species of Agarista (Ericaceae) endemic to the Chapada Diamantina, Brazil, segregated from A. revoluta by multiple evidence

Agarista is a genus belonging to the family Ericaceae that includes ca. 32 species. It occurs predominantly in South America, mainly in Brazil, where 21 species have been documented. During our floristic and taxonomic studies of Ericaceae from the state of Bahia, in northeastern Brazil, we found specimens from the Chapada Diamantina region identified in herbaria as Agarista aff. revoluta. Those samples were clearly distinct from A. revoluta by the greater length and width of the leaves, and the absence of indument on the rachis, flowers, and leaves, as well as leaf anatomy features. Thus, we recognize these as separate taxonomic entities and the new species is herein described as A. revolutissima, which is endemic to the campo rupestre of Morro do Chapéu municipality, while A. revoluta occurs along the Atlantic Forest, being known from the restinga and humid forests.

Chromium isotopes track redox fluctuations in Proterozoic successions of the Chapada Diamantina, São Francisco craton, Brazil

AbstractThe Chapada Diamantina region in the São Francisco craton of eastern Brazil is composed of sedimentary successions containing both Mesoproterozoic and Neoproterozoic carbonate levels, making it a key natural laboratory for understanding the fluctuations of Earth's biogeochemical cycles during its middle age. The ca. 1.4–1.2 Ga Caboclo Formation stromatolites yielded unfractionated δ53Crauth (authigenic) (~−0.54‰ to +0.08‰). Ediacaran cap carbonates and phosphatic stromatolites of the Salitre Formation, on the other hand, yielded fractionated δ53Crauth reaching as high as +0.51‰, suggesting the input of 53Cr-rich Cr(VI), first delivered through meltwater-induced post–snowball Earth fluctuating redox conditions and then through weathering and mobilization under a fully oxygenated environment. The acquired data set highlights the very distinct redox conditions throughout the Proterozoic and reinforces the suggestion that after the Cryogenian global glaciations, Earth's atmosphere and hydrosphere became progressively oxygenated during the Ediacaran-Cambrian transition.

Tectonic shortening and strain magnitudes across the Chapada Diamantina Fold and Thrust Belt: New insights into the tectonic evolution of the Paramirim Aulacogen

In this study, strain magnitudes and tectonic shortening across the Chapada Diamantina fold-and-thrust belt are calculated by finite strain analysis, cross-section restoration and kinematic forward models. A total of 9 complete 3D strain analyses on oriented samples were conducted by the Inertia Tensor method and best fit ellipsoids were computed, resulting in strain ratios (X/Z) varying from 1.190 to 2.504. Predominant oblate shaped ellipsoids related to down-dipping stretching directions are associated with regional transport direction from SW to NE, with reverse faults, upright axial-plane fold and sub-horizontal axis. The restoration of the cross-section yielded a shortening of 19.37%, understood as the minimum tectonic shortening. The adopted model assumes the inversion of former extensional faults (steep thrusts), where the structural architecture of the area is mainly controlled by the inherited rift basin architecture, with basement involvement in a combination of thick and thin skin deformation. Similarly, the assessment of kinematic forward models resulted in a minimum shortening of 18.5%. Comparably, finite strain data integration techniques yielded a total of 21.65% of regional tectonic shortening, representing the horizontal component of ductile flattening strain across the section due to penetrative strain. Therefore, we present, by three different and independent approaches, an estimate range of tectonic shortening between 18%–22% at the western Chapada Diamantina region, but the total amount of shortening across the Paramirim aulacogen might have been greater. These results suggest that the western and eastern parts of the São Francisco craton could not be considered as rigidly linked during the Neoproterozoic–Cambrian Brasiliano orogeny, with the Paramirim aulacogen exerting an import role.

Two new species of Microlicia (Melastomataceae) from Chapada Diamantina, Bahia, Northeastern Brazil

Microlicia is a Neotropical genus with about 245 species centered in central-eastern Brazil, in areas of campo rupestre and Cerrado. The majority of species occur in the states of Minas Gerais, Bahia, and Goiás. Based on specimens from the herbaria ALCB, HUEFS, MBM, SPF, HUFU, and US, we here describe two new species from the Chapada Diamantina region, Microlicia decumbens and Microlicia macaubensis. Microlicia decumbens is apparently endemic to Abaíra municipality, whereas M. macaubensis is known only from Brotas de Macaúbas municipality. We provide morphological descriptions, line drawings, a distribution map, and comparisons with putative relatives for both species.

Taxonomic notes on genera Bourrellyodesmus and Xanthidium (Zygnematophyceae) from Chapada Diamantina, Bahia, Brazil

Here, we report some interesting periphytic desmids, collected in the Chapada Diamantina region, Caatinga domain, northeastern Brazil. Overall, seven taxa were identified, including two species (Bourrellyodesmus comperei, Xanthidium verrucosum) and one variety (Xanthidium concinnum var. longispinum), which are taxonomic novelties, in addition to other taxa of the desmid flora of Brazil. Taxonomic notes and ecological information were provided for each taxon.

Integrated Assessment of Drought Impacts on Rural Areas: The Case of the Chapada Diamantina Region in Brazil

Drought is one of the most significant hazards that farmers face in rural areas. This study aims to examine an integrated assessment of the drought impacts in rural territories, considering the social perceptions related to the effects of natural hazards on health, social relations, income, and other impacts. The study area is located in the rural area of the Chapada Diamantina region in Northern Brazil. The characterization of the region was carried out based on historical meteorological and agricultural productivity data. The method used in this study was based on a survey of social perceptions regarding drought impacts by small rural producers through a participatory process. The results indicated how extreme events such as drought influence rural areas. In addition to agricultural productivity (~50%), aspects such as social migration and health problems were observed.

PHYSICAL, CHEMICAL AND SENSORY ATTRIBUTES OF FRUITS OF TEN MANGO VARIETIES GROWN UNDER ORGANIC PRODUCTION SYSTEM

ABSTRACT This study aimed to assess the physical, chemical, and sensory attributes of mango varieties grown under the organic farming. Fruits from ten varieties of mango grown under the organic system in the Chapada Diamantina region, BA, Brazil, were assessed. The following physical and chemical characteristics were assessed: fruit mass, pulp yield, pulp color (L*, C*, and h*), soluble solids (SS), titratable acidity (TA), total carotenoids, and ascorbic acid. The sensory acceptance test was performed with 50 consumers using the nine-point structured hedonic scale and the attributes acidity, sweetness, and firmness of the pulp were assessed using the just-about-right scale. Differences among the varieties of mango grown under the organic production system were observed for physical, chemical and sensory attributes. The varieties showed a percentage of pulp equal or above 60%, which makes them more suitable for processing. According to the PCA analysis, the characteristics soluble solids, total carotenoids, fruit mass, titratable acidity, h* and L* were considered the most important to differentiate the mango varieties evaluated. Ubá and Beta varieties had the highest levels of SS, while Favo de Mel was characterized by the highest values of TA and L*. The varieties Favo de Mel, Palmer, Surpresa, Juazeiro 2, Imperial and Joa had fruits with higher mass and h* values and the varieties Amrapali and Roxa Embrapa 141 had the highest levels of total carotenoids. Imperial, Palmer, Beta and Joa varieties were the most accepted for all sensory attributes.

How hidden is the diversity of the genus Cosmarium (Desmidiaceae) in the Brazilian Caatinga?

The Caatinga domain is the largest and most diverse tropical semiarid ecoregion of South America; however, little is known about the diversity of desmids it harbors, especially the genus Cosmarium (Desmidiaceae, Zygnematophyceae). Our study contributes to the knowledge of Cosmarium in the Caatinga through the report of 42 interesting taxa, including a new species (Cosmarium imperiale), 22 new records for South America, and 19 additions to the desmid flora from Brazil. The samples were gathered from periphytic material from the “Pantanal dos Marimbus” in the Chapada Diamantina region of Northeast Brazil. We provide taxonomic notes, ecological information, including habitat conditions with limnological data, and updated global distributions for all taxa of Cosmarium. A complementary quantitative study was performed during the last year of sampling (2018), which revealed that most taxa have their highest densities in the months with low precipitation and when the water's conductivity and transparency are greater. Our results also have implications for the conservation of the biota from Marimbus do Baiano and understand South America's desmids' biogeography since some rare taxa identified here were previously only known from other continents such as Europe and Africa.

Landscape Structure Is a Major Driver of Bee Functional Diversity in Crops

Land-use change is having a negative effect on pollinator communities, and these changes in community structure may have unexpected impacts on the functional composition of those communities. Such changes in functional composition may impact the capacity of these assemblages to deliver pollination services, affecting the reproduction of native and wild plants. However, elucidating those relationships requires studies in multiple spatial scales because effects and consequences are different considering biological groups and interactions. In that sense, by using a multi-trait approach, we evaluated whether the landscape structure and/or local environmental characteristics could explain the functional richness, divergence, and dispersion of bee communities in agroecosystems. In addition, we investigated to what extent this approach helps to predict effects on pollination services. This study was conducted in an agroecosystem situated in the Chapada Diamantina region, State of Bahia, Brazil. Bees were collected using two complementary techniques in 27 sample units. They were classified according to their response traits (e.g., body size, nesting location) and effect traits (e.g., means of pollen transportation, specialty in obtaining resources). The Akaike information criterion was used to select the best models created through the additive combination of landscape descriptors (landscape diversity, mean patch shape, and local vegetation structure) at the local, proximal, and broad landscape levels. Our results indicate that both landscape heterogeneity and configuration matter in explaining the three properties of bee functional diversity. We indicate that functional diversity is positively correlated with compositional and configurational heterogeneity. These results suggest that landscape and local scale management to promote functional diversity in pollinator communities may be an effective mechanism for supporting increased pollination services.

First Report of HLB Causal Agent in Psyllid in State of Bahia, Brazil.

The state of Bahia ranks fourth in the national rank for citrus production, and the region of Chapada Diamantina is emerging an important producer of orange for fresh fruit market. Huanglongbing (HLB) is the major phytosanitary threat to Bahia citriculture. In Brazil, the disease was first reported in 2004 in São Paulo state. The bacterium Candidatus Liberibacter asiaticus (CLas) is one of the causal agents of HLB, which is transmitted by the insect vector Diaphorina citri Kuwayama (Hemiptera: Liviidae). Bahia is a HLB-free area; therefore, it is essential to monitor its citrus-producing areas to early detect any possible introduction of the CLas. This study aimed to monitor the presence of the bacteria in the insect vector. Diaphorina citri samples were collected from 2011 to 2014 in different cities located at Chapada Diamantina region and tested by qPCR for the presence of CLas. Three samples were considered positive to bacterium, and all from psyllids collected on Murraya paniculata in the city of Seabra.

Learning and educating with ecological ink: a tutorial teaching practice in the Serra do Espinhaço

The present work is an extension project developed by the Tutorial Education Program (PET) - Strategies to reduce the retention and dropout of academics at UFVJM. This project aimed to develop and teach the lay population in the Diamantina region to produce ecological, inexpensive and efficient paints, from the sieved soil under dilution with water and PVA - Polyvinyl Acetate glue, in order to use them to paint facades of houses and buildings of poor families or communities present in the locality. Therefore, for the performance of the project, volunteer students were selected who had an academic performance coefficient (CRA) of less than 60 or with one or more failures in subjects, in order to meet the purposes of this PET group, combating retention and evasion. During the project, the volunteer team was monitored for the performance of CRA, trained in the production of paints and in the promotion of workshops in educational institutions, which brought up issues inherent to environmental education and the production and viability of ecological paints. The project contributed to the exchange of experiences and bonds between the external and academic community, through technical visits and offered workshops.

ANOMALIAS MAGNETOMÉTRICAS DA REGIÃO DE DIAMANTINA (SERRA DO ESPINHAÇO, MINAS GERAIS) E SEUS SIGNIFICADOS GEOLÓGICOS, ESTRUTURAIS E TECTÔNICOS

A região de Diamantina, Serra do Espinhaço Meridional, constitui foco de inúmeros estudos geológicos, particularmente pelos depósitos diamantíferos do Supergrupo Espinhaço, principal unidade litoestratigráfica que sustenta a serra. Uma área relativamente ainda pouco abrangida por tais estudos é a geofísica. O levantamento aeromagnetométrico realizado pelo órgão estadual CODEMIG tem permitido a aplicação de novas metodologias para o entendimento do arcabouço tectônico dessa região, cuja geologia básica está bem caracterizada. Com o intuito de complementar tais conhecimentos em subsuperfície, aplicaram-se modernos softwares, para que com a metodologia “Deconvolução de Euler” sobre dados magnetométricos, fossem confeccionados modelos tridimensionais representativos para anomalias selecionadas, buscando-se compreender seus significados geológicos. Perfis geofísicos de deconvolução foram gerados e comparados com dados de campo, selecionados em locais onde as anomalias (lineares e circulares) eram mais evidentes, encontrando-se profundidades de até 1.500m para as primeiras e 1.900m para as segundas, o que demonstrou suas raízes profundas. Juntamente com os dados deconvoluídos foram gerados mapas temáticos que permitiram integração de informações, considerando-se a Formação Sopa Brumadinho como principal foco das anomalias. A magnetometria facilitou a identificação de estruturas em subsuperfície fornecendo resultados a respeito da conformação do rifte gerador da Bacia Espinhaço, definindo a “falha mestra” do rifteamento.

O Grace Memorial Hospital e a Missão Presbiteriana norte-americana no Brasil: fontes para a história da assistência à saúde, 1955-1971

The paper presents aspects of the history and archives of Grace Memorial Hospital, founded in 1926 in the former town of Ponte Nova, now Wagner, in the Chapada Diamantina region of Bahia state, Brazil, by the American Presbyterian missionary and doctor Walter Welcome Wood. The documents in question have been kept at the Universidade do Estado da Bahia, campus II, Alagoinhas, since the hospital closed down definitively. They constitute a source of research for different areas of scholarship, especially the history of healthcare in Brazil. The documents are used in analyses of the incidence of diseases, medical treatments, and other care given to a population that had no access to other institutions working in this area.

Obtaining Triploid Hybrids by Means of Open Pollinations and Controlled Crosses Involving Diploids Parental

The creation of triploid hybrids is an important genetic improvement strategy for the development of new commercial citrus scion varieties. The objective of this work was to quantify the frequency of triploids obtained from natural and controlled crosses of different mandarin varieties under varying environmental conditions in the state of Bahia. The experiments were conducted in the municipalities of Cruz das Almas (Recôncavo Baiano region) and Mucugê (Chapada Diamantina region). The first experiment was based on fruits from open pollinations of the varieties ‘Page’, ‘Ortanique’, ‘Ellendale’, ‘Clemenules’, ‘Swatow’, ‘Piemonte’, ‘Fortune’, ‘South Africa’, ‘Montenegrina’, ‘Kincy’, ‘Span Americana’, ‘Fremont, ‘Nova’, ‘Dancy’ and ‘Murcott’, and the second involved fruits from controlled crosses of female parents ‘Nova’, ‘Fortune’ and ‘Ortanique’ and male parents ‘Page’, ‘Montenegrina’, ‘Swatow’, ‘Fremont’ and ‘Kincy’. The seeds selected were inoculated in test tubes containing approximately 10 mL of Woody Plant Medium (WPM). When the plants reached circa 60 days of age, leaf samples were removed for quantification of the DNA by the flow cytometry technique. In Mucugê, three triploids were identified from open pollinations, ‘Clemenules’ (1) and ‘Ortanique’ (2), while in Cruz das Almas, no triploids were obtained. In the controlled crosses, triploids were only obtained in Mucugê: ‘Ortanique’ × ‘Montenegrina’ (4), ‘Ortanique’ × ‘Kincy’ (1) and ‘Ortanique’ × ‘Swatow’ (2). Based on the data, it is suggested that the environmental conditions of Mucugê favored the formation of triploids.

Two new species and new records of terrestrial isopods (Crustacea, Isopoda, Oniscidea) from Brazilian caves

To date, approximately 190 species of terrestrial isopods are known from Brazil and only 14 are considered troglobiotic. After the examination of a large collection from caves in Bambuí and Una geomorphological areas, along the states of Bahia, Minas Gerais and Goiás, two new troglobiotic species were recognized. Pectenoniscus liliae Campos-Filho, Bichuette Taiti sp. n. (Styloniscidae) is described from Serra do Ramalho karst area, and Benthana xiquinhoi Campos-Filho, Bichuette Taiti sp. n. (Philosciidae) from sandstone caves of Chapada Diamantina region. The latter constitutes the second troglomorphic species of the genus. Xangoniscus aganju (Styloniscidae) is also recorded from two caves in the Serra do Ramalho karst area. The systematic position of Iuiuniscus iuiuensis is briefly discussed and Venezillo congener (Armadillidae) is redescribed from São Domingos karst area.

Paleoenvironment and age constraints of Paleoproterozoic alluvial fans in the Sao Francisco Craton, Brazil

The Ouricuri do Ouro Formation represents sedimentary deposits of the Statherian period in São Francisco Craton. Previous works have focused just on the Formation mapping, interpreting the depositional system only in general aspects. However, this study focuses on detailed facies analysis and geochronological investigations of the Ouricuri do Ouro Formation in the central area of São Francisco Craton, Brazil. Four facies associations are recognized: i) Proximal deposits dominated by non-cohesive debris flow; ii) Proximal sheetfloods; iii) Intermediate sheetfloods; and iv) Sandy plains of distal floods. Paleocurrent directions derived from cross-bedding indicate a radial pattern to NE-N. The vertical stacking of distal deposits overlying the proximal facies association suggests a retrogradation of the alluvial fan system, indicating a change in the dynamic of the depositional system. Retrogradation might have been caused by a decrease in the regional gradient declining of the tectonic activity or the retreat of the basin's margin faults system. Furthermore, the presence of higher frequency fining-upward cycles also suggests a climatic control in those deposits. These cycles could be results of the progressive decrease in flow capacity and competence, associated with a decrease of superficial runoff over time. Allied with the dominant paleocurrent, the geochronological data of four tuffaceous sandstones reveal the contribution of Rhyacian to Mesoarchean zircons, suggesting that they came with sediments transported from SW and S of the studied area during the Statherian. The transported sediments came from the southern portion of Gavião Paleoplate. The contribution of volcanic zircons recognized in the tuffaceous sandstones is related to syndepositional magmatism of Statherian Rift of Espinhaço Supergroup. The tuff layer at the base of drill hole (Sample FLV-61 A) contains a zircon age with dominant fraction represented by Statherian zircons defining the syn-sedimentary age of 1722 ± 13 Ma at the basal section of the Ouricuri do Ouro Formation. The present results and available geochronological data constraints the depositional interval of Lower Espinhaço Basin or Megasequence (in sense of Chemale et al., 2012; Guadagnin et al., 2015a, b) between <1.80 and >1.68 Ga in the Chapada Diamantina Region.

Taxonomic novelties, new records, and rare species of desmids from the Chapada Diamantina region, Brazil

We report here taxonomic novelties and interesting records of desmids, including new taxa, rare species and new occurrences, collected at three areas (Piatã, Rio de Contas and Palmeiras) in the Chapada Diamantina region, northeastern Brazil. We identified 16 desmids, including six taxa new to science (Cosmarium diamantinum, Euastrum bicudoi, E. piataense, Micrasterias jenneri var. semicirculare, M. torreyi var. pseudocurvata, and Tetmemorus furcatus), as well as new records for Brazil (Euastrum subcyclopicum var. elongatum and Euastrum octogibbosum). Taxonomic notes and ecological information are provided.

Five new taxa and a new record of Euastrum (Desmidiaceae) from the Chapada Diamantina region, Bahia State, Brazil

We describe five new taxa of Euastrum (E. abruptum var. chapadae, E. fissum var. nordestinum, E. marimbusense, E. ornatiscrobiculatum and E. praemorsum var. foersteri), and report a new record for the Northeastern Region of Brazil (E. groenbladii) from periphyton samples collected in the Pantanal dos Marimbus in the Chapada Diamantina, Bahia State, Brazil. Taxonomic notes and ecological characteristics of the taxa are provided.

Minerais do grupo da crichtonita em veios de quartzo da Serra do Espinhaço (Minas Gerais e Bahia)

O trabalho descreve quatro minerais do grupo da crichtonita encontrados em veios hidrotermais de quartzo, que cortam diversas formações geológicas da Serra do Espinhaço (Supergrupo Espinhaço). Esses minerais – senaíta, crichtonita, almeidaíta e gramaccioliíta-(Y) – foram coletados em duas regiões: Presidente Kubitschek, ao sul de Diamantina (MG), e Novo Horizonte, na Chapada Diamantina Ocidental (BA). A idade de tais veios é relacionada ao final do Ciclo Brasiliano, em ca. 490 Ma. A senaíta é um mineral descoberto no Brasil e classicamente identificado nos aluviões diamantíferos da região de Diamantina; sua primeira ocorrência primária é aqui descrita. A crichtonita, apesar de conhecida desde longa data, teve seu primeiro depósito no país reportado nessa mesma região. A almeidaíta é o 61º e um dos mais recentes dos “minerais brasileiros”, sendo encontrada na região de Novo Horizonte. A gramaccioliíta-(Y), uma espécie descoberta na última década (Itália), tem sua primeira ocorrência brasileira descrita também nessa região. Os depósitos e as composições químicas desses minerais são caracterizados, bem como as problemáticas envolvidas até suas definições finais.