scholarly journals Iron bands, fragipans and duripans in the northeastern plateaus of Brazil — properties and genesis

1998 ◽  
Vol 78 (3) ◽  
pp. 519-530 ◽  
Author(s):  
R. Boulet ◽  
E. Fritsch ◽  
H. F. Filizola ◽  
J. C. De Araujo Filho ◽  
J. C. Leprun ◽  
...  
Keyword(s):  
Northeastern Brazil ◽  
Arid Zones ◽  
Northeast Brazil ◽  
Arid Environments ◽  
Bonding Agents ◽  
Soil Features ◽  
Compact Clay ◽  
Sequential Processes ◽  
Soil Hardening ◽  
Low Activity

Iron bands, fragipans and duripans are common in yellow low-activity clay soils developed from the Barreiras Group in coastal plateaus of northeastern Brazil. Such indurated horizons are found in depressions of the plateaus where sugar cane growth is greatly reduced. Little research has being done on the nature of their bonding agents and their genesis. Research carried out in arid zones has frequently attributed duripan consistency to amorphous silica; however, duripans in northeast Brazil occur under higher rainfall (1500–2000 mm). The objective of this work was to study the nature and distribution of soil features in a plateau to better understand the processes associated with soil hardening. Two transects, across a small and a large depression, were investigated using field soil characterisation, micromorphological techniques, and mineralogical and geochemical analyses.The formation of the indurated horizons studied is due to two sequential processes: development of aquic conditions and incipient podzolization. Such processes have affected the upper part of a thin (<0.6 m in small depressions) or thick (>0.6 m in large depressions) compact clay horizon, showing horizontal plans likely inherited from the sediment. Onset of aquatic conditions formed the first fragipans overlying iron bands. Later, aquic conditions are combined with incipient podzolization to produce bleached loose horizons overlying duripans and iron bands. As the bonding agents in the duripans are organo-metallic complexes, these duripans appear to be very different from those described in arid environments. Key words: Low activity clay Ultisols, Barreiras Group, iron bands, fragipans and duripans, organo-metallic complexes

scholarly journals Isognomon bicolor (C. B. Adams, 1845) (Mollusca: Bivalvia): first record of this invasive species for the States of Paraíba and Alagoas and new records for other localities of Northeastern Brazil

Check List ◽  
2013 ◽  
Vol 9 (1) ◽  
pp. 157 ◽  
Author(s):  
Thelma Lúcia Pereira Dias ◽  
Ellori Laíse Silva Mota ◽  
Anne Isabelley Gondim ◽  
Jacicleide Macedo Oliveira ◽  
Emanuelle Fontenele Rabelo ◽  
...  
Keyword(s):  
Invasive Species ◽  
New Record ◽  
New Records ◽  
Rio Grande ◽  
First Record ◽  
The State ◽  
Northeastern Brazil ◽  
Northeast Brazil ◽  
Littoral Region ◽  
Exotic Invasive

This study provides the first record of the exotic invasive bivalve Isognomon bicolor for the State of Paraíba, Northeastern Brazil. It has been found to occur in at least twelve coastal reefs along the coast. We also present its first record for the State of Alagoas and new record localities for the States of Rio Grande do Norte and Pernambuco, including its occurrence in hypersaline estuaries. From these records the distribution range of I. bicolor has been expanded to the littoral region of Northeast Brazil, where this invasive species seems well established.

scholarly journals The Effect of Formation Processes on The Frequency of Palaeolithic Cave Sites in Semi-Arid Zones: Insights From Kazakhstan

2021 ◽  
Author(s):  
Aristeidis Varis ◽  
Christopher Miller ◽  
Patrick Cuthbertson ◽  
Abay Namen ◽  
Zhaken Taimagambetov ◽  
...  
Keyword(s):  
Central Asia ◽  
Arid Zones ◽  
Arid Environments ◽  
Formation Processes ◽  
Cave Deposits ◽  
Central Asian ◽  
Cave Sediments ◽  
Analytical Potential ◽  
Sediment Cover ◽  
Semi Arid

Central Asian caves with Palaeolithic deposits are few but they provide a rich record of human fossils and cultural assemblages that has been used to model Late Pleistocene hominin dispersals. However, previous research has not yet systematically evaluated the formation processes that influence the frequency of Palaeolithic cave sites in the region. To address this deficiency, we combined field survey and micromorphological analyses in the piedmont zone of south Kazakhstan. Here we present our preliminary results focusing on selected sites of the Qaratau mountains. Sediment cover varies among the surveyed caves and loess-like sediments dominate the cave sequences. The preservation of cave deposits is influenced by reworking of cave sediments within the caves but also by the broader erosional processes that shape semi-arid landscapes. Ultimately, deposits of potentially Pleistocene age are scarce. Our study provides new data in the geoarchaeologically neglected region of Central Asia and demonstrates that micromorphology has great analytical potential even within the limitations of rigorous survey projects. We outline some of the processes that influence the formation and preservation of cave deposits inKazakhstan, as well as broader implications for the distribution of Palaeolithic cave sites in Central Asia and other semi-arid environments.

Ticks (Acari: Argasidae and Ixodidae) infesting amphibians and reptiles in Northeastern Brazil

2018 ◽  
Vol 23 (8) ◽  
pp. 1497 ◽  
Author(s):  
Edna Paulino Alcantara ◽  
Cristiana Ferreira Silva ◽  
Robson Waldemar Ávila ◽  
Richard Campos Pacheco ◽  
Thiago Fernandes Martins ◽  
...  
Keyword(s):  
Northeastern Brazil ◽  
Northeast Brazil ◽  
Brazilian Northeast ◽  
Host Associations

Ticks collected on 21 different species of amphibians and reptiles captured during 2001 to 2017 in the northeast Brazil were identified. Overall, 227 individuals (185 larvae, 32 nymphs, 7 adults females and 3 males) identified as follow: Amblyomma dissimile, Amblyomma rotundatum, Amblyomma sp. larvae, Ornithodoros mimon, Ornithodoros rietcorreai, and an Ornithodoros sp. Herein, we present 25 new tick-host associations, thus contributing to the knowledge on tick-fauna associated to amphibians and reptiles from Brazilian northeast.

scholarly journals New species of Hassalstrongylus (Trichostrongyloidea: Heligmonellidae) in the large-headed rice rat Hylaeamys seuanezi, in the Atlantic Forest of northeast Brazil

2021 ◽  
Vol 30 (2) ◽  
Author(s):  
Natália Alves Costa ◽  
Rosana Gentile ◽  
Maíra Guimarães Kersul ◽  
Martin Roberto Del Valle Alvarez ◽  
Arnaldo Maldonado Junior
Keyword(s):  
Small Intestine ◽  
New Species ◽  
Atlantic Forest ◽  
Northeastern Brazil ◽  
Northeast Brazil ◽  
Genital Cone ◽  
Right Lobe ◽  
A New Species ◽  
Caudal Bursa

Abstract A new species of Trichostrongyloidea (Nematoda: Heligmonellidae), Hassalstrongylus lauroi n. sp., is described from specimens collected from the small intestine of the rodent Hylaeamys seuanezi in the Atlantic Forest of northeastern Brazil (Igrapiúna, state of Bahia). The genus Hassalstrongylus includes 17 species, which parasitize rodents occurring in the Neotropical and Nearctic regions. It differs from the genus Stilestrongylus through its smaller number of ridges in the synlophe and through the size of the genital cone. The main taxonomic characteristics of this new species are the subsymmetrical caudal bursa of type 2-2-1, ray 8 branching out at the base of the dorsal trunk, right lobe smaller than the left, and rays 4 and 5 of robust nature. In addition, the ornamental ray 5 and the robustness of ray 4 on the male caudal bursa, along with the modification of the ridges of the posterior end of the female, allow us to consider the specimens found to be a new species.

scholarly journals Occurrence and distribution of the Ceratiomyxales (Myxomycetes) in northeastern Brazil

2008 ◽  
Vol 51 (5) ◽  
pp. 971-980 ◽  
Author(s):  
Laise de Holanda Cavalcanti ◽  
Andrea Carla Caldas Bezerra ◽  
Antônia Aurelice Aurélio Costa ◽  
Inaldo do Nascimento Ferreira ◽  
Maria de Fátima de Andrade Bezerra
Keyword(s):  
Geographical Distribution ◽  
The State ◽  
Northeastern Brazil ◽  
Northeast Brazil ◽  
Herbarium Collections ◽  
Species Descriptions ◽  
First Time

Order Ceratiomyxales, which belongs to subclass Ceratiomyxomycetidae, includes the exospore bearing Myxomycetes, solely comprising family Ceratiomyxaceae and genus Ceratiomyxa, with four species. Based on the literature, on herbarium collections, and on recent surveys carried out by the authors in different states and ecosystems, it was possible to determine the occurrence and distribution of C. fruticulosa (cosmopolitan),C. morchella and C. sphaerosperma (predominantly tropical or subtropical) in northeastern Brazil. Species descriptions and illustrations are presented, as well as a map of their geographical distribution in eight of the nine states of Northeast Brazil. This order is being recorded for the first time for the state of Sergipe. Ceratiomyxa morchella and C. sphaerosperma are being cited for the first time for the state of Paraíba.

Checklist of the marine and estuarine Brachyura (Crustacea: Decapoda) of northern and northeastern Brazil

Zootaxa ◽  
2008 ◽  
Vol 1956 (1) ◽  
pp. 1-58 ◽  
Author(s):  
PETRÔNIO ALVES COELHO ◽  
ALEXANDRE OLIVEIRA DE ALMEIDA ◽  
LUIS ERNESTO ARRUDA BEZERRA
Keyword(s):  
Northeastern Brazil ◽  
Longitudinal Distribution ◽  
Indigenous Species ◽  
South American ◽  
Northeast Brazil ◽  
Latitudinal Distribution ◽  
Western Atlantic ◽  
Number Of Species ◽  
Non Indigenous Species ◽  
Central South

A total of 272 species of brachyuran crabs are reported from marine and estuarine environments in northern and northeast Brazil. The checklist is derived from the literature published from 1847 to 2008, and includes all species that have been reported at least once from the study area. It is also partially supported by material deposited in the crustacean collection of the Departamento de Oceanografia, Universidade Federal de Pernambuco, city of Recife, Brazil (DOUFPE). The families containing the highest number of species in northern and northeastern Brazil are Majidae (31), Portunidae (22), Epialtidae (20), Panopeidae (20), and Xanthidae (18). The remaining species are distributed in 39 families. The analysis of the distribution of the species in the region, allows for identification of four patterns of longitudinal distribution (western Atlantic, Amphi-Atlantic, Amphi-American, and circumtropical species) and, in the western Atlantic, six patterns of latitudinal distribution (Virginian, Carolinian, Antillean, Central-South American, Boreal, and Endemic). Two non-indigenous species have also been reported. Most of the species represented in northern and northeastern Brazil have Antillean (94 species; 34.5%) and Carolinian (75 species; 27.6%) pattern of distribution.

scholarly journals SPATIAL DISTRIBUTION OF FIREWOOD PRODUCTION IN NORTHEASTERN BRAZIL (1994-2013)

2018 ◽  
Vol 42 (4) ◽  
Author(s):  
Luiz Moreira Coelho Junior ◽  
Kalyne de Lourdes da Costa Martins ◽  
Pablo Aurélio Lacerda de Almeida Pinto ◽  
Magno Vamberto Batista da Silva
Keyword(s):  
Spatial Distribution ◽  
Spatial Data ◽  
Nearest Neighbors ◽  
Spatial Cluster ◽  
Weight Matrix ◽  
Northeastern Brazil ◽  
Northeast Brazil ◽  
Spatial Clusters ◽  
Exploratory Approach ◽  
Production Value

ABSTRACT This paper analyzed the effects of the spatial distribution of the firewood gross production value (GPV) of northeast Brazil through an exploratory approach using spatial data for the period from 1994 to 2013. Identification of spatial clusters in firewood production through the spatial weighting matrices of 2 nearest neighbors and “queen” and “rook” contiguity matrices were used. Based on the analyses, the following can be concluded: there is a positive autocorrelation for firewood GPV; the high-high spatial cluster was formed predominantly in the Bahia region; the high-high spatial cluster, which considers the weight matrix per area, was composed of the Ceará and Pernambuco mesoregions; the low-low spatial cluster consisted of the Sergipe and Alagoas mesoregions; and the low-low cluster, which considers the weight matrix per area, was formed by the Sergipe, Alagoas and Piauí regions.

Lost in time and space: re-assessment of conservation status in an arid-zone flora through targeted field survey

2014 ◽  
Vol 62 (8) ◽  
pp. 674 ◽  
Author(s):  
J. L. Silcock ◽  
A. J. Healy ◽  
R. J. Fensham
Keyword(s):  
Plant Species ◽  
Arid Zone ◽  
Conservation Status ◽  
Vascular Plant ◽  
Iucn Red List ◽  
Arid Zones ◽  
Arid Environments ◽  
Eastern Australia ◽  
The Status ◽  
Conservation Assessments

Lack of basic data to assess plant species against IUCN Red List criteria is a major impediment to assigning accurate conservation status throughout large areas of the world. Erroneous assessments will be most prevalent in vast poorly surveyed areas where herbarium collections are sparse. In arid environments, assessments are further confounded by extreme temporal variability and poor understanding of the nature and magnitude of threats. We systematically re-assess the conservation status of an arid-zone flora. The status of all 1781 vascular plant species occurring across 635 300 km2 of inland eastern Australia was initially assessed through herbarium records and expert interviews. This process generated a list of apparently rare and potentially threatened species, which guided a targeted survey program over 4 years. Search effort and key data on populations of candidate species found were recorded and used to assess 91 species against IUCN criteria. One-third of species were widespread and abundant at least in certain seasons, but had been deemed rare due to sparse collections. The conservation status of 20, mostly newly recognised species from restricted habitats, was upgraded and 14 remained listed because of having restricted areas of occupancy. With the exception of 12 artesian spring species, continuing declines were documented for just six species. The criterion that allows for listing of species because of extreme fluctuations (in combination with restricted and fragmented populations) needs to be carefully interpreted in arid zones, where these fluctuations may be apparent rather than real, and may actually confer resilience to grazing for some species. Our approach facilitates robust conservation assessments across vast and poorly known arid regions, distinguishing species that have merely been lost in space and time from those that are at risk of extinction.

scholarly journals The conservation agriculture in northwest of Morocco (Merchouch area): The impact of no-till systems on physical properties of soils in semi-arid climate

2021 ◽  
Vol 234 ◽  
pp. 00037
Author(s):  
Abdelali El Mekkaoui ◽  
Rachid Moussadek ◽  
Rachid Mrabet ◽  
Said Chakiri ◽  
Ahmed Douaik ◽  
...  
Keyword(s):  
Conservation Agriculture ◽  
Biological Properties ◽  
Water Retention Capacity ◽  
Arid Zones ◽  
Arid Environments ◽  
Retention Capacity ◽  
No Till ◽  
Significant Difference ◽  
The Impact ◽  
Semi Arid

Conservation agriculture (CA) is characterized by three principles: minimum tillage, even the total absence of tillage in the case of direct seeding (NT), permanent soil cover by mulch, and diversification of crops. Its main objective is to control soil degradation by conserving the physical and biological properties and fertility of the soil, which leads to an improvement in productivity, while preserving the environment. Conventional tillage (CT) used in the arid and semi-arid environments of Morocco (particularly in the study site area of Merchouch) compromise the productivity of established crops in these regions. The work presented consists in the study of the impact of NT on the physico-chemical properties of the soil, especially organic matter (SOM), bulk density (BD), soil moisture (θg), and structural stability (SS) in semi-arid zones. The results show that the use of the NT system positively influences the accumulation of SOM, especially at the soil surface horizon (0-5cm). Concerning θg, there is a significant difference between the two treatments (NT and CT) at the average of the three depths and especially at the horizon 20-40 cm so NT increases the water retention capacity. This study also shows that the mean weight diameter (MWD) of the 3 tests (water, ethanol, and rehumectation) is higher for NT compared to CT. This shows that no-till helped to build a good soil structure over time, which is highly desirable for improving agricultural productivity and conserving natural resources, especially water.

Yield Gain and Risk Minimization in Maize (Zea Mays) through Cultivar Mixtures in Semi-arid Zones of the Rift Valley in Ethiopia

1995 ◽  
Vol 31 (2) ◽  
pp. 161-168 ◽  
Author(s):  
Amede Tilahun
Keyword(s):  
Arid Regions ◽  
Arid Zones ◽  
Pure Stand ◽  
Arid Environments ◽  
Risk Minimization ◽  
Growing Seasons ◽  
Maize Cultivars ◽  
Dry Spell ◽  
Yield Gain ◽  
Semi Arid

SUMMARYThe effect of mixtures of cultivars on yield and risk distribution in four maize cultivars grown at four different population levels was studied in semi-arid environments in Ethiopia. Mixtures yielded between 2 and 29% more than the pure stands, but late maturing pure stands produced more biomass than mixtures. Mixtures of cultivars with similar flowering periods yielded 60% more than the pure stands in dry growing seasons, but only 30% more when there was more rain. Yield gain was associated mainly with varietal synchrony of anthesis and silking. Mixtures composed of cultivars with different flowering times were less at risk from yield loss in the case of end-of-season drought and yielded 100% more than their late flowering component in pure stand. But in long growing seasons, with an early dry spell, pure stands of the late cultivar outyielded the mixtures whereas pure stands of the early flowering cultivars yielded less than the mixtures, except in years with a serious end-of-season drought. The results indicate that it would be profitable to grow mixtures in semi-arid regions if cultivars with similar height and synchronized flowering time were grown at populations of between 65 000 and 90 000 plants ha−1.

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