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Land use and land cover map of a semiarid region of Brazil for meteorological and climatic models

Vieira,Rita Marcia da Silva Pinto; Cunha,Ana Paula Martins do Amaral; Alvalá,Regina Célia dos Santos; Carvalho,Vitor Celso; Ferraz Neto,Sebastião; Sestini,Marcelo Francisco
Fonte: Sociedade Brasileira de Meteorologia Publicador: Sociedade Brasileira de Meteorologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2013 EN
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An updated vegetation cover and land use map over a semiarid region of Brazil has been produced at a 1 km spatial resolution, using satellite data and remote sensing techniques, for application in climate modeling. The map presents the location and distribution of major vegetation types and non-vegetated land surface formations for the Northeast Brazil Region, which includes the semiarid region. In this study, Radambrasil and IBGE vegetation maps, a digital mosaic of ETM+ Landsat 7, and TM Landsat 5 images from the period 1999-2000 were used. To update the map, the techniques of segmentation and unsupervised classification (ISOSEG) were applied. A total of 7 land cover and land use categories were mapped according to the "Simplified Simple Biosphere"(SSiB) model legend. This map shows that there has been a considerable increase in agricultural activities and pasture area. The vegetation in this region is an intricate combination of different life forms (e.g., trees and shrubs forming a closed cover) in this region. The semiarid region of Brazil is susceptible to desertification due to climatic and environmental conditions. This updated map should provide important input for regional stratification in climate studies.

Salinity and freshwater discharge determine rotifer distribution at the Mossoró River Estuary (Semiarid Region of Brazil)

Medeiros,AMA.; Barbosa,JEL.; Medeiros,PR.; Rocha,RM.; Silva,LF.
Fonte: Instituto Internacional de Ecologia Publicador: Instituto Internacional de Ecologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2010 EN
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The present study aimed at evaluating differences in rotifer distribution in three estuarine zones in an inverse estuary located in the Semiarid Region of Brazil. Zones were chosen based on their proximity to the ocean and river border as a means of reflecting a horizontal salinity gradient. High freshwater discharge during the rainy season was the major determinant of rotifer composition. On the other hand, due to higher salinity values during the dry season, very low values of species richness and abundance were observed in all zones. Therefore, the study highlights the constraints of salinity and the positive influence of seasonality and river proximity on rotifer species in a semiarid estuarine environment.

Comunidade fitoplanctônica como discriminador ambiental em açude eutrófico tropical semiárido (Barragem Armando Ribeiro Gonçalves, RN) e divulgação científica para reflexão social; Phytoplankton discriminator as environmental semiarid tropical eutrophic reservoir ( Dam Armando Ribeiro Gonçalves , RN ) and popular science for social reflection

Vieira, Pryscila Cynara Soares
Fonte: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa Regional de Pós-Graduação em Desenvolvimento e Meio Ambiente PRODEMA; Meio Ambiente, Cultura e Desenvolvimento Publicador: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa Regional de Pós-Graduação em Desenvolvimento e Meio Ambiente PRODEMA; Meio Ambiente, Cultura e Desenvolvimento
Tipo: Dissertação Formato: application/pdf
POR
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The knowledge of the phytoplankton community, as an integral and dynamic processes of eutrophication, provides information essential for proper management and handling. A growing problem of cyanobacteria in reservoirs around the world as a result of artificial eutrophication processes, generating a particular concern, because some species produce cyanotoxins, which can cause adverse effects on human health. The present work aims to characterize the spatial and temporal dynamics of phytoplankton, assessing their potential as ecological indicator of water quality in reservoirs semiarid region. The samples of water were collected monthly between 2009 and 2011, at three points along the dam Armando Ribeiro Gonçalves / RN. In each sample were measured physico - chemical analysis of water and biological components. We conducted a scientific dissemination activity, with distribution and reading primer on eutrophication, informative talk about water quality, questionnaires and performing a play in a public school in the city of Itajá / RN. The reservoir was considered eutrophic in three points, taking into account the values of chlorophyll -a and phosphorus, adopted to characterize eutrophic environments of semi-arid areas. High density of cyanobacteria...

Limnological characteristics of a reservoir in semiarid Northeastern Brazil subject to intensive tilapia farming (Orechromis niloticus Linnaeus, 1758)

Bezerra,Luis Artur Valões; Paulino,Walt Disney; Garcez,Danielle Sequeira; Becker,Helena; Sánchez-Botero,Jorge Iván
Fonte: Associação Brasileira de Limnologia Publicador: Associação Brasileira de Limnologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2014 EN
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AIM: There is currently no consensus regarding the physical and chemical variability of tropical reservoirs. In semiarid Northeastern Brazil, reservoirs are among other things used for human consumption, industrial water supply and intensive fish farming, all of which can impact water quality. The objective of this study was to evaluate the physical and chemical variability of the water in Sítios Novos, a reservoir in semiarid Northeastern Brazil, comparing samples collected in areas of intensive tilapia (Oreochromis niloticus) farming to samples from areas not directly impacted by aquaculture, in both the dry and the rainy season. METHODS: Between October 2010 and July 2011, data were collected on temperature, conductivity, pH, turbidity, salinity, chlorophyll a, dissolved oxygen, oxygen demand, total phosphorus and total nitrogen levels in the water column using a multiparametric probe at four different sampling locations. Physical and chemical differences between the four locations were evaluated with the Kruskal-Wallis (KW) test and Dunn's post test, while the t test, followed by Welchʼs correction, was used to compare samples collected in different seasons. RESULTS: No influence of intensive aquaculture was detected when comparing sampling locations near fish farms (180C and 300C) to locations not directly impacted by aquaculture (LIMN1...

Nutritional management to improve sheep and goat performances in semiarid regions

Salem,Hichem Ben
Fonte: Sociedade Brasileira de Zootecnia Publicador: Sociedade Brasileira de Zootecnia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/07/2010 EN
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Small ruminant production is the main source of income of farmers living in arid and semiarid regions. Sheep and goats raised in these areas are generally confronted with severe nutritional deficits during food scarcity period which exacerbate disease and health problems and consequently low productive and reproductive performances. These areas are characterized by rainfall seasonality and scarcity resulting in a low fodder potential. Therefore, native rangelands are degrading due to overgrazing, high stocking rates and mismanagement. Options to improve small ruminant-based production systems include i) innovative technologies targeting the increase of feed resources availability, rumen manipulation using natural compounds to boost microbial activity, improving diets' quality, alleviation of feeding cost, and better control of livestock watering. Although this paper is focussing on the benefits from these technical options, we should bear in mind that i) the organization of local institutions for better adoption of these technologies and for protecting the main natural resources (rangelands and water) and ii) the participatory approach involving all partners concerned with the improvement of farmer's income and livelihood are key tools for promoting livestock sector in the target areas. A set of simple...

The introduced snail Melanoides Tuberculatus (Muller, 1774) (Mollusca: Thiaridae) in aquatic ecosystems of the Brazilian Semiarid Northeast (Piranhas-Assu River basin, State of Rio Grande do Norte)

Santos,CM.; Eskinazi-Sant'Anna,EM.
Fonte: Instituto Internacional de Ecologia Publicador: Instituto Internacional de Ecologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/02/2010 EN
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Records of the gastropod Melanoides tuberculatus (Müller, 1774), family Thiaridae, in the Piranhas-Assu River basin in Rio Grande do Norte reveal the dispersal of this native Southeast Asian and East African species into aquatic environments of the Brazilian semiarid region, including artificial environments (reservoirs) and lotic systems. The eutrophic conditions of the local waterbodies appear to favor the present situation, where this invasive species reaches extremely high densities, sometimes over 10,000 ind.m-2 as in Armando Ribeiro Gonçalves Reservoir. These observations indicate the immediate need for new studies on the spatial distribution of the species and its potential impact on the biodiversity and water quality of the waterbodies of the semiarid region of the state. Implantation of regular and systematic monitoring of the aquatic resources of the region is urgently required.

Ability of different plant species to promote microbiological processes in semiarid soil

García Izquierdo, Carlos; Roldán Garrigos, Antonio; Hernández Fernández Muñoz, María Teresa
Fonte: Elsevier Publicador: Elsevier
Tipo: Artículo Formato: 259768 bytes; application/pdf
ENG
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10 pages, 5 tables, 2 figures.; In semiarid climate soils, the establishment of a plant cover is fundamental to avoid degradation and desertification processes. A better understanding of the ability of plants to promote soil microbial processes in these conditions is necessary for successful soil reclamation. Six different plant species were planted in a semiarid soil, in order to know which species are the most effective for the reclamation of semiarid areas. Six years after planting, the rhizosphere soils were studied by measuring chemical (pH, electrical conductivity, total organic carbon and other carbon fractions), physical (% of saggregates), microbiological (microbial biomass carbon and soil respiration), and biochemical (dehydrogenase, phosphatase, β-glucosidase and urease activities) parameters. In general, in all the soil–plant systems plant nutrients, organic matter and microbial activity increased compared to the control soil. For some species, such as Rhamnus lycioides, the increase in the total organic carbon content (TOC) in the rhizosphere zone was almost 200%. A positive correlation was found between TOC and water-soluble carbon (p<0.001); both parameters were negatively correlated with electrical conductivity. Microbial biomass carbon and soil respiration were highest in the rhizosphere of Stipa tenacissima (98% and 60%...

Factors regulating spatial distribution of soil water content in a small semiarid catchment

Gómez-Plaza, A.; Martínez-Mena García, M. Dolores; Albaladejo Montoro, Juan; Castillo Sánchez, Victor Manuel
Fonte: Elsevier Publicador: Elsevier
Tipo: Artículo Formato: 579917 bytes; image/jpeg
ENG
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The factors which control soil moisture patterns in a semiarid area are determined in two different locations: a burnt zone with little vegetation and an unburnt zone with a greater vegetal cover. In the burnt area, the factors affecting the spatial variability of the soil water content are those considered as local controls such as soil texture and slope. These factors are able to explain a significant part of the spatial distribution of soil moisture in this zone independently of the soil moisture state. In the unburnt area, the factors affecting soil moisture were those related with the presence or absence of vegetation in semiarid environments. The upslope contributing area, aspect, soil profile curvature and soil depth best explained the spatial variability of the soil moisture content in the vegetated zone. The actual influence of these factors showed marked seasonal variations due to changes in the physiological activity of the vegetal cover. These factors, which are in part responsible for the distribution of soil moisture, are not commonly integrated in traditional topographic wetness indices. The topographic index of Beven and Kirkby (Beven, K.J., Kirkby, M., 1979. Hydrological Sciences Bulletin 24, 43–69) is extended to account for the interstorm soil water losses. The new indices incorporating the hillslope aspect improve the prediction power of soil water content patterns in semiarid areas.; Financial support from Spanish CICYT (HID98-1056-CO2-01) and Dirección General de Conservación de la Naturaleza-MIMAM (Programa RESEL).; Peer reviewed

Aggregate stability changes after organic amendment and mycorrhizal inoculation in the afforestation of a semiarid site with Pinus halepensis

Caravaca Ballester, María Fuensanta; García Izquierdo, Carlos; Hernández Fernández Muñoz, María Teresa; Roldán Garrigos, Antonio
Fonte: Elsevier Publicador: Elsevier
Tipo: Artículo Formato: 259768 bytes; application/pdf
ENG
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10 pages, 6 tables, 3 figures.; The recovery of soil structural stability is a precondition for successful afforestation programmes in semiarid environments. A multifactorial field experiment was carried out in a semiarid rangeland in south-eastern Spain to evaluate the influence of a fresh organic residue addition (first factor), mycorrhizal inoculation with Pisolithus arhizus (second factor), and the rhizosphere of Pinus halepensis (third factor) on soil aggregate stability. A total of 6 years after planting, the addition of residue was seen to increase the levels of stable aggregates to a greater extent than the mycorrhizal inoculation. Both reafforestation methods increased C-fractions and enzyme activities measured (dehydrogenase and phosphatase). The rhizosphere also affected aggregate stability, particularly when P. halepensis was inoculated with P. arhizus. Aggregate stability in the rhizosphere of P. halepensis was strongly correlated (P<0.01) with the C-biomass and soluble C-fractions (WSC and WSCH) as well as with dehydrogenase (r=0.901, P<0.05) and phosphatase (r=0.903, P<0.05) activities. It was concluded that the combination of residue amendment and inoculation of P. halepensis with P. arhizus significantly improves soil aggregate stability...

Afforestation method affects the isotopic composition of planted Pinus halepensis in a semiarid region of Spain

Querejeta Mercader, José Ignacio; González Barberá, Gonzalo; Granados, Arsenio; Castillo Sánchez, Victor Manuel
Fonte: Elsevier Publicador: Elsevier
Tipo: Artículo Formato: 579917 bytes; image/jpeg
ENG
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We used an isotopic approach to evaluate the effects of three afforestation methods on the ecophysiology of an Aleppo pine plantation in semiarid Spain. The site preparation methods tested were excavation of planting holes (H), subsoiling (S), and subsoiling with addition of urban solid refuse to soil (S + USR). Five years after plantation establishment, trees in the S + USR treatment were over three times larger than those in the S treatment, and nearly five-fold larger than those planted in holes. Differences in tree biomass per hectare were even greater due to disparities in initial planting density and pine tree mortality among treatments. Pine trees in the S + USR treatment showed higher foliar P concentration, δ13C and δ15N than those in the S or H treatments. Foliar δ15N data proved that trees in the S + USR treatment utilized USR as a source of nitrogen. Foliar δ13C and δ18O data suggest that improved nutrient status differentially stimulated photosynthesis over stomatal conductance in the pine trees of the S + USR treatment, thus enhancing water use efficiency and growth. In the spring of 2002, trees in the S + USR treatment exhibited the most negative predawn water potentials of all the treatments, indicating that the rapid early growth induced by USR accelerated the onset of intense intra-specific competition for water. The results of this study have implications for the establishment and management of Aleppo pine plantations on semiarid soils. Planting seedlings at low density and/or early thinning of pine stands are strongly recommended if fast tree growth is to be maintained beyond the first few years after USR addition to soil. Foliar C...

Tillage and cropping intensification effects on soil aggregation: Temporal dynamics and controlling factors under semiarid conditions

Álvaro-Fuentes, Jorge; Arrúe Ugarte, José Luis; Gracia Ballarín, Ricardo; López Sánchez, María Victoria
Fonte: Elsevier Publicador: Elsevier
Tipo: Artículo Formato: 310419 bytes; application/pdf
ENG
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The definitive version is available at: http://www.sciencedirect.com/science/journal/00167061; During decades, in semiarid agroecosystems of the Ebro valley, intensive soil tillage and low crop residue input has led to a loss of soil structure. Conservation tillage and cropping intensification can improve soil structure in these areas. The objective of this study was to determine the influence of three different tillage systems (conventional tillage, CT; reduced tillage, RT; and no-tillage, NT) under two cropping systems (barley–fallow rotation, CF; and continuous barley, CC) on soil aggregation dynamics during two consecutive growing seasons (2003–2004 and 2004–2005). At the same time, the role that different soil and climatic factors play on soil aggregation in these semiarid areas was studied. Soil samples were collected at the soil surface (0–5 cm depth) from a long-term tillage experiment with a loamy soil (Xerollic Calciorthid). Two aggregation indexes were studied: dry aggregate size distribution and water aggregate stability from both air-dried and field-moist macroaggregates. A decrease in tillage intensity resulted in a higher mean size of dry aggregates and a greater water aggregate stability in both cropping systems particularly under NT. During the whole experiment...

Differential modulation of host plant δ13C and δ18O by native and nonnative arbuscular mycorrhizal fungi in a semiarid environment

Querejeta Mercader, José Ignacio; Allen, Michael F.; Caravaca Ballester, María Fuensanta; Roldán Garrigos, Antonio
Fonte: John Wiley & Sons Publicador: John Wiley & Sons
Tipo: Artículo Formato: 579917 bytes; image/jpeg
ENG
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Native, drought-adapted arbuscular mycorrhizal fungi (AMF) often improve host-plant performance to a greater extent than nonnative AMF in dry environments. However, little is known about the physiological basis for this differential plant response. • Seedlings of Olea europaea and Rhamnus lycioides were inoculated with either a mixture of eight native Glomus species or with the nonnative Glomus claroideum before field transplanting in a semiarid area. • Inoculation with native AMF produced the greatest improvement in nutrient and water status as well as in long-term growth for both Olea and Rhamnus. Foliar δ18O measurements indicated that native AMF enhanced stomatal conductance to a greater extent than nonnative AMF in Olea and Rhamnus.δ13C data showed that intrinsic water-use efficiency in Olea was differentially stimulated by native AMF compared with nonnative AMF. • Our results suggest that modulation of leaf gas exchange by native, drought-adapted AMF is critical to the long-term performance of host plants in semiarid environments. δ18O can provide a time-integrated measure of the effect of mycorrhizal infection on host-plant water relations.; This research was supported by the EC + CICYT cofinanced FEDER programme (1FD97-0507 FOREST) and by the Biocomplexity Program (DEB 9981548) of the US National Science Foundation. J. I. Q. acknowledges a Fulbright postdoctoral fellowship from the Spanish Ministry of Education and Science.; Peer reviewed

Aggregate stability and carbon characteristics of particle-size fractions in cultivated and forested soils of semiarid Spain

Caravaca Ballester, María Fuensanta; Lax, Antonio; Albaladejo Montoro, Juan
Fonte: Elsevier Publicador: Elsevier
Tipo: Artículo Formato: 259768 bytes; application/pdf
ENG
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8 pages, 1 figure, 2 tables.; Organo-mineral particle-size fractions play a major role in soil structure. However, our knowledge of these size fractions must increase if we are to optimise the physical regeneration of degraded soils in semiarid areas. Twenty soils (sieved <2 mm) used for two contrasting purposes (agriculture and forestry) in southeastern Spain were fractionated into <2 and 2–20 μm particle-size fractions by ultrasonic dispersion in water followed by sedimentation. The organic matter from these size fractions was separated by extraction with 0.1 M Na4P2O7 (pH 9.8) and by oxidation with H2O2. The different size fractions were analysed for C concentration before and after treatment with pyrophosphate and peroxide. For both cultivated and forested soils, the highest proportion of organic C was associated with 2–20 μm particle-size fraction. The <2 and 2–20 μm particle-size fractions were characterised by a high proportion of organic matter non-extractable with sodium pyrophosphate, which was partly resistant to peroxidation. The aggregate stability of cultivated soils was significantly lower (mean 40%) than that of forested soils (mean 82%). Soil aggregate stability was not correlated with the organic constituents associated with the <2 and 2–20 μm particle-size fractions...

Medium-term effects of mycorrhizal inoculation and composted municipal waste addition on the establishment of two Mediterranean shrub species under semiarid field conditions

Caravaca Ballester, María Fuensanta; Figueroa, Dino; Azcón González de Aguilar, Concepción; Barea Navarro, José Miguel; Roldán Garrigos, Antonio
Fonte: Elsevier Publicador: Elsevier
Tipo: Artículo Formato: 259768 bytes; application/pdf
ENG
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11 pages, 2 figures, 4 tables.; The development of appropriate revegetation techniques is essential to reduce and to remediate the processes of erosion and desertification in semiarid Mediterranean areas. A factorial field experiment was carried out in a degraded semiarid Mediterranean area to assess the effectiveness of composted municipal waste addition to soil, mycorrhizal inoculation with Glomus intraradices and the combination of both treatments on the viability, growth and nutrition of Olea europaea L. subsp. sylvestris and Rhamnus lycioides L., over a 2-year growth period. Six months after planting, only mycorrhizal inoculation of O. europaea subsp. sylvestris and R. lycioides seedlings grown in the soil, with or without addition of composted municipal waste, statistically and significantly increased the shoot biomass and contents of foliar nutrients (N, P and K). During the last 6 months of the growth period, both shrub species displayed sharp increases in the shoot biomass. Two years after planting, the highest increases in the shoot biomass of O. europaea plants were recorded in the combined treatment of composted municipal waste addition and mycorrhizal inoculation (about 12-fold greater than control plants). The shoot biomass of R. lycioides was increased by composted municipal waste addition (about 226%) to a greater extent than by mycorrhizal inoculation (about 87%)...

A wind-based qualitative calibration of the Hargreaves ET0 estimation equation in semiarid regions

Martínez-Cob, Antonio; Tejero-Juste, Miguel
Fonte: Elsevier Publicador: Elsevier
Tipo: Artículo Formato: 191602 bytes; application/pdf
ENG
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The definitive version is available at: http://www.sciencedirect.com/science/journal/03783774; This study evaluates the Hargreaves (HARG) equation for estimation of monthly ET0 under the semiarid conditions of the middle Ebro River Valley (NE Spain). First, the Hargreaves equation was compared against measured lysimeter ET0 values at Zaragoza for the period May 1997–October 2000. The average of estimated values was only 5.6% above the average of measured values. Later, the Hargreaves equation was compared against the FAO Penman–Monteith equation for monthly ET0 estimation at nine locations. These locations can be grouped as non-windy (Alcañiz, Daroca and Tamarite) and windy (Almudévar, Ejea, Gallocanta, Monflorite, Sariñena and Zaragoza). Simple linear regression and error analysis statistics suggest that agreement between the two estimation methods was quite good for the windy locations. Average errors ranged between 2 and 5% for Almudévar, Ejea, Sariñena and Zaragoza, and between 7 and 10% for Gallocanta and Monflorite where some underestimation was observed. However, the agreement between the Hargreaves and FAO Penman–Monteith equations was lower for the non-windy locations. In this case, the Hargreaves equation overestimated ET0 and average errors varied between 14 and 20%. According to these results...

Influence of orientation, vegetation and season on soil microbial and biochemical characteristics under semiarid conditions

Bastida, F.; González Barberá, Gonzalo; García Izquierdo, Carlos; Hernández Fernández Muñoz, María Teresa
Fonte: Elsevier Publicador: Elsevier
Tipo: Artículo Formato: 509829 bytes; application/pdf
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9 pages, 2 figures, 4 tables.; The semiarid climatic conditions of southeast Spain prevent the growth of stable vegetation that would help preserve soil fertility. The aim of this work was to evaluate the effect of orientation, vegetation and season on soil microbial and biochemical properties in a semiarid climate. For this purpose four experimental sites were chosen: two southerly orientated (SO) and two northerly orientated (NO). One of the SO sites had a vegetal cover of shrubs (SOS) and the other of Pinus halepensis (SOP). Similarly, one of the north-facing sites had a cover of shrubs (NOS) and the other of P. halepensis (NOP). The vegetal cover of north-facing sites was about 75% while on the south-facing sites it was less than 25%. Orientation significantly influenced the C fractions, which were higher on north-facing sites than on south-facing sites. Microbial biomass C (MBC) reached 400 mg C kg−1 soil in north-facing sites. Microbial activity was also greater in NO than in SO sites, the NOP site showing basal respiration of 15 mg CO2-C kg−1 soil−1 day−1, while basal respiration did not reach 2 mg CO2-C kg−1 soil−1 day−1 in either SO sites. Urease, β-glucosidase and N-α-benzoyl- l-argininamide (BAA) protease showed higher values in NO sites than in SO sites...

CONFRONTANDO A VULNERABILIDADE E INDEFENSABILIDADE SOCIAL: A EXPERIÊNCIA DA ARTICULAÇÃO NO SEMIÁRIDO BRASILEIRO (ASA).; CONFRONTING THE VULNERABILITY AND SOCIAL defencelessness: THE EXPERIENCE OF THE JOINT Brazilian semiarid region (ASA)

Gomes, Uende Aparecida Figueiredo; Pena, João Luiz
Fonte: Programa de Pós-Graduação em Geografia Humana. Universidade de São Paulo. Publicador: Programa de Pós-Graduação em Geografia Humana. Universidade de São Paulo.
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Formato: application/pdf
Publicado em 30/08/2012 POR
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This paper aims to present and discuss the actions of the Program of Training and Social Mobilization for Living with the Semi-arid - One Million Rural Cisterns (P1MC) and the work done by the Brazilian Semiarid Articulation (ASA). To evaluate the actions of the program were made interviews with managers of the Ministry of Social Development and Hunger Alleviation, member of the coordination with the ASA and a beneficiary of the Landless Rural Workers Movement. Content analysis of interviews indicate that the actions of ASA have been to introduce effectives practices of coexistence with the semiarid through technologies for collecting and storing rainwater, however, the political empowerment of the people benefited by the actions still remains a challenge.;  Este trabalho tem por objetivo apresentar e discutir as ações do Programa de Formação e Mobilização Social para Convivência com o Semiárido – Um milhão de Cisternas Rurais (P1MC) e o trabalho realizado pela Articulação no Semiárido Brasileiro (ASA). Para avaliar as ações do programa foram realizadas entrevistas abertas com gestor do Ministério do Desenvolvimento Social e Combate à Fome, com membro da coordenação da ASA e com um beneficiário integrante do Movimento dos Trabalhadores Rurais Sem Terra. A análise dos dados indica que as ações da ASA têm sido efetivas ao instituírem práticas de convivência com o semiárido por meio de tecnologias de coleta e armazenamento de água de chuva...

Prosopis laevigata and Mimosa biuncifera (Leguminosae), jointly influence plant diversity and soil fertility of a Mexican semiarid ecosystem

García-Sánchez,Rosalva; Camargo-Ricalde,Sara Lucía; García-Moya,Edmundo; Luna-Cavazos,Mario; Romero-Manzanares,Angélica; Manuel Montaño,Noé
Fonte: Revista de Biología Tropical Publicador: Revista de Biología Tropical
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2012 EN
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Prosopis laevigata and Mimosa biuncifera are frequently found in arid and semiarid shrublands, but scarce information is available about their influence on plant community structure and soil fertility. We compared plant community structure, diversity and soil nutrients of three semiarid shrubland sites located in Mezquital Valley, Mexico. These sites differ in their dominant species: Site 1 (Bingu) P. laevigata, Site 2 (González) M. biuncifera, and Site 3 (Rincón) with the presence of both legumes. The results showed that the plant community with P. laevigata and M. biuncifera (Site 3) had more cover, taller plants and higher plant diversity than sites with only one legume (Site 1 and Site 2). Soil organic matter (SOM), soil organic carbon (SOC), total nitrogen (TN), phosphorus-Olsen (P) and C mineralization were higher in the soil under the canopy of both legumes than in bare soil. In contrast, soil cation concentrations were lower under the canopy of P. laevigata, but not for M. biuncifera. In addition, the density of arbuscular mycorrhizal fungi spores was higher within the soil under the canopy of M. biuncifera than in the soil under the canopy of P. laevigata. Thus, resource islands (RI) created by P. laevigata increased the amounts of SOC...

A mass collection of Triatoma ryckmani (Hemiptera:Reduviidae)from Stenocereus eichlamii (Cactaceae)in the semiarid region of Guatemala

Marroquín M,Ricardo; Bor A,Silvia; Monroy E,M.Carlota
Fonte: Revista de Biología Tropical Publicador: Revista de Biología Tropical
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2004 EN
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A population of 216 specimens of Stenocereus eichlamii (Cactaceae,Subfamily Cereoideae) was surveyed for Triatoma ryckmani (vector of Chagas disease)in a one hectare plot of semiarid habitat in Guatemala. Out of 44 plants that had dead and dry sections,24 plants had a total of 103 specimens of T.ryckmani .In comparison with other areas of Guatemala,T.ryckmani is well established in the semiarid ecosystem (Infestation index 54.5,density =2.3 and crowding index 4.3).The insects were mainly found (52.4%)in the dead portions of S.eichlamii 2.0 to 3.2 m above the ground (X² =26.0,P<0.00001),followed by dry cactus sections between 3.2 and 5.0 m (35.9%).They were less frequent 0.2 to 2.0 m above the ground.A considerable proportion (75.7%)had no aparent blood in their digestive systems.To determine the presence of flagellates,43 of the bugs were dissected,but none were found.This is the first report on T.ryckmani population dynamics in this habitat. Rev. Biol. Trop. 52(4):931-936.Epub 2005 Jun 24.

Infâncias do Semiárido lançando olhares; Glancing at childhoods in the Semiarid; ; ;

Ribeiro, Marcelo Silva de Souza
Fonte: Labor & Engenho; Labor & Engenho Publicador: Labor & Engenho; Labor & Engenho
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Artigo Avaliado pelos Pares Formato: application/pdf
Publicado em 24/06/2015 POR
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Deflagrando alguns flashes, que laçam olhares para o universo infantil, este ensaio traz discussões, a partir de um panorama cultural, sócio-histórico e ambiental do lugar/tempo chamado, hoje, de Semiárido nordestino brasileiro. Essas discussões, por meio de problematizações, visam provocar reflexões sobre as construções de infâncias. Assim, o Semiárido nordestino e toda sua diversidade redescoberta, apesar das contradições e enormes ameaças ambientais, deve ser encarada também sob o ponto de vista da subjetividade. Seria possível, então, falar de uma subjetividade infantil do semiárido? De maneira mais específica, como pensar e abordar suas infâncias? Estas perguntas nortearam o ensaio, que se pautou em analisar literaturas de cordéis, registros fotográficos e conteúdos oriundos da interação direta com as crianças em contextos diversos. As idiossincrasias do semiárido, suas carências históricas e as inúmeras construções sociais desse lugar/tempo forjaram o humano também de maneira diversa, apesar de algumas possíveis apreensões comuns. As infâncias, que já somadas aos legados do mundo ocidental, acompanharam, fizeram parte, criaram e feneceram no próprio movimento do vir-a-ser do semiárido.; Triggering some flashes that glance at the childhood universe...