Atlantic Coast Of Brazil Research Articles

Variação do índice de área foliar em clones de eucalipto ao longo de seu ciclo de crescimento

O índice de área foliar (IAF) é uma das principais variáveis biofísicas de um dossel florestal, estando diretamente relacionado com a sua evapotranspiração e sua produtividade. Este trabalho apresenta um levantamento da variabilidade temporal do IAF em cinco diferentes clones (designados para efeito deste trabalho como MG1, MG2, MG3, MG4 e MG5) de plantações de eucalipto (híbridos de Eucalyptus grandis), na regional de produção de Aracruz-ES, Brasil. Utilizou-se o equipamento LAI-2000 para medir o IAF em 98 talhões, com didade variando de 12 a 84 meses. o IAF variou de 1,7 a 4,3. Houve correlação negativa significativa entre IAF e idade para os clones MG1, MG2, e MG3. Para os clones MG4 e MG5 foi constatado que não houve relação significativa entre IAF e idade, o que evidencia que sejam adotados valores médios de IAF destes clones como descritores estruturais do dossel para fins de modelagem ou outros (2,57 e 3,04, respectivamente).

Use of space and temporal distribution of Trichechus manatus manatus Linnaeus in the region of Sagi, Rio Grande do Norte State, Brazil (Sirenia, Trichechidae)

The marine manatee Trichechus manatus manatus Linnaeus, 1758 is endangered in the Brazilian Atlantic coast due to indiscriminate hunting practiced in the past, and to the low reproductive rate of the species. This work studies its use of space and temporal occurrence in the coastal area of Sagi, Northeastern Brazil. Daily observations from the beach of the animals in the sea were made during daytime from 1990 through 1993. The presence of reefs covered with marine algae is a determinant factor in the occurrence of the manatee. They were sighted feeding on algae that grow over the reefs close to beaches that were of high energy during high tide. The range used by manatees shifted according to tide. They occur in depths of 0.4 to 3.8 m; the distance from the beach varies according to the tide level. They show marked seasonality of occurrence, with higher frequencies in December - January and lowest in June - July. Two possible causes of the seasonal occurrence are discussed. Sagi is important for the conservation of the species in Northeastern Brazil as feeding and reproductive grounds.

The Dodo Went Extinct (And Other Ecological Myths)

The scientific consensus is that human impacts are driving species to extinction hundreds to thousands of times faster than expected from the natural background rate. Critics challenge this. Perhaps giving them more credit than they deserve, I examine four concerns. First, that the extinction crisis is not real. It is and high rates of extinction are the rule, not the exception, within well-known taxa. The second criticism dismisses the problem as one restricted just to islands. It is not. Island species have special vulnerabilities, but they are far more locally abundant within their ranges than are continental species with the same range size. There are large numbers of locally rare, continental species with small geographic ranges that are threatened by human impacts A third criticism notes the few species that became extinct following the clearing of forests from eastern North America in the 19th century, casting doubt upon the relationship between habitat loss and species loss. Analysis of this case history shows that exactly as many species of birds were lost as expected, for the region had very few species to lose. Extensions to species-rich areas such as Southeast Asia and the Atlantic coast of Brazil confirm the expected calibrations with an interesting caveat Forest losses predict the number of threatened species-those on the verge of extinction-not the number of extinctions. This leads to the final criticism: that there have been too few recent extinctions. The reply is that in these regions the deforestation is more recent and species do not go extinct immediately. Some doomed species can linger for decadesas did the now-extinct species in eastern North America.

New species and combinations in Thelypteris subg. Goniopteris (Thelypteridaceae)

Abstract New species and combinations in Thelypteris subg. Goniopteris (Thelypteridaceae). Brittonia 54: 331–339. 2002.—Three new species of Thelypteris are described and illustrated: T. littoralis and T. paranaensis, endemic to the rainforest of the southern Brazilian Atlantic coast, and T. multigemmifera, endemic to inland gallery forests of the Sao Paulo state. In addition, four new combinations are made: T. cutiataensis (Brade) Salino, T. iguapensis (C. Chr.) Salino, T. monosora (C. Presl) Salino, and T. schwackeana (H. Christ in C. Chr.) Salino. A new name is proposed for Dryopteris lugubris var. quadrangularis: T. montana Salino. The species treated here belong to Thelypteris subg. Goniopteris due to the indument of furcate and stellate trichomes.

Cytogenetic Analysis of Coral Reef Fishes from Brazil (Families Pomacanthidae and Chaetodontidae).

Three perciform species associated to coral reefs were, for the first time, investigated under a cytogenetic focus: Holacanthus ciliaris and H. tricolor from family Pomacanthidae and Chaetodon striatus from family Chaetodontidae. Individuals were collected at different sites along Atlantic coast of Brazil. All of them showed similar chromosomal features, considered primitive for the order. These characteristics are 2n=48, NF=48, NORs located at interstitial position on long arms of a single chromosomal pair and discrete heterochromatic blocks at centromeres and NORs.

Neoproterozoic western gondwana assembly and subductionrelated plutonism: the role of the Rio Negro Complex in the Ribeira Belt

The assembly of Western Gondwana, during the Neoproterozoic, involved the Sao Francisco/West Congo Craton and its passive margins. The Ribeira Belt lies along the Brazilian Atlantic Coast and is one of the products of the supercontinent amalgamation. Collisional processes were preceded by subduction, recorded by the Rio Negro Complex orthogneisses at the Ribeira Belt. Its plutonites represent a gabbrodiorite- tonalite-throndhjemite plutonic series that evolved from 637 Ma (U-Pb zircon age of the tonalite gneiss) to nearly 600 Ma, at the beginning of the collisional event. Field, petrographic, litogeochemical, and isotopic characteristics of the Rio Negro Complex point to magmatism at a very mature oceanic arc or an immature continental crust as seen along attenuated passive margins. In the latter hypothesis, the margin could be related to a microplate or to the Congo/Angola Craton.

NEOPROTEROZOIC WESTERN GONDWANA ASSEMBLY AND SUBDUCTIONRELATED PLUTONISM: THE ROLE OF THE RIO NEGRO COMPLEX IN THE RIBEIRA BELT

The assembly of Western Gondwana, during the Neoproterozoic, involved the São Francisco/West Congo Craton and its passive margins. The Ribeira Belt lies along the Brazilian Atlantic Coast and is one of the products of the supercontinent amalgamation. Collisional processes were preceded by subduction, recorded by the Rio Negro Complex orthogneisses at the Ribeira Belt. Its plutonites represent a gabbrodiorite-tonalite-throndhjemite plutonic series that evolved from 637 Ma (U-Pb zircon age of the tonalite gneiss) to nearly 600 Ma, at the beginning of the collisional event. Field, petrographic, litogeochemical, and isotopic characteristics of the Rio Negro Complex point to magmatism at a very mature oceanic arc or an immature continental crust as seen along attenuated passive margins. In the latter hypothesis, the margin could be related to a microplate or to the Congo/Angola Craton.

Atmospheric Pollution in a Tropical Rain Forest: Effects of Deposition Upon Biosphere and Hydrosphere I. Concentrations of Chemicals

The effects of atmospheric deposition upon elementcycling and turnover in three rain forest ecosystems ofthe Serra do Mar, a mountain range along the atlanticcoast of Brazil, have been investigated as part of aninterdisciplinary German-Brazilian research project ondispersion, transformation and deposition of airpollutants in the vicinity the industrial complex ofCubatao, State of Sao Paulo. The projectincluded on-site measurements from 1991 to 1995, fieldexperiments and mathematical modelling with the goalof providing damage evaluation and risk assessment,and elucidating damage mechanisms with respect tosoils and vegetation. The role of the `Soil Module'sub-project reported here was to assess atmosphericdeposition and fluxes with precipitation and soilwater, and to investigate possible soil changesinduced by atmospheric deposition as well asbiological effects of pollutants via the soil path.Part I of this paper deals with concentrations ofchemicals in precipitation, soil water, surface waterand in litter. Part II will cover fluxes of chemicalsand element budgets.Three sites were chosen which differed significantlywith respect to pollution impact. Annual averages ofionic concentrations in precipitation found in openfield and below the tree canopy amounted to 5 and10 mg L-1, respectively, for sulfate-S, 0.4 and0.7 mg L-1 for nitrate, 0.65 and 1.1 mg L-1 for fluoride,1.8 and 2.6 mg L-1 for ammonium-N, 0.76 and 2.3 mg L-1for Mg, and 3.5 and 7.5 mg L-1 for Ca at the mostpolluted site. The relatively `clean' reference siteattained 1/3 to 1/9 of these averages, thus clearlyreflecting the difference in air pollution load.Chemical composition in the liquid phase is completelychanged when precipitation infiltrates the soilprofile. Nitrate concentration increases by the factor5 to 20. A clear increase is also found for sulfateand chloride. Concentration changes during ecosystempassage of seepage are interpreted in relation tochemical reactions taking place in differentcompartments. They are characterized by an almostcomplete retention of ammonium and some retention ofsulfate in the upper soil layers, and at the mostpolluted site by mobilization of Al from soil mineralsand very high leaching of nitrate as a consequence ofnitirification of organic matter.

Hampsonellus Brasiliensis N. Gen., N. Sp., a Cephalocarid from Brazil

Abstract A new genus and species, Hampsonellus brasiliensis, is described. This species has been found in shallow, marine, soft bottoms on the southern Atlantic coast of Brazil. We discuss the principal generic differences in the Cephalocarida, which are in reproductive modifications of limb structure of posterior thoracopods.

The vegetation of granite rock outcrops in Rio de Janeiro, Brazil, and the need for its protection

Rock outcrop communities usually receive very little attention from scientists and environmentalists. We examined the vegetation occurring in eight gneiss-granite rock outcrops at Rio de Janeiro State (Brazilian Atlantic coast) which exists in natural associations on soil islands. A total of 86 vascular plant species, belonging to 30 families, was found on 347 soil islands. Bromeliaceae, Asteraceae and Velloziaceae species were the most frequent plants, many of them endemic to these habitats. Ordination and cluster analyses using species frequency on each site made evident some major distinctions related to local influences, most probably the proximity to the sea. Each outcrop presented high values of the Shannon-Wiener index of species diversity. Species richness was very dependent on the total area, and high beta diversity was observed amongst sites. Similarities with the South American and African rock-outcrop communities were found. Despite their uniqueness as habitats, their possession of several endemic species and the fragility of the ecosystem involved, Brazilian rock outcrops are not protected by specific environmental legislation and we propose urgent actions for their protection.

A high resolution Holocene pollen record from Lago do Pires, SE Brazil: vegetation, climate and fire history

Lago do Pires (17° 57′ S, 42° 13′ W) is situated at 390 m a.s.l. in the foothills of the Serra do Espinhaco, 250 km from the Brazilian Atlantic coast. The original vegetation of the study area has been almost destroyed by pastoral activity. Relicts of a dense 20–30 m tall tropical semidciduous forest are present only on a few hill tops. The dry season of the Lago do Pires region lasts for 4 months and the annual precipitation is 1250 mm. A high resolution pollen record from a 16 m long sediment core, composed of 77 samples, subdivided in 7 zones and 4 subzones, allows a reconstruction of Holocene paleoenvironments. For the early Holocene (9720-8810 B.P.), the results indicate that the region surrounding the lake was dominated by a herb savanna (campo cerrado) withCuratella americana (cerrado tree) and high fire frequency. Species ofCecropia, Urticales and a few others, form small gallery forests along the water courses. This vegetation pattern is consistent with a long dry season (perhaps 6 months) and a low annual precipitation. Between 8810 and 7500 years B.P. gallery forests expanded in the valleys and suggest a period of higher rainfall with shortened dry season (perhaps 5 months). Fire was less frequent. Reduction of gallery forests followed (7500-5530 B.P.), probably related to a return of drier climatic conditions (5–6 months dry season, lower precipitation). Fires were more frequent. Between 5530 and 2780 years B.P. in the vallyes were forests and on the hills still an open cerrado. The dry season probably was about 5 months and the rainfall was higher than in the previous period. Later (2780-970 B.P.) the more open cerrado on the hills changed to more closed cerrado. A dense and closed semideciduous forest existed in the region only in the latest Holocene period (since 970 B.P.) under the current climatic conditions. The vegetation was no longer influenced by fire. A very strong human impact by deforestation and use of fire occurred in the last decades. Today cerrado vegetation is generally restricted to central Brazil and exists in several small isolated ‘Islands’ (Hueck, 1956) in the area of semideciduous forest in SE Brazil which were more widespread during the drier periods of the Holocene. The wettest period of Holocene occurs in the present millenium.

Potentially pathogenic vibrios associated with mussels from a tropical region on the Atlantic coast of Brazil

Mussels (Perna perna) harvested on the coast of Ubatuba, in three different stations in the State of São Paulo, Brazil, were examined for Vibrio spp. over a 1 year period. The ranges of most probable number (MPN 100 g-1) were: Vibrio alginolyticus (< 3-24,000), V. parahaemolyticus (< 3-24,000), V. fluvialis (< 3-1100), V. cholerae non-O1 (< 3-23), V. furnissii (< 3-30), V. mimicus (< 3-9) and V. vulnificus (< 3-3). The highest incidence was observed for V. alginolyticus (92-100%), followed by V. parahaemolyticus (67-92%), V. fluvialis (34-67%), V. vulnificus (8-17%), V. furnissii (0-17%), V. mimicus (0-17%) and V. cholerae non-O1 (0-8%). Tests for virulence factors were positive in 34.1% of the vibrios in the rabbit ileal loop and 31.7% in the Dean test. Positive results in the Kanagawa test were obtained with 0.51% of V. parahaemolyticus strains. The mean values (MPN 100 g-1) of faecal coliforms in mussels from the three regions varied from 1100 to 44,000, and seawater collected at the same stations gave average values for faecal coliforms in the range 18-3300 MPN 100 ml-1. These results highlight the potential risks of food poisoning associated with raw or undercooked seafood.

Style and pattern of salt diapirs due to thin-skinned gravitational gliding, Campos and Santos basins, offshore Brazil

Portions of seismic lines and a structure-contour map illustrate the patterns and shapes of salt diapirs and related structures in the Campos and Santos areas, off the Atlantic coast of Brazil. We interpret the structures both kinematically and mechanically, drawing on our experience with similar salt structures worldwide, with the results of recent physical modelling and with geometric restorations in section and in plan. Salt diapirs and related structures have a variety of structural styles, distributed in domains and provinces. Near the coast, there is an upper domain, 100–200 km wide, with a suite of structures that we attribute to horizontal downdip extension: these are salt rollers, in the footwalls of listric normal growth faults; salt walls of triangular cross section, beneath intersecting conjugate normal faults; turtle anticlines; and salt welds. Downslope extension started in the Albian and has continued to the present day. In the Campos area, from simple line balancing, the accumulated downslope displacement is about 100 km. Seawards of this, there is a lower domain, 100–400 km wide, with a different suite of structures, that we attribute to downdip contraction: these are growth folds of various wavelengths, in sedimentary sequences of various thicknesses; asymmetric salt walls, emplaced above reverse faults; deep basins, wedged down between conjugate reverse faults; and salt tongues above thrusts. For Campos, we estimate the total downslope contraction, accumulated since the Albian, to be about 100 km. From the balance between extension and contraction, we infer that the thin-skinned salt tectonics are gravitationally driven and independent of any basement tectonics. The structure-contour map on the top of the salt shows that structural style is variable also along strike. Seismic sections along regional contours indicate differing amounts of strain. On this basis, we distinguish five provinces, separated by NW-SE-trending lines. For the Northern Campos province, we infer radially convergent gliding; for the Campos or Cabo Frio provinces, radially divergent gliding; and for Northern Santos, divergent gliding at a large scale. The pattern in Southern Santos is complicated by right-lateral wrenching against the southern edge of the salt.

A new species ofPodapolipus(Acari: Podapolipidae) fromLophacris olfersii(Acrididae) from South America

Abstract Podapolipus welbourni new species (Acari: Podapolipidae) is decribed from Lophacris olfersii Brun. 1838 (Orthoptera: Acrididae) from the Atlantic coast of Brazil.

Influência do cloro, sôbre a composição do caldo da cana de açúcar Co 290, aplicado no solo, na forma de cloreto de sódio

Considering the economic importance of the sugar industry among ourselves, the authors carried out a field experiment (Latin square) with Co 290 sugar cane, on a white sandy soil of Piracicaba, State of Sao Paulo, Brazil, applying NaCl in increasing rates (from 6.8 to 54.5 grams per plant), in order to study the effects of chlorides, on productivity and on the composition of juice. No toxic or stimulating effect was found, and there was no change in yield, in degree of purity of the juice, in general aspect of plants or in colour of leaves and culms. No difference was observed between potassium sulphate or chloride, as source of potash for sugar cane culture. Data collected and the literature cited suggest: (a) that the use of the variety Co 290 is indicated for soils rich in chlorine, such as the saline soils of the North-east and Atlantic Coast of Brazil; (b) that it is necessary to extend studies in Research Institutes and Agricultural Experiment Stations of the country to verify the behaviour of other varieties of sugar cane in the types of soils mentioned, especially with respect their yielding capacity. The authors are already planning such investigations.