915 resultados para Forest, Fred, 1933-
Resumo:
Translocation experiments showed that a woodcreeper bird species is able to move between isolated forest fragments, but this ability is limited by increasing interpatch distances. Larger distances (> 100 m) were overcome by using small stepping-stones (isolated trees), which enhance connectivity and are useful for the species conservation in fragmented landscapes.
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Based on the fact that streamwater quality reflects landscape conditions, the objectives of this study were: to investigate nitrogen (N), carbon (C), and major ion concentrations in six streams crossing minimally disturbed Atlantic Forest areas, with similar geomorphological characteristics; to determine N and C fluxes in one of these pristine streams (Indaia); and assess the impact of human activity on the biogeochemistry of two other streams in the same region, crossing urbanized areas. The distribution pattern of carbon and inorganic nitrogen dissolved forms, as well as the major ion and biogenic gas concentrations in the streamwater, was similar in pristine streams, indicating that the C and N dynamics were determined by influence of some factors, such as climate, atmospheric deposition, geology, soil type, and land covering, which were analogous in the forested watersheds. The urban streams were significantly different from the pristine streams, showing low dissolved oxygen concentrations, high respiration rates, and high concentrations of carbon dioxide, dissolved inorganic nitrogen, dissolved inorganic carbon, and major ion. These differences were attributed to anthropogenic impact on water quality, especially domestic sewage discharge. Additionally, in the Indaia stream, it was possible to observe the importance of rainfall over temporal dynamics of dissolved carbon forms, and also, the obtained specific flux of dissolved inorganic nitrogen was relatively elevated (approximately 11 kg ha(-1) year(-1)). These results reveal the influence of human activity over the biogeochemistry of coastal streams and also indicate the importance N export of Atlantic Forest to the ocean.
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We describe the advertisement call, tadpole, karyotype, and additional information on the natural history of Cycloramphus lutzorum from southern Brazil. Sonograms were generated from digitally recorded calls. Tadpoles were collected in the field for description in the lab, and an adult was collected for karyotyping. Data on seasonal activity were gathered monthly from November 2005 to November 2007. All tadpoles (N = 21), juveniles (N = 18), and adults (N = 52) were found exclusively in streams. Reproduction, as identified by calling frogs, occurred from July through November. Frogs call all day long, but mostly at dusk, from rock crevices inside the stream edges near the splash zone. The call is short and loud, with 11 pulsed notes, of 491-641 ms, with a dominant frequency of 0.98-1.39 kHz. We describe the exotrophic and semiterrestrial tadpoles, always found in constantly humid vertical rock walls in the stream. Tadpoles of C. lutzorum are recognized by differences in labial tooth row formula, eye diameter, body shape, position of nares, and development of tail. Like congeneric species, the karyotype of C. lutzorum comprises 26 metacentric and submetacentric chromosomes. Cycloramphus lutzorum is restricted to and adapted for living in fast flowing streams, many of which are threatened by deforestation, pollution, and habitat loss. Therefore, we recommend the status of C. lutzorum be changed from its current ""Data Deficient"" to ""Near Threatened (NT)"" in the IUCN species red list.
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The open vegetation corridor of South America is a region dominated by savanna biomes. It contains forests (i.e. riverine forests) that may act as corridors for rainforest specialists between the open vegetation corridor and its neighbouring biomes (i.e. the Amazonian and Atlantic forests). A prediction for this scenario is that populations of rainforest specialists in the open vegetation corridor and in the forested biomes show no significant genetic divergence. We addressed this hypothesis by studying plumage and genetic variation of the Planalto woodcreeper Dendrocolaptes platyrostris Spix (1824) (Aves: Furnariidae), a forest specialist that occurs in both open habitat and in the Atlantic forest. The study questions were: (1) is there any evidence of genetic continuity between populations of the open habitat and the Atlantic forest and (2) is plumage variation congruent with patterns of neutral genetic structure or with ecological factors related to habitat type? We used cytochrome b and mitochondrial DNA control region sequences to show that D. platyrostris is monophyletic and presents substantial intraspecific differentiation. We found two areas of plumage stability: one associated with Cerrado and the other associated with southern Atlantic Forest. Multiple Mantel tests showed that most of the plumage variation followed the transition of habitats but not phylogeographical gaps, suggesting that selection may be related to the evolution of the plumage of the species. The results were not compatible with the idea that forest specialists in the open vegetation corridor and in the Atlantic forest are linked at the population level because birds from each region were not part of the same genetic unit. Divergence in the presence of gene flow across the ecotone between both regions might explain our results. Also, our findings indicate that the southern Atlantic forest may have been significantly affected by Pleistocene climatic alteration, although such events did not cause local extinction of most taxa, as occurred in other regions of the globe where forests were significantly affected by global glaciations. Finally, our results neither support plumage stability areas, nor subspecies as full species. (C) 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 103, 801-820.
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To elucidate the relationship between forest dynamics and fire frequency pollen percentages and charcoal amounts from a 120 cm long peat core and from samples of modern pollen rain were collected along a transect. The study site in southern Brazil is characterized by a species-rich mosaic of grassland-Araucaria forest. It is of crucial importance for management strategies for conservation to understand the development and maintenance of these vegetation mosaics including their sharp forest-grassland boundaries. During the late Holocene, considerable changes occurred in the area. From Anno Domini (AD) 1360 to 1410, the area was dominated by Campos (grassland) vegetation and fire was very common. From AD 1410 to 1500, Araucaria forest expanded and fire was less frequent. From AD 1500 to 1580, Campos grassland spread and the Araucaria forest ceased its development, apparently due to the increase of fire. From AD 1580 to 1935, after a decrease in fire frequency, Araucaria forest expanded again. From AD 1935 to the present, the Araucaria forest expanded while the Campos area decreased. Fire was very rare in this period. The results indicate a strong interaction of forest expansion, forming a mosaic of Campos and Araucaria forest, and the frequency of fire during the past 600 years. A possible collapse of the indigenous population following the post-Colombian colonization in southern Brazil after about AD 1550 may have caused a great reduction of fire frequency. The introduction of cattle (probably after AD 1780) and the resulting decrease of fire frequency might be the reason for forest expansion. Fire is probably the most important factor controlling the dynamics of the forest-grassland mosaics and the formation of sharp borders between these two vegetation types. (C) 2010 Elsevier B.V. All rights reserved.
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In the present study, we compared 2 methods for collecting ixodid ticks on the verges of animal trails in a primary Amazon forest area in northern Brazil. (i) Dragging: This method was based on passing a 1-m(2) white flannel over the vegetation and checking the flannel for the presence of caught ticks every 5-10 m. (ii) Visual search: This method consisted of looking for guesting ticks on the tips of leaves of the vegetation bordering animal trails in the forest. A total of 103 adult ticks belonging to 4 Amblyomma species were collected by the visual search method on 5 collecting dates, while only 44 adult ticks belonging to 3 Amblyomma species were collected by dragging on 5 other collecting dates. These values were statistically different (Mann-Whitney Test, P = 0.0472). On the other hand, dragging was more efficient for subadult ticks, since no larva or nymph was collected by visual search, whereas 18 nymphs and 7 larvae were collected by dragging. The visual search method proved to be suitable for collecting adult ticks in the Amazon forest: however, field studies should include a second method, such as dragging in order to maximize the collection of subadult ticks. Indeed, these 2 methods can be performed by a single investigator at the same time, while he/she walks on an animal trail in the forest. (C) 2010 Elsevier GmbH. All rights reserved.
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Sand fly populations of different ecological niches in the Amaraji endemic American Cutaneous Leishmaniasis (ACL) focus of the Pernambuco Atlantic Forest region of northeastern Brazil were monitored spatiotemporally. Lutzomyia whitmani was dominant in all niches but occurred in smaller numbers in forested locations. L. whitmani was significantly less seasonal than the other species, being present throughout the year while other species were more abundant between February and April. These results suggest that L. whitmani may potentially be the principal vector of ACL in the region, even though the sand fly fauna was diverse: 88% were L.whitmani and 12% belonged to 11 other species. Two other species, L. complexa (1.3%) and L. migonei (0.8%), considered to be ACL vectors in other regions, were also present. This detailed picture of the sand fly population`s abundance and spatiotemporal distribution provides a basis for future modeling studies of forecasting sand fly activity patterns and ACL occurence.
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Aerosol physical and chemical properties were measured in a forest site in central Amazonia (Cuieiras reservation, 2.61S; 60.21W) during the dry season of 2004 (Aug-Oct). Aerosol light scattering and absorption, mass concentration, elemental composition and size distributions were measured at three tower levels (Ground: 2 m; Canopy: 28 m, and Top: 40 m). For the first time, simultaneous eddy covariance fluxes of fine mode particles and volatile organic compounds (VOC) were measured above the Amazonian forest canopy. Aerosol fluxes were measured by eddy covariance using a Condensation Particle Counter (CPC) and a sonic anemometer. VOC fluxes were measured by disjunct eddy covariance using a Proton Transfer Reaction Mass Spectrometer (PTR-MS). At nighttime, a strong vertical gradient of phosphorus and potassium in the aerosol coarse mode was observed, with higher concentrations at Ground level. This suggests a source of primary biogenic particles below the canopy. Equivalent black carbon measurements indicate the presence of light-absorbing aerosols from biogenic origin. Aerosol number size distributions typically consisted of superimposed Aitken (76 nm) and accumulation modes (144 nm), without clear events of new particle formation. Isoprene and monoterpene fluxes reached respectively 7.4 and 0.82 mg m(-2) s(-1) around noon. An average fine particle flux of 0.05 +/- 0.10 10(6) m(-2) s(-1) was calculated, denoting an equilibrium between emission and deposition fluxes of fine mode particles at daytime. No significant correlations were found between VOC and fine mode aerosol concentrations or fluxes. (C) 2009 Elsevier Ltd. All rights reserved.
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This article discusses seasonal and interannual variations of the evapotranspiration (ET) rates in Bananal Island floodplain, Brazil. Measurements included ET and sensible heat flux using the eddy covariance method, atmospheric forcings (net radiation, Rn, vapor pressure deficit, VPD, wind speed and air temperature), soil moisture profiles, groundwater level and flood height, taken from November 2003 to December 2006. For the hydrological years (October-September) of 2003/2004, 2004/2005 and 2005/2006, the accumulated precipitation was 1692, 1471, 1914 mm and the accumulated ET was 1361, 1318 and 1317 mm, respectively. Seasonal analyses indicated that ET decreased in the dry season (average 3.7 mm day(-1)), despite the simultaneous increase in Rn, air temperature and VPD. The increase of ET in the wet season and particularly in the flood period (average 4.1 mm day(-1)) showed that the free water surface evaporation strongly influenced the energy exchange. Soil moisture, which was substantially depleted during the dry season, and adaptative vegetation mechanisms such as leaf senescence contributed to limit the dry season ET. Strong drainage within permeable sandy soils helped to explain the soil moisture depletion. These results suggest that the Bananal flooding area shows a different pattern in relation to the upland Amazon forests, being more similar to the savanna strictu senso areas in central Brazil. For example, seasonal ET variation was not in phase with Rn; the wet season ET was higher than the dry season ET; and the system stored only a tiny memory of the flooding period, being sensitive to extended drought periods.
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We investigated the seasonal patterns of water vapor and sensible heat flux along a tropical biome gradient from forest to savanna. We analyzed data from a network of flux towers in Brazil that were operated within the Large-Scale Biosphere-Atmosphere Experiment in Amazonia (LBA). These tower sites included tropical humid and semideciduous forest, transitional forest, floodplain (with physiognomies of cerrado), and cerrado sensu stricto. The mean annual sensible heat flux at all sites ranged from 20 to 38 Wm(-2), and was generally reduced in the wet season and increased in the late dry season, coincident with seasonal variations of net radiation and soil moisture. The sites were easily divisible into two functional groups based on the seasonality of evaporation: tropical forest and savanna. At sites with an annual precipitation above 1900 mm and a dry season length less than 4 months (Manaus, Santarem and Rondonia), evaporation rates increased in the dry season, coincident with increased radiation. Evaporation rates were as high as 4.0 mm d(-1) in these evergreen or semidecidous forests. In contrast, ecosystems with precipitation less than 1700 mm and a longer dry season (Mato Grosso, Tocantins and Sao Paulo) showed clear evidence of reduced evaporation in the dry season. Evaporation rates were as low as 2.5 mm d(-1) in the transitional forests and 1 mm d(-1) in the cerrado. The controls on evapotranspiration seasonality changed along the biome gradient, with evaporative demand (especially net radiation) playing a more important role in the wetter forests, and soil moisture playing a more important role in the drier savannah sites.
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This study was conducted at three sites of different characteristics in Sao Paulo State Sao Paulo (SPA), Piracicaba (PRB) and Mate Atlantica Forest (MAT) PM(10), n-alkanes. pristane and phytane, PAHs, water-soluble ions and biomass burning tracers like levoglucosan and retene, were determined in quartz fiber filters. Samplings occurred on May 8th to August 8th, 2007 at the MAT site; on August 15th to 29th in 2007 and November 10th to 29th in 2008 at the PRB site and, March 13th to April 4th in 2007 and August 7th to 29th in 2008 at the SPA site Aliphatic compounds emitted biogenically were less abundant at the urban sites than at the forest site, and its distribution showed the influence of tropical vascular plants Air mass transport front biomass burning regions is likely to impact the sites with specific molecular markers The concentrations of all species were variable and dependent of seasonal changes In the most dry and polluted seasons, n-alkane and canon total concentrations were similar between the megacity and the biomass burning site PAHs and inorganic ion abundances were higher at Sao Paulo than Piracicaba, yet, the site influenced by biomass burning seems lobe the most impacted by the organic anion abundance in the atmosphere Pristane and phytane confirm the contamination by petroleum residues at urban sites, at the MAT site, biological activity and long range transport of pollutants might influence the levels of pristane (C) 2010 Elsevier B V All rights reserved
Resumo:
The volatile oil composition and anti-acetyl cholinesterase activity were analyzed in two specimens of Marlierea racemosa growing in different areas of the Atlantic Rain Forest (Cananeia and Caraguatatuba, SP, Brazil). Component identifications were performed by GUMS and their acetyl cholinesterase inhibitory activity was measured through colorimetric analysis. The major constituent in both specimens was spathulenol (25.1 % in Cananeia and 31.9% in Caraguatatuba). However, the first one also presented monoterpenes (41.2%), while in the Carguatatuba plants, this class was not detected. The oils from the plants collected in Cananeia were able to inhibit the acetyl cholinesterase activity by LIP to 75%, but for oils from the other locality the maximal inhibition achieved was 35%. These results suggested that the monoterpenes are more effective in the inhibition of acetyl cholinesterase activity than sesquiterpenes as these compounds are present in higher amounts in the M. racemosa plants collected in Cananeia.
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Denna uppsats dokumenterar uppkomst, frontpersoner och verksamhet för Dalarnes sjuksköterskeförening (DSF) mellan åren 1920-1933, vilket är en lokal sjuksköterskeförening som senare blev underavdelning till riksföreningen Svensk sjuksköterskeförening (SSF). DSF var den första lokala sjuksköterskeföreningen och startades 1920 av sjuksköterskor kring området Falun/Borlänge. Det var inte en elitförening likt SSF som i sin professionalisering enbart ville avskärma sig från de underordnade som biträden och kämpa för status och kalltanken. DSF var en förening som ville stärka kårandan men även arbeta för löne- och arbetsförhållandefrågor, vilket på den tiden egentligen hörde samman med socialistiska föreningar. I sin verksamhet ville de även få till stånd en platsbyrå för föreningens medlemmar. Det var en politiskt oberoende förening som arbetade fackligt. År 1933 blev Dalarnes sjuksköterskeförening en underavdelning till SSF som från och med det året började arbeta fackligt på lokalföreningars begäran.
Resumo:
Syftet med uppsatsen är att kartlägga bildandet av Dalarnas mejeriförening med hjälp avfrågeställningar angående hur, varför och av vilka personer föreningen skapades samt hurorganisationen Dalarnas mejeriförening kan tolkas med teorier om sociala rörelser och sociala nätverk. Undersökningen baserar sig på källmaterial från Dalarnas mejeriförening ochKopparbergs läns hushållningssällskap. Resultatet av undersökningen är att Dalarnasmejeriförening kan anses vara en social rörelse som bildades för att kontrollera mejerihanteringen i Dalarna. Dalarnas mejeriförening implementerade en omorganisering ilinje med den kooperationsteoretiska rörelseteorin. Rörelsens organisation var baserad på enregelorienterad tolkning av kooperationsprinciperna och rörelseideologin på envärdeorienterad tolkning av desamma. Rörelsens mobiliseringsstruktur var god på grund av en fördelaktig politisk möjlighetsstruktur och framgångsrika nätverksrelationer både inom rörelsen men också mellan rörelsen och andra jordbruksorganisationer.
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Denna uppsats kretsar kring att pröva hur en av de främsta företrädarna för den realistiska skolan, förklarar de amerikanska anfallen mot Afghanistan (2001) och Irak (2003). Hans namn är Robert Kagan och uppsatsen syftar till ge en realists tolkning till varför USA handlade som man gjorde. Man måste därför försöka uppfatta världen utifrån USA:s horisont och försöka tolka samt sätta sig in i den amerikanska positionen på den internationella arenan. Problemformuleringarna kretsar kring att få insikt i grundstenarna i Kagans teori, samt hur Kagans grundsyn skiljer sig gentemot den idealistiska. Vidare hur USA:s militära styrka, enligt Kagan, påverkar dess beteende på den internationella arenan, men även hur Kagan ser på USA:s kommande globala engagemang. Robert Kagans bok Om paradiset och makten USA och Europa i den nya världsordningen kommer att utgöra fundamentet i studien. I boken kretsar bl.a. Kagans resonemang kring att USA och Europa distanserar från varandra, men även kring militär styrka. Därför ger boken oss en väldigt bra bild av USA:s position på den internationella arenan. Kagans resonemang vävs sedan ihop med kritik, realism, idealism och geopolitik. Slutsatsen blir att grundstenarna i Kagans resonemang återfinns i den s.k. realismteorin, men även till viss del i geopolitiken. Han sätter stor vikt vid militära medel och ser staterna som de mest betydelsefulla aktörerna, samt ser världen som allmänt hotfull. Han realistiska resonemang grundas på amerikanska spelregler och ledarskap på den internationella arenan. Skillnaden mellan Kagans grundsyn och den idealistiska bottnar främst i idealisternas fokusering på integration mellan stater. Vidare att de sätter tilltro till internationell rätt, samt har ett mer multilateralt förhållningssätt till omvärlden. Kagan menar vidare att starka stater är mer villiga att använda tvång och hot i internationella relationer. De bedömer dessutom hot och risker annorlunda jämfört med svagare stater. Enligt Kagan beter sig USA som en internationell sheriff på den globala arenan och beteendet bottnar i militär styrka. Vidare anser Kagan att USA har haft samma kurs i flera århundraden. USA har expanderat in i Europa och Asien och aldrig dragit sig tillbaka. Man hade redan före den 11 september 2001 fokuserat på Kina som motspelare. Dessutom, menar Kagan, att USA varit villiga att satsa på ny militär teknik, vilken kan förändra krigföringen. Han skriver även att både Clinton och Bushadministrationen varit grundade på att USA är en nödvändig nation, samt att amerikaner vill beskydda och sprida det liberala systemet i världen.