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The role of abrupt climate change in the formation of an open vegetation enclave in northern Amazonia during the late Quaternary
No full textThe effects of climate changes on biotic expansion or divergence is a widely debated topic. This discussion is particularly relevant for northern Amazonia where patches of open vegetation environments that harbor high endemic and specialized species are present in a matrix of tall closed canopy forest. This paper presents the depositional chronology and evolution of an 8.7-m thick stabilized fluvial and eolian sediment profile in a sandy plain substrate that underpins the largest open vegetation enclave in northern Amazonia. Three depositional units were identified using optically stimulated luminescence and radiocarbon ages coupled with grain size, magnetic susceptibility, and reflectance analyses. A lower unit of coarse fluvial silt deposited between 53 and 28 ka is overlain unconformably by a 5-m thick middle unit of fine eolian sand deposited at high accumulation rates between the Last Glacial Maximum (23–19 ka) and Heinrich Stadial 1 (HS1; 18.1–14.7 ka) when persistent and long-lasting shifts of the Intertropical Convergence Zone (ITCZ) to the Southern Hemisphere promoted dry and windy conditions in northern South America. An upper ~2-m thick unit was deposited when the climate became wetter after HS1, promoting the formation of soils that support open vegetation habitats. This study indicates that abrupt millennial-scale climate events can induce significant changes in the Amazonian landscape, which in turn play an essential role in the distribution and diversification of specialized biota. © 2018 Elsevier B.V
ATLANTIC EPIPHYTES: a data set of vascular and non-vascular epiphyte plants and lichens from the Atlantic Forest
Get PDFEpiphytes are hyper-diverse and one of the frequently undervalued life forms in plant surveys and biodiversity inventories. Epiphytes of the Atlantic Forest, one of the most endangered ecosystems in the world, have high endemism and radiated recently in the Pliocene. We aimed to (1) compile an extensive Atlantic Forest data set on vascular, non-vascular plants (including hemiepiphytes), and lichen epiphyte species occurrence and abundance; (2) describe the epiphyte distribution in the Atlantic Forest, in order to indicate future sampling efforts. Our work presents the first epiphyte data set with information on abundance and occurrence of epiphyte phorophyte species. All data compiled here come from three main sources provided by the authors: published sources (comprising peer-reviewed articles, books, and theses), unpublished data, and herbarium data. We compiled a data set composed of 2,095 species, from 89,270 holo/hemiepiphyte records, in the Atlantic Forest of Brazil, Argentina, Paraguay, and Uruguay, recorded from 1824 to early 2018. Most of the records were from qualitative data (occurrence only, 88%), well distributed throughout the Atlantic Forest. For quantitative records, the most common sampling method was individual trees (71%), followed by plot sampling (19%), and transect sampling (10%). Angiosperms (81%) were the most frequently registered group, and Bromeliaceae and Orchidaceae were the families with the greatest number of records (27,272 and 21,945, respectively). Ferns and Lycophytes presented fewer records than Angiosperms, and Polypodiaceae were the most recorded family, and more concentrated in the Southern and Southeastern regions. Data on non-vascular plants and lichens were scarce, with a few disjunct records concentrated in the Northeastern region of the Atlantic Forest. For all non-vascular plant records, Lejeuneaceae, a family of liverworts, was the most recorded family. We hope that our effort to organize scattered epiphyte data help advance the knowledge of epiphyte ecology, as well as our understanding of macroecological and biogeographical patterns in the Atlantic Forest. No copyright restrictions are associated with the data set. Please cite this Ecology Data Paper if the data are used in publication and teaching events. © 2019 The Authors. Ecology © 2019 The Ecological Society of Americ
Fungos micorrízicos arbusculares e aspectos nutricionais de três espécies perenes de um SAF em Manaus-AM
Get PDFOs fungos micorrízicos arbusculares (FMAs) são seres simbiontes de solo que
exercem um papel significativo na funcionalidade e manutenção dos ecossistemas
naturais manejados e principalmente degradados. A colonização dos FMAs permite um
melhor aproveitamento dos nutrientes e água disponíveis no solo pelas plantas
hospedeiras, contribuindo na nutrição por serem facilitadores dessa absorção. O
presente estudou objetivou avaliar a ocorrência de FMAs na rizosfera de Andirobeira,
Sapoteira do Solimões e Cupuaçuzeiro presentes em um Sistema Agroflorestal, sendo
avaliados em quatro meses (março, junho, setembro e dezembro) de 2018. O esquema
fatorial 3x4 foi usado e as médias dos tratamentos foram comparadas pelo teste de
Tukey. O coeficiente de correlação linear de Person foi utilizado para correlacionar a
colonização micorrízica com as características químicas das rizosferas e os teores de
macro e micronutrientes nos tecidos foliares das plantas. A densidade de esporos de
FMAs nas rizosferas apresentou variação significativa (p < 0,05) tanto entre os meses
de coleta, como também entre as espécies perenes. Verificou-se que as rizosferas da
Sapoteira do Solimões e da Andirobeira apresentaram as maiores médias de densidade
de esporos (76,2 e 70,4 esporos.50 g de solo-1
), no mês de março encontrou-se uma
amostra com 97 esporos.50 g de solo-1
, sendo a maior encontrada. As maiores taxas de
colonização micorrízica (%) foram observadas nas rizosferas da Sapoteira do Solimões
e da Andirobeira, as quais diferiram estatisticamente do Cupuaçuzeiro, não havendo
diferença estatística entre os meses de coleta. O gênero Glomus spp. foi dominante nas
rizosferas das plantas (43,1 %), sendo o menos abundante o Gigaspora spp. (10,04 %).
As correlações globais mostraram ser positivas para as variáveis Ca, Mg, Fe, Zn, Mn,
MO e pH (H2O) do solo rizosférico. Diante do exposto conclui-se que apesar dos baixos
valores de r encontrados nas correlações, houve correlações positivas entre a associação
simbiótica dos FMAs e o teor de nutrientes das espécies perenes do SAF. A espécie do
Cupuaçuzeiro obteve mais correlações positivas entre os nutrientes e a colonização
micorrízica, dentre as espécies. Mostrando a importância da associação simbiótica para
a sobrevivência da espécie.The arbuscular mycorrhizal fungi (FMAs) are symbionts of soil have been
studied for exercising a significant role in the functionality and maintenance of natural
ecosystems managed and mostly degraded. The colonization of AMF allows better
utilization of nutrients and water available in the soil by the host plants, contributing to
the nutrition as they facilitate this absorption. The present study aimed to evaluate the
occurrence of AMFs in the Andirobeira, Sapoteira do Solimões and Cupuaçuzeiro
rhizosphere present in an Agroforestry System, being evaluated in four months (march,
june, september and december) of 2018. The 3x4 factorial scheme was analyzed and the
the treatment means were compared by Tukey test. Person's linear correlation
coefficient was used to correlate mycorrhizal colonization with the chemical
characteristics of rhizospheres and the macro and micronutrient contents in plant leaf
tissues. The spore density of AMF in the rhizospheres showed significant variation (p
<0,05) between the months of collection and perennial species. It was verified that the
rhizospheres of Sapoteira do Solimões and Andirobeira presented the highest spore
density averages (76,2 and 70,4 spores.50 g of soil-1
). In march, a sample with 97
spores.50 g of soil-1 was found. The highest rates of mycorrhizal colonization (%) were
observed in the Sapoteira do Solimões and Andirobeira rhizospheres, which differed
statistically from Cupuaçuzeiro, with no statistical difference between the months of
collection. The genus Glomus spp. was dominant in plant rhizospheres (43,1%), being
the least abundant Gigaspora spp. (10,04%). The global correlations were positive for
the Ca, Mg, Fe, Zn, Mn, MO and pH (H2O) variables of the rhizospheric soil. n view of
the above, it can be concluded that despite the low r values found in the correlations,
there were positive correlations between the symbiotic association of AMFs and the
nutrient content of perennial SAF species. The Cupuaçuzeiro species had more positive
correlations between nutrients and mycorrhizal colonization among the species.
Showing the importance of symbiotic association for the survival of the species
Atividade larvicida do óleo essencial de Piper alatipetiolatum (Piperaceae) contra Anopheles albitarsis, Anopheles nuneztovari e Anopheles triangulates (Diptera: Culicidae)
No full textUltrasound-assisted homogenization and gum Arabic combined to physicochemical quality of cupuaçu juice
No full textThe influence of ultrasound (US)-assisted homogenization and gum Arabic (GA) on the colloidal stability of cupuaçu juice has been studied. The experimental design was a complete factorial with two levels for US (750 and 1,000 J/cm3) and GA (0.5 and 1% w/w). The increase in energy density and GA concentration increased the viscosity of the juice, reducing its sedimentation. Increased energy density occurs to increased bioavailability of vitamin C in cupuaçu juice serum. The two levels of energy density of US were effective in the denaturation of the polyphenol oxidase and peroxidase enzymes. The use of US and GA may be a good alternative for the food industry to maintain the physicochemical properties of cupuaçu juice during storage. Practical applications: Cupuaçu is a fruit with great economic importance for the region of the Amazon Rainforest. Due to their physical characteristics, the juices present a rapid phase separation and it can compromise their processing and sensorial acceptance. The use of the ultrasonic homogenization process and the addition of natural hydrocolloids (GA) can improve the physical juice quality because the US reduces the particles size and the hydrocolloid increases the viscosity of the serum, reducing the separation of the phases of the juice. Also, the study is interesting due to the use of nonthermal technologies and natural additives, maintaining the nutritional juices quality. © 2019 Wiley Periodicals, Inc
Orchidaceae occurring in white-sand ecosystems of the Uatumã Sustainable Development Reserve in Central Amazon
No full textWe studied the Orchidaceae flora of white-sand ecosystems (campinaranas) in the Uatumã Sustainable Development Reserve, Amazonas State, Brazil. The family was represented by 60 species and 31 genera, with Maxillaria (10 spp.), Epidendrum (9 spp.) and Octomeria (6 spp.) being the most rich genera. Among the listed species, approximately 40% have a restricted distribution in the Amazonian domain, ocurring in different ecosystems. Four species, Cattleya wallisii, Maxillaria brasiliensis, Octomeria sagittata and Prosthechea vespa are known only from Brazil. Epiphytism was the most common habit, and Aldina heterophylla (Fabaceae) was the preferential phorophyte, with 67% of the total taxa occurring associated with this tree species. Taxonomic descriptions, illustrations, ecological comments, phenological information, geographical distribution and an identification key of the taxa are provided. Copyright © 2019 Magnolia Pres
Conditions for the maintenance of seasonal flood dynamics, conservation of the aquatic ecosystem and maintenance of the modes of life of the people of the volta grande do xingu
No full textOccurrence of triatomines (Hemiptera: Reduviidae) in domestic and natural environments in novo remanso, itacoatiara, amazonas, Brazil
Get PDFIntroduction: The present study reports the presence of triatomines in natural, peridomestic, and intradomicile environments in Itacoatiara municipality, state of Amazonas, a non-endemic region for Chagas disease. Methods: Active search was performed inside tree trunks, and palm trees, residences, and peridomiciles localized near the forest area. Results: Twenty adults and ten triatomines nymphs were collected, fifteen of which were from natural forests, thirteen from intradomiciles, and two from peridomicile areas. Conclusions: The new records of adults and nymphs of triatomines in the intra-and peridomiciles suggest the adoption of prophylactic measures for vector surveillance in the study area. © 2019, Sociedade Brasileira de Medicina Tropical. All rights reserved
Avaliação da habilidade do modelo WRF em representar a precipitação na amazônia usando diferentes escalas
Get PDFPrecipitation over the northern Amazon during the austral summer and autumn seasons of the 1988-1999 was simulated using the Regional Weather Research and Forecasting (WRF) model, with downscaling approach with nested domains of 45 and 15 km. The boundary and initial conditions were obtained from the Climate Forecast System Reanalysis (CFSR) of the National Centers for Environmental Prediction (NCEP). The model skill was tested using different rea-nalyzed precipitation datasets that represent different space scales. The bias of the model shows seasonal and spatial dependences, with positive bias in southwestern Brazilian Amazon during summer and in northwestern South America during autumn. The downscaling was needed to reproduce the surface influences on the regional and local systems that affect the rainfall distribution in the region. The WRF model, in general, reproduces the main observed precipitation patterns, without the dry bias, typical of general circulation models (GCM). The results indicate that the dynamic downscaling technique improves the WRF model performance for the seasonal climate forecast in the Amazon region. © 2019, Sociedade Brasileira de Meteorologia. All rights reserved
First record of Lasiurus egregius (Peters, 1870) (Chiroptera, vespertilionidae) in Paraná state, Southern Brazil
Get PDFLasiurus egregius (Peters, 1870) is an insectivorous bat species known from Central and South America. This species has few confirmed records throughout its distribution. Here we report the first record of L. egregius from the northern coast of Paraná state, southern Brazil. We captured a female individual of L. egregius using an ultrathin mist-net installed over a river knee, at Salto Morato Natural Reserve, municipality of Guaraqueçaba. This is the fourteenth locality with confirmed occurrence of L. egregius, being eight of them in Brazil. The knowledge on the bat fauna in Paraná has been increasing in recent decades, mainly due to the new studies in coast areas of this state. In addition to contributing to the knowledge of the bat fauna from Paraná, the new record of L. egregius reinforces the essential role of the Salto Morato Natural Reserve in conserving bats in the southern portion of the Atlantic Forest. © 2019, Pensoft Publishers. All rights reserved