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Sample records for brazilian tropical plants

  1. Antiviral evaluation of plants from Brazilian Atlantic Tropical Forest.

    PubMed

    Andrighetti-Fröhner, C R; Sincero, T C M; da Silva, A C; Savi, L A; Gaido, C M; Bettega, J M R; Mancini, M; de Almeida, M T R; Barbosa, R A; Farias, M R; Barardi, C R M; Simões, C M O

    2005-06-01

    The antiviral activity of six medicinal plants from Brazilian Atlantic Tropical Forest was investigated against two viruses: herpes simplex virus type 1 (HSV-1) and poliovirus type 2 (PV-2). Cuphea carthagenensis and Tillandsia usneoides extracts showed the best antiherpes activity. T. usneoides dichloromethane, ethyl acetate and n-butanol extracts, and Lippia alba n-butanol extract showed inhibition of HSV-1, strain 29R/acyclovir resistant. In addition, only L. alba ethyl acetate extract showed antipoliovirus activity. These results corroborate that medicinal plants can be a rich source of potential antiviral compounds.

  2. Plant Sexual Systems and a Review of the Breeding System Studies in the Caatinga, a Brazilian Tropical Dry Forest

    PubMed Central

    MACHADO, ISABEL CRISTINA; LOPES, ARIADNA VALENTINA; SAZIMA, MARLIES

    2006-01-01

    • Backgrounds and Aims The reproductive biology of a community can provide answers to questions related to the maintenance of the intraspecific pollen flow and reproductive success of populations, sharing and competition for pollinators and also questions on conservation of natural habitats affected by fragmentation processes. This work presents, for the first time, data on the occurrence and frequency of plant sexual systems for Caatinga communities, and a review of the breeding system studies of Caatinga species. • Methods The sexual systems of 147 species from 34 families and 91 genera occurring in three Caatinga areas in north-eastern Brazil were analysed and compared with worldwide studies focusing on reproductive biology of different tropical communities. • Key Results The frequency of hermaphrodite species was 83·0 % (122 species), seven of these (or 4·8 % of the total) being heterostylous. Monoecy occurred in 9·5 % (14) of the species, and andromonoecy in 4·8 % (seven). Only 2·7 % (four) of the species were dioecious. A high percentage of hermaphrodite species was expected and has been reported for other tropical ecosystems. With respect to the breeding system studies with species of the Caatinga, the authors' data for 21 species and an additional 18 species studied by others (n = 39) revealed a high percentage (61·5 %) of obligatory self-incompatibility. Agamospermy was not recorded among the Caatinga studied species. • Conclusions The plant sexual systems in the Caatinga, despite the semi-arid climate, are similar to other tropical dry and wet forest communities, including those with high rainfall levels, except for the much lower percentage of dioecious species. The high frequency of self-incompatible species is similar to that reported for Savanna areas in Brazil, and also for dry (deciduous and semideciduous) and humid tropical forest communities. PMID:16377654

  3. Plant sexual systems and a review of the breeding system studies in the Caatinga, a Brazilian tropical dry forest.

    PubMed

    Machado, Isabel Cristina; Lopes, Ariadna Valentina; Sazima, Marlies

    2006-02-01

    The reproductive biology of a community can provide answers to questions related to the maintenance of the intraspecific pollen flow and reproductive success of populations, sharing and competition for pollinators and also questions on conservation of natural habitats affected by fragmentation processes. This work presents, for the first time, data on the occurrence and frequency of plant sexual systems for Caatinga communities, and a review of the breeding system studies of Caatinga species. The sexual systems of 147 species from 34 families and 91 genera occurring in three Caatinga areas in north-eastern Brazil were analysed and compared with worldwide studies focusing on reproductive biology of different tropical communities. The frequency of hermaphrodite species was 83.0 % (122 species), seven of these (or 4.8 % of the total) being heterostylous. Monoecy occurred in 9.5 % (14) of the species, and andromonoecy in 4.8 % (seven). Only 2.7 % (four) of the species were dioecious. A high percentage of hermaphrodite species was expected and has been reported for other tropical ecosystems. With respect to the breeding system studies with species of the Caatinga, the authors' data for 21 species and an additional 18 species studied by others (n = 39) revealed a high percentage (61.5 %) of obligatory self-incompatibility. Agamospermy was not recorded among the Caatinga studied species. The plant sexual systems in the Caatinga, despite the semi-arid climate, are similar to other tropical dry and wet forest communities, including those with high rainfall levels, except for the much lower percentage of dioecious species. The high frequency of self-incompatible species is similar to that reported for Savanna areas in Brazil, and also for dry (deciduous and semideciduous) and humid tropical forest communities.

  4. Conservation of tropical plant species

    USDA-ARS?s Scientific Manuscript database

    This book is designed to provide a review of the methods and current status of conservation of many tropical plant species. Future perspectives of conservation of tropical species will also be discussed. The section on methods covers the range of conservation techniques, in situ, seed banking, in vi...

  5. Challenges in tropical plant nematology.

    PubMed

    De Waele, Dirk; Elsen, Annemie

    2007-01-01

    A major challenge facing agricultural scientists today is the need to secure food for an increasing world population. This growth occurs predominantly in developing, mostly tropical countries, where the majority of hungry people live. Reducing yield losses caused by pathogens of tropical agricultural crops is one measure that can contribute to increased food production. Although plant-parasitic nematodes are often not as important as some other biotic and nonbiotic constraints on crop production in the tropics, they can nevertheless cause extensive damage and substantial yield losses. The effects of agricultural, environmental, socioeconomic, and policy changes on the occurrence of plant-parasitic nematodes in the tropics and the losses these pathogens cause are largely undocumented. Recent developments pose new challenges to tropical nematology. The increased application of molecular diagnostics may widen the knowledge gap between nematologists working in developed countries and in the tropics. Uncertainties concerning the validity of nematode species will lead to practical problems related to quarantine measures and nematode management. The study of interactions between nematodes and other pathogens in disease complexes provide opportunities for multidisciplinary research with scientists from other disciplines but remain underexploited. Difficulties in recognizing emerging nematode threats prevent the timely implementation of management strategies, thus increasing yield losses. Research is needed to address these challenges. Examples are presented mainly but not exclusively from banana, peanut, and rice nematology.

  6. Shoot-tip cryopreservation by droplet vitrification of Byrsonima intermedia A. Juss.: a woody tropical and medicinal plant species from Brazilian cerrado.

    PubMed

    Silva, L C; Paiva, R; Swennen, R; Andre, E; Panis, B

    2013-01-01

    Cryopreservation of plant species is poorly investigated in Brazil. The aim of this study was to cryopreserve Byrsonima intermedia shoot apical meristems through droplet vitrification. A culture medium for shoot-tips growth was established using the Woody Plant Medium supplemented with 2.22 uM 6-benzylaminopurine. Excised shoot-tips were subjected to pre-culture and/or post-culture treatments on Murashige and Skoog medium with 0.3 M sucrose for 24 h prior dehydration on PVS2 at 0°C for 15, 30 or 45 minutes prior to plunging in liquid nitrogen. The effect of 15 days of shoot pre-growth on a high osmotic medium (0.3 M sucrose or 0.21 M sorbitol + 0.09 M sucrose) prior to meristem excision and cryopreservation was also investigated. Pre-culturing shoot-tips on 0.3 M sucrose for 24 h prior to cryopreservation increased the regrowth level after thawing to 90%. Shoot-tips excised from shoots pre-grown on MS + 0.21 M sorbitol + 0.09 M sucrose for 15 days presented a satisfactory regrowth level (67%).

  7. Methyl Chloride Emission from Tropical Plants

    NASA Astrophysics Data System (ADS)

    Yokouchi, Y.; Ikeda, M.; Ikeda, M.; Inuzuka, Y.; Yukawa, T.

    2001-12-01

    We studied CH3Cl emissions from tropical plants in Tropical Rainforest Glasshouse (25 m x 20 m x 10-24 m high) in Tsukuba Botanical Gardens, where more than 200 representative species from lowland tropical forests of Southeast Asia grow. CH3Cl concentrations were always higher in the glasshouse than outside and increased significantly when the windows were closed. The fluxes of CH3Cl from the tropical rainforest system in the glasshouse were calculated from the averages of their accumulation rates when the windows were closed (average; 142 pptv”h-1) with the dimension of the glasshouse. Emission rates per unit area for CH3Cl was 5.4 mg m-2 h-1. In order to determine which of the plants or whether the soil is responsible for the increase of CH3Cl, flux measurements were done by using an enclosure method. The soil was found to take up CH3Cl at a small rate. On the other hand, some plants from the Marattiaceae, Cyatheaceae (tree fern), Dicksoniaceae, and Dipterocarpaceae families were found to significantly emit CH3Cl. The first three families are ferns commonly growing in tropical forests, and Dipterocarpaceae species are dominant in the tropical rainforests of Southeast Asia. The average CH3Cl emission rate from the 9 plants in these families was around 0.5 mg (g dry leaf)-1”h-1. As for Cyatheaceae, we conducted a flux measurement from Cyathea lepifera E.Copel. in a subtropical forest in Okinawa and detected high emissions of CH3Cl amounting to 1.1 mg (g dry leaf)-1”h-1. Strong emissions of CH3Cl from tropical forests raises questions about the trends of chlorine compounds in the future and in the past.

  8. Antileishmanial activity and cytotoxicity of Brazilian plants.

    PubMed

    Ribeiro, Tatiana G; Chávez-Fumagalli, Miguel A; Valadares, Diogo G; Franca, Juçara R; Lage, Paula S; Duarte, Mariana C; Andrade, Pedro H R; Martins, Vivian T; Costa, Lourena E; Arruda, Ana L A; Faraco, André A G; Coelho, Eduardo A F; Castilho, Rachel O

    2014-08-01

    Leishmaniasis is a major public health problem, and the alarming spread of parasite resistance has increased the importance of discovering new therapeutic products. The present study aimed to investigate the in vitro leishmanicidal activity from 16 different Brazilian medicinal plants. Stationary-phase promastigotes of Leishmania amazonensis and murine macrophages were exposed to 44 plant extracts or fractions for 48 h at 37°C, in order to evaluate their antileishmanial activity and cytotoxicity, respectively. The most potent extracts against L. amazonensis were the hexanic extract of Dipteryx alata (IC50 of 0.08 μg/mL), the hexanic extract of Syzygium cumini (IC50 of 31.64 μg/mL), the ethanolic and hexanic extracts of leaves of Hymenaea courbaril (IC50 of 44.10 μg/mL and 35.84 μg/mL, respectively), the ethanolic extract of H. stignocarpa (IC50 of 4.69 μg/mL), the ethanolic extract of Jacaranda caroba (IC50 of 13.22 μg/mL), and the ethanolic extract of J. cuspidifolia leaves (IC50 of 10.96 μg/mL). Extracts of D. alata and J. cuspidifolia presented higher selectivity index, with high leishmanicidal activity and low cytotoxicity in the mammalian cells. The capacity in treated infected macrophages using the extracts and/or fractions of D. alata and J. cuspidifolia was also analyzed, and reductions of 95.80%, 98.31%, and 97.16%, respectively, in the parasite burden, were observed. No nitric oxide (NO) production could be observed in the treated macrophages, after stimulation with the extracts and/or fractions of D. alata and J. cuspidifolia, suggesting that the biological activity could be due to mechanisms other than macrophage activation mediated by NO production. Based on phytochemistry studies, the classes of compounds that could contribute to the observed activities are also discussed. In conclusion, the data presented in this study indicated that traditional medicinal plant extracts present effective antileishmanial activity. Future studies could focus on

  9. Angiotensin-converting enzyme inhibition by Brazilian plants.

    PubMed

    Braga, Fernão C; Serra, Carla P; Viana, Nilton S; Oliveira, Alaíde B; Côrtes, Steyner F; Lombardi, Júlio A

    2007-07-01

    The potential antihypertensive activity of Brazilian plants was evaluated in vitro by its ability to inhibit the angiotensin-converting enzyme (ACE). Forty-four plants belonging to 30 families were investigated. Plants were selected based on their popular use as antihypertensive and/or diuretics. The following plants presented significant ACE inhibition rates: Calophyllum brasiliense, Combretum fruticosum, Leea rubra, Phoenix roebelinii and Terminalia catappa.

  10. Pollinator recognition by a keystone tropical plant.

    PubMed

    Betts, Matthew G; Hadley, Adam S; Kress, W John

    2015-03-17

    Understanding the mechanisms enabling coevolution in complex mutualistic networks remains a central challenge in evolutionary biology. We show for the first time, to our knowledge, that a tropical plant species has the capacity to discriminate among floral visitors, investing in reproduction differentially across the pollinator community. After we standardized pollen quality in 223 aviary experiments, successful pollination of Heliconia tortuosa (measured as pollen tube abundance) occurred frequently when plants were visited by long-distance traplining hummingbird species with specialized bills (mean pollen tubes = 1.21 ± 0.12 SE) but was reduced 5.7 times when visited by straight-billed territorial birds (mean pollen tubes = 0.20 ± 0.074 SE) or insects. Our subsequent experiments revealed that plants use the nectar extraction capacity of tropical hummingbirds, a positive function of bill length, as a cue to turn on reproductively. Furthermore, we show that hummingbirds with long bills and high nectar extraction efficiency engaged in daily movements at broad spatial scales (∼1 km), but that territorial species moved only short distances (<100 m). Such pollinator recognition may therefore affect mate selection and maximize receipt of high-quality pollen from multiple parents. Although a diffuse pollinator network is implied, because all six species of hummingbirds carry pollen of H. tortuosa, only two species with specialized bills contribute meaningfully to its reproduction. We hypothesize that this pollinator filtering behavior constitutes a crucial mechanism facilitating coevolution in multispecies plant-pollinator networks. However, pollinator recognition also greatly reduces the number of realized pollinators, thereby rendering mutualistic networks more vulnerable to environmental change.

  11. Pollinator recognition by a keystone tropical plant

    PubMed Central

    Betts, Matthew G.; Hadley, Adam S.; Kress, W. John

    2015-01-01

    Understanding the mechanisms enabling coevolution in complex mutualistic networks remains a central challenge in evolutionary biology. We show for the first time, to our knowledge, that a tropical plant species has the capacity to discriminate among floral visitors, investing in reproduction differentially across the pollinator community. After we standardized pollen quality in 223 aviary experiments, successful pollination of Heliconia tortuosa (measured as pollen tube abundance) occurred frequently when plants were visited by long-distance traplining hummingbird species with specialized bills (x¯ pollen tubes = 1.21 ± 0.12 SE) but was reduced 5.7 times when visited by straight-billed territorial birds (x¯ pollen tubes = 0.20 ± 0.074 SE) or insects. Our subsequent experiments revealed that plants use the nectar extraction capacity of tropical hummingbirds, a positive function of bill length, as a cue to turn on reproductively. Furthermore, we show that hummingbirds with long bills and high nectar extraction efficiency engaged in daily movements at broad spatial scales (∼1 km), but that territorial species moved only short distances (<100 m). Such pollinator recognition may therefore affect mate selection and maximize receipt of high-quality pollen from multiple parents. Although a diffuse pollinator network is implied, because all six species of hummingbirds carry pollen of H. tortuosa, only two species with specialized bills contribute meaningfully to its reproduction. We hypothesize that this pollinator filtering behavior constitutes a crucial mechanism facilitating coevolution in multispecies plant–pollinator networks. However, pollinator recognition also greatly reduces the number of realized pollinators, thereby rendering mutualistic networks more vulnerable to environmental change. PMID:25733902

  12. Exotic plant invasions in tropical forests: Patterns and hypotheses

    Treesearch

    J.S. Denslow; S.J. DeWalt

    2008-01-01

    In the tropics, exotic plants have been widely introduced for industrial timber, for land reclamation and forage crops, and as ornamentals. In spite of the apparent opportunity for naturalization and spread, invasive exotic plants are scarce in many continental tropical forests. We examine several conditions under which exotic species do pose substantial threats to...

  13. Aboveground Biomass Modeling from Field and LiDAR Data in Brazilian Amazon Tropical Rain Forest

    NASA Astrophysics Data System (ADS)

    Silva, C. A.; Hudak, A. T.; Vierling, L. A.; Keller, M. M.; Klauberg Silva, C. K.

    2015-12-01

    Tropical forests are an important component of global carbon stocks, but tropical forest responses to climate change are not sufficiently studied or understood. Among remote sensing technologies, airborne LiDAR (Light Detection and Ranging) may be best suited for quantifying tropical forest carbon stocks. Our objective was to estimate aboveground biomass (AGB) using airborne LiDAR and field plot data in Brazilian tropical rain forest. Forest attributes such as tree density, diameter at breast height, and heights were measured at a combination of square plots and linear transects (n=82) distributed across six different geographic zones in the Amazon. Using previously published allometric equations, tree AGB was computed and then summed to calculate total AGB at each sample plot. LiDAR-derived canopy structure metrics were also computed at each sample plot, and random forest regression modelling was applied to predict AGB from selected LiDAR metrics. The LiDAR-derived AGB model was assessed using the random forest explained variation, adjusted coefficient of determination (Adj. R²), root mean square error (RMSE, both absolute and relative) and BIAS (both absolute and relative). Our findings showed that the 99th percentile of height and height skewness were the best LiDAR metrics for AGB prediction. The AGB model using these two best predictors explained 59.59% of AGB variation, with an Adj. R² of 0.92, RMSE of 33.37 Mg/ha (20.28%), and bias of -0.69 (-0.42%). This study showed that LiDAR canopy structure metrics can be used to predict AGC stocks in Tropical Forest with acceptable precision and accuracy. Therefore, we conclude that there is good potential to monitor carbon sequestration in Brazilian Tropical Rain Forest using airborne LiDAR data, large field plots, and the random forest algorithm.

  14. Widespread mistaken identity in tropical plant collections.

    PubMed

    Goodwin, Zoë A; Harris, David J; Filer, Denis; Wood, John R I; Scotland, Robert W

    2015-11-16

    Specimens of plants and animals preserved in museums are the primary source of verifiable data on the geographical and temporal distribution of organisms. Museum datasets are increasingly being uploaded to aggregated regional and global databases (e.g. the Global Biodiversity Information Facility; GBIF) for use in a wide range of analyses. Thus, digitisation of natural history collections is providing unprecedented information to facilitate the study of the natural world on a global scale. The digitisation of this information utilises information provided on specimen labels, and assumes they are correctly identified. Here we evaluate the accuracy of names associated with 4,500 specimens of African gingers from 40 herbaria in 21 countries. Our data show that at least 58% of the specimens had the wrong name prior to a recent taxonomic study. A similar pattern of wrongly named specimens is also shown for Dipterocarps and Ipomoea (morning glory). We also examine the number of available plant specimens worldwide. Our data demonstrate that, while the world's collections have more than doubled since 1970, more than 50% of tropical specimens, on average, are likely to be incorrectly named. This finding has serious implications for the uncritical use of specimen data from natural history collections. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  15. Plant phenology, resource seasonality and climate change in a Brazilian cerrado savanna

    NASA Astrophysics Data System (ADS)

    Gutierrez de Camargo, Maria Gabriela; de Camargo Guaraldo, André; Reys, Paula; Patrícia Cerdeira Morellato, Leonor

    2010-05-01

    Plant phenology, the study of recurring events and its relationship to climate, contributes with key information for the understanding of forest dynamics and plant resource availability to the fauna. Plant reproduction and growth are affected by proximate factors such as precipitation, temperature and photoperiod, ecological factors such as plant-animal interaction, for instance pollination and seed dispersal, and by phylogeny. Therefore, phenological changes may have enormous consequences for both, plants and animals depending upon the periodical availability of plant resources. The Brazilian tropical savannas, the cerrado, is a highly diverse vegetation with around 70% of the woody flora relaying on animal vectors for pollination and seed dispersal. We consider the cerrado savanna a good model to investigate shifts on tropical phenology and climate change. This vegetation presents a very seasonal phenology shaped by the climate characterized by the alternation of a hot, wet season and a dry, cooler one. The onset of leafing, flowering and fruiting is defined by the duration and intensity of the dry season, and changes on precipitation patterns and dryness may likely affect the plant species reproductive pattern as well as the resource availability to the fauna. In that context, we are carrying out a long-term project to investigate the phenology of growth and reproduction of a cerrado savanna woody community in Southeastern Brazil. Our aim is to understand the cerrado savanna long-term phenological patterns, its relationship to local climate, and whether phenological shifts over time may occur due to variations on climate. We are collecting data on crop size, species abundance and fruit consumption by birds to understand the fruit-frugivore network. Additionally, analyses are underway to explore the relationship among fruit season, fruit production, color and nutritional contents, and the activity of frugivores. Our final goal is to verify at which extension

  16. Antiviral activity of south Brazilian medicinal plant extracts.

    PubMed

    Simões, C M; Falkenberg, M; Mentz, L A; Schenkel, E P; Amoros, M; Girre, L

    1999-07-01

    Brazilian plants are potential sources of useful edible and medicinal plants. Hydromethanolic extracts prepared from 54 medicinal plants used in folk medicine to treat infections were screened for antiviral properties against five different viruses (HSV-1, HSV-2, poliovirus type 2, adenovirus type 2 and VSV). Fifty-two percent of the plant extracts exhibited antiviral against one or more tested viruses. More specifically, 42.6% showed activity against HSV-1 (herpes simplex virus type 1), 42.6% against HSV-2 (herpes simplex virus type 2), 26% against poliovirus and 24% against VSV (vesicular stomatitis virus). None of the extracts was active against adenovirus. Trixis praestans (Vell.) Cabr. and Cunila spicata Benth. extracts were further characterized for antiviral activity.

  17. Strategies for reducing carbon emissions on the tropical rain forest: The case of the Brazilian Amazon

    SciTech Connect

    Freitas, M.A.V. de; Rosa, L.P.

    1995-11-01

    Forests systems are renewable resources that can be used by present generations and that should be available to future generations if they are exploited on a sustainable basis. The tropical forest is still an immense and unknown field. The issues are: What means a sustainable basis in the tropical rain forests? What are the means of harmonising an economic development with an environmental equilibrium in tropical regions? One way to meet this requirement is to analyse the potentially {open_quotes}no regrets{close_quotes} options on which it is possible to agree upon despite controversies about what will be the true long run costs and benefits of various courses of actions. In the case of the Brazilian Amazon, in the last thirty years, the use of biomass and land has increased rapidly. Therefore, environmental and social problems have emerged with some intensity and have had repercussions on local and global scales. In relation to the recent global environmental changes, the Brazilian Amazon is considered as a key region for biodiversity conservation and preserving a carbon sink. In this paper, the main methodological option is to conceive a set of {open_quotes}no-regret{close_quotes} options, related with the land uses and biomass valorisation, which are analysed through the same framework. The options considered here are: decrease of the great cattle ranching and of the predatory timber extraction; the increase of forest management (harvest of timber and nontimber extractive products) and forest plantations in the degraded lands. The aims to focus on three elements: job creation, technico-economic adequation and environmental impacts, with special regards concerning the limitation of the atmospheric emissions of greenhouse gases (carbon flow).

  18. Landscape Variation in Plant Defense Syndromes across a Tropical Rainforest

    NASA Astrophysics Data System (ADS)

    McManus, K. M.; Asner, G. P.; Martin, R.; Field, C. B.

    2014-12-01

    Plant defenses against herbivores shape tropical rainforest biodiversity, yet community- and landscape-scale patterns of plant defense and the phylogenetic and environmental factors that may shape them are poorly known. We measured foliar defense, growth, and longevity traits for 345 canopy trees across 84 species in a tropical rainforest and examined whether patterns of trait co-variation indicated the existence of plant defense syndromes. Using a DNA-barcode phylogeny and remote sensing and land-use data, we investigated how phylogeny and topo-edaphic properties influenced the distribution of syndromes. We found evidence for three distinct defense syndromes, characterized by rapid growth, growth compensated by defense, or limited palatability/low nutrition. Phylogenetic signal was generally lower for defense traits than traits related to growth or longevity. Individual defense syndromes were organized at different taxonomic levels and responded to different spatial-environmental gradients. The results suggest that a diverse set of tropical canopy trees converge on a limited number of strategies to secure resources and mitigate fitness losses due to herbivory, with patterns of distribution mediated by evolutionary histories and local habitat associations. Plant defense syndromes are multidimensional plant strategies, and thus are a useful means of discerning ecologically-relevant variation in highly diverse tropical rainforest communities. Scaling this approach to the landscape level, if plant defense syndromes can be distinguished in remotely-sensed data, they may yield new insights into the role of plant defense in structuring diverse tropical rainforest communities.

  19. Seasonality of freshwater bacterioplankton diversity in two tropical shallow lakes from the Brazilian Atlantic Forest.

    PubMed

    Ávila, Marcelo P; Staehr, Peter A; Barbosa, Francisco A R; Chartone-Souza, Edmar; Nascimento, Andréa M A

    2017-01-01

    Bacteria are highly important for the cycling of organic and inorganic matter in freshwater environments; however, little is known about the diversity of bacterioplankton in tropical systems. Studies on carbon and nutrient cycling in tropical lakes suggest a very different seasonality from that of temperate climates. Here, we used 16S rRNA gene next-generation sequencing (NGS) to investigate seasonal changes in bacterioplankton communities of two tropical lakes, which differed in trophic status and mixing regime. Our findings revealed seasonally and depth-wise highly dynamic bacterioplankton communities. Differences in richness and structure appeared strongly related to the physicochemical characteristics of the water column, especially phosphate, pH and oxygen. Bacterioplankton communities were dominated by common taxonomic groups, such as Synechococcus and Actinobacteria acI, as well as rare and poorly characterized taxa such as 'Candidatus Methylacidiphilum' (Verrucomicrobia). Stratification and oxygen depletion during the rainy season promoted the occurrence of anoxygenic phototrophic and methanotrophic bacteria important for carbon and nutrient cycling. Differences in lake mixing regime were associated with seasonal beta diversity. Our study is the first attempt to use NGS for cataloging the diversity of bacterioplankton communities in Brazilian lakes and thus contributes to the ongoing worldwide endeavor to characterize freshwater lake bacterioplankton signatures. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  20. Accumulation and distribution of 137Cs in tropical plants

    NASA Astrophysics Data System (ADS)

    Anjos, R. M.; Carvalho, C.; Mosquera, B.; Veiga, R.; Sanches, N.; Bastos, J.; Macario, K.

    2007-02-01

    The accumulation and distribution of 40K and 137Cs in several tropical plant species were studied through measurements of gamma-ray spectra, focusing on establishing the suitability of using radiocesium to trace the plant uptake of nutrients such as potassium.

  1. Propagating native plants at the National Tropical Botanical Garden

    Treesearch

    Diane Ragone

    2002-01-01

    Hawaii has the dubious distinction of being the extinction capital of the United States with close to 30 percent of native plant species listed as endangered. The National Tropical Botanical Garden has been a leader in efforts to propagate and conserve native Hawaiian plants with close to 800 species collected for ex situ conservation since 1990....

  2. Parasite-host interactions of bat flies (Diptera: Hippoboscoidea) in Brazilian tropical dry forests.

    PubMed

    de Vasconcelos, Pedro Fonseca; Falcão, Luiz Alberto Dolabela; Graciolli, Gustavo; Borges, Magno Augusto Zazá

    2016-01-01

    Studies on the parasitology of ectoparasitic bat flies are scarce, and they are needed to identify patterns in parasitism. Hence, in the present study, we assessed community composition, prevalence, average infestation intensity, and specificity in the fly-bat associations in Brazilian tropical dry forests. In order to do that, we used the parasitological indices known as prevalence and average infestation intensity, along with an index of host specificity. We collected 1098 bat flies of 38 species. Five of the associations found are new to Brazil, 9 are new to southeastern Brazil, and 10 are new to science. Average infestation intensity varied from 1 to 9 and prevalence 0 to 100 %. In terms of specificity, 76 % of the bat flies were associated to a single host (monoxenic). These results highlight the low capacity of bat flies to survive on a not usual host especially due to an immunological incompatibility between parasites and hosts and dispersal barriers.

  3. DNA sampling from eggshells and microsatellite genotyping in rare tropical birds: Case study on Brazilian Merganser.

    PubMed

    Maia, Thais Augusta; Vilaça, Sibelle Torres; Silva, Luciana Resende da; Santos, Fabricio Rodrigues; Dantas, Gisele Pires de Mendonça

    2017-10-02

    This study shows that sampling maternal DNA from hatched and abandoned eggshells is a viable noninvasive strategy for studying the genetics of rare or endangered tropical birds, as exemplified here by the Brazilian Merganser (Mergus octosetaceus). Eighteen microsatellites were isolated from enriched libraries and nine heterologous loci from related species were tested. Seven loci were amplified successfully, with five of them being polymorphic. These loci exhibited amplicons ranging from 110 to 254 bp for 132 samples, with 60 from eggshells and 72 from blood or muscle samples. The number of alleles for M. octosetaceus ranged from one to six (mean = 3.71), which is low compared to M. merganser (1-15 alleles), a 'least concern' species. Genetic diversity did not differ significantly between noninvasive and invasive samples (Z(u) = 0.31, p = 0.37). Thus, noninvasive sampling, as demonstrated here with eggshells, provides an efficient means to assess genetic diversity in tropical birds without the need to capture and handle them.

  4. High diversity of Bradyrhizobium strains isolated from several legume species and land uses in Brazilian tropical ecosystems.

    PubMed

    Azarias Guimarães, Amanda; Florentino, Ligiane Aparecida; Alves Almeida, Kize; Lebbe, Liesbeth; Barroso Silva, Karina; Willems, Anne; de Souza Moreira, Fatima Maria

    2015-09-01

    The genus Bradyrhizobium stands out among nitrogen-fixing legume-nodulating bacteria because it predominates among the efficient microsymbionts of forest, forage, and green manure legume species, as well as important species of grain legumes, such as soybean, cowpea, and peanut. Therefore, the diversity of Bradyrhizobium strains is a relevant resource from environmental and economic perspectives, and strains isolated from diverse legume species and land uses in Brazilian tropical ecosystems were assessed in this study. To accomplish this, sequences of four housekeeping genes (atpD, dnaK, gyrB, and recA) were individually analysed, with the first three also being considered using multilocus sequence analysis (MLSA). The sensitivity of the strains to different antibiotics, their tolerance to different levels of salinity, and their ability to nodulate soybean plants were also measured. The phylogenetic trees based on each individual gene, and on the concatenated housekeeping genes, revealed several strain clusters separated from any currently described species. The Bradyrhizobium strains studied were generally resistant to antibiotics. All strains were able to grow at salinity levels of up to 0.5% NaCl, whereas only strains UFLA03-142, UFLA03-143, UFLA03-145, and UFLA03-146 grew in the presence of 1% NaCl. Together, the results indicated that some of the strains studied were potential novel species, indicating that the various soils and ecosystems in Brazil may harbour an as yet unknown diversity of rhizobia.

  5. The influence of Brazilian plant extracts on Streptococcus mutans biofilm

    PubMed Central

    BARNABÉ, Michele; SARACENI, Cíntia Helena Coury; DUTRA-CORREA, Maristela; SUFFREDINI, Ivana Barbosa

    2014-01-01

    Nineteen plant extracts obtained from plants from the Brazilian Amazon showed activity against planktonic Streptococcus mutans, an important bacterium involved in the first steps of biofilm formation and the subsequent initiation of several oral diseases. Objective Our goal was to verify whether plant extracts that showed activity against planktonic S. mutans could prevent the organization of or even disrupt a single-species biofilm made by the same bacteria. Material and Methods Plant extracts were tested on a single-bacteria biofilm prepared using the Zürich method. Each plant extract was tested at a concentration 5 times higher than its minimum inhibitory concentration (MIC). Discs of hydroxyapatite were submersed overnight in brain-heart infusion broth enriched with saccharose 5%, which provided sufficient time for biofilm formation. The discs were then submersed in extract solutions for one minute, three times per day, for two subsequent days. The discs were then washed with saline three times, at ten seconds each, after each treatment. Supports were allowed to remain in the enriched medium for one additional night. At the end of the process, the bacteria were removed from the discs by vortexing and were counted. Results Only two of 19 plant extracts showed activity in the present assay: EB1779, obtained from Dioscorea altissima, and EB1673, obtained from Annona hypoglauca. Although the antibacterial activity of the plant extracts was first observed against planktonic S. mutans, influence over biofilm formation was not necessarily observed in the biofilm model. The present results motivate us to find new natural products to be used in dentistry. PMID:25466471

  6. Evaluation of the cytotoxic activity of some Brazilian medicinal plants.

    PubMed

    Ribeiro, Sandra S; de Jesus, Aline M; dos Anjos, Charlene S; da Silva, Thanany B; Santos, Alan D C; de Jesus, Jemmyson R; Andrade, Moacir S; Sampaio, Tais S; Gomes, Wesley F; Alves, Péricles B; Carvalho, Adriana A; Pessoa, Claudia; de Moraes, Manoel O; Pinheiro, Maria L B; Prata, Ana Paula N; Blank, Arie F; Silva-Mann, Renata; Moraes, Valeria R S; Costa, Emmanoel V; Nogueira, Paulo Cesar L; Bezerra, Daniel P

    2012-09-01

    Plants are promising sources of new bioactive compounds. The aim of this study was to investigate the cytotoxic potential of nine plants found in Brazil. The species studied were: Annona pickelii Diels (Annonaceae), Annona salzmannii A. DC. (Annonaceae), Guatteria blepharophylla Mart. (Annonaceae), Guatteria hispida (R. E. Fr.) Erkens & Maas (Annonaceae), Hancornia speciosa Gomes (Apocynaceae), Jatropha curcas L. (Euphorbiaceae), Kielmeyera rugosa Choisy (Clusiaceae), Lippia gracilis Schauer (Verbenaceae), and Hyptis calida Mart. Ex Benth (Lamiaceae). Different types of extractions from several parts of plants resulted in 43 extracts. Their cytotoxicity was tested against HCT-8 (colon carcinoma), MDA-MB-435 (melanoma), SF-295 (glioblastoma), and HL-60 (promielocitic leukemia) human tumor cell lines, using the thiazolyl blue test (MTT) assay. The active extracts were those obtained from G. blepharophylla, G. hispida, J. curcas, K. rugosa, and L. gracilis. In addition, seven compounds isolated from the active extracts were tested; among them, β-pinene found in G. hispida and one coumarin isolated from K. rugora showed weak cytotoxic activity. In summary, this manuscript contributes to the understanding of the potentialities of Brazilian plants as sources of new anticancer drugs.

  7. Phylloepiphytic interaction between bacteria and different plant species in a tropical agricultural system.

    PubMed

    Baldotto, Lílian Estrela Borges; Olivares, Fábio Lopes

    2008-11-01

    Plant surfaces are a favourable niche for bacterial establishment, and hypothetically, plant species differ in their capacity to harbour epiphytic bacterial communities. This study was conducted to evaluate and describe the structural relationship of a bacterial community at the phyllosphere level with different plant species in a tropical ecosystem. Leaf blades of 47 plant species distributed in 27 botanical families were collected on a typical small Brazilian farm and prepared for observation under light and scanning electron microscopy. Naturally occurring bacteria were the most abundant settlers of the phylloplane, followed by fungal spore or hyphae. All plant species studied were colonized by phylloepiphytic bacteria, which were observed as solitary cells, microcolonies, and biofilms. However, independent of the family, the plant species differed in the pattern of phyllosphere colonization, as reflected in bacteria frequency and presence or absence of anatomical features that would favour the association. The phylloepiphytic bacteria were preferentially established on the following sites: epidermal cell wall junctions, glandular and nonglandular trichomes, veins, stomata, and epidermal cell wall surface. Profuse bacteria and fungi colonization was observed, at a level that was at least comparable with temperate regions. Interestingly, fungi seemed to alter the bacteria colonization pattern, most probably by microenvironmental modifications. The trichome type and density as well as the presence of epicuticular wax on the leaf blade surface seemed to be the most determinant anatomical features for the pattern of phyllosphere colonization. The presence of trichomes has a favourable, and epicuticular wax an unfavourable influence on the plant-bacteria interaction.

  8. Anticariogenic activity of some tropical medicinal plants against Streptococcus mutans.

    PubMed

    Hwang, Jae-Kwan; Shim, Jae-Seok; Chung, Jae-Youn

    2004-09-01

    The methanol extracts of five tropical plants, Baeckea frutescens, Glycyrrhiza glabra, Kaempferia pandurata, Physalis angulata and Quercus infectoria, exhibited potent antibacterial activity against the cariogenic bacterium Streptococcus mutans. In particular, G. glabra, K. pandurata and P. angulata conferred fast killing bactericidal effect against S. mutans in 2 min at 50 microg/ml of extract concentration.

  9. Cardiovascular properties of yangambin, a lignan isolated from Brazilian plants.

    PubMed

    Tibiriçá, E

    2001-01-01

    Yangambin was initially selected from a number of lignans isolated from Brazilian plants for its ability to antagonize Platelet-Activating Factor (PAF, 1-O-hexadecyl-2-acetyl- sn-glyceryl-3-phosphorylcholine)-induced biological effects. Subsequently it was shown that, besides its antagonistic properties at PAF receptors, yangambin also prevents the cardiovascular collapse observed during anaphylactic and endotoxic/septic shocks, as well as the vascular and cardiac hyporesponsiveness to catecholamines in endotoxic shock. It is suggested that this naturally occurring compound could be of potential interest in the adjunctive management of the above mentioned pathologies. In the present article, we review the main studies investigating the pharmacological properties of yangambin related to the cardiovascular function.

  10. The Brazilian research contribution to knowledge of the plant communities from Antarctic ice free areas.

    PubMed

    Pereira, Antonio B; Putzke, Jair

    2013-09-01

    This work aims to summarize the results of research carried out by Brazilian researchers on the plant communities of Antarctic ice free areas during the last twenty five years. Since 1988 field work has been carried out in Elephant Island, King George Island, Nelson Island and Deception Island. During this period six papers were published on the chemistry of lichens, seven papers on plant taxonomy, five papers on plant biology, two studies on UVB photoprotection, three studies about the relationships between plant communities and bird colonies and eleven papers on plant communities from ice free areas. At the present, Brazilian botanists are researching the plant communities of Antarctic ice free areas in order to understand their relationships to soil microbial communities, the biodiversity, the distribution of the plants populations and their relationship with birds colonies. In addition to these activities, a group of Brazilian researchers are undertaking studies related to Antarctic plant genetic diversity, plant chemistry and their biotechnological applications.

  11. Tropical American plants in the treatment of infectious diseases.

    PubMed

    Dvorkin-Camiel, Lana; Whelan, Julia S

    2008-01-01

    The increasingly diverse U.S. immigrant populations and the growing use of medicinal herbs create a need for health care professionals to expand their knowledge in this area. This is a review of tropical plants, Annona Muricata, Artemisia absinthium, Cinchona officinalis, Illicium verum, Momordica charantia, Opuntia streptacantha, Schinus terebinthifolius, and Tabebuia avellanedae (impetiginosa), commonly used by Latino and Haitian populations for the treatment of infectious disease. All the eight plants discussed here have one or more of the following: antibacterial, antiviral, antifungal, or antiparasitic properties. All of these plants are primarily known and used in the tropical region, but they are also readily available for purchase in the United States, specifically in the ethnic markets. This review discusses their traditional uses, chemical constituents, proven scientific evidence, and toxicities.

  12. Accumulation of K+ and Cs+ in Tropical Plant Species

    NASA Astrophysics Data System (ADS)

    Velasco, H.; Anjos, R. M.; Zamboni, C. B.; Macario, K. D.; Rizzotto, M.; Cid, A. S.; Medeiros, I. M. A.; Fernández, J.; Rubio, L.; Audicio, P.; Lacerda, T.

    2010-08-01

    Concentrations of K+ and 137Cs+ in tissues of the Citrus aurantifolia were measured both by gamma spectrometry and neutron activation analysis, aiming to understand the behavior of monovalent inorganic cations in plants as well as its capability to store these elements. In contrast to K+, Cs+ ions are not essential elements to plants, what might explain the difference in bioavailability. However, our results have shown that 137Cs+ is positively correlated to 40K+ concentration within tropical plant species, suggesting that these elements might be assimilated in a similar way, and that they pass through the biological cycle together. A simple mathematical model was also proposed to describe the temporal evolution of 40K activity concentration in such tropical woody fruit species. This model exhibited close agreement with the 40K experimental results in the fruit ripening processes of lemon trees.

  13. Acetamiprid, carbendazim, diuron and thiamethoxam sorption in two Brazilian tropical soils.

    PubMed

    Carbo, Leandro; Martins, Eucarlos L; Dores, Eliana F G C; Spadotto, Cláudio A; Weber, Oscarlina L S; De-Lamonica-Freire, Ermelinda M

    2007-01-01

    Sorption of acetamiprid ((E)-N1-[(6-chloro-3-pyridyl)methyl]-N2-cyano-N1-methylacetamidine), carbendazim (methyl benzimidazol-2-ylcarbamate), diuron (N-(3,4-dichlorophenyl)-N, N-dimethyl urea) and thiamethoxam (3-(2-chloro-thiazol-5-ylmethyl)-5-methyl-[1,3,5]oxadiazinan-4-ylidene-N-nitroamine) was evaluated in two Brazilian tropical soils, Oxisol and Entisol, from Primavera do Leste region, Mato Grosso State, Brazil. To describe the sorption process, batch experiments were carried out. Linear and Freundlich isotherm models were used to calculate the K(d) and K(f) coefficients from experimental data. The K(d) values were utilized to calculate the partition coefficient normalized to soil organic carbon (K(oc)). For the pesticides acetamiprid, carbendazim, diuron and thiamenthoxan the K(oc) (mL g(- 1)) values ranged in both soils from 98 - 3235, 1024 - 2644, 145 - 2631 and 104 - 2877, respectively. From the studied pesticides, only carbendazim presented correlation (r(2) = 0.82 and p < 0.01) with soil organic carbon (OC) content. Acetamiprid and thiamethoxam showed low sorption coefficients, representing a high risk of surface and ground water contamination.

  14. From tropics to tundra: global convergence in plant functioning.

    PubMed

    Reich, P B; Walters, M B; Ellsworth, D S

    1997-12-09

    Despite striking differences in climate, soils, and evolutionary history among diverse biomes ranging from tropical and temperate forests to alpine tundra and desert, we found similar interspecific relationships among leaf structure and function and plant growth in all biomes. Our results thus demonstrate convergent evolution and global generality in plant functioning, despite the enormous diversity of plant species and biomes. For 280 plant species from two global data sets, we found that potential carbon gain (photosynthesis) and carbon loss (respiration) increase in similar proportion with decreasing leaf life-span, increasing leaf nitrogen concentration, and increasing leaf surface area-to-mass ratio. Productivity of individual plants and of leaves in vegetation canopies also changes in constant proportion to leaf life-span and surface area-to-mass ratio. These global plant functional relationships have significant implications for global scale modeling of vegetation-atmosphere CO2 exchange.

  15. Plants from Brazilian Cerrado with Potent Tyrosinase Inhibitory Activity

    PubMed Central

    Souza, Paula Monteiro; Elias, Silvia Taveira; Simeoni, Luiz Alberto; de Paula, José Elias; Gomes, Sueli Maria; Guerra, Eliete Neves Silva; Fonseca, Yris Maria; Silva, Elton Clementino; Silveira, Dâmaris; Magalhães, Pérola Oliveira

    2012-01-01

    The increased amount of melanin leads to skin disorders such as age spots, freckles, melasma and malignant melanoma. Tyrosinase is known to be the key enzyme in melanin production. Plants and their extracts are inexpensive and rich resources of active compounds that can be utilized to inhibit tyrosinase as well as can be used for the treatment of dermatological disorders associated with melanin hyperpigmentation. Using in vitro tyrosinase inhibitory activity assay, extracts from 13 plant species from Brazilian Cerrado were evaluated. The results showed that Pouteria torta and Eugenia dysenterica extracts presented potent in vitro tyrosinase inhibition compared to positive control kojic acid. Ethanol extract of Eugenia dysenterica leaves showed significant (p<0.05) tyrosinase inhibitory activity exhibiting the IC50 value of 11.88 µg/mL, compared to kojic acid (IC50 value of 13.14 µg/mL). Pouteria torta aqueous extract leaves also showed significant inhibitory activity with IC50 value of 30.01 µg/mL. These results indicate that Pouteria torta and Eugenia dysenterica extracts and their isolated constituents are promising agents for skin-whitening or antimelanogenesis formulations. PMID:23173036

  16. Biological studies on Brazilian plants used in wound healing.

    PubMed

    Schmidt, C; Fronza, M; Goettert, M; Geller, F; Luik, S; Flores, E M M; Bittencourt, C F; Zanetti, G D; Heinzmann, B M; Laufer, S; Merfort, I

    2009-04-21

    n-Hexanic and ethanolic extracts from twelve plants (Brugmansia suaveolens Brecht. et Presl., Eupatorium laevigatum Lam., Galinsoga parviflora Cav., Iresine herbstii Hook., Kalanchöe tubiflora Hamet-Ahti, Petiveria alliacea L., Pluchea sagittalis (Lam.) Cabrera, Piper regnellii DC., Schinus molle L., Sedum dendroideum Moç et Sessé ex DC., Waltheria douradinha St. Hill., Xanthium cavanillesii Schouw.) used in traditional South Brazilian medicine as wound healing agents were investigated in various biological assays, targeting different aspects in this complex process. The extracts were investigated on NF-kappaB DNA binding, p38alpha MAPK, TNF-alpha release, direct elastase inhibition and its release as well as on caspase-3. Fibroblasts migration to and proliferation into the wounded monolayers were evaluated in the scratch assay, the agar diffusion test for antibacterial and the MTT assay for cytotoxic effects. The hydrophilic extracts from Galinsoga parviflora, Petiveria alliacea, Schinus molle, Waltheria douradinha and Xanthium cavanillesii as well as the lipophilic extract of Waltheria douradinha turned out to be the most active ones. These results increase our knowledge on the wound healing effects of the investigated medicinal plants. Further studies are necessary to find out the effective secondary metabolites responsible for the observed effects.

  17. Biological Invasion Influences the Outcome of Plant-Soil Feedback in the Invasive Plant Species from the Brazilian Semi-arid.

    PubMed

    de Souza, Tancredo Augusto Feitosa; de Andrade, Leonaldo Alves; Freitas, Helena; da Silva Sandim, Aline

    2017-05-30

    Plant-soil feedback is recognized as the mutual interaction between plants and soil microorganisms, but its role on the biological invasion of the Brazilian tropical seasonal dry forest by invasive plants still remains unclear. Here, we analyzed and compared the arbuscular mycorrhizal fungi (AMF) communities and soil characteristics from the root zone of invasive and native plants, and tested how these AMF communities affect the development of four invasive plant species (Cryptostegia madagascariensis, Parkinsonia aculeata, Prosopis juliflora, and Sesbania virgata). Our field sampling revealed that AMF diversity and frequency of the Order Diversisporales were positively correlated with the root zone of the native plants, whereas AMF dominance and frequency of the Order Glomerales were positively correlated with the root zone of invasive plants. We grew the invasive plants in soil inoculated with AMF species from the root zone of invasive (I changed) and native (I unaltered) plant species. We also performed a third treatment with sterilized soil inoculum (control). We examined the effects of these three AMF inoculums on plant dry biomass, root colonization, plant phosphorous concentration, and plant responsiveness to mycorrhizas. We found that I unaltered and I changed promoted the growth of all invasive plants and led to a higher plant dry biomass, mycorrhizal colonization, and P uptake than control, but I changed showed better results on these variables than I unaltered. For plant responsiveness to mycorrhizas and fungal inoculum effect on plant P concentration, we found positive feedback between changed-AMF community (I changed) and three of the studied invasive plants: C. madagascariensis, P. aculeata, and S. virgata.

  18. Antileishmanial Potential of Tropical Rainforest Plant Extracts

    PubMed Central

    Monzote, Lianet; Piñón, Abel; Setzer, William N.

    2014-01-01

    A total of 115 different plant extracts from our collection, representing 96 plant species, have been evaluated for in vitro antileishmanial activity against L. amazonensis promastigotes. In addition, the extracts were screened for cytotoxic activity against BALB/c mouse macrophages in order to assess a selectivity index. Crude extracts that showed a selectivity index (CC50 for macrophage / IC50 for promastigotes) ≥ 5 or with IC50 < 12.5 μg/mL against promastigotes, a total of 28 extracts, were further screened for anti-amastigote activity. A total of 25 extracts showed promising activity against L. amazonensis promastigotes with low cytotoxic activity. Ten of these extracts showed selectivity indices, (CC50 for macrophages / IC50 for amastigotes) greater than 10 and are considered “hits”, worthy candidates for further phytochemical exploration: Conostegia xalapensis methanol bark extract, Endiandra palmerstonii bark extract, Eugenia monteverdensis acetone bark extract, Eugenia sp. “fine leaf” acetone bark extract, Exothea paniculata chloroform bark extract, Mallotus paniculatus ethanol bark extract, Matelea pseudobarbata ethanol extract, Quercus insignis ethanol bark extract, Sassafras albidum dichloromethane bark extract, and Stemmadenia donnell-smithii acetone bark extract. PMID:28933376

  19. Antileishmanial Potential of Tropical Rainforest Plant Extracts.

    PubMed

    Monzote, Lianet; Piñón, Abel; Setzer, William N

    2014-11-19

    A total of 115 different plant extracts from our collection, representing 96 plant species, have been evaluated for in vitro antileishmanial activity against L. amazonensis promastigotes. In addition, the extracts were screened for cytotoxic activity against BALB/c mouse macrophages in order to assess a selectivity index. Crude extracts that showed a selectivity index (CC50 for macrophage / IC50 for promastigotes) ³ 5 or with IC50 < 12.5 μg/mL against promastigotes, a total of 28 extracts, were further screened for anti-amastigote activity. A total of 25 extracts showed promising activity against L. amazonensis promastigotes with low cytotoxic activity. Ten of these extracts showed selectivity indices, (CC50 for macrophages / IC50 for amastigotes) greater than 10 and are considered "hits", worthy candidates for further phytochemical exploration: Conostegia xalapensis methanol bark extract, Endiandra palmerstonii bark extract, Eugenia monteverdensis acetone bark extract, Eugenia sp. "fine leaf" acetone bark extract, Exothea paniculata chloroform bark extract, Mallotus paniculatus ethanol bark extract, Matelea pseudobarbata ethanol extract, Quercus insignis ethanol bark extract, Sassafras albidum dichloromethane bark extract, and Stemmadenia donnell-smithii acetone bark extract.

  20. Biosynthetic potential of phylogenetically unique endophytic actinomycetes from tropical plants.

    PubMed

    Janso, Jeffrey E; Carter, Guy T

    2010-07-01

    The culturable diversity of endophytic actinomycetes associated with tropical, native plants is essentially unexplored. In this study, 123 endophytic actinomycetes were isolated from tropical plants collected from several locations in Papua New Guinea and Mborokua Island, Solomon Islands. Isolates were found to be prevalent in roots but uncommon in leaves. Initially, isolates were dereplicated to the strain level by ribotyping. Subsequent characterization of 105 unique strains by 16S rRNA gene sequence analysis revealed that 17 different genera were represented, and rare genera, such as Sphaerisporangium and Planotetraspora, which have never been previously reported to be endophytic, were quite prevalent. Phylogenetic analyses grouped many of the strains into clades distinct from known genera within Thermomonosporaceae and Micromonosporaceae, indicating that they may be unique genera. Bioactivity testing and liquid chromatography-mass spectrometry (LC-MS) profiling of crude fermentation extracts were performed on 91 strains. About 60% of the extracts exhibited bioactivity or displayed LC-MS profiles with spectra indicative of secondary metabolites. The biosynthetic potential of 29 nonproductive strains was further investigated by the detection of putative polyketide synthase (PKS) and nonribosomal peptide synthetase (NRPS) genes. Despite their lack of detectable secondary metabolite production in fermentation, most were positive for type I (66%) and type II (79%) PKS genes, and all were positive for NRPS genes. These results suggest that tropical plants from New Guinea and the adjacent archipelago are hosts to unique endophytic actinomycetes that possess significant biosynthetic potential.

  1. Evaluation of Brazilian plants on cancer chemoprevention targets in vitro.

    PubMed

    Endringer, Denise C; Valadares, Ydia M; Campana, Priscilla R V; Campos, Jussara J; Guimarães, Keller G; Pezzuto, John M; Braga, Fernão C

    2010-06-01

    Cancer is a leading cause of death worldwide. Cancer chemoprevention is one of the promising strategies to decrease its incidence and both plant extracts and natural products may constitute sources of new chemoprevention agents. Some Brazilian species popularly used to treat inflammatory conditions were selected for evaluation for cancer chemoprevention. A total of 32 extracts/fractions from Hancornia speciosa, Davilla elliptica, Jacaranda caroba, Mansoa hirsuta, Remija ferrugina, Solanum paniculatum and Xyris pterygoblephara, along with a mixture of ursolic and oleanolic acids obtained from J. caroba and a dihydroisocoumarin isolated from aerial parts of X. pterygoblephara were tested for their cancer chemoprevention activity [inhibition of 12-O-tetradecanoyl-13-acetate (TPA)-mediated NF-kappaB activation, ornithine decarboxylase (ODC) and cyclooxygenase-1 (COX-1); induction of antioxidant response element (ARE)]. Several extracts/fractions were active in more than one assay and those from H. speciosa, M. hirsuta and J. caroba mediated strong responses with NF-kappaB, COX-1 and ARE, respectively.

  2. Challenges for measuring and modeling carbon cycling in degraded tropical forests: Examples from the Brazilian Amazon

    NASA Astrophysics Data System (ADS)

    Keller, M. M.; Longo, M.; Morton, D. C.; Leitold, V.; Pinagé, E. R.; dos-Santos, M. N.; Scaranello, M. A., Sr.

    2016-12-01

    Deforestation has cleared almost 20% of the forest in the Brazilian Amazon region. Logging, and understory forest fires may have degraded a similar area of forest. Despite the significant reduction of deforestation over the past decade, forest degradation through logging and understory fire continues to affect carbon stocks and fluxes. Recent studies using atmospheric data show that uptake by Amazon ecosystems balances or exceeds the carbon dioxide release by deforestation in normal (non-drought) years. However, old growth forest carbon dioxide uptake appears to be declining. Therefore, regeneration of degraded and secondary forests may be playing an ever more important role in the carbon balance of the world's largest extent of tropical forest. There are multiple challenges for understanding the role of degraded forests in regional and global carbon cycling. First, to date, no reliable estimates of the total area of degraded forest or the carbon losses associated with degradation exist in the Amazon. Remote sensing detection of forest degradation is far more difficult than detection of deforestation because changes in canopy characteristics are subtler. Second, forests may be subject to multiple degradation events and forest structure and species composition resulting from degradation is highly variable. Third, the structure of forests that result from degradation can be radically different from more commonly studied old-growth and secondary forests. Finally, there are few measurements that quantify degraded forest function. We will demonstrate pathways to resolving these challenges including (i) multi-temporal remote sensing studies of forest degradation dynamics on the Amazon frontier; (ii) forest structure and biomass estimates using airborne lidar data; (iii) changes in species composition based on forest inventory; and (iv) approaches for incorporating lidar data into a demographic modeling framework.

  3. Spatio-Temporal Distribution of Bark and Ambrosia Beetles in a Brazilian Tropical Dry Forest.

    PubMed

    Macedo-Reis, Luiz Eduardo; Novais, Samuel Matos Antunes de; Monteiro, Graziela França; Flechtmann, Carlos Alberto Hector; Faria, Maurício Lopes de; Neves, Frederico de Siqueira

    2016-01-01

    Bark and the ambrosia beetles dig into host plants and live most of their lives in concealed tunnels. We assessed beetle community dynamics in tropical dry forest sites in early, intermediate, and late successional stages, evaluating the influence of resource availability and seasonal variations in guild structure. We collected a total of 763 beetles from 23 species, including 14 bark beetle species, and 9 ambrosia beetle species. Local richness of bark and ambrosia beetles was estimated at 31 species. Bark and ambrosia composition was similar over the successional stages gradient, and beta diversity among sites was primarily determined by species turnover, mainly in the bark beetle community. Bark beetle richness and abundance were higher at intermediate stages; availability of wood was the main spatial mechanism. Climate factors were effectively non-seasonal. Ambrosia beetles were not influenced by successional stages, however the increase in wood resulted in increased abundance. We found higher richness at the end of the dry and wet seasons, and abundance increased with air moisture and decreased with higher temperatures and greater rainfall. In summary, bark beetle species accumulation was higher at sites with better wood production, while the needs of fungi (host and air moisture), resulted in a favorable conditions for species accumulation of ambrosia. The overall biological pattern among guilds differed from tropical rain forests, showing patterns similar to dry forest areas.

  4. Spatio-Temporal Distribution of Bark and Ambrosia Beetles in a Brazilian Tropical Dry Forest

    PubMed Central

    de Novais, Samuel Matos Antunes; Monteiro, Graziela França; Flechtmann, Carlos Alberto Hector; de Faria, Maurício Lopes; Neves, Frederico de Siqueira

    2016-01-01

    Bark and the ambrosia beetles dig into host plants and live most of their lives in concealed tunnels. We assessed beetle community dynamics in tropical dry forest sites in early, intermediate, and late successional stages, evaluating the influence of resource availability and seasonal variations in guild structure. We collected a total of 763 beetles from 23 species, including 14 bark beetle species, and 9 ambrosia beetle species. Local richness of bark and ambrosia beetles was estimated at 31 species. Bark and ambrosia composition was similar over the successional stages gradient, and beta diversity among sites was primarily determined by species turnover, mainly in the bark beetle community. Bark beetle richness and abundance were higher at intermediate stages; availability of wood was the main spatial mechanism. Climate factors were effectively non-seasonal. Ambrosia beetles were not influenced by successional stages, however the increase in wood resulted in increased abundance. We found higher richness at the end of the dry and wet seasons, and abundance increased with air moisture and decreased with higher temperatures and greater rainfall. In summary, bark beetle species accumulation was higher at sites with better wood production, while the needs of fungi (host and air moisture), resulted in a favorable conditions for species accumulation of ambrosia. The overall biological pattern among guilds differed from tropical rain forests, showing patterns similar to dry forest areas. PMID:27271969

  5. Floral Traits and Pollination Systems in the Caatinga, a Brazilian Tropical Dry Forest

    PubMed Central

    Machado, Isabel Cristina; Lopes, Ariadna Valentina

    2004-01-01

    • Background and aims Pollination is a critical stage in plant reproduction and thus in the maintenance and evolution of species and communities. The Caatinga is the fourth largest ecosystem in Brazil, but despite its great extent and its importance few studies providing ecological information are available, with a notable lack of work focusing on pollination biology. Here, general data are presented regarding the frequency of pollination systems within Caatinga communities, with the aim of characterizing patterns related to floral attributes in order to make possible comparisons with data for plant communities in other tropical areas, and to test ideas about the utility of syndromes. This paper also intends to provide a reference point for further studies on pollination ecology in this threatened ecosystem. • Methods The floral traits and the pollination systems of 147 species were analysed in three areas of Caatinga vegetation in northeastern Brazil, and compared with world-wide studies focusing on the same subject. For each species, floral attributes were recorded as form, size, colour, rewards and pollination units. The species were grouped into 12 guilds according to the main pollinator vector. Analyses of the frequencies of the floral traits and pollination systems were undertaken. • Key Results Nectar and pollen were the most common floral resources and insect pollination was the most frequent, occurring in 69·9 % of the studied species. Of the entomophilous species, 61·7 % were considered to be melittophilous (43·1 % of the total). Vertebrate pollination occurred in 28·1 % of the species (ornithophily in 15·0 % and chiropterophily in 13·1 %), and anemophily was recorded in only 2·0 %. • Conclusions The results indicated that the pollination systems in Caatinga, despite climatic restrictions, are diversified, with a low percentage of generalist flowers, and similar to other tropical dry and wet forest communities, including those with high

  6. Tropical Plant Extracts Modulating the Growth of Mycobacterium ulcerans.

    PubMed

    Mougin, Benjamin; Tian, Roger B D; Drancourt, Michel

    2015-01-01

    Mycobacterium ulcerans, the etiologic agent of Buruli ulcer, has been detected on aquatic plants in endemic tropical regions. Here, we tested the effect of several tropical plant extracts on the growth of M. ulcerans and the closely related Mycobacterium marinum. M. ulcerans and M. marinum were inoculated on Middlebrook 7H11 medium with and without extracts from tropical aquatic plants, including Ammannia gracilis, Crinum calamistratum, Echinodorus africanus, Vallisneria nana and Vallisneria torta. Delay of detection of the first colony and the number of colonies at day 7 (M. marinum) or day 16 (M. ulcerans) were used as endpoints. The first M. ulcerans colonies were detected at 8 ± 0 days on control Middlebrook 7H11 medium, 6.34 ± 0.75 days on A. gracilis-enriched medium (p<0.01), 6 ± 1 days on E. africanus- and V. torta-enriched media (p<0.01), 6 ± 0 days on V. nana-enriched medium (p<0.01) and 5.67 ± 0.47 days on C. calamistratum-enriched medium (p<0.01). Furthermore, the number of detected colonies was significantly increased in C. calamistratum- and E. africanus-enriched media at each time point compared to Middlebrook 7H11 (p<0.05). V. nana- and V. torta-enriched media significantly increased the number of detected colonies starting from day 6 and day 10, respectively (p<0.001). At the opposite, A. gracilis-enriched medium significantly decreased the number of detected colonies starting from day 8 PI (p<0.05). In conclusion, some aquatic plant extracts, could be added as adjuvants to the Middlebrook 7H11 medium for the culturing of M. marinum and M. ulcerans.

  7. Cryopreservation of Radopholus similis, a tropical plant-parasitic nematode.

    PubMed

    Elsen, Annemie; Vallterra, Salvador Ferrandis; Van Wauwe, Tom; Thuy, Trinh Thi Thu; Swennen, Rony; De Waele, Dirk; Panis, Bart

    2007-10-01

    For obligate plant-parasitic nematodes, cryopreservation has advantages over the usual preservation methods on whole plants or axenic culture systems, because the latter two are labourious and time and space consuming. In addition, cross contamination among different isolates can occur easily. Moreover, specific genetic studies require maintenance of the original population. The nematode under investigation, Radopholus similis, is a plant-parasitic nematode from the humid tropics. Therefore, any treatment at low temperatures is likely to add extra stress to the nematode, making the development of a cryopreservation protocol extremely difficult. In this paper, we describe experiments to achieve a successful cryopreservation protocol for the tropical nematode R. similis using vitrification solution-based methods based on a well defined mixture of cryoprotectants in combination with ultra-rapid cooling and thawing rates. A two-step treatment was used consisting of an incubation in glycerol followed by the application of a vitrifying mixture of methanol, glycerol and glucose. After cryopreservation, the pathogenicity of the nematodes was not altered, since they could infect and reproduce on carrot discs after recovery in the Ringer solution. The cryopreservation method described can be used for routine cryopreservation of R. similis lines from different origins.

  8. Strong emission of methyl chloride from tropical plants.

    PubMed

    Yokouchi, Yoko; Ikeda, Masumi; Inuzuka, Yoko; Yukawa, Tomohisa

    2002-03-14

    Methyl chloride is the largest natural source of ozone-depleting chlorine compounds, and accounts for about 15 per cent of the present atmospheric chlorine content. This contribution was likely to have been relatively greater in pre-industrial times, when additional anthropogenic sources-such as chlorofluorocarbons-were absent. Although it has been shown that there are large emissions of methyl chloride from coastal lands in the tropics, there remains a substantial shortfall in the overall methyl chloride budget. Here we present observations of large emissions of methyl chloride from some common tropical plants (certain types of ferns and Dipterocarpaceae), ranging from 0.1 to 3.7 microg per gram of dry leaf per hour. On the basis of these preliminary measurements, the methyl chloride flux from Dipterocarpaceae in southeast Asia alone is estimated at 0.91 Tg yr-1, which could explain a large portion of missing methyl chloride sources. With continuing tropical deforestation, natural sources of chlorine compounds may accordingly decrease in the future. Conversely, the abundance of massive ferns in the Carboniferous period may have created an atmosphere rich in methyl chloride.

  9. Flowering plant physiology triggered the expansion of tropical rainforest

    NASA Astrophysics Data System (ADS)

    Lee, J.; Boyce, C. K.

    2009-12-01

    Transpiration has long been known to feed precipitation, but unique hydraulic characteristics of flowering plants recently have been recognized to impart transpiration capacities dramatically higher than any other plants, living or extinct. Here we show through climate modeling that the replacement of angiosperm with non-angiosperm vegetation would result in a hotter, drier, and more seasonal Amazon basin—dry season length increases by 80 days over the eastern Amazon and overall area of everwet conditions decreases by a factor of five. Evolution of angiosperm physiology has uniquely facilitated spread of warm everwet forests and their enormous biodiversity, perhaps including their early Cenozoic expansion to extra-tropical latitudes. Divergent responses may be expected to general climate parameters and discrete environmental perturbations before and after evolution of angiosperm dominated ecosystems.

  10. Influence of Antecedent Precipitation on MODIS Active Fire and Fire Radiative Power Retrievals in the Brazilian Tropical Moist Forest Biome

    NASA Astrophysics Data System (ADS)

    Sathyachandran, S.; Roy, D. P.

    2013-12-01

    The Brazilian Tropical Moist Forest Biome (BTMFB) is the world's largest contiguous area of tropical forests and is prone to frequent burning. Although fire ignitions are predominantly anthropogenic, set deliberately to clear forest land and for agricultural and pastoral maintenance, the timing and extent of fire may largely be governed by local environmental conditions and the time since previous fire occurrence. Precipitation controls the fuel flammability and also the biomass accumulation. Previous research has indicated that the number of satellite detected fires follow lagged cyclic patterns of precipitation. In this research eight years (2003-2010) of MODerate resolution Imaging Spectroradiometer (MODIS) Terra and Aqua satellite active fire detections and their Fire Radiative Power (FRP) retrievals (related to the fire intensity) are considered for all the BTMBF. The antecedent precipitation derived from the Tropical Rainfall Measuring Mission (TRMM) best-estimate precipitation rate product accumulated for periods from one month to six months prior to each active fire detection date and location are considered. The regional number of MODIS active fire detections and the FRP values exhibit an inverse exponential decrease with the antecedent precipitation. The strongest relationships are observed for antecedent accumulated precipitation over three months and one month for the number of active fire detections and the FRP respectively. The relationships are similar across the seven Brazilian States within the BTMFB and among the eight years. The results indicate that wetter conditions reduce fuel flammability and result in fewer fires burning with lower intensity. The quantitative relationships developed in this study are expected to be useful for fire occurrence and emissions modeling in the BTMF.

  11. Tropical Nursery Manual: A guide to starting and operating a nursery for native and traditional plants

    Treesearch

    Kim M. Wilkinson; Thomas D. Landis; Diane L. Haase; Brian F. Daley; R. Kasten Dumroese

    2014-01-01

    This handbook was written for anyone endeavoring to start and operate a nursery for native and traditional plants in the tropics. Because the tropics cover a vast area of the world, however, the scope of the handbook is geared toward readers in the U.S. affiliated tropics. Specifically, the U.S. affiliated tropics are a diverse area spanning two oceans and half the...

  12. Structure, function and floristic relationships of plant communities in stressful habitats marginal to the Brazilian Atlantic rainforest.

    PubMed

    Scarano, Fabio R

    2002-10-01

    The Brazilian Atlantic rainforest consists of a typical tropical rainforest on mountain slopes, and stands out as a biodiversity hotspot for its high species richness and high level of species endemism. This forest is bordered by plant communities with lower species diversity, due mostly to more extreme environmental conditions than those found in the mesic rainforest. Between the mountain slopes and the sea, the coastal plains have swamp forests, dry semi-deciduous forests and open thicket vegetation on marine sand deposits. At the other extreme, on top of the mountains (>2000 m a.s.l.), the rainforest is substituted by high altitude fields and open thicket vegetation on rocky outcrops. Thus, the plant communities that are marginal to the rainforest are subjected either to flooding, drought, oceanicity or cold winter temperatures. It was found that positive interactions among plants play an important role in the structuring and functioning of a swamp forest, a coastal sandy vegetation and a cold, high altitude vegetation in the state of Rio de Janeiro. Moreover, only a few species seem to adopt this positive role and, therefore, the functioning of these entire systems may rely on them. Curiously, these nurse plants are often epiphytes in the rainforest, and at the study sites are typically terrestrial. Many exhibit crassulacean acid metabolism. Conservation initiatives must treat the Atlantic coastal vegetation as a complex rather than a rainforest alone.

  13. Structure, Function and Floristic Relationships of Plant Communities in Stressful Habitats Marginal to the Brazilian Atlantic Rainforest

    PubMed Central

    SCARANO, FABIO R.

    2002-01-01

    The Brazilian Atlantic rainforest consists of a typical tropical rainforest on mountain slopes, and stands out as a biodiversity hotspot for its high species richness and high level of species endemism. This forest is bordered by plant communities with lower species diversity, due mostly to more extreme environmental conditions than those found in the mesic rainforest. Between the mountain slopes and the sea, the coastal plains have swamp forests, dry semi‐deciduous forests and open thicket vegetation on marine sand deposits. At the other extreme, on top of the mountains (>2000 m a.s.l.), the rainforest is substituted by high altitude fields and open thicket vegetation on rocky outcrops. Thus, the plant communities that are marginal to the rainforest are subjected either to flooding, drought, oceanicity or cold winter temperatures. It was found that positive interactions among plants play an important role in the structuring and functioning of a swamp forest, a coastal sandy vegetation and a cold, high altitude vegetation in the state of Rio de Janeiro. Moreover, only a few species seem to adopt this positive role and, therefore, the functioning of these entire systems may rely on them. Curiously, these nurse plants are often epiphytes in the rainforest, and at the study sites are typically terrestrial. Many exhibit crassulacean acid metabolism. Conservation initiatives must treat the Atlantic coastal vegetation as a complex rather than a rainforest alone. PMID:12324276

  14. A phosphorus threshold for mycoheterotrophic plants in tropical forests.

    PubMed

    Sheldrake, Merlin; Rosenstock, Nicholas P; Revillini, Daniel; Olsson, Pål Axel; Wright, S Joseph; Turner, Benjamin L

    2017-02-08

    The majority of terrestrial plants associate with arbuscular mycorrhizal (AM) fungi, which typically facilitate the uptake of limiting mineral nutrients by plants in exchange for plant carbon. However, hundreds of non-photosynthetic plant species-mycoheterotrophs-depend entirely on AM fungi for carbon as well as mineral nutrition. Mycoheterotrophs can provide insight into the operation and regulation of AM fungal relationships, but little is known about the factors, fungal or otherwise, that affect mycoheterotroph abundance and distribution. In a lowland tropical forest in Panama, we conducted the first systematic investigation into the influence of abiotic factors on the abundance and distribution of mycoheterotrophs, to ask whether the availability of nitrogen and phosphorus altered the occurrence of mycoheterotrophs and their AM fungal partners. Across a natural fertility gradient spanning the isthmus of Panama, and also in a long-term nutrient-addition experiment, mycoheterotrophs were entirely absent when soil exchangeable phosphate concentrations exceeded 2 mg P kg(-1) Experimental phosphorus addition reduced the abundance of AM fungi, and also reduced the abundance of the specific AM fungal taxa required by the mycoheterotrophs, suggesting that the phosphorus sensitivity of mycoheterotrophs is underpinned by the phosphorus sensitivity of their AM fungal hosts. The soil phosphorus concentration of 2 mg P kg(-1) also corresponds to a marked shift in tree community composition and soil phosphatase activity across the fertility gradient, suggesting that our findings have broad ecological significance.

  15. Restoring tropical forests on bauxite mined lands: lessons from the Brazilian Amazon

    Treesearch

    John A. Parrotta; Oliver H. Knowles

    2001-01-01

    Restoring self-sustaining tropical forest ecosystems on surface mined sites is a formidable challenge that requires the integration of proven reclamation techniques and reforestation strategies appropriate to specific site conditions, including landscape biodiversity patterns. Restorationists working in most tropical settings are usually hampered by lack of basic...

  16. Multispecies impingement in a tropical power plant, Straits of Malacca.

    PubMed

    Azila, A; Chong, V C

    2010-07-01

    Marine organisms comprised about 70% of the total impinged materials by weight at water intake screens in the Kapar Power Station (KPS), Malaysia. The general groupings of 'fish', 'shrimp', 'crab', 'cephalopod' and 'others' contributed 26% (87 species), 65% (29), 2% (17), 2% (3) and 5% (42) of the total number of impinged organisms, respectively. In general, higher impingement occurred during spring tide, at nighttime and in shallow water. The glass perchlet, anchovies, ponyfishes, mojarra, catfishes, hairtail, scat and young croakers were the most vulnerable fishes. Vulnerable invertebrates included cephalopods, sea urchin, rockshells and jellyfishes, but penaeid shrimps were the most susceptible in terms of both mortality and body injury. Annually, KPS is estimated to kill 8.5 x 10(6) marine organisms (42 tons) by impingement. This amount, however, is minimal compared to commercial fishery harvests. Multispecies impingement at Malaysian power plants poses the problem of finding the best mitigation options for tropical situations.

  17. The water balance components of undisturbed tropical woodlands in the Brazilian cerrado

    USDA-ARS?s Scientific Manuscript database

    Deforestation of the Brazilian cerrado region has caused major changes in hydrological processes. These changes in water balance components are still poorly understood but are important for making land management decisions in this region. To better understand pre-deforestation conditions, we determi...

  18. Silicon Isotopic Fractionation in a Tropical Soil-Plant System

    NASA Astrophysics Data System (ADS)

    Opfergelt, S.; Delstanche, S.; Cardinal, D.; Andre, L.; Delvaux, B.

    2006-12-01

    Silica fluxes to soil solutions and water streams are controlled by both abiotic and biotic processes occurring in a Si soil-plant cycle that can be significant in comparison with Si weathering input and hydrological output. The quantification of Si-isotopic fractionation by these processes is highly promising to study the Si soil-plant cycle. Therein, the fate of aqueous monosilicic acid H4SiO4, as produced by silicate weathering, may take four paths: (1) uptake by plants and recycling through falling litter, (2) formation of clay minerals, (3) specific adsorption onto Al and Fe oxides, (4) leaching in drainage waters and export from watersheds. Here we report on detailed Si-isotopic compositions of various Si pools in a tropical soil-plant system involving old stands of banana (Musa acuminata Colla, cv Grande Naine) cropped on a weathering sequence of soils derived from andesitic volcanic ash and pumice deposits in Cameroon, West Africa. Si-isotopic compositions were measured by MC-ICP-MS in dry plasma mode with external Mg doping with a reproducibility of 0.08 permil (2stdev). Results were expressed as delta29Si vs NBS28. The compositions were determined in plant parts, bulk soils, clay fractions (less than 2um) and stream waters used for crop irrigation. Of the weathering sequence, we selected young (Y) and old (O) volcanic soils (vs). Yvs are rich in weatherable minerals, and contain large amounts of pumice gravels; their clay fraction (10-35 percent) contains allophane, halloysite and ferrihydrite. Oppositely, Ovs are strongly weathered and fine clayey soils (75-96 percent clay) rich in halloysite, kaolinite, gibbsite and goethite. Intra-plant fractionation between roots and shoots and within shoots confirmed our previous data measured on banana plants grown in hydroponics. The bulk plant isotopic composition was heavier at Ovs than at Yvs giving a fractionation factor per atomic mass unit between plants and their irrigation water Si source (+0.61 permil) of

  19. Nutrient budgets (C, N and P) and trophic dynamics of a Brazilian tropical estuary: Barra das Jangadas.

    PubMed

    Noriega, Carlos E D; Araujo, Moacyr

    2011-06-01

    This paper focuses on the nutrient dynamics of a tropical estuary on the northeastern Brazilian coast, studied using the LOICZ biogeochemical budgeting protocol. We describe the methodology and assumptions underlying this model. Input data (monthly for rainfall, evaporation, river discharge, and concentrations of salt, phosphorus and nitrogen) were obtained during field campaigns in the Barra das Jangadas Estuary (BJE) over a 5 years period (1999 to 2003). Mass balance results indicate large inputs of nutrients to the system. The model shows that the seasonal variation of the Net Ecosystem Metabolism (NEM) indicates that the system passes from a stage of organic matter liquid production and mineralization during the dry season (-0.5 mmoles C m(-2) d(-1)) to liquid mineralization during the rainy season (-19 mmoles C m(-2) d(-1)). We suggest that the system varies slightly between autotrophy and heterotrophy during the year due to the rainfall regime, human activities in the basin (density population and sugarcane plantations), and associated DIP riverine loads. High per capita loads of N and P indicate a high population density and high runoff. The application of flux balance modeling was useful to understand the nutrient dynamics of this typical small tropical estuary.

  20. Review of procedures used for the extraction of anti-cancer compounds from tropical plants.

    PubMed

    Pandey, Saurabh; Shaw, Paul N; Hewavitharana, Amitha K

    2015-01-01

    Tropical plants are important sources of anti-cancer lead molecules. According to the US National Cancer Institute, out of the 3000 plants identified as active against cancer using in vitro studies, 70% are of tropical origin. The extraction of bioactive compounds from the plant materials is a fundamental step whose efficiency is critical for the success of drug discovery efforts. There has been no review published of the extraction procedures of anti-cancer compounds from tropical plants and hence the following is a critical evaluation of such procedures undertaken prior to the use of these compounds in cancer cell line studies, during the last five years. It presents a comprehensive analysis of all approaches taken to extract anti-cancer compounds from various tropical plants. (Databases searched were PubMed, SciFinder, Web of Knowledge, Scopus, Embase and Google Scholar).

  1. New phytotoxic diterpenoids from Vellozia gigantea (Velloziaceae), an endemic neotropical plant living in the endangered Brazilian biome Rupestrian grasslands

    USDA-ARS?s Scientific Manuscript database

    Vellozia gigantea is a rare, ancient and endemic neotropical plant present in the Brazilian Rupestrian grasslands. The dichloromethane extract of V. gigantea adventitious roots was phytotoxic against Lactuca sativa, Agrostis stolonifera and Lemna paucicostata, and showed larvicidal activity against ...

  2. New phytotoxic diterpenoids from Vellozia gigantea (Velloziaceae), an endemic neotropical plant living in the endangered Brazilian biome Rupestrian grasslands

    USDA-ARS?s Scientific Manuscript database

    Vellozia gigantea is a rare, ancient and endemic neotropical plant present in the Brazilian Rupestrian grasslands. The dichloromethane extract of V. gigantea adventitious roots was phytotoxic against Lactuca sativa, Agrostis stolonifera and Lemna paucicostata, and showed larvicidal activity against ...

  3. Ability of crassulacean acid metabolism plants to overcome interacting stresses in tropical environments.

    PubMed

    Lüttge, Ulrich

    2010-01-01

    Single stressors such as scarcity of water and extreme temperatures dominate the struggle for life in severely dry desert ecosystems or cold polar regions and at high elevations. In contrast, stress in the tropics typically arises from a dynamic network of interacting stressors, such as availability of water, CO(2), light and nutrients, temperature and salinity. This requires more plastic spatio-temporal responsiveness and versatility in the acquisition and defence of ecological niches. The mode of photosynthesis of crassulacean acid metabolism (CAM) is described and its flexible expression endows plants with powerful strategies for both acclimation and adaptation. Thus, CAM plants are able to inhabit many diverse habitats in the tropics and are not, as commonly thought, successful predominantly in dry, high-insolation habitats. Typical tropical CAM habitats or ecosystems include exposed lava fields, rock outcrops of inselbergs, salinas, savannas, restingas, high-altitude páramos, dry forests and moist forests. Morphotypical and physiotypical plasticity of CAM phenotypes allow a wide ecophysiological amplitude of niche occupation in the tropics. Physiological and biochemical plasticity appear more responsive by having more readily reversible variations in performance than do morphological adaptations. This makes CAM plants particularly fit for the multi-factor stressor networks of tropical forests. Thus, while the physiognomy of semi-deserts outside the tropics is often determined by tall succulent CAM plants, tropical forests house many more CAM plants in terms of quantity (biomass) and quality (species diversity).

  4. Changes in the trade in native medicinal plants in Brazilian public markets.

    PubMed

    Brandão, Maria das Graças Lins; Cosenza, Gustavo Pereira; Pereira, Flávia Liparini; Vasconcelos, Ariela Silva; Fagg, Christopher William

    2013-08-01

    Plants continue to be an important source of new bioactive substances. Brazil is one of the world's mega-diverse countries, with 20 % of the world's flora. However, the accelerated destruction of botanically rich ecosystems has contributed to a gradual loss of native medicinal species. In previous study, we have observed a fast and intensive change in trade of medicinal plants in an area of Amazon, where human occupation took place. In this study, we surveyed 15 public markets in different parts of Brazil in search of samples of 40 plants used in traditional medicine and present in first edition of Brazilian Official Pharmacopoeia (FBRAS), published in 1926. Samples of plants commercialized as the same vernacular name as in Pharmacopoeia were acquired and submitted to analysis for authentication. A total of 252 plant samples were purchased, but the laboratory analyses showed that only one-half of the samples (126, 50.2 %) were confirmed as the same plant species so named in FBRAS. The high number of unauthenticated samples demonstrates a loss of knowledge of the original native species. The proximity of the market from areas in which the plant occurs does not guarantee that trade of false samples occurs. The impact of the commerce of the substitute species on their conservation and in public health is worrying. Strategies are necessary to promote the better use and conservation of this rich heritage offered by Brazilian biodiversity.

  5. Plant and litter influences on earthworm abundance and community structures in a tropical wet forest

    Treesearch

    G. Gonzalez; X. Zou

    1999-01-01

    Plant communities differ in species composition and litter input. To examine the influence of plant species on the abundance and community structure of soil fauna, we sampled earthworms in areas close to and away from the bases of Dacryodes excelsa and Heliconia caribaea, two distinct plant communities within a tropical wet forest in Puerto Rico. We also carried out a...

  6. Anthelmintic activity of plant extracts from Brazilian savanna.

    PubMed

    Oliveira, Andreia F; Costa Junior, Livio M; Lima, Aldilene S; Silva, Carolina R; Ribeiro, Maria N S; Mesquista, José W C; Rocha, Cláudia Q; Tangerina, Marcelo M P; Vilegas, Wagner

    2017-03-15

    Helminth infections represent a serious problem for the production of small ruminants that is currently aggravated by resistance to anthelmintic products and has induced a search for control alternatives, such as natural products. In this study, extracts of Turnera ulmifolia L. (leaves and roots), Parkia platycephala Benth. (leaves and seeds) and Dimorphandra gardneriana Tul. (leaves and bark), which have been cited in ethnoveterinary studies and selected naturally by goats in the cerrado (Brazilian savanna), were tested in vitro against Haemonchus contortus. Hydroacetonic (ACT) and hydroalcoholic (ETH) extracts were evaluated using an Egg Hatching Assay (EHA), a Larval Exsheathment Inhibition Assay (LEIA) and a Larval Development Assay (LDA). A second set of incubations was performed using polyvinylpolypyrrolidone (PVPP) to determine the influence of polyphenols on the anthelmintic effects of EHA and LEIA. Data from each extract were used to calculate inhibition concentrations (IC50). All tested extracts showed activity against at least one life stage of H. contortus. The use of PVPP revealed that the tannins are not the only extracts of secondary metabolites responsible for the anthelmintic effects. The results showed clear in vitro anthelmintic activities against H. contortus at different stages and indicated the potential use of these species as a promising alternative approach to control helminthic infections of small ruminants.

  7. Self-reported discomfort associated with Daylight Saving Time in Brazilian tropical and subtropical zones.

    PubMed

    Alencar, João Carlos Nascimento de; Leocadio-Miguel, Mario André; Duarte, Leandro Lourenção; Louzada, Fernando; Fontenele Araujo, John; Pedrazzoli, Mario

    2017-08-23

    Daylight Saving Time (DST) annually moves clocks 1 hour forward, when daytime is longer than night. Previous studies from medium and high latitude locations have pointed to a disruptive effect of DST on human circadian rhythms. Since Brazil is an equatorial country implementing DST, a different relationship between photic and social synchronisers may interfere with DST effects. To explore the prevalence and duration of self-reported discomfort related to DST among Brazilian residents (latitude 12-33° S, longditude 39-57° W). It was hypothesised that an elevated prevalence of self-reported discomfort would be found in Brazil, due to the pronounced uncoupling between social and geophysical synchronisers. In total, 12 467 volunteers completed a web-based, Brazilian version of Horne-Östberg Morningness-Eveningness Questionnaire, provided demographic information, and answered questions related to DST complaints (discomfort, duration of discomfort). Of the total sample, 45.43% reported no discomfort related to DST, with meaningful proportions for all chronotypes. However, eveningness was most associated with discomfort. About one fourth of the total sample reported discomfort over the whole DST period. Gender interaction is largely supported by these results. DST at low latitude locations may be disruptive for circadian rhythms, since seasonality of sunrise near the equator is negligible or very mild.

  8. The Development of Brazilian Municipalities Flooded by Hydropower Plants

    NASA Astrophysics Data System (ADS)

    Araujo, N.; Moretto, E. M.; Roquetti, D. R.; Beduschi, L. C.; Praia, A.; Pulice, S.; Albiach, E.; Athayde, S.

    2016-12-01

    Hydropower plants cause negative environmental impacts during the phases of construction and operation. On the other hand, there is a general assumption that these projects also induce local development of the affected places, since there is a great influx of social and financial capital brought locally, especially during the construction phase the relationship between hydropower plant implementation s and local development has been controversial in the Environmental Impact Assessment field, and there is no empirical evidence showing how hydroelectric dam construction affects local development. Considering municipal development as a kind of local development and operationalizing the concept of human development by adopting income, longevity and education dimensions defined by Amartya Sen, this study aimed to verify empirical evidences regarding the role of hydropower plants in human development of their flooded municipalities in Brazil. For this, we considered 134 hydroelectric plants and correspondent 641 flooded municipalities, for which 155 human development indicators were obtained for the period of 2000 to 2010. Results obtained from statistical correlation analysis and their assumption tests showed that increases in the municipal flooded area and increases in the period of flooding - to which a given municipality is submitted - were associated with lower performances of human development indicators. Specifically, increases in social inequality, poverty and lower performances of longevity and education were detected for the flooded municipalities. We also found that the financial compensation was associated with better performance of municipal income and lower performances of education and longevity. Finally, approaching the growth poles theory of François Perroux and the productive linkages theory of Albert Hirschman, we suggest that the size of the flooded areas, the flooding period and the financial compensation may lead to an enclave situation in

  9. Impact of livestock on a mosquito community (Diptera: Culicidae) in a Brazilian tropical dry forest.

    PubMed

    Santos, Cleandson Ferreira; Borges, Magno

    2015-01-01

    This study evaluated the effects of cattle removal on the Culicidae mosquito community structure in a tropical dry forest in Brazil. Culicidae were collected during dry and wet seasons in cattle presence and absence between August 2008 and October 2010 and assessed using multivariate statistical models. Cattle removal did not significantly alter Culicidae species richness and abundance. However, alterations were noted in Culicidae community composition. This is the first study to evaluate the impact of cattle removal on Culicidae community structure in Brazil and demonstrates the importance of assessing ecological parameters such as community species composition.

  10. A study of the Brazilian Fernando de Noronha island and Rocas atoll wakes in the tropical Atlantic

    NASA Astrophysics Data System (ADS)

    Tchamabi, Christine C.; Araujo, Moacyr; Silva, Marcus; Bourlès, Bernard

    2017-03-01

    Observational data and numerical modeling were used to investigate oceanic current wakes surrounding Fernando de Noronha Island (3°51‧S-32°25‧W) and Rocas Atoll (3°52‧S-33°49‧W). These two Brazilian systems are located in the western tropical Atlantic region and are under the influence of the westward flow of the central South Equatorial Current (cSEC). In order to highlight the effects of wakes on ocean dynamics, two different numerical simulations were performed, using the Regional Oceanic Modeling System (ROMS): the first one including Fernando de Noronha Island and Rocas Atoll (Scenario I) and the second one with artificial removal of the island and atoll (Scenario NI). Simulations are validated through the Scenario I that well reproduces the wakes that give rise to the development of eddies downstream of FN and AR. These mesoscale structures have a strong influence on the thermodynamic properties surrounding the Island and the Atoll. Scenario NI allows evidence of the presence of an Island and Atoll shoaling mixed layer throughout the year, primarily on the western side of the Island and the Atoll. Mixing at the base of the mixed layer, inducing a subsurface cooling, is also enhanced in the downstream portion of the Island and Atoll, particularly when the cSEC is strengthened. These simulations support the ;island mass effect; on the high productivity of subsurface waters generally observed on the western side of these islands.

  11. Anti-Candida activity of Brazilian medicinal plants.

    PubMed

    Duarte, Marta Cristina Teixeira; Figueira, Glyn Mara; Sartoratto, Adilson; Rehder, Vera Lúcia Garcia; Delarmelina, Camila

    2005-02-28

    Essential oils and ethanolic extracts from the leaves and/or roots of 35 medicinal plants commonly used in Brazil were screened for anti-Candida albicans activity. The oils were obtained by water-distillation using a Clevenger-type system. Essential oils from 13 plants showed anti-Candida activity, including Aloysia triphylla, Anthemis nobilis, Cymbopogon martini, Cymbopogon winterianus, Cyperus articulatus, Cyperus rotundus, Lippia alba, Mentha arvensis, Mikania glomerata, Mentha piperita, Mentha sp., Stachys byzantina, and Solidago chilensis. The ethanol extract was not effective at any of the concentrations tested. Chemical analyses showed the presence of compounds with known antimicrobial activity, including 1,8-cineole, geranial, germacrene-D, limonene, linalool, and menthol.

  12. An engine for global plant diversity: highest evolutionary turnover and emigration in the American tropics

    PubMed Central

    Antonelli, Alexandre; Zizka, Alexander; Silvestro, Daniele; Scharn, Ruud; Cascales-Miñana, Borja; Bacon, Christine D.

    2015-01-01

    Understanding the processes that have generated the latitudinal biodiversity gradient and the continental differences in tropical biodiversity remains a major goal of evolutionary biology. Here we estimate the timing and direction of range shifts of extant flowering plants (angiosperms) between tropical and non-tropical zones, and into and out of the major tropical regions of the world. We then calculate rates of speciation and extinction taking into account incomplete taxonomic sampling. We use a recently published fossil calibrated phylogeny and apply novel bioinformatic tools to code species into user-defined polygons. We reconstruct biogeographic history using stochastic character mapping to compute relative numbers of range shifts in proportion to the number of available lineages through time. Our results, based on the analysis of c. 22,600 species and c. 20 million geo-referenced occurrence records, show no significant differences between the speciation and extinction of tropical and non-tropical angiosperms. This suggests that at least in plants, the latitudinal biodiversity gradient primarily derives from other factors than differential rates of diversification. In contrast, the outstanding species richness found today in the American tropics (the Neotropics), as compared to tropical Africa and tropical Asia, is associated with significantly higher speciation and extinction rates. This suggests an exceedingly rapid evolutionary turnover, i.e., Neotropical species being formed and replaced by one another at unparalleled rates. In addition, tropical America stands out from other continents by having “pumped out” more species than it received through most of the last 66 million years. These results imply that the Neotropics have acted as an engine for global plant diversity. PMID:25904934

  13. An engine for global plant diversity: highest evolutionary turnover and emigration in the American tropics.

    PubMed

    Antonelli, Alexandre; Zizka, Alexander; Silvestro, Daniele; Scharn, Ruud; Cascales-Miñana, Borja; Bacon, Christine D

    2015-01-01

    Understanding the processes that have generated the latitudinal biodiversity gradient and the continental differences in tropical biodiversity remains a major goal of evolutionary biology. Here we estimate the timing and direction of range shifts of extant flowering plants (angiosperms) between tropical and non-tropical zones, and into and out of the major tropical regions of the world. We then calculate rates of speciation and extinction taking into account incomplete taxonomic sampling. We use a recently published fossil calibrated phylogeny and apply novel bioinformatic tools to code species into user-defined polygons. We reconstruct biogeographic history using stochastic character mapping to compute relative numbers of range shifts in proportion to the number of available lineages through time. Our results, based on the analysis of c. 22,600 species and c. 20 million geo-referenced occurrence records, show no significant differences between the speciation and extinction of tropical and non-tropical angiosperms. This suggests that at least in plants, the latitudinal biodiversity gradient primarily derives from other factors than differential rates of diversification. In contrast, the outstanding species richness found today in the American tropics (the Neotropics), as compared to tropical Africa and tropical Asia, is associated with significantly higher speciation and extinction rates. This suggests an exceedingly rapid evolutionary turnover, i.e., Neotropical species being formed and replaced by one another at unparalleled rates. In addition, tropical America stands out from other continents by having "pumped out" more species than it received through most of the last 66 million years. These results imply that the Neotropics have acted as an engine for global plant diversity.

  14. ANTIFUNGAL POTENTIAL OF PLANT SPECIES FROM BRAZILIAN CAATINGA AGAINST DERMATOPHYTES

    PubMed Central

    BIASI-GARBIN, Renata Perugini; DEMITTO, Fernanda de Oliveira; do AMARAL, Renata Claro Ribeiro; FERREIRA, Magda Rhayanny Assunção; SOARES, Luiz Alberto Lira; SVIDZINSKI, Terezinha Inez Estivalet; BAEZA, Lilian Cristiane; YAMADA-OGATTA, Sueli Fumie

    2016-01-01

    Trichophyton rubrum and Trichophyton mentagrophytes complex, or Trichophyton spp. are the main etiologic agents of dermatophytosis, whose treatment is limited by the high cost of antifungal treatments, their various side effects, and the emergence of resistance amongst these species. This study evaluated the in vitro antidermatophytic activity of 23 crude extracts from nine plant species of semiarid vegetation (caatinga) found in Brazil. The extracts were tested at concentrations ranging from 1.95 to 1,000.0 mg/mL by broth microdilution assay against the reference strains T. rubrum ATCC 28189 and T. mentagrophytesATCC 11481, and 33 clinical isolates of dermatophytes. All plants showed a fungicidal effect against both fungal species, with MIC/MFC values of the active extracts ranging from 15.6 to 250.0 µg/mL. Selected extracts of Eugenia uniflora (AcE), Libidibia ferrea (AE), and Persea americana (AcE) also exhibited a fungicidal effect against all clinical isolates of T. rubrum and T. mentagrophytes complex. This is the first report of the antifungal activity of Schinus terebinthifolius, Piptadenia colubrina, Parapiptadenia rigida, Mimosa ophthalmocentra, and Persea americana against both dermatophyte species. PMID:27007561

  15. ANTIFUNGAL POTENTIAL OF PLANT SPECIES FROM BRAZILIAN CAATINGA AGAINST DERMATOPHYTES.

    PubMed

    Biasi-Garbin, Renata Perugini; Demitto, Fernanda de Oliveira; Amaral, Renata Claro Ribeiro do; Ferreira, Magda Rhayanny Assunção; Soares, Luiz Alberto Lira; Svidzinski, Terezinha Inez Estivalet; Baeza, Lilian Cristiane; Yamada-Ogatta, Sueli Fumie

    2016-01-01

    Trichophyton rubrum and Trichophyton mentagrophytes complex, or Trichophyton spp. are the main etiologic agents of dermatophytosis, whose treatment is limited by the high cost of antifungal treatments, their various side effects, and the emergence of resistance amongst these species. This study evaluated the in vitro antidermatophytic activity of 23 crude extracts from nine plant species of semiarid vegetation (caatinga) found in Brazil. The extracts were tested at concentrations ranging from 1.95 to 1,000.0 mg/mL by broth microdilution assay against the reference strains T. rubrum ATCC 28189 and T. mentagrophytes ATCC 11481, and 33 clinical isolates of dermatophytes. All plants showed a fungicidal effect against both fungal species, with MIC/MFC values of the active extracts ranging from 15.6 to 250.0 µg/mL. Selected extracts of Eugenia uniflora (AcE), Libidibia ferrea (AE), and Persea americana (AcE) also exhibited a fungicidal effect against all clinical isolates of T. rubrum and T. mentagrophytes complex. This is the first report of the antifungal activity of Schinus terebinthifolius, Piptadenia colubrina, Parapiptadenia rigida, Mimosa ophthalmocentra, and Persea americana against both dermatophyte species.

  16. Ability of crassulacean acid metabolism plants to overcome interacting stresses in tropical environments

    PubMed Central

    Lüttge, Ulrich

    2010-01-01

    Background and aims Single stressors such as scarcity of water and extreme temperatures dominate the struggle for life in severely dry desert ecosystems or cold polar regions and at high elevations. In contrast, stress in the tropics typically arises from a dynamic network of interacting stressors, such as availability of water, CO2, light and nutrients, temperature and salinity. This requires more plastic spatio-temporal responsiveness and versatility in the acquisition and defence of ecological niches. Crassulacean acid metabolism The mode of photosynthesis of crassulacean acid metabolism (CAM) is described and its flexible expression endows plants with powerful strategies for both acclimation and adaptation. Thus, CAM plants are able to inhabit many diverse habitats in the tropics and are not, as commonly thought, successful predominantly in dry, high-insolation habitats. Tropical CAM habitats Typical tropical CAM habitats or ecosystems include exposed lava fields, rock outcrops of inselbergs, salinas, savannas, restingas, high-altitude páramos, dry forests and moist forests. Morphotypical and physiotypical plasticity of CAM Morphotypical and physiotypical plasticity of CAM phenotypes allow a wide ecophysiological amplitude of niche occupation in the tropics. Physiological and biochemical plasticity appear more responsive by having more readily reversible variations in performance than do morphological adaptations. This makes CAM plants particularly fit for the multi-factor stressor networks of tropical forests. Thus, while the physiognomy of semi-deserts outside the tropics is often determined by tall succulent CAM plants, tropical forests house many more CAM plants in terms of quantity (biomass) and quality (species diversity). PMID:22476063

  17. Ant diversity in Brazilian tropical dry forests across multiple vegetation domains

    NASA Astrophysics Data System (ADS)

    Figueiredo Silva, Luciana; Mello Souza, Rayana; Solar, Ricardo R. C.; de Siqueira Neves, Frederico

    2017-03-01

    Understanding the environmental drivers of biodiversity persistence and community organization in natural ecosystems is of great importance for planning the conservation of those ecosystems. This comprehension is even more important in severely threatened ecosystems. In this context, we analyzed ant communities in tropical dry forests (TDFs) in Brazil. These forests are embedded within other biomes, such as Cerrado and Caatinga. In this study, we asked whether (i) ant species richness and composition changes between TDFs within different vegetation domains; (ii) whether ant species richness and β-diversity increase north-to-south, possibly related to changes in tree richness and tree density; and (iii) species replacement contributes relatively more to β-diversity than does nestedness. We found that species composition is unique to each TDF within different biomes, and that species richness and β-diversity differ among the vegetation domains, being smaller in the Caatinga. We also found that replacement contributes most to β-diversity, although this contribution is lower in Caatinga than in Cerrado. We show that regional context is the main driver of species diversity, which is likely to be driven by both historical and ecological mechanisms. By analyzing large spatial scale variation in TDF environmental characteristics, we were able to evaluate how ant diversity changes along an environmental gradient. The high levels of species replacement and unique species composition of each region indicates that, to fully conserve TDFs, we need to have various conservation areas distributed across the entire range of vegetation domains in which these forests can be found. Thus, we demonstrate that a landscape-wise planning is urgent and necessary in order to preserve tropical dry forests.

  18. Antioxidant Properties of Brazilian Tropical Fruits by Correlation between Different Assays

    PubMed Central

    Pereira Lima, Giuseppina Pace; Fabris, Sabrina

    2013-01-01

    Four different assays (the Folin-Ciocalteu, DPPH, enzymatic method, and inhibitory activity on lipid peroxidation) based on radically different physicochemical principles and normally used to determine the antioxidant activity of food have been confronted and utilized to investigate the antioxidant activity of fruits originated from Brazil, with particular attention to more exotic and less-studied species (jurubeba, Solanum paniculatum; pequi, Caryocar brasiliense; pitaya, Hylocereus undatus; siriguela, Spondias purpurea; umbu, Spondias tuberosa) in order to (i) verify the correlations between results obtained by the different assays, with the final purpose to obtain more reliable results avoiding possible measuring-method linked mistakes and (ii) individuate the more active fruit species. As expected, the different methods give different responses, depending on the specific assay reaction. Anyhow all results indicate high antioxidant properties for siriguela and jurubeba and poor values for pitaya, umbu, and pequi. Considering that no marked difference of ascorbic acid content has been detected among the different fruits, experimental data suggest that antioxidant activities of the investigated Brazilian fruits are poorly correlated with this molecule, principally depending on their total polyphenolic content. PMID:24106692

  19. Antioxidant properties of Brazilian tropical fruits by correlation between different assays.

    PubMed

    Gregoris, Elena; Pereira Lima, Giuseppina Pace; Fabris, Sabrina; Bertelle, Mariangela; Sicari, Michela; Stevanato, Roberto

    2013-01-01

    Four different assays (the Folin-Ciocalteu, DPPH, enzymatic method, and inhibitory activity on lipid peroxidation) based on radically different physicochemical principles and normally used to determine the antioxidant activity of food have been confronted and utilized to investigate the antioxidant activity of fruits originated from Brazil, with particular attention to more exotic and less-studied species (jurubeba, Solanum paniculatum; pequi, Caryocar brasiliense; pitaya, Hylocereus undatus; siriguela, Spondias purpurea; umbu, Spondias tuberosa) in order to (i) verify the correlations between results obtained by the different assays, with the final purpose to obtain more reliable results avoiding possible measuring-method linked mistakes and (ii) individuate the more active fruit species. As expected, the different methods give different responses, depending on the specific assay reaction. Anyhow all results indicate high antioxidant properties for siriguela and jurubeba and poor values for pitaya, umbu, and pequi. Considering that no marked difference of ascorbic acid content has been detected among the different fruits, experimental data suggest that antioxidant activities of the investigated Brazilian fruits are poorly correlated with this molecule, principally depending on their total polyphenolic content.

  20. Response of plant nutrient stoichiometry to fertilization varied with plant tissues in a tropical forest

    PubMed Central

    Mo, Qifeng; Zou, Bi; Li, Yingwen; Chen, Yao; Zhang, Weixin; Mao, Rong; Ding, Yongzhen; Wang, Jun; Lu, Xiankai; Li, Xiaobo; Tang, Jianwu; Li, Zhian; Wang, Faming

    2015-01-01

    Plant N:P ratios are widely used as indices of nutrient limitation in terrestrial ecosystems, but the response of these metrics in different plant tissues to altered N and P availability and their interactions remains largely unclear. We evaluated changes in N and P concentrations, N:P ratios of new leaves (<1 yr), older leaves (>1 yr), stems and mixed fine roots of seven species after 3-years of an N and P addition experiment in a tropical forest. Nitrogen addition only increased fine root N concentrations. P addition increased P concentrations among all tissues. The N × P interaction reduced leaf and stem P concentrations, suggesting a negative effect of N addition on P concentrations under P addition. The reliability of using nutrient ratios as indices of soil nutrient availability varied with tissues: the stoichiometric metrics of stems and older leaves were more responsive indicators of changed soil nutrient availability than those of new leaves and fine roots. However, leaf N:P ratios can be a useful indicator of inter-specific variation in plant response to nutrients availability. This study suggests that older leaf is a better choice than other tissues in the assessment of soil nutrient status and predicting plant response to altered nutrients using nutrients ratios. PMID:26416169

  1. Freezing tolerance and avoidance in high tropical Andean plants: Is it equally represented in species with different plant height?

    PubMed

    Squeo, F A; Rada, F; Azocar, A; Goldstein, G

    1991-05-01

    Freezing tolerance and avoidance were studied in several different sized species of the tropical high Andes (4200 m) to determine whether there was a relationship between plant height and cold resistance mechanisms. Freezing injury and supercooling capacity were determined in ground level plants (i.e. cushions, small rosettes and a perennial herb), intermediate height plants (shrubs and perennial herbs) and arborescent forms (i.e. giant rosettes and small trees). All ground-level plants showed tolerance as the main mechanism of resistance to cold temperatures. Arborescent forms showed avoidance mechanisms mainly through supercooling, while intermediate plants exhibited both. Insulation mechanisms to avoid low temperatures were present in the two extreme life-forms. We suggest that a combination of freezing tolerance and avoidance by insulation is least expensive and is a more secure mechanism for high tropical mountain plants than supercooling alone.

  2. Tree planting by small producers in the tropics: A comparative study of Brazil and Panama.

    Treesearch

    Cynthia S. Simmons; Robert T. Walker; Charles H. Wood

    2002-01-01

    Forest regrowth is a notable phenomenon across the tropical forest latitudes. Such reforestation takes place in the wake of land abandonment, occurs cyclically in a rotational agricultural system, and may result from the deliberate planting of trees by farmers. Although less extensive than successional forest regeneration, tree planting by small farmers can have...

  3. Effects of an exotic plant invasion on native understory plants in a tropical dry forest.

    PubMed

    Prasad, Ayesha E

    2010-06-01

    The dry forests of southern India, which are endangered tropical ecosystems and among the world's most important tiger (Panthera tigris) habitats, are extensively invaded by exotic plants. Yet, experimental studies exploring the impacts of these invasions on native plants in these forests are scarce. Consequently, little is known about associated implications for the long-term conservation of tigers and other biodiversity in these habitats. I studied the impacts of the exotic plant Lantana camara on understory vegetation in a dry-forest tiger habitat in southern India. I compared the richness, composition, and abundance of tree seedlings, herbs, and shrubs and the abundance of grass among plots in which Lantana was cleared or left standing. These plots were distributed across two blocks-livestock free and livestock grazed. Removal of Lantana had an immediate positive effect on herb-shrub richness in the livestock-free block, but had no effect on that of tree seedlings in either livestock block. Tree-seedling and herb-shrub composition differed significantly between Lantana treatment and livestock block, and Lantana removal significantly decreased survival of tree seedlings. Nevertheless, the absence of trees, in any stage between seedling and adult, indicates that Lantana may stall tree regeneration. Lantana removal decreased the abundance of all understory strata, probably because forage plants beneath Lantana are less accessible to herbivores, and plants in Lantana-free open plots experienced greater herbivory. Reduced access to forage in invaded habitats could negatively affect ungulate populations and ultimately compromise the ability of these forests to sustain prey-dependent large carnivores. Additional research focused on understanding and mitigating threats posed by exotic plants may be crucial to the long-term protection of these forests as viable tiger habitats.

  4. Responses of tropical legumes from the Brazilian Atlantic Rainforest to simulated acid rain.

    PubMed

    Andrade, Guilherme C; Silva, Luzimar C

    2017-07-01

    We investigated the morphological and anatomical effects of simulated acid rain on leaves of two species native to the Brazilian Atlantic Rainforest: Paubrasilia echinata and Libidibia ferrea var. leiostachya. Saplings were subjected to acid rain in a simulation chamber during 10 days for 15 min daily, using H2SO4 solution pH 3.0 and, in the control, deionized water. At the end of the experiment, fragments from young and expanding leaves were anatomically analyzed. Although L. ferrea var. leiostachya leaves are more hydrophobic, rain droplets remained in contact with them for a longer time, as in the hydrophilic P. echinata leaves, droplets coalesce and rapidly run off. Visual symptomatology consisted in interveinal and marginal necrotic dots. Microscopic damage found included epicuticular wax flaking, turgor loss and epidermal cell shape alteration, hypertrophy of parenchymatous cells, and epidermal and mesophyll cell collapse. Formation of a wound tissue was observed in P. echinata, and it isolated the necrosis to the adaxial leaf surface. Acid rain increased thickness of all leaf tissues except spongy parenchyma in young leaves of L. ferrea var. leiostachya, and such thickness was maintained throughout leaf expansion. To our knowledge, this is the first report of acidity causing increase in leaf tissue thickness. This could represent the beginning of cell hypertrophy, which was seen in visually affected leaf regions. Paubrasilia echinata was more sensitive, showing earlier symptoms, but the anatomical damage in L. ferrea var. leiostachya was more severe, probably due to the higher time of contact with acid solution in this species.

  5. Antibacterial and cytotoxic activity of Brazilian plant extracts--Clusiaceae.

    PubMed

    Suffredini, Ivana B; Paciencia, Mateus Lb; Nepomuceno, Daniela C; Younes, Riad N; Varella, Antonio D

    2006-05-01

    Twelve extracts obtained from nine plants belonging to six different genera of Clusiaceae were analyzed against Gram-negative (Escherichia coli and Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus and Enterococcus faecalis) bacteria using the microdilution broth assay. Tovomita aff. longifolia, T. brasiliensis, Clusia columnaris, Garcinia madruno, Haploclathra paniculata, and Caraipa grandifolia extracts showed significant results against the bacteria. The organic extract obtained from the leaves of T. aff. longifolia showed minimal inhibitory concentration (MIC) = 70 microg/ml and minimal bactericidal concentration (MBC) = 90 microg/ml against E. faecalis and the organic extract made with the stem of C. columnaris showed MIC = 180 microg/ml and MBC = 270 microg/ml against P. aeruginosa. None of the antibacterial extracts showed lethal activity against brine shrimp nauplii. On the other hand, both aqueous and organic extracts obtained from the aerial organs of Vismia guianensis that were cytotoxic to brine shrimp nauplii did not show a significant antibacterial activity in the assay.

  6. Diversity and symbiotic effectiveness of beta-rhizobia isolated from sub-tropical legumes of a Brazilian Araucaria Forest.

    PubMed

    Lammel, Daniel R; Cruz, Leonardo M; Carrer, Helaine; Cardoso, Elke J B N

    2013-12-01

    While the occurrence of Betaproteobacteria occupying the nodules of tropical legumes has been shown, little is known about subtropical areas. Araucaria Forest is a subtropical endangered ecosystem, and a better understanding of the legume-rhizobial symbionts may allow their use in land reclamation. The 16S rRNA gene of bacteria isolated from nine leguminous species was sequenced and their nodulation tested in Mimosa scabrella and Phaseolus vulgaris. 196 isolates were identified as eight genotypes: Pantoea, Pseudomonas, Bradyrhizobium sp1-2, Rhizobium, and Burkholderia sp1-3. The majority of the isolates from native plants (87 %) were taxonomically related to β-rhizobia, namely Burkholderia, however the legumes Galactia crassifolia and Collea speciosa were nodulated by both α and β-rhizobia, and Acacia dealbata, an exotic plant, only by α-rhizobia. The nifH genes of some isolates were sequenced and N-fixing potential shown by the acetylene reduction test. Most of the isolates nodulated the test plants, some were effective in M. scabrella, but all presented low efficiency in the exotic promiscuous legume P. vulgaris. Pantoea and Pseudomonas did not nodulate and probably are endophytic bacteria. The presented data shows diversity of α, β and γ-Proteobacteria in nodules of subtropical legumes, and suggests host specificity with β-rhizobia. Potential isolates were found for M. scabrella, indicating that a high N-fixing strain may be further inoculated in plants for use in reforestation.

  7. Predictors of Arbuscular Mycorrhizal Fungal Communities in the Brazilian Tropical Dry Forest.

    PubMed

    Sousa, Natália M F; Veresoglou, Stavros D; Oehl, Fritz; Rillig, Matthias C; Maia, Leonor C

    2017-08-04

    Arbuscular mycorrhizal fungi (AMF) are symbiotic fungi with a broad distribution, and many taxa have physiological and ecological adaptations to specific environments, including semiarid ecosystems. Our aim was to address regional distribution patterns of AMF communities in such semiarid environments based on spore morphological techniques. We assessed AMF spores at the bottom and top of inselbergs distributed throughout the tropical dry forest in the Northeast region of Brazil. Across 10 replicate inselbergs and the surrounding area, spanning a range of altitude between 140 and 2000 m, we scored the AMF soil diversity and properties in 52 plots. We fitted parsimonious ordination analyses and variance partitioning models to determine the environmental factors which explained the variation in AMF community, based on morphological spore analysis. The diversity of AMF was similar at the bottom and top of inselbergs; however, we detected high variation in abundance and richness across sites. We formulated a parsimonious richness model that used physical soil factors as predictors. The AMF community structure could be best explained through the variables coarse and total sand, iron, organic matter, potassium, silt, and sodium which together accounted for 17.8% of total variance. Several AMF species were indicators of either deficiency or high values of specific soil properties. We demonstrated that habitat isolation of the inselbergs compared with surrounding areas did not trigger differences in AMF communities in semiarid regions of Brazil. At the regional scale, soil predictors across sites drove the distribution of symbiotic mycorrhizal fungi.

  8. INVENTORY OF MOSQUITOES (DIPTERA: CULICIDAE) IN CONSERVATION UNITS IN BRAZILIAN TROPICAL DRY FORESTS

    PubMed Central

    SANTOS, Cleandson Ferreira; SILVA, Alex Chavier; RODRIGUES, Raquel Andrade; de JESUS, Jamilli Sanndy Ramos; BORGES, Magno Augusto Zazá

    2015-01-01

    In Brazil, most studies of the Culicidae family are concentrated in rainforest regions. As such, there is a lack of knowledge regarding the diversity of Culicidae in regions with different climatic and vegetational characteristics. The aim of this study was to compile an inventory of Culicidae in protected areas of the semi-arid region of the state of Minas Gerais, Brazil, in order to better understand the diversity of the family within this region. The study was conducted across four protected areas in the northern region of the state, in tropical dry forest (TDF) fragments. Sampling methods included Shannon trap and CDC light trap, as well as active collection. A total of 11,219 mosquito specimens were collected between August 2008 and July 2012, belonging to 11 genera and 45 species; 15 new records for the state of Minas Gerais were registered, as well as 26 new records for semi-arid regions within the state. The high number of new Culicidae records in this region demonstrates the importance of inventory studies for increasing the knowledge of culicid biodiversity in Minas Gerais, and in particular within semi-arid regions of the state. PMID:26200963

  9. Analyzing the edge effects in a Brazilian seasonally dry tropical forest.

    PubMed

    Arruda, D M; Eisenlohr, P V

    2016-01-22

    Due to the deciduous nature of dry forests (widely known as seasonally dry tropical forests) they are subject to microclimatic conditions not experienced in other forest formations. Close examinations of the theory of edge effects in dry forests are still rare and a number of questions arise in terms of this topic. In light of this situation we examined a fragment of the dry forest to respond to the following questions: (I) Are there differences in canopy cover along the edge-interior gradient during the dry season? (II) How does the microclimate (air temperature, soil temperature, and relative humidity) vary along that gradient? (III) How does the microclimate influence tree species richness, evenness and abundance along that gradient? (IV) Are certain tree species more dominant closer to the forest edges? Regressions were performed to address these questions. Their coefficients did not significantly vary from zero. Apparently, the uniform openness of the forest canopy caused a homogeneous internal microclimate, without significant differentiation in habitats that would allow modifications in biotic variables tested. We conclude that the processes of edge effect commonly seen in humid forests, not was shared with the dry forest assessed.

  10. Analyzing the edge effects in a Brazilian seasonally dry tropical forest.

    PubMed

    Arruda, D M; Eisenlohr, P V

    2016-02-01

    Due to the deciduous nature of dry forests (widely known as seasonally dry tropical forests) they are subject to microclimatic conditions not experienced in other forest formations. Close examinations of the theory of edge effects in dry forests are still rare and a number of questions arise in terms of this topic. In light of this situation we examined a fragment of the dry forest to respond to the following questions: (I) Are there differences in canopy cover along the edge-interior gradient during the dry season? (II) How does the microclimate (air temperature, soil temperature, and relative humidity) vary along that gradient? (III) How does the microclimate influence tree species richness, evenness and abundance along that gradient? (IV) Are certain tree species more dominant closer to the forest edges? Regressions were performed to address these questions. Their coefficients did not significantly vary from zero. Apparently, the uniform openness of the forest canopy caused a homogeneous internal microclimate, without significant differentiation in habitats that would allow modifications in biotic variables tested. We conclude that the processes of edge effect commonly seen in humid forests, not was shared with the dry forest assessed.

  11. Seasonality in the dung beetle community in a Brazilian tropical dry forest: Do small changes make a difference?

    PubMed

    Medina, Anderson Matos; Lopes, Priscila Paixão

    2014-01-01

    Dung beetle (Coleoptera: Scarabaeoidea: Scarabaeinae) activity is influenced by rainfall seasonality. We hypothesized that rainfall might also play a major role in regulating the community structure of this group. In this study, we describe seasonal changes in the richness, composition, and structure of the Scarabaeinae community in a Brazilian tropical dry forest. A fragment of arboreal Caatinga was sampled using baited pitfall traps during the early dry season (EDS), late dry season (LDS), early wet season (EWS), and middle wet season (MWS). We compared the dung beetle community in each season in relationship to species richness, rank-dominance, curves, and composition. We collected 1352 Scarabaeinae individuals , belonging to 15 species. Dichotomius aff. laevicollis Felsche (Coleoptera: Scarabaeidae) was the dominant species, representing 73.89% of the individuals. There were no seasonal changes in the rank dominance curves; all had a single dominant species and a few species with low abundance, typical for arid areas. Estimated richness was highest in MWS, followed by EWS. Dry-season samples (EDS and LDS) had lower richness, with no significant difference between the dry seasons. Although species richness increased as the habitat became wetter, the difference between the wet and dry seasons was small, which differs completely from the findings of other studies in Neotropical dry forests, where almost all species cease activities in the dry season. Species composition changes were found in non-metric multidimensional scaling and sustained by analysis of similarity. All the seasons had pairwise differences in composition, with the exception of EDS and MWS, which indicates that the dung beetle community in this fragment requires more than three months of drought to trigger changes in species composition; this is probably due to small changes in the forest canopy. There was no difference in composition between EDS and MWS. As in other tropical dry forests, although

  12. Seasonality in the Dung Beetle Community in a Brazilian Tropical Dry Forest: Do Small Changes Make a Difference?

    PubMed Central

    Medina, Anderson Matos; Lopes, Priscila Paixão

    2014-01-01

    Dung beetle (Coleoptera: Scarabaeoidea: Scarabaeinae) activity is influenced by rainfall seasonality. We hypothesized that rainfall might also play a major role in regulating the community structure of this group. In this study, we describe seasonal changes in the richness, composition, and structure of the Scarabaeinae community in a Brazilian tropical dry forest. A fragment of arboreal Caatinga was sampled using baited pitfall traps during the early dry season (EDS), late dry season (LDS), early wet season (EWS), and middle wet season (MWS). We compared the dung beetle community in each season in relationship to species richness, rank-dominance, curves, and composition. We collected 1352 Scarabaeinae individuals , belonging to 15 species. Dichotomius aff. laevicollis Felsche (Coleoptera: Scarabaeidae) was the dominant species, representing 73.89% of the individuals. There were no seasonal changes in the rank dominance curves; all had a single dominant species and a few species with low abundance, typical for arid areas. Estimated richness was highest in MWS, followed by EWS. Dry-season samples (EDS and LDS) had lower richness, with no significant difference between the dry seasons. Although species richness increased as the habitat became wetter, the difference between the wet and dry seasons was small, which differs completely from the findings of other studies in Neotropical dry forests, where almost all species cease activities in the dry season. Species composition changes were found in non-metric multidimensional scaling and sustained by analysis of similarity. All the seasons had pairwise differences in composition, with the exception of EDS and MWS, which indicates that the dung beetle community in this fragment requires more than three months of drought to trigger changes in species composition; this is probably due to small changes in the forest canopy. There was no difference in composition between EDS and MWS. As in other tropical dry forests, although

  13. Restoration of tropical moist forest on bauxite mined lands in the Brazilian Amazon

    Treesearch

    John A Parrotta; Oliver H. Knowles

    1999-01-01

    We evaluated forest structure and composition in 9- to 13-year-old stands established on a bauxite-mined site at Trombetas (Pará), Brazil, using four different reforestation techniques following initial site preparation and topsoil replacement. These techniques included reliance on natural forest regeneration, mixed commercial species plantings of mostly exotic timber...

  14. 40K/137Cs discrimination ratios to the aboveground organs of tropical plants.

    PubMed

    Sanches, N; Anjos, R M; Mosquera, B

    2008-07-01

    In the present work, the accumulation of caesium and potassium in aboveground plant parts was studied in order to improve the understanding on the behaviour of monovalent cations in several compartments of tropical plants. We present the results for activity concentrations of (137)Cs and (40)K, measured by gamma spectrometry, from five tropical plant species: guava (Psidium guajava), mango (Mangifera indica), papaya (Carica papaya), banana (Musa paradisíaca), and manioc (Manihot esculenta). Caesium and potassium have shown a high level of mobility within the plants, exhibiting the highest values of concentration in the growing parts (fruits, leaves, twigs, and barks) of the woody fruit and large herbaceous shrub (such as manioc) species. In contrast, the banana and papaya plants exhibited the lowest levels of (137)Cs and (40)K in their growing parts. However, a significant correlation between activity concentrations of (137)Cs and (40)K was observed in these tropical plants. The (40)K/(137)Cs discrimination ratios were approximately equal to unity in different compartments of each individual plant, suggesting the possibility of using caesium to predict the behaviour of potassium in several tropical species.

  15. Useful Brazilian plants listed in the manuscripts and publications of the Scottish medic and naturalist George Gardner (1812-1849).

    PubMed

    Fagg, Christopher W; Lughadha, Eimear Nic; Milliken, William; Nicholas Hind, D J; Brandão, Maria G L

    2015-02-23

    Information regarding the beneficial use of native Brazilian plants was compiled by a number of European naturalists in the 19th century. The Scottish surgeon botanist George Gardner (1812-1849) was one such naturalist; however, the useful plants recorded in his manuscripts have not yet been studied in depth. To present data recorded by Gardner in his manuscript Catalogue of Brazilian Plants regarding the use of native plants by Brazilian people and evaluate the extent to which they have been explored. Data on useful plants were obtained from Gardner׳s manuscript Catalogue of Brazilian Plants deposited in the Archives of the Royal Botanic Gardens, Kew, UK. The identification of each plant was determined and/or updated by consulting the preserved botanical collections of Gardner deposited in the Herbarium of the Royal Botanic Gardens, Kew (hereafter K), and expert determinations in other herbaria where duplicates are held. Correlated pharmacological studies for each plant were obtained from the PubMed database. Information recorded in Gardner׳s diary and previously published elsewhere complemented these data. A total of 63 useful plants was recorded from the Catalogue and a further 30 from Gardner׳s book Travels in the Interior of Brazil (Gardner, 1846). Of the recorded names in the Catalogue, 46 (73%) could be identified to species by consulting specimens collected by Gardner and held at Kew. Thirty-six different traditional uses were registered for the identified plants, the most common being as febrifuges, to treat venereal complaints and as purgatives. Fewer than 50% of these species have been the focus of published pharmacological studies, yet for those which have been thus investigated, the efficacies reported by Gardner were confirmed. The data recorded by Gardner represent a rich, relatively unexplored source of information regarding the traditional uses of Brazilian plants which merits further investigation. Copyright © 2014 Elsevier Ireland Ltd. All

  16. Brazilian plants as possible adaptogens: an ethnopharmacological survey of books edited in Brazil.

    PubMed

    Mendes, Fúlvio Rieli; Carlini, Elisaldo A

    2007-02-12

    In a survey, from Brazilian books, we searched plants that are in popular use for purposes resembling those of an adaptogen. This study focused on 24 books by authors from diverse regions in the country, resulting in a total of 1317 citations of uses related to a possible adaptogen effect from approximately 766 plants. Only species native to Brazil, cited in at least four books, were selected, resulting a total of 33 species, belonging to 24 families. Of these, four species have been studied previously in relation to effects that are considered as part of an adaptogen effect (anti-stress, memory enhancement, increased physical and/or sexual performance): Heteropterys aphrodisiaca (Malpighiaceae), Paullinia cupana (Sapindaceae), Ptychopetalum olacoides (Olacaceae), and Turnera diffusa (Turneraceae). Three others--Pfaffia glomerata, Pfaffia paniculata (Amaranthaceae), and Trichilia catigua (Meliaceae)--have also been the object of pharmacological studies that support their use as a possible adaptogen, but they are listed in less than four books. The overall results obtained in the present review of Brazilian folk literature reveals that Brazil is rich in plants with potential adaptogen-like effect, but lacks pharmacological studies (mostly clinical ones) to confirm these therapeutic properties.

  17. Screening of Brazilian cacti rhizobacteria for plant growth promotion under drought.

    PubMed

    Kavamura, Vanessa Nessner; Santos, Suikinai Nobre; Silva, João Luiz da; Parma, Márcia Maria; Avila, Luciana Aparecida; Visconti, Alexandre; Zucchi, Tiago Domingues; Taketani, Rodrigo Gouvêa; Andreote, Fernando Dini; Melo, Itamar Soares de

    2013-05-06

    Drought is one of the major problems worldwide. The search for new and efficient microorganisms, from unexplored environments, to be used in association with plants to alleviate the negative effects imposed by water stress, is an interesting alternative. Thus, cacti-associated bacteria from the Brazilian semi-arid region were isolated based on their ability to grow in medium with reduced water availability. Strains were tested for the production of exopolysaccharides (EPS), as well as in vitro plant growth promotion traits. A great proportion of the isolates belong to the genus Bacillus. From a total of forty-eight bacteria, 65% were able to grow in medium with reduced water availability (0.919Aw), exopolysaccharide production was observed for 65% of the strains. The production of indole acetic acid (IAA) exceeding 51μgmL(-1) was observed for 4% and the high solubilization of Ca-P was verified for 6% of the isolates. No strain was able to produce hydrogen cyanide (HCN), 71% produced ammonia and 79% showed a halo of carboxymethyl cellulose (CMC) degradation. Zea mays L. growth promotion under water stress (30% of field capacity) was achieved by two strains of Bacillus spp. This is the first report to describe cacti-associated bacteria from Brazilian semi-arid with plant growth-promoting abilities.

  18. Native Brazilian plants against nosocomial infections: a critical review on their potential and the antimicrobial methodology.

    PubMed

    H Moreno, Paulo Roberto; da Costa-Issa, Fabiana Inácio; Rajca-Ferreira, Agnieszka K; Pereira, Marcos A A; Kaneko, Telma M

    2013-01-01

    The growing incidences of drug-resistant pathogens have increased the attention on several medicinal plants and their metabolites for antimicrobial properties. These pathogens are the main cause of nosocomial infections which led to an increasing mortality among hospitalized patients. Taking into consideration those factors, this paper reviews the state-of-the-art of the research on antibacterial agents from native Brazilian plant species related to nosocomial infections as well as the current methods used in the investigations of the antimicrobial activity and points out the differences in techniques employed by the authors. The antimicrobial assays most frequently used were broth microdilution, agar diffusion, agar dilution and bioautography. The broth microdilution method should be the method of choice for testing new antimicrobial agents from plant extracts or isolated compounds due to its advantages. At the moment, only a small part of the rich Brazilian flora has been investigated for antimicrobial activity, mostly with unfractionated extracts presenting a weak or moderate antibacterial activity. The combination of crude extract with conventional antibiotics represents a largely unexploited new form of chemotherapy with novel and multiple mechanisms of action that can overcome microbial resistance that needs to be further investigated. The antibacterial activity of essential oil vapours might also be an interesting alternative treatment of hospital environment due to their ability in preventing biofilm formation. However, in both alternatives more studies should be done on their mode of action and toxicological effects in order to optimize their use.

  19. Tropical ulcer plant treatments used by Papua New Guinea's Apsokok nomads.

    PubMed

    Prescott, Thomas A K; Homot, Peter; Lundy, Fionnuala T; Fang, Rui; Patrick, Sheila; Cámara-Leret, Rodrigo; Kiapranis, Robert

    2017-06-09

    The tropical ulcer is a debilitating bacterial infection that is common in Papua New Guinea. Deploying healthcare infrastructure to remote and inaccessible rainforest locations is not practical, therefore local plants may be the best treatment option. Here we present an ethnobotanical survey of the tropical ulcer plant medicines used by the semi-nomadic Apsokok who roam the remote central mountains of Papua New Guinea's West New Britain Province. In vitro biological activity in assays relevant to tropical ulcer wound healing is also presented. Focus groups and semi-structured interviews were used to acquire information on the uses of plants, vouchers of which were identified by comparison with authentic herbarium specimens. Antibacterial disc diffusion assays with Staphylococcus aureus and Fusobacterium ulcerans, MMP-9 enzyme inhibition and dermal fibroblast stimulation assays were carried out on plant saps and aqueous extracts of plant material. LC-MS was used to identify known plant metabolites. The ethnobotanical survey identified sixteen species that were used to treat tropical ulcers, all of which were applied topically. A subset of twelve species were investigated further in vitro. Four species produced zones of inhibition with S. aureus, all 12 species provided low level inhibition of MMP-9 and 8 species stimulated dermal fibroblast proliferation, although cytotoxicity occurred at higher concentrations. The extract of Homalium foetidum Benth. inhibited S. aureus and MMP-9 while at lower sub-cytotoxic concentrations stimulated fibroblast proliferation. Trans-3-O-p-coumaroylquinic acid cis-3-O-p-coumaroylquinic acid were detected in the aqueous extract of H. foetidum. Topical application of plant saps to wounds results in very high localised concentrations of plant metabolites which is likely to result in inhibition of MMP proteases. H. foetidum is a candidate plant for tropical ulcer treatment in remote areas. Crown Copyright © 2017. Published by Elsevier B

  20. Carotenoids and flavonoids identification in Brazilian tropical fruits and vegetables using photoacoustic technique

    NASA Astrophysics Data System (ADS)

    Lima, R. J. S.; Vasconcelos, A. S.; Suassuna, J. F.

    2005-06-01

    In this work we present results of the application of PAS technique in the UV-Vis region in a variety of organic materials in natural form such as plant leaves, fruits and vegetables. The observed PAS spectra were associated to the presence of several carotenoids and flavonoids molecules in leaves, fruits and vegetables. Our results confirm PAS as a rapid direct and efficient analytical method in material science, particularly in the very promising field of photochemistry and photobiology.

  1. Hydrogen Isotope Biogeochemistry of Plant Biomarkers in Tropical Trees from the Andes to Amazon

    NASA Astrophysics Data System (ADS)

    Feakins, S. J.; Ponton, C.; West, A. J.; Malhi, Y.; Goldsmith, G.; Salinas, N.; Bentley, L. P.

    2014-12-01

    Plant leaf waxes are well known biomarkers for terrestrial vegetation. Generally, their hydrogen isotopic composition (D/H) records the isotopic composition of precipitation, modulated by leaf water processes and a large biosynthetic fractionation. In addition, the D/H of methoxyl groups on tree wood lignin is an emerging technique thought to record the D/H of source waters, without leaf water complications. Using each of these biomarkers as proxies requires understanding D/H fractionations in plant systems, but few studies have directly studied hydrogen isotope biogeochemistry in tropical plants. An approach that has proven helpful is the paired analysis of plant waters and plant biomarkers: in order that fractionations can be directly computed rather than assumed. This presents logistical challenges in remote tropical forest environments. We report on a unique dataset collected by tree-climbers from 6 well-studied vegetation plots across a 4km elevation transect in the Peruvian Andes and Amazonia. We have measured the D/H of stem water and leaf water, and we compare these to precipitation isotopes and stream waters. The goal of the plant water studies is to understand plant water uptake and stem-leaf water isotopic offsets which can vary due to both transpiration and foliar uptake of water in tropical montane forests. We are in the process of measuring the D/H of plant biomarkers (n-alkanoic acids, n-alkanes and lignin methoxyl) in order to assess how these water isotopic signals are encoded in plant biomarkers. We compare the species-specific modern plant insights to the plant leaf wax n-alkanoic acid D/H that we have recently reported from soils and river sediments from the same region, in order to understand how signals of plant biogeochemistry are integrated into geological sedimentary archives. Progress and open questions in tropical isotope biogeochemistry will be discussed at the meeting.

  2. Psychoactive plants described in a Brazilian literary work and their chemical compounds.

    PubMed

    Otsuka, Rafaela Denise; Lago, João Henrique Ghilardi; Rossi, Lucia; Galduróz, José Carlos Fernandes; Rodrigues, Eliana

    2010-09-01

    Ethnopharmacological research investigates the plants and other medicinal and toxic substances utilized by different traditional populations. One approach in this field is a literature search of the available publications on medicinal plants. The purpose of the current study was to select plants with psychoactive effects described in a Brazilian literary work written by Pio Correa in 1926. Those mentioned plants were classified in accordance with their indications for use as stimulants and depressors of the central nervous system. For the phytochemical study herein, we researched these species via a database search, and all the obtained information was compiled into a new database to analyze possible correlations between the chemical compounds and the psychoactive categories. Of the 813 plants searched in the literary work, 104 presented chemical data in the scientific periodicals consulted. Seventy-five of them belong to the stimulant category, while 31 are depressors and two of them belong to both categories. Phenols and flavonoids were the main compounds observed in plants of both categories, though at different frequencies. Monoterpenes (29.9%) and sesquiterpenes (28.6%) were also observed in plants from the stimulant category, while 25.8% of plants from the depressor category were comprised of carotenoids and 22.6% of steroids. The main specific compounds were identified as ferulic acid, α-pinene, limonene, α-humulene and kaempferol among the stimulant plants. Otherwise, in depressor plants were characterized caffeic acid, kaempferol, quercetin, β-carotene, physalins and withanolides as specific compounds. The association between ethnopharmacological and chemotaxonomic data, as presented in this study, could support plant selection in further investigations by research groups whose studies focus on psychoactive plants as potential therapeutics.

  3. Climate change effects on the geographic distribution of specialist tree species of the Brazilian tropical dry forests.

    PubMed

    Rodrigues, P M S; Silva, J O; Eisenlohr, P V; Schaefer, C E G R

    2015-08-01

    The aim of this study was to evaluate the ecological niche models (ENMs) for three specialist trees (Anadenanthera colubrina, Aspidosperma pyrifolium and Myracrodruon urundeuva) in seasonally dry tropical forests (SDTFs) in Brazil, considering present and future pessimist scenarios (2080) of climate change. These three species exhibit typical deciduousness and are widely distributed by SDTF in South America, being important in studies of the historical and evolutionary processes experienced by this ecosystem. The modeling of the potential geographic distribution of species was done by the method of maximum entropy (Maxent).We verified a general expansion of suitable areas for occurrence of the three species in future (c.a., 18%), although there was reduction of areas with high environmental suitability in Caatinga region. Precipitation of wettest quarter and temperature seasonality were the predictor variables that most contributed to our models. Climatic changes can provide more severe and longer dry season with increasing temperature and tree mortality in tropics. On this scenario, areas currently occupied by rainforest and savannas could become more suitable for occurrence of the SDTF specialist trees, whereas regions occupied by Caatinga could not support the future level of unsustainable (e.g., aridity). Long-term multidisciplinary studies are necessary to make reliable predictions of the plant's adaptation strategies and responses to climate changes in dry forest at community level. Based on the high deforestation rate, endemism and threat, public policies to minimize the effects of climate change on the biodiversity found within SDTFs must be undertaken rapidly.

  4. RAINBIO: a mega-database of tropical African vascular plants distributions.

    PubMed

    Dauby, Gilles; Zaiss, Rainer; Blach-Overgaard, Anne; Catarino, Luís; Damen, Theo; Deblauwe, Vincent; Dessein, Steven; Dransfield, John; Droissart, Vincent; Duarte, Maria Cristina; Engledow, Henry; Fadeur, Geoffrey; Figueira, Rui; Gereau, Roy E; Hardy, Olivier J; Harris, David J; de Heij, Janneke; Janssens, Steven; Klomberg, Yannick; Ley, Alexandra C; Mackinder, Barbara A; Meerts, Pierre; van de Poel, Jeike L; Sonké, Bonaventure; Sosef, Marc S M; Stévart, Tariq; Stoffelen, Piet; Svenning, Jens-Christian; Sepulchre, Pierre; van der Burgt, Xander; Wieringa, Jan J; Couvreur, Thomas L P

    2016-01-01

    The tropical vegetation of Africa is characterized by high levels of species diversity but is undergoing important shifts in response to ongoing climate change and increasing anthropogenic pressures. Although our knowledge of plant species distribution patterns in the African tropics has been improving over the years, it remains limited. Here we present RAINBIO, a unique comprehensive mega-database of georeferenced records for vascular plants in continental tropical Africa. The geographic focus of the database is the region south of the Sahel and north of Southern Africa, and the majority of data originate from tropical forest regions. RAINBIO is a compilation of 13 datasets either publicly available or personal ones. Numerous in depth data quality checks, automatic and manual via several African flora experts, were undertaken for georeferencing, standardization of taxonomic names and identification and merging of duplicated records. The resulting RAINBIO data allows exploration and extraction of distribution data for 25,356 native tropical African vascular plant species, which represents ca. 89% of all known plant species in the area of interest. Habit information is also provided for 91% of these species.

  5. RAINBIO: a mega-database of tropical African vascular plants distributions

    PubMed Central

    Dauby, Gilles; Zaiss, Rainer; Blach-Overgaard, Anne; Catarino, Luís; Damen, Theo; Deblauwe, Vincent; Dessein, Steven; Dransfield, John; Droissart, Vincent; Duarte, Maria Cristina; Engledow, Henry; Fadeur, Geoffrey; Figueira, Rui; Gereau, Roy E.; Hardy, Olivier J.; Harris, David J.; de Heij, Janneke; Janssens, Steven; Klomberg, Yannick; Ley, Alexandra C.; Mackinder, Barbara A.; Meerts, Pierre; van de Poel, Jeike L.; Sonké, Bonaventure; Sosef, Marc S. M.; Stévart, Tariq; Stoffelen, Piet; Svenning, Jens-Christian; Sepulchre, Pierre; van der Burgt, Xander; Wieringa, Jan J.; Couvreur, Thomas L. P.

    2016-01-01

    Abstract The tropical vegetation of Africa is characterized by high levels of species diversity but is undergoing important shifts in response to ongoing climate change and increasing anthropogenic pressures. Although our knowledge of plant species distribution patterns in the African tropics has been improving over the years, it remains limited. Here we present RAINBIO, a unique comprehensive mega-database of georeferenced records for vascular plants in continental tropical Africa. The geographic focus of the database is the region south of the Sahel and north of Southern Africa, and the majority of data originate from tropical forest regions. RAINBIO is a compilation of 13 datasets either publicly available or personal ones. Numerous in depth data quality checks, automatic and manual via several African flora experts, were undertaken for georeferencing, standardization of taxonomic names and identification and merging of duplicated records. The resulting RAINBIO data allows exploration and extraction of distribution data for 25,356 native tropical African vascular plant species, which represents ca. 89% of all known plant species in the area of interest. Habit information is also provided for 91% of these species. PMID:28127234

  6. [Biological activity tests of chemical constituents from two Brazilian Labiatae plants].

    PubMed

    Isobe, Takahiko; Doe, Matsumi; Morimoto, Yoshiki; Nagata, Kumiko; Masuoka, Noriyoshi; Ohsaki, Ayumi

    2007-02-01

    We studied the bioactivities of constituents from two tropical medicinal plants, Cunila spicata and Hyptis fasciculata. These plants found in Brazil belong to the Labiatae family. Four known compounds obtained from these herbs were identified as 3alpha, 24-dihydoxylurs-12-en-28-oic acid, betulinic acid, aurantiamide acetate, and aurantiamide benzoate by spectroscopic means. 3alpha, 24-Dihydoxylurs-12-en-28-oic acid has potent inhibitory activity against Streptococcus salivarius, Streptococcus pneumoniae, Streptococcus pyogenes, and Porphyromomas gingivalis. Aurantiamide benzoate exhibited moderate inhibitory activity against xanthine oxidase. It was clarified that herbs Cunila spicata and Hyptis fasciculata are effective against bronchitis and gout.

  7. Natural compounds isolated from Brazilian plants are potent inhibitors of hepatitis C virus replication in vitro.

    PubMed

    Jardim, A C G; Igloi, Z; Shimizu, J F; Santos, V A F F M; Felippe, L G; Mazzeu, B F; Amako, Y; Furlan, M; Harris, M; Rahal, P

    2015-03-01

    Compounds extracted from plants can provide an alternative approach to new therapies. They present characteristics such as high chemical diversity, lower cost of production and milder or inexistent side effects compared with conventional treatment. The Brazilian flora represents a vast, largely untapped, resource of potential antiviral compounds. In this study, we investigate the antiviral effects of a panel of natural compounds isolated from Brazilian plants species on hepatitis C virus (HCV) genome replication. To do this we used firefly luciferase-based HCV sub-genomic replicons of genotypes 2a (JFH-1), 1b and 3a and the compounds were assessed for their effects on both HCV replication and cellular toxicity. Initial screening of compounds was performed using the maximum non-toxic concentration and 4 compounds that exhibited a useful therapeutic index (favourable ratio of cytotoxicity to antiviral potency) were selected for extra analysis. The compounds APS (EC50=2.3μM), a natural alkaloid isolated from Maytrenus ilicifolia, and the lignans 3(∗)43 (EC50=4.0μM), 3(∗)20 (EC50=8.2μM) and 5(∗)362 (EC50=38.9μM) from Peperomia blanda dramatically inhibited HCV replication as judged by reductions in luciferase activity and HCV protein expression in both the subgenomic and infectious systems. We further show that these compounds are active against a daclatasvir resistance mutant subgenomic replicon. Consistent with inhibition of genome replication, production of infectious JFH-1 virus was significantly reduced by all 4 compounds. These data are the first description of Brazilian natural compounds possessing anti-HCV activity and further analyses are being performed in order to investigate the mode of action of those compounds.

  8. Aridity, not fire, favors nitrogen-fixing plants across tropical savanna and forest biomes.

    PubMed

    Pellegrini, Adam F A; Staver, A Carla; Hedin, Lars O; Charles-Dominique, Tristan; Tourgee, Amy

    2016-09-01

    Tropical savannas are hypothesized to be hot spots of nitrogen-fixer diversity and activity because of the high disturbance and low nitrogen characteristic of savanna landscapes. Here we compare the abundances of nitrogen-fixing and non-fixing trees in both tropical savannas and tropical forests under climatically equivalent conditions, using plant inventory studies across 566 plots in South America and Africa. A single factor, aridity, explained 19-54% of the variance in fixer abundance, and unexpectedly was more important than fire frequency, biome, and continent. Nitrogen fixers were more abundant in arid environments; as a result, African savannas, which tend to be drier, were richer in nitrogen fixers than South American savannas. Fixer abundance converged on similar levels in forests in both continents. We conclude that climate plays a greater role than fire in determining the distribution of nitrogen fixers across tropical savanna and forest biomes.

  9. Screening of some plants used in the Brazilian folk medicine for the treatment of infectious diseases.

    PubMed

    Holetz, Fabíola Barbiéri; Pessini, Greisiele Lorena; Sanches, Neviton Rogério; Cortez, Diógenes Aparício Garcia; Nakamura, Celso Vataru; Filho, Benedito Prado Dias

    2002-10-01

    Extracts of 13 Brazilian medicinal plants were screened for their antimicrobial activity against bacteria and yeasts. Of these, 10 plant extracts showed varied levels of antibacterial activity. Piper regnellii presented a good activity against Staphylococus aureus and Bacillus subtilis, a moderate activity on Pseudomonas aeruginosa, and a weak activity against Escherichia coli. Punica granatum showed good activity on S. aureus and was inactive against the other standard strains. Eugenia uniflora presented moderate activity on both S. aureus and E. coli. Psidium guajava,Tanacetum vulgare, Arctium lappa, Mikania glomerata, Sambucus canadensis, Plantago major and Erythrina speciosa presented some degree of antibacterial activity. Spilanthes acmella, Lippia alba, and Achillea millefolium were considered inactive. Five of the plant extracts presented compounds with Rf values similar to the antibacterial compounds visible on bioautogram. Of these, three plants belong to the Asteraceae family. This may mean that the same compounds are responsible for the antibacterial activity in these plants. Anticandidal activity was detected in nine plant extracts (P. guajava, E. uniflora, P. granatum, A. lappa, T. vulgare, M. glomerata, L. alba, P. regnellii, and P. major). The results might explain the ethnobotanical use of the studied species for the treatment of various infectious diseases.

  10. Anti-TNF-α Activity of Brazilian Medicinal Plants and Compounds from Ouratea semiserrata.

    PubMed

    Campana, Priscilla R V; Mansur, Daniel S; Gusman, Grasielle S; Ferreira, Daneel; Teixeira, Mauro M; Braga, Fernão C

    2015-10-01

    Several plant species are used in Brazil to treat inflammatory diseases and associated conditions. TNF-α plays a pivotal role on inflammation, and several plant extracts have been assayed against this target, both in vitro and in vivo. The effect of 11 Brazilian medicinal plants on TNF-α release by LPS-activated THP-1 cells was evaluated. The plant materials were percolated with different solvents to afford 15 crude extracts, whose effect on TNF-α release was determined by ELISA. Among the evaluated extracts, only Jacaranda caroba (Bignoniaceae) presented strong toxicity to THP-1 cells. Considering the 14 non-toxic extracts, TNF-α release was significantly reduced by seven of them (inhibition > 80%), originating from six plants, namely Cuphea carthagenensis (Lythraceae), Echinodorus grandiflorus (Alismataceae), Mansoa hirsuta (Bignoniaceae), Ouratea semiserrata (Ochnaceae), Ouratea spectabilis and Remijia ferruginea (Rubiaceae). The ethanol extract from O. semiserrata leaves was fractionated over Sephadex LH-20 and RP-HPLC to give three compounds previously reported for the species, along with agathisflavone and epicatechin, here described for the first time in the plant. Epicatechin and lanceoloside A elicited significant inhibition of TNF-α release, indicating that they may account for the effect produced by O. semiserrata crude extract.

  11. Possibilities to reduce carbon emissions in Brazilian Amazon region with non timber biomass valorization: The case of biofuels produced by vegetable tropical oils

    SciTech Connect

    Freitas, M.A.V. de; Rosa, L.P.; Lascio, M.A. Di |

    1996-12-31

    Brazil`s annual rate of deforestation reached 2.1 million ha or about 13.6% of the total annual rate of deforestation for the whole tropical area in the world during 1981--1990. Today, the extent of gross deforestation is 10.9% of the tropical closed forest area. Relative to Brazilian participation in the greenhouse effect, the changes in forest area and associated biomass burning in Amazon region are responsible for about 25.5% of CO{sub 2} emissions in the tropics. Harvest of the non-timber biomass products may be important as a potentially sustainable use of forest in some areas. An excellent option to promote these biomass products is to provide energy and industrial goods for the Amazon communities and other external markets. In this work, the biofuels produced by vegetable tropical oils and their by-products are analyzed in relation to job creation, economics and environmental impacts, with special regards concerning the limitation of the atmospheric emissions of greenhouse gases.

  12. Ecological responses to el Niño-induced surface fires in central Brazilian Amazonia: management implications for flammable tropical forests.

    PubMed Central

    Barlow, Jos; Peres, Carlos A

    2004-01-01

    Over the past 20 years the combined effects of El Niño-induced droughts and land-use change have dramatically increased the frequency of fire in humid tropical forests. Despite the potential for rapid ecosystem alteration and the current prevalence of wildfire disturbance, the consequences of such fires for tropical forest biodiversity remain poorly understood. We provide a pan-tropical review of the current state of knowledge of these fires, and include data from a study in a seasonally dry terra firme forest of central Brazilian Amazonia. Overall, this study supports predictions that rates of tree mortality and changes in forest structure are strongly linked to burn severity. The potential consequences for biomass loss and carbon emissions are explored. Despite the paucity of data on faunal responses to tropical forest fires, some trends are becoming apparent; for example, large canopy frugivores and understorey insectivorous birds appear to be highly sensitive to changes in forest structure and composition during the first 3 years after fires. Finally, we appraise the management implications of fires and evaluate the viability of techniques and legislation that can be used to reduce forest flammability, prevent anthropogenic ignition sources from coming into contact with flammable forests and aid the post-fire recovery process. PMID:15212091

  13. Ecological responses to el Niño-induced surface fires in central Brazilian Amazonia: management implications for flammable tropical forests.

    PubMed

    Barlow, Jos; Peres, Carlos A

    2004-03-29

    Over the past 20 years the combined effects of El Niño-induced droughts and land-use change have dramatically increased the frequency of fire in humid tropical forests. Despite the potential for rapid ecosystem alteration and the current prevalence of wildfire disturbance, the consequences of such fires for tropical forest biodiversity remain poorly understood. We provide a pan-tropical review of the current state of knowledge of these fires, and include data from a study in a seasonally dry terra firme forest of central Brazilian Amazonia. Overall, this study supports predictions that rates of tree mortality and changes in forest structure are strongly linked to burn severity. The potential consequences for biomass loss and carbon emissions are explored. Despite the paucity of data on faunal responses to tropical forest fires, some trends are becoming apparent; for example, large canopy frugivores and understorey insectivorous birds appear to be highly sensitive to changes in forest structure and composition during the first 3 years after fires. Finally, we appraise the management implications of fires and evaluate the viability of techniques and legislation that can be used to reduce forest flammability, prevent anthropogenic ignition sources from coming into contact with flammable forests and aid the post-fire recovery process.

  14. Roles of mesophyll conductance and plant functional diversities in tropical photosynthesis

    NASA Astrophysics Data System (ADS)

    Gu, L.

    2013-12-01

    Tropical photosynthesis dominates global terrestrial gross primary production (GPP) and will likely play a defining role in determining how global GPP will respond to climate change. Yet, our current understanding of biological, ecological, edaphic and environmental controls on tropical photosynthesis is poor. The overly simplistic schemes that current Earth System Models use to simulate tropical photosynthesis cannot capture the functional diversities associated with high species diversities in the tropics. New approaches that explicitly represent the functional diversities of tropical photosynthesis in Earth System Models are needed in order to realistically model responses of tropical photosynthesis to increased atmospheric CO2 concentrations and associated climate changes. To establish a basis for such approaches, we conducted intensive field measurements of leaf photosynthesis at three forest sites along a strong rainfall gradient in Panama in 2012-2013. The three sites are Parque Natural Metropolitano, Gamboa, and Parque Nacional San Lorenzo. The Parque Natural Metropolitano receives an annual precipitation of less than 1800mm and Parque Nacional San Lorenzo over 3300 mm with Gamboa in between. The three sites differ in species diversity with Parque Nacional San Lorenzo having the highest species diversity and Parque Nacional San Lorenzo the lowest. At the three contrasting sites, we measured A/Ci curves, leaf traits and leaf nutrient (N and P) contents of about 100 species. We determined mesophyll conductance with the LeafWeb approach. From these measurements, we developed practical but realistic parameterizations of functional diversities of tropical plant species at the three sites and implemented these parameterizations in the latest version of the Community Land Model. We found that mesophyll conductance is key to representing functional diversities of tropical forest species. Without it, responses of tropical photosynthesis to increased atmospheric CO2

  15. Spatial and phylogenetic variation in plant defense in a tropical moist forest canopy community

    NASA Astrophysics Data System (ADS)

    McManus, K. M.; Asner, G. P.; Martin, R.

    2013-12-01

    Plants employ physical and chemical defenses to mitigate damage caused by herbivory. Spatial patterns of plant defense may provide insight into the role of plant-herbivore interactions in the assembly of plant communities. Within plant communities, the spatial overdispersion of anti-herbivore defenses by individuals may reflect a strategy to avoid host shifts from herbivore assemblages of neighboring plants. However, variation in plant defense may also result from trade-offs between foliar investment into defense and growth, mediated by variations in abiotic nutrient availability, or constrained by phylogeny. We measured four defensive traits (leaf toughness, total phenols, condensed tannins, and hydrolysable tannins) and three growth traits (LMA, C:N, total protein) of outer canopy foliage for 345 canopy trees representing 78 species, 65 genera, and 34 families in a moist tropical rainforest on Barro Colorado Island, Panama. The outer canopy provides an important, but rarely evaluated, cross-sectional image of the tropical forest ecosystem, and observations at this scale may provide an important link between field and remote sensing based studies. We used existing data on edaphic and geological properties to investigate the relationships of abiotic nutrient variation on variation in defense. Using regression and nested random-effects variance modeling, we found strong phylogenetic association with defensive traits at the family and species level, and little evidence for a trade-off between defensive traits. Greater understanding of phylogenetic structure in trait variation may yield improved characterizations of tropical biodiversity, from functional traits to risk assessments.

  16. Effects of Litter Removal and Addition on the Nutrient Mineralization Dynamics in Hyperseasonal Tropical Savannas of the Brazilian Pantanal

    NASA Astrophysics Data System (ADS)

    Hentz, C. S.; Pinto-Jr, O. B.; Vourlitis, G. L.

    2015-12-01

    The tropical savanna of Brazil (cerrado) is extremely species diverse and it encompasses many different physiognomic features, which are influenced by rainfall, fire, and soil nutrient availability. Plant litter decomposition recycles nutrients to the soil, and in turn, assists plant growth. However the rate at which these nutrients become available to the soil is poorly understood. Thus, a six month field experiment that encompassed the wet and dry seasons was conducted to assess how different quantities of litter inputs affect nutrient (P, N, C, K, Ca, and Mg) availability. It was hypothesized that nutrient mineralization would be significantly influenced by manipulation of the surface litter and that there would be a positive correlation between soil moisture and nutrient mineralization. Initial results indicate that there were significant differences in mineralization over time for all nutrients, except P, supporting our hypothesis of changes in mineralization with soil moisture. However, there were no significant differences between litter treatments and net mineralization rates for all the nutrients tested. Our results indicate that litterpool size has little effect on short-term nutrient mineralization dynamics.

  17. Maximising Synergy among Tropical Plant Systematists, Ecologists, and Evolutionary Biologists.

    PubMed

    Baker, Timothy R; Pennington, R Toby; Dexter, Kyle G; Fine, Paul V A; Fortune-Hopkins, Helen; Honorio, Euridice N; Huamantupa-Chuquimaco, Isau; Klitgård, Bente B; Lewis, Gwilym P; de Lima, Haroldo C; Ashton, Peter; Baraloto, Christopher; Davies, Stuart; Donoghue, Michael J; Kaye, Maria; Kress, W John; Lehmann, Caroline E R; Monteagudo, Abel; Phillips, Oliver L; Vasquez, Rodolfo

    2017-04-01

    Closer collaboration among ecologists, systematists, and evolutionary biologists working in tropical forests, centred on studies within long-term permanent plots, would be highly beneficial for their respective fields. With a key unifying theme of the importance of vouchered collection and precise identification of species, especially rare ones, we identify four priority areas where improving links between these communities could achieve significant progress in biodiversity and conservation science: (i) increasing the pace of species discovery; (ii) documenting species turnover across space and time; (iii) improving models of ecosystem change; and (iv) understanding the evolutionary assembly of communities and biomes.

  18. Studies on saponin production in tropical medicinal plants Maesa argentea and Maesa lanceolata

    NASA Astrophysics Data System (ADS)

    Faizal, Ahmad; Geelen, Danny

    2015-09-01

    The continuous need for new compounds with important medicinal activities has lead to the identification and characterization of various plant-derived natural products. As a part of this program, we studied the saponin production from two tropical medicinal plants Maesa argentea and M. lanceolata and evaluated several treatments to enhance their saponin production. In this experiment, we present the analyses of saponin production from greenhouse grown plants by means of TLC and HPLC-MS. We observed that the content of saponin from these plants varied depending on organ and physiological age of the plants. In addition, the impact of elicitors on saponin accumulation on in vitro grown plants was analyzed using TLC. The production of saponin was very stable and not affected by treatment with methyl jasmonate, and salicylic acid. In conclusion, Maesa saponins are constitutively produced in plants and the level of these compounds in plants is mainly affected by the developmental or physiological stage.

  19. Correlation between earthworms and plant litter decomposition in a tropical wet forest of Puerto Rico.

    Treesearch

    Jennifer Dechainea; Honghua Ruanb; Yaniria Sanchez-de Leon; Xiaoming Zou

    2005-01-01

    Earthworms are recognized to play an important role in the decomposition of organic materials. To test the use of earthworms as an indicator of plant litter decomposition, we examined the abundance and biomass of earthworms in relation to plant litter decomposition in a tropical wet forest of Puerto Rico. We collected earthworms at 0–0.1m and 0.1–0.25m soil depths from...

  20. Antibacterial properties of tropical plants from Puerto Rico.

    PubMed

    Meléndez, P A; Capriles, V A

    2006-03-01

    In an effort to document the antibacterial properties of plants commonly used by the people of Puerto Rico, we studied the effects of 172 plant species, utilizing the disc diffusion method, against Escherichia coli and Staphylococcus aureus. The methanolic extracts of 14 species showed antibacterial activities during this preliminary screen. These positive plant extracts were tested successively over 15 additional species. The results showed that extracts from Citrus aurantifolia (Rutaceae), Citrus aurantium (Rutaceae), Punica granatum (Punicaceae), Phyllanthus acidus (Euphorbiaceae) and Tamarindus indica (Caesalpiniaceae) possess strong in vitro antibacterial activity against the bacteria tested.

  1. On the factors that promote the diversity of herbivorous insects and plants in tropical forests.

    PubMed

    Becerra, Judith X

    2015-05-12

    Some of the most fascinating and challenging questions in ecology are why biodiversity is highest in tropical forests and whether the factors involved are unique to these habitats. I did a worldwide test of the hypotheses that plant community divergence in antiherbivore traits results in higher insect herbivore diversity, and that predominant attack by specialized herbivores promotes plant richness. I found strong correlative support for both ideas. Butterfly diversity was greatest in regions where the community average species-pairwise dissimilarity in antiherbivore traits among plant species was highest. There was also a strong positive relationship between specialized (insect) vs. generalized (mammal) herbivores and plant richness. Regions where herbivory impact by mammals was higher than that of insects tended to have lower plant diversities. In contrast, regions in which insects are the main consumers, particularly in the Central and South American tropics, had the highest plant richness. Latitude did not explain any residual variance in insect or plant richness. The strong connections found between insect specialization, plant defense divergence, and plant and insect diversities suggest that increasing our understanding of the ecology of biological communities can aid in considerations of how to preserve biodiversity in the future.

  2. On the factors that promote the diversity of herbivorous insects and plants in tropical forests

    PubMed Central

    Becerra, Judith X.

    2015-01-01

    Some of the most fascinating and challenging questions in ecology are why biodiversity is highest in tropical forests and whether the factors involved are unique to these habitats. I did a worldwide test of the hypotheses that plant community divergence in antiherbivore traits results in higher insect herbivore diversity, and that predominant attack by specialized herbivores promotes plant richness. I found strong correlative support for both ideas. Butterfly diversity was greatest in regions where the community average species-pairwise dissimilarity in antiherbivore traits among plant species was highest. There was also a strong positive relationship between specialized (insect) vs. generalized (mammal) herbivores and plant richness. Regions where herbivory impact by mammals was higher than that of insects tended to have lower plant diversities. In contrast, regions in which insects are the main consumers, particularly in the Central and South American tropics, had the highest plant richness. Latitude did not explain any residual variance in insect or plant richness. The strong connections found between insect specialization, plant defense divergence, and plant and insect diversities suggest that increasing our understanding of the ecology of biological communities can aid in considerations of how to preserve biodiversity in the future. PMID:25902509

  3. Azospirillum spp. from native forage grasses in Brazilian Pantanal floodplain: biodiversity and plant growth promotion potential.

    PubMed

    Souza, Mayara S T; de Baura, Valter A; Santos, Sandra A; Fernandes-Júnior, Paulo Ivan; Reis Junior, Fábio B; Marques, Maria Rita; Paggi, Gecele Matos; da Silva Brasil, Marivaine

    2017-04-01

    A sustainable alternative to improve yield and the nutritive value of forage is the use of plant growth-promoting bacteria (PGPB) that release nutrients, synthesize plant hormones and protect against phytopathogens (among other mechanisms). Azospirillum genus is considered an important PGPB, due to the beneficial effects observed when inoculated in several plants. The aim of this study was to evaluate the diversity of new Azospirillum isolates and select bacteria according to the plant growth promotion ability in three forage species from the Brazilian Pantanal floodplain: Axonopus purpusii, Hymenachne amplexicaulis and Mesosetum chaseae. The identification of bacterial isolates was performed using specific primers for Azospirillum in PCR reactions and partial sequencing of the 16S rRNA and nifH genes. The isolates were evaluated in vitro considering biological nitrogen fixation (BNF) and indole-3-acetic acid (IAA) production. Based on the results of BNF and IAA, selected isolates and two reference strains were tested by inoculation. At 31 days after planting the plant height, shoot dry matter, shoot protein content and root volume were evaluated. All isolates were able to fix nitrogen and produce IAA, with values ranging from 25.86 to 51.26 mg N mL(-1) and 107-1038 µmol L(-1), respectively. The inoculation of H. amplexicaulis and A. purpusii increased root volume and shoot dry matter. There were positive effects of Azospirillum inoculation on Mesosetum chaseae regarding plant height, shoot dry matter and root volume. Isolates MAY1, MAY3 and MAY12 were considered promising for subsequent inoculation studies in field conditions.

  4. Does the selection of medicinal plants by Brazilian local populations suffer taxonomic influence?

    PubMed

    deMedeiros, Patrícia Muniz; Ladio, Ana Haydée; Santos, André Maurício Melo; de Albuquerque, Ulysses Paulino

    2013-04-19

    The analysis of the influence of taxonomic affiliation on the selection of medicinal plants by Brazilian local populations can help elucidate theoretical aspects of medicinal plant selection. Ethnobotanical medicinal plant studies were compiled and the resulting medicinal flora was compared to the total angiosperm flora with a Bayesian approach and the IDM model. A total of 35 families were considered to be overused and six were classified as underused for the Bayesian approach. On the other hand, the IDM model considered 13 families as overused and five as underused (all of them were also highlighted by the Bayesian approach). A high overuse level of Bixaceae, Amaranthaceae, Anacardiaceae and Smilacaceae was recorded for both Bayesian and IDM model, while Orchidaceae, Melastomataceae, Eriocaulaceae, Poaceae and Bromeliaceae were considered as underused for both analyses. The most dissimilar body system in terms of family composition was 'mental and behavioral disorders'. It was also found that the body systems are different from one another in the proportion of taxonomic groups, which could indicate chemical specificity in the treatment of diseases. Results indicate that the chemical specificity of taxonomic groups directly influences medicinal plant selection. Moreover, when data presented here are compared to other studies, there is clearly an overuse pattern for families like Lamiaceae, Rosaceae and Euphorbiaceae and an underuse pattern for Poaceae and Orchidaceae. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  5. Plants used for poison fishing in tropical Africa.

    PubMed

    Neuwinger, H D

    2004-09-15

    Fishing with the aid of poisonous plants was formerly very common in Africa. Today this easy and simple method of fishing is forbidden but still practised in remote areas. The poisonous ingredients are pounded and thrown into a pool or dammed sections of a small river. After a time which varies according to conditions the fish begin to rise to the surface of the water and can readily be taken by hand. In general, the fish can be eaten without problems. 325 fish-poisoning plants, spread among 71 plant families with 183 genera, are presented. The closely related groups of Caesalpiniaceae, Mimosaceae and Papilionaceae clearly dominate. It is also remarkable that a great proportion are Euphorbiaceae. The plants most used are Tephrosia vogelii, Mundulea sericea, Euphorbia tirucalli, Gnidia kraussiana, Adenia lobat, Balanites aegyptiaca, Swartzia madagascariensis, Neoratanenia mitis, Tetrapleura tetraptera and Strychnos aculeata. Many fishing poisons play an important part in the preparation of arrow poisons and in traditional medicine.

  6. Search for antibacterial agents from Malaysian rainforest and tropical plants.

    PubMed

    Othman, Mukhrizah; Genapathy, Sivaneswary; Liew, Pit Sze; Ch'ng, Qin Ting; Loh, Hwei San; Khoo, Teng Jin; Wiart, Christophe; Ting, Kang Nee

    2011-11-01

    The world's rainforests hold untold potential for drug discovery. Rainforest plants are thought to contain evolved defensive active metabolites of greater diversity compared to plants from temperate regions. In recent years, the interest and overall output from pharmaceutical companies on novel antibacterial agents has diminished at a time when there is a critical need for them to fight the threat of resistance. In this study, we have investigated the antimicrobial properties of 21 flowering plants from 16 different families against six bacterial strains consisting of two Gram negative and four Gram positive. Using the pour plate disc diffusion technique, almost all extracts from these plants were found to be active against some of the bacterial strains tested. The most interesting and active plants with broad spectrum activities include Duabanga grandiflora, Acalypha wilkesiana and Pseuduvaria macrophylla where the minimum inhibitory concentration, minimum bactericidal concentration and phytochemical analysis were carried out. This is the first report describing the antimicrobial and phytochemical properties of D. grandiflora and P. macrophylla. Our findings support the utilisation of higher plant species in the search for new antimicrobial molecules to combat new emerging infective diseases and the problem of drug resistant pathogens.

  7. Accumulation of K{sup +} and Cs{sup +} in Tropical Plant Species

    SciTech Connect

    Velasco, H.; Rizzotto, M.; Lacerda, T.; Anjos, R. M.; Macario, K. D.; Cid, A. S.; Zamboni, C. B.; Medeiros, I. M. A.; Fernandez, J.; Rubio, L.; Audicio, P.

    2010-08-04

    Concentrations of K{sup +} and {sup 137}Cs{sup +} in tissues of the Citrus aurantifolia were measured both by gamma spectrometry and neutron activation analysis, aiming to understand the behavior of monovalent inorganic cations in plants as well as its capability to store these elements. In contrast to K{sup +},Cs{sup +} ions are not essential elements to plants, what might explain the difference in bioavailability. However, our results have shown that {sup 137}Cs{sup +} is positively correlated to {sup 40}K{sup +} concentration within tropical plant species, suggesting that these elements might be assimilated in a similar way, and that they pass through the biological cycle together. A simple mathematical model was also proposed to describe the temporal evolution of {sup 40}K activity concentration in such tropical woody fruit species. This model exhibited close agreement with the {sup 40}K experimental results in the fruit ripening processes of lemon trees.

  8. Plant functional traits with particular reference to tropical deciduous forests: a review.

    PubMed

    Chaturvedi, R K; Raghubanshi, A S; Singh, J S

    2011-12-01

    Functional traits (FTs) integrate the ecological and evolutionary history of a species, and can potentially be used to predict its response as well as its influence on ecosystem functioning. Study of inter-specific variation in the FTs of plants aids in classifying species into plant functional types (PFTs) and provides insights into fundamental patterns and trade-offs in plant form and functioning and the effect of changing species composition on ecosystem functions. Specifically, this paper focuses on those FTs that make a species successful in the dry tropical environment. Following a brief overview, we discuss plant FTs that may be particularly relevant to tropical deciduous forests (TDFs). We consider the traits under the following categories: leaf traits, stem and root traits, reproductive traits, and traits particularly relevant to water availability. We compile quantitative information on functional traits of dry tropical forest species. We also discuss trait-based grouping of plants into PFTs. We recognize that there is incomplete knowledge about many FTs and their effects on TDFs and point out the need for further research on PFTs of TDF species, which can enable prediction of the dynamics of these forests in the face of disturbance and global climate change. Correlations between structural and ecophysiological traits and ecosystem functioning should also be established which could make it possible to generate predictions of changes in ecosystem services from changes in functional composition.

  9. Plant compensation to grazing and soil carbon dynamics in a tropical grassland

    PubMed Central

    2014-01-01

    The effects of grazing on soil organic carbon (SOC) dynamics, particularly in the tropics, are still poorly understood. Plant compensation to grazing, whereby plants maintain leaf area (C input capacity) despite consumption (C removal) by grazers, has been demonstrated in tropical grasslands but its influence on SOC is largely unexplored. Here, the effect of grazing on plant leaf area index (LAI) was measured in a field experiment in Serengeti National Park, Tanzania. LAI changed little for grazing intensities up to 70%. The response curve of LAI versus grazing intensity was used in a mass balance model, called SNAP, of SOC dynamics based on previous data from the Serengeti. The model predicted SOC to increase at intermediate grazing intensity, but then to decline rapidly at the highest grazing intensities. The SNAP model predictions were compared with observed SOC stocks in the 24 grazed plots of a 10-year grazing exclosure experiment at eight sites across the park that varied in mean annual rainfall, soil texture, grazing intensity and plant lignin and cellulose. The model predicted current SOC stocks very well (R2 > 0.75), and suggests that compensatory plant responses to grazing are an important means of how herbivores might maintain or increase SOC in tropical grasslands. PMID:24498573

  10. Participation of the Nuclear Power Plants in the New Brazilian Electric Energy Market

    SciTech Connect

    Mathias, S.G.

    2004-10-06

    A new regulation framework has been established for the Brazilian electric energy market by a law put into effect on March 15,2004. The main overall goals of this new regulation are: to allow the lowest possible tariffs for end users, while providing the necessary economic incentives for the operation of present installations (generating plants, transmission lines, distribution networks) and the expansion of the system; long-term planning of the extension of the installations required to meet the demand growth; separation of the generation, transmission and distribution activities by allocating them into different companies; new contracts between generating and distribution companies must result from bidding processes based on lowest-tariff criteria; and energy from new generating units required to meet the demand growth must be contracted by all distributing companies integrated to the National Interconnected Grid, in individual amounts proportional to their respective markets.

  11. Vasodilator and antioxidant effect of xanthones isolated from Brazilian medicinal plants.

    PubMed

    Capettini, Luciano S; Campos, Lucas Vicente A; Dos Santos, Marcelo H; Nagem, Tanus J; Lemos, Virgínia S; Cortes, Steyner F

    2009-02-01

    Vasorelaxant and antioxidant activities are important in the therapy for cardiovascular diseases. We aimed at investigating the vasorelaxant and antioxidant activities of six xanthones isolated from Brazilian medicinal plants. Xanthone ( 1), 1-hydroxyxanthone ( 2), 4-hydroxyxanthone ( 3), 1-hydroxy-8-methoxyxanthone ( 4), 1,3-dihydroxy-7-methoxyxanthone ( 5) and 2,6,8-trihydroxy-1-methoxyxanthone ( 6) induced concentration-dependent vasorelaxant effects in endothelium-intact mice aortic rings. The presence of a hydroxy group in position 1 seemed to decrease the vasodilator effect while a hydroxy in position 4 and an increased number of hydroxy groups improved the vasorelaxatory potential of xanthones. All xanthones showed antioxidant activity but their potencies did not correlate with the vasodilator effect. Our results suggest that the tested xanthones are potentially vasorelaxant and antioxidant compounds but the two activities are not interrelated.

  12. Generalist birds promote tropical forest regeneration and increase plant diversity via rare-biased seed dispersal.

    PubMed

    Carlo, Tomás A; Morales, Juan M

    2016-07-01

    Regenerated forests now compose over half of the world's tropical forest cover and are increasingly important as providers of ecosystem services, freshwater, and biodiversity conservation. Much of the value and functionality of regenerating forests depends on the plant diversity they contain. Tropical forest diversity is strongly shaped by mutualistic interactions between plants and fruit-eating animals (frugivores) that disperse seeds. Here we show how seed dispersal by birds can influence the speed and diversity of early successional forests in Puerto Rico. For two years, we monitored the monthly fruit production of bird-dispersed plants on a fragmented landscape, and measured seed dispersal activity of birds and plant establishment in experimental plots located in deforested areas. Two predominantly omnivorous bird species, the Northern Mockingbird (Mimus polyglottos) and the Gray Kingbird (Tyrannus dominicensis), proved critical for speeding up the establishment of woody plants and increasing the species richness and diversity of the seed rain in deforested areas. Seed dispersal by these generalists increased the odds for rare plant species to disperse and establish in experimental forest-regeneration plots. Results indicate that birds that mix fruit and insects in their diets and actively forage across open and forested habitats can play keystone roles in the regeneration of mutualistic plant-animal communities. Furthermore, our analyses reveal that rare-biased (antiapostatic) frugivory and seed dispersal is the mechanism responsible for increasing plant diversity in the early-regenerating community. © 2016 by the Ecological Society of America.

  13. In vivo antimutagenic activity of the medicinal plants Pfaffia glomerata (Brazilian ginseng) and Ginkgo biloba.

    PubMed

    Almeida, I V; Düsman, E; Mattge, G I; Toledo, F; Reusing, A F; Vicentini, V E P

    2017-09-27

    Complementary and alternative therapies, including the use of medicinal plants, have become almost standard among the world's population. Pfaffia glomerata (PG), popularly known as Brazilian ginseng, is widely used as a restorer of vital functions, increasing mental balance, and is used for the treatment of diabetes and rheumatism. Ginkgo biloba (GB) is one of the oldest known gymnosperms, whose leaves are widely used for its potentiating action on the nervous system. The biological activities of these plants were determined on bone marrow cells of Wistar rats treated in vivo. For cytotoxic and mutagenic acute analysis, plant extracts were administered by gavage at concentrations of 0.15, 1.5, and 15 mg PG/mL water and 1, 2, and 3 mg GB/mL water. For antimutagenic analysis, plant extracts aqueous solution (PG, 1.5 mg/mL or GB, 2 mg/mL) were administered by gavage before (pretreatment), simultaneous to (simultaneous treatment), or after (post-treatment) the administration of cyclophosphamide (1.5 mg/mL, intraperitoneally). Both plant extracts have no cytotoxic or mutagenic potential, and they significantly reduce the percentage of chromosomal aberrations induced by the cyclophosphamide given simultaneously (PG, 87%; GB, 75%), pretreatment (PG, 98%, GB, 78%) and post-treatment (PG, 99%, GB, 75%). This beneficial antimutagenic property of the medicinal plants P. glomerata and G. biloba presented here, with no cytotoxic or mutagenic activity, can efficiently contribute to improvements in quality of life and recovery for people undergoing chemotherapeutic treatment, or those looking for health and preventive habits.

  14. [Comparison of two plant-bird mutualistic systems in Asian tropical rainforests].

    PubMed

    Sanityan, Sawat; Chen, Jin; Wang, Bo

    2011-06-01

    Abstract: To deeply understand how the morphological features of plants affect the visiting of pollen- and seed dispersal birds is beneficial to elucidate the ecological and evolutionary consequences of plant-bird interactions. In this paper, a comparative study was conducted on the avian pollen- and seed dispersal networks across four tropical rainforest habitats having experienced different levels of anthropological disturbance in Southwest China. It was observed that the inter-active network of plant-frugivorous bird was highly asymmetrical, while that of plant-seed dispersal bird was not asymmetrical. The differences between the two networks mainly manifested in the bird abundance, bird movable capability, and plant features attracting bird visiting. The understanding of these differences allowed us to reveal the mutualistic relationship between plant and bird.

  15. Tropical community tree guide: benefits, costs, and strategic planting

    Treesearch

    Kelaine E. Vargas; Gregory E. McPherson; James R. Simpson; Paula J. Peper; Shelley L. Gardner; Qingfu Xiao

    2008-01-01

    Even as they increase the beauty of our surroundings, trees provide us with a great many ecosystem services, including air quality improvement, energy conservation, stormwater interception, and atmospheric carbon dioxide reduction. These benefits must be weighed against the costs of maintaining trees, including planting, pruning, irrigation, administration, pest...

  16. Function of blue iridescence in tropical understorey plants

    PubMed Central

    Thomas, Katherine R.; Kolle, Mathias; Whitney, Heather M.; Glover, Beverley J.; Steiner, Ullrich

    2010-01-01

    The blue colouration seen in the leaves of Selaginella willdenowii is shown to be iridescent. Transmission electron microscopy studies confirm the presence of a layered lamellar structure of the upper cuticle of iridescent leaves. Modelling of these multi-layer structures suggests that they are responsible for the blue iridescence, confirming the link between the observed lamellae and the recorded optical properties. Comparison of blue and green leaves from the same plant indicates that the loss of the blue iridescence corresponds to a loss of the multi-layer structure. The results reported here do not support the idea that iridescence in plants acts to enhance light capture of photosynthetically important wavelengths. The reflectance of light in the range 600–700 nm is very similar for both iridescent and non-iridescent leaves. However, owing to the occurrence of blue colouration in a wide variety of shade dwelling plants it is probable that this iridescence has some adaptive benefit. Possible adaptive advantages of the blue iridescence in these plants are discussed. PMID:20519208

  17. Spatial variation in vegetation structure coupled to plant available water determined by two-dimensional soil resistivity profiling in a Brazilian savanna.

    PubMed

    Ferreira, Joice N; Bustamante, Mercedes; Garcia-Montiel, Diana C; Caylor, Kelly K; Davidson, Eric A

    2007-08-01

    Tropical savannas commonly exhibit large spatial heterogeneity in vegetation structure. Fine-scale patterns of soil moisture, particularly in the deeper soil layers, have not been well investigated as factors possibly influencing vegetation patterns in savannas. Here we investigate the role of soil water availability and heterogeneity related to vegetation structure in an area of the Brazilian savanna (Cerrado). Our objective was to determine whether horizontal spatial variations of soil water are coupled with patterns of vegetation structure across tens of meters. We applied a novel methodological approach to convert soil electrical resistivity measurements along three 275-m transects to volumetric water content and then to estimates of plant available water (PAW). Structural attributes of the woody vegetation, including plant position, height, basal circumference, crown dimensions, and leaf area index, were surveyed within twenty-two 100-m(2) plots along the same transects, where no obvious vegetation gradients had been apparent. Spatial heterogeneity was evaluated through measurements of spatial autocorrelation in both PAW and vegetation structure. Comparisons with null models suggest that plants were randomly distributed over the transect with the greatest mean PAW and lowest PAW heterogeneity, and clustered in the driest and most heterogeneous transect. Plant density was positively related with PAW in the top 4 m of soil. The density-dependent vegetation attributes that are related to plot biomass, such as sum of tree heights per plot, exhibited spatial variation patterns that were remarkably similar to spatial variation of PAW in the top 4 m of soil. For PAW below 4 m depth, mean vegetation attributes, such as mean height, were negatively correlated with PAW, suggesting greater water uptake from the deep soil by plants of larger stature. These results are consistent with PAW heterogeneity being an important structuring factor in the plant distribution at the

  18. Useful Brazilian plants listed in the field books of the French naturalist Auguste de Saint-Hilaire (1779-1853).

    PubMed

    Brandão, Maria G L; Pignal, Marc; Romaniuc, Sergio; Grael, Cristiane F F; Fagg, Christopher W

    2012-09-28

    Information regarding the use of beneficial, native Brazilian plants was compiled by European naturalists in the 19th century. The French botanist Auguste de Saint-Hilaire (1779-1853) was one of the most important such naturalists; however, his manuscripts (field books) have not yet been studied, especially in the context of useful plants. To present data documented by Saint-Hilaire in his field book regarding the use of native plants by the Brazilians. Data on useful plants were obtained from field books (six volumes) deposited in the Muséum national d' Histoire naturelle in Paris, France. The vernacular names of the plants, registered as "N.V." or "Nom Vulg." in the field book, were carefully searched. Traditional information about these plants was translated and organised using a computer. The botanical identification of each plant was determined and updated from the original descriptions and names cited in the field books by A. de Saint-Hilaire. Correlated pharmacological studies were obtained from PubMed. A total of 283 useful plants were recorded from the field books and 165 (58.3%) could be identified to genus or species. Fifty-eight different traditional uses were registered for the identified plants; the most common were as purgatives and febrifuges. Other data recovered were related to edible fruits and plants with interesting sensorial characteristics. For the few species that have been subjected to laboratory studies, the efficacy of the recorded traditional uses was confirmed. The data recorded by the French naturalist A. de Saint-Hilaire represent a rich, unexplored source of information regarding the traditional uses of Brazilian plants. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  19. Morphological patterns of extrafloral nectaries in woody plant species of the Brazilian cerrado.

    PubMed

    Machado, S R; Morellato, L P C; Sajo, M G; Oliveira, P S

    2008-09-01

    Extrafloral nectaries are nectar-secreting structures that are especially common among the woody flora of the Brazilian cerrado, a savanna-like vegetation. In this study, we provide morphological and anatomical descriptions of extrafloral nectaries (EFNs) occurring on vegetative and reproductive organs of several plant species from the cerrado, and discuss their function and ecological relevance. We describe the morphology and anatomy of EFNs of 40 species belonging to 15 woody families using scanning electron microscopy and light microscopy. We categorise EFNs following a structural-topographical classification, and characterise the vascularised and complex nectaries, amorphous nectaries and secretory trichomes. Fabaceae, Bignoniaceae, Malpighiaceae and Vochysiaceae were the plant families with the majority of species having EFNs. Ten species possess more than one morphotype of gland structure. Observations and experimental field studies in the cerrado support the anti-herbivore role of EFN-gathering ants in this habitat. Additional morphological studies of EFNs-bearing plants, including other growth forms (e.g. herbs and lianas), are being undertaken and will hopefully cast further light on the ecological relevance of these glands in the cerrado, especially with respect to their attractiveness to multiple visitors.

  20. Application of digital field photographs as documents for tropical plant inventory1

    PubMed Central

    LaFrankie, James V.; Chua, Anna I.

    2015-01-01

    Premise of the study: We tested the credibility and significance of digital field photographs as supplements or substitutes for conventional herbarium specimens with particular relevance to exploration of the tropics. Methods: We made 113 collections in triplicate at a species-rich mountain in the Philippines while we took 1238 digital photographs of the same plants. We then identified the plants from the photographs alone, categorized the confidence of the identification and the reason for failure to identify, and compared the results to identifications based on the dried specimens. Results: We identified 72.6% of the photographic sets with high confidence and 27.4% with low confidence or only to genus. In no case was a confident identification altered by subsequent examination of the dried specimen. The failure to identify photographic sets to species was due to the lack of a key feature in 67.8% of the cases and due to a poorly understood taxonomy in 32.2%. Discussion: We conclude that digital photographs cannot replace traditional herbarium specimens as the primary elements that document tropical plant diversity. However, photographs represent a new and important artifact that aids an expedient survey of tropical plant diversity while encouraging broad public participation. PMID:25995976

  1. Trade-offs between savanna woody plant diversity and carbon storage in the Brazilian Cerrado.

    PubMed

    Pellegrini, Adam F A; Socolar, Jacob B; Elsen, Paul R; Giam, Xingli

    2016-10-01

    Incentivizing carbon storage can be a win-win pathway to conserving biodiversity and mitigating climate change. In savannas, however, the situation is more complex. Promoting carbon storage through woody encroachment may reduce plant diversity of savanna endemics, even as the diversity of encroaching forest species increases. This trade-off has important implications for the management of biodiversity and carbon in savanna habitats, but has rarely been evaluated empirically. We quantified the nature of carbon-diversity relationships in the Brazilian Cerrado by analyzing how woody plant species richness changed with carbon storage in 206 sites across the 2.2 million km(2) region at two spatial scales. We show that total woody plant species diversity increases with carbon storage, as expected, but that the richness of endemic savanna woody plant species declines with carbon storage both at the local scale, as woody biomass accumulates within plots, and at the landscape scale, as forest replaces savanna. The sharpest trade-offs between carbon storage and savanna diversity occurred at the early stages of carbon accumulation at the local scale but the final stages of forest encroachment at the landscape scale. Furthermore, the loss of savanna species quickens in the final stages of forest encroachment, and beyond a point, savanna species losses outpace forest species gains with increasing carbon accumulation. Our results suggest that although woody encroachment in savanna ecosystems may provide substantial carbon benefits, it comes at the rapidly accruing cost of woody plant species adapted to the open savanna environment. Moreover, the dependence of carbon-diversity trade-offs on the amount of savanna area remaining requires land managers to carefully consider local conditions. Widespread woody encroachment in both Australian and African savannas and grasslands may present similar threats to biodiversity. © 2016 John Wiley & Sons Ltd.

  2. Plant Ecology of Australia's Tropical Floodplain Wetlands: A Review

    PubMed Central

    FINLAYSON, C. M.

    2005-01-01

    • Aims Despite the biodiversity values of the freshwater floodplains of northern Australia being widely recognized, there has not been a concomitant investment in developing the extent of knowledge of the basic functions and ecological processes that underpin the ecological character of these habitats. This review addresses the extent of our knowledge on the plant ecology of these wetlands and covers: the relationships between the climate and the hydrological regime on the floodplain; the vegetation patterns, succession and adaptation; and primary production. • Scope Information is available on the seasonal, but less regularly on the inter-annual, dynamics of the macrophytic vegetation and its evident inter-relationship with the extent, depth and duration of inundation by seasonal flooding. The available scientifically collected information on plant distribution and relationship with the water regime could be complemented by more attention to traditional knowledge. The productivity of the vegetation is high—the dominant wetland grass species have an annual dry weight production of 0·5–2·1 kg m−2 and the surrounding riparian (Melaleuca) trees contribute litterfall of 0·7–1·5 kg (dry weight) m−2 year−1, ∼70 % due to leaf-fall. The availability of dissolved oxygen in the water is known to vary diurnally and seasonally, at least in some habitats. The importance of seasonal differences in the availability of dissolved oxygen for the growth of micro- and macrophytic vegetation has not been investigated. The seasonal distribution and growth of plant species on a few floodplains have been investigated, and maps at scales of 1 : 10 000 to 1 : 100 000 are available for these. However, only on a few occasions have longer term analyses been conducted and long-term changes in the vegetation measured and assessed. Species lists and categorization of growth strategies and forms are available and provide a basis for further ecological

  3. An exceptional role for flowering plant physiology in the expansion of tropical rainforests and biodiversity

    PubMed Central

    Boyce, C. Kevin; Lee, Jung-Eun

    2010-01-01

    Movement of water from soil to atmosphere by plant transpiration can feed precipitation, but is limited by the hydraulic capacities of plants, which have not been uniform through time. The flowering plants that dominate modern vegetation possess transpiration capacities that are dramatically higher than any other plants, living or extinct. Transpiration operates at the level of the leaf, however, and how the impact of this physiological revolution scales up to the landscape and larger environment remains unclear. Here, climate modelling demonstrates that angiosperms help ensure aseasonally high levels of precipitation in the modern tropics. Most strikingly, replacement of angiosperm with non-angiosperm vegetation would result in a hotter, drier and more seasonal Amazon basin, decreasing the overall area of ever-wet rainforest by 80 per cent. Thus, flowering plant ecological dominance has strongly altered climate and the global hydrological cycle. Because tropical biodiversity is closely tied to precipitation and rainforest area, angiosperm climate modification may have promoted diversification of the angiosperms themselves, as well as radiations of diverse vertebrate and invertebrate animal lineages and of epiphytic plants. Their exceptional potential for environmental modification may have contributed to divergent responses to similar climates and global perturbations, like mass extinctions, before and after angiosperm evolution. PMID:20554551

  4. Phylogenetic impoverishment of plant communities following chronic human disturbances in the Brazilian Caatinga.

    PubMed

    Ribeiro, Elâine M S; Santos, Bráulio A; Arroyo-Rodríguez, Víctor; Tabarelli, Marcelo; Souza, Gustavo; Leal, Inara R

    2016-06-01

    Chronic disturbances, such as selective logging, firewood extraction and extensive grazing, may lead to the taxonomic and phylogenetic impoverishment of remaining old-growth forest communities worldwide; however, the empirical evidence on this topic is limited. We tested this hypothesis in the Caatinga vegetation--a seasonally dry tropical forest restricted to northeast Brazil. We sampled 11,653 individuals (adults, saplings, and seedlings) from 51 species in 29 plots distributed along a gradient of chronic disturbance. The gradient was assessed using a chronic disturbance index (CDI) based on five recognized indicators of chronic disturbances: proximity to urban center, houses and roads and the density of both people and livestock. We used linear models to test if mean effective number of lineages, mean phylogenetic distance and phylogenetic dispersion decreased with CDI and if such relationships differed among ontogenetic stages. As expected, the mean effective number of lineages and the mean phylogenetic distance were negatively related to CDI, and such diversity losses occurred irrespective of ontogeny. Yet the increase in phylogenetic clustering in more disturbed plots was only evident in seedlings and saplings, mostly because clades with more descendent taxa than expected by chance (e.g., Euphorbiaceae) thrived in more disturbed plots. This novel study indicates that chronic human disturbances are promoting the phylogenetic impoverishment of the irreplaceable woody flora of the Brazilian Caatinga forest. The highest impoverishment was observed in seedlings and saplings, indicating that if current chronic disturbances remain, they will result in increasingly poorer phylogenetically forests. This loss of evolutionary history will potentially limit the capacity of this ecosystem to respond to human disturbances (i.e., lower ecological resilience) and particularly their ability to adapt to rapid climatic changes in the region.

  5. Heavy-metal-contaminated industrial soil: Uptake assessment in native plant species from Brazilian Cerrado.

    PubMed

    Meyer, Sylvia Therese; Castro, Samuel Rodrigues; Fernandes, Marcus Manoel; Soares, Aylton Carlos; de Souza Freitas, Guilherme Augusto; Ribeiro, Edvan

    2016-08-02

    Plants of the Cerrado have shown some potential for restoration and/or phytoremediation projects due to their ability to grow in and tolerate acidic soils rich in metals. The aim of this study is to evaluate the tolerance and accumulation of metals (Cd, Cu, Pb, and Zn) in five native tree species of the Brazilian Cerrado (Copaifera langsdorffii, Eugenia dysenterica, Inga laurina, Cedrela fissilis, Handroanthus impetiginosus) subjected to three experiments with contaminated soils obtained from a zinc processing industry (S1, S2, S3) and control soil (S0). The experimental design was completely randomized (factorial 5 × 4 × 3) and conducted in a greenhouse environment during a 90-day experimentation time. The plant species behavior was assessed by visual symptoms of toxicity, tolerance index (TI), translocation factor (TF), and bioaccumulation factor (BF). C. fissilis has performed as a Zn accumulator by the higher BFs obtained in the experiments, equal to 3.72, 0.88, and 0.41 for S1, S2, and S3 respectively. This species had some ability of uptake control as a defense mechanism in high stress conditions with the best behavior for phytoremediation and high tolerance to contamination. With economical and technical benefits, this study may support a preliminary analysis necessary for using native tree species in environmental projects.

  6. Impact of the hydraulic capacity of plants on water and carbon fluxes in tropical South America

    NASA Astrophysics Data System (ADS)

    Lee, Jung-Eun; Boyce, Kevin

    2010-12-01

    Angiosperms (flowering plants) have higher transpirational capacities than any other plants. Here we use climate model simulation to test the hypothesis that the high transpirational capacity of angiosperms plays a unique role in the maintenance of tropical rainforest. Their elevated transpiration rates are shown to increase recycling of precipitation up to ˜300 mm/yr (˜20% of total precipitation) averaged over the whole of tropical South America and to increase the wet season duration over the Amazon basin. Transpiration triggers convection by increasing moisture in the boundary layer and thereby decreasing atmospheric stability. If the moisture content of the boundary layer is sufficient, a double Intertropical Convergence Zone (ITCZ) is generated in October around 60°W-50°W, as observed in present-day climate, and the eastern part of the Amazon basin becomes wet (˜200 mm/month of precipitation). This double ITCZ is lost, however, and the region becomes dry (<50 mm/month of precipitation) in the absence of full angiosperm transpiration. Although higher water use efficiency is usually associated with plants with lower transpiration rates, water use efficiency actually increases with higher hydraulic capacity in our simulations as a result of the higher humidity and, thus, lower vapor pressure gradient between the intercellular air space within the leaf and the external atmosphere. We speculate that the high transpirational capacity of angiosperms played a significant role in the expansion of tropical rain forest.

  7. Are community-based forest enterprises in the tropics financially viable? Case studies from the Brazilian Amazon

    Treesearch

    Shoana Humphries; Thomas P. Holmes; Karen Kainer; Carlos Gabriel Goncalves Koury; Edson Cruz; Rosana de Miranda Rocha

    2012-01-01

    Community-based forest management is an integral component of sustainable forest management and conservation in the Brazilian Amazon, where it has been heavily subsidized for the last ten years. Yet knowledge of the financial viability and impact of community-based forest enterprises (CFEs) is lacking. This study evaluates the profitability of three CFEs in the...

  8. Treatment of natural tropical theileriosis with the extract of the plant Peganum harmala

    PubMed Central

    2007-01-01

    Theileria annulata, a protozoan parasite of cattle and domestic buffaloes, is transmitted by ticks of the genus Hyalomma, and causes a disease named Mediterranean or tropical theileriosis. In this research 50 cattle naturally infected with Theileria annulata were treated with the extract of the plant Peganum harmala. The treatment was continued for 5 days, the dose of the extract being 5 mg/kg per day. After the treatment, 39 cattle responded to the treatment and recovered, but 11 did not respond to the treatment and died. The recovery rate of animals treated with the extract of the plant Peganum harmala was 78%. PMID:18165708

  9. Treatment of natural tropical theileriosis with the extract of the plant Peganum harmala.

    PubMed

    Mirzaei, Mohammad

    2007-12-01

    Theileria annulata, a protozoan parasite of cattle and domestic buffaloes, is transmitted by ticks of the genus Hyalomma, and causes a disease named Mediterranean or tropical theileriosis. In this research 50 cattle naturally infected with Theileria annulata were treated with the extract of the plant Peganum harmala. The treatment was continued for 5 days, the dose of the extract being 5 mg/kg per day. After the treatment, 39 cattle responded to the treatment and recovered, but 11 did not respond to the treatment and died. The recovery rate of animals treated with the extract of the plant Peganum harmala was 78%.

  10. Alpha-tocopherol content in 62 edible tropical plants.

    PubMed

    Ching, L S; Mohamed, S

    2001-06-01

    Vitamin E was determined by the high-performance liquid chromatography (HPLC) method. All the plants tested showed differences in their alpha-tocopherol content and the differences were significant (p < 0.05). The highest alpha-tocopherol content was in Sauropus androgynus leaves (426.8 mg/kg edible portion), followed by Citrus hystrix leaves (398.3 mg/kg), Calamus scipronum (193.8 mg/kg), starfruit leaves Averrhoa belimbi (168.3 mg/kg), red pepper Capsicum annum (155.4 mg/kg), local celery Apium graveolens (136.4 mg/kg), sweet potato shoots Ipomoea batatas (130.1 mg/kg), Pandanus odorus (131.5 mg/kg), Oenanthe javanica (146.8 mg/kg), black tea Camelia chinensis (183.3 mg/kg),papaya Carica papaya shoots (111.3 mg/kg), wolfberry leaves Lycium chinense (94.4 mg/kg), bird chili Capsicum frutescens leaves (95.4 mg/kg), drumstick Moringa oleifera leaves (90.0 mg/kg), green chili Capsicum annum (87 mg/kg), Allium fistulosum leaves (74.6 mg/kg), and bell pepper Capsicum annum (71.0 mg/kg). alpha-Tocopherol was not detected in Brassica oleracea, Phaeomeria speciosa, Pachyrrhizus speciosa, Pleurotus sajor-caju, and Solanum melongena.

  11. Anti-infective effects of Brazilian Caatinga plants against pathogenic bacterial biofilm formation.

    PubMed

    Silva, Laura Nunes; Trentin, Danielle da Silva; Zimmer, Karine Rigon; Treter, Janine; Brandelli, Clara Lia Costa; Frasson, Amanda Piccoli; Tasca, Tiana; da Silva, Alexandre Gomes; da Silva, Márcia Vanusa; Macedo, Alexandre José

    2015-03-01

    The local communities living in the Brazilian Caatinga biome have a significant body of traditional knowledge on a considerable number of medicinal plants used to heal several maladies. Based on ethnopharmacological data, this study screened 23 aqueous plant extracts against two well-known models of biofilm-forming bacteria: Staphylococcus epidermidis and Pseudomonas aeruginosa. Crystal violet assay and scanning electron microscopy (SEM) were used to evaluate the effect of extracts on biofilm formation and measurements of the absorbance at 600 nm to assess bacterial growth. Selected extracts were investigated regarding the cytotoxicity by MTT assay using mammal cells and the qualitative phytochemical fingerprint by thin layer chromatography. Harpochilus neesianus Mart. ex Nees. (Acanthaceae) leaves, Apuleia leiocarpa Vogel J. F. Macbr. (Fabaceae), and Poincianella microphylla Mart. ex G. Don L. P. Queiroz (Fabaceae) fruits showed non-biocidal antibiofilm action against S. epidermidis with activities of 69, 52, and 63%, respectively. SEM confirmed that biofilm structure was strongly prevented and that extracts promoted overproduction of the matrix and/or bacterial morphology modification. Poincianella microphylla demonstrated toxicity at 4.0 mg/mL and 2.0 mg/mL, A. leiocarpa presented toxicity only at 4.0 mg/mL, whereas H. neesianus presented the absence of toxicity against Vero cell line. Preliminary phytochemical analysis revealed the presence of flavonoids, terpenoids, steroids, amines, and polyphenols. This work provides a scientific basis which may justify the ethnopharmacological use of the plants herein studied, indicating extracts that possess limited mammal cytotoxicity in vitro and a high potential as a source of antibiofilm drugs prototypes.

  12. Inorganic profile of some Brazilian medicinal plants obtained from ethanolic extract and ''in natura'' samples

    SciTech Connect

    Ferreira, M.O.M.; de Sousa, P.T.; Salvador, V.L.R.; Sato, I.M.

    2004-10-03

    The Anadenathera macrocarpa, Schinus molle, Hymenaea courbaril, Cariniana legalis, Solidago microglossa and Stryphnodendron barbatiman, were collected ''in natura'' samples (leaves, flowers, barks and seeds) from different commercial suppliers. The pharmaco-active compounds in ethanolic extracts had been made by the Mato Grosso Federal University (UFMT). The energy-dispersive x-ray fluorescence (ED-XRF) spectrometry was used for the elemental analysis in different parts of the plants and respective ethanolic extracts. The Ca, Cl, Cu, Fe, K, Mg, Mn, Na, Ni, P, Rb, S, Sr and Zn concentrations were determined by the fundamental parameters method. Some specimens showed a similar inorganic profile for ''in natura'' and ethanolic extract samples and some ones showed a distinct inorganic profile. For example, the Anadenathera macrocarpa showed a similar concentration in Mg, P, Cu, Zn and Rb elements in ''in natura'' and ethanolic extract samples; however very different concentration in Na, S, Cl, K , Ca, Mn, Fe and Sr was observed in distinctive samples. The Solidago microglossa showed the K, Ca, Cl, S, Mg, P and Fe elements as major constituents in both samples, suggesting that the extraction process did not affect in a considerable way the ''in natura'' inorganic composition. The elemental composition of the different parts of the plants (leaves, flowers, barks and seeds) has been also determined. For example, the Schinus molle specimen showed P, K, Cl and Ca elements as major constituents in the seeds, Mg, K and Sr in the barks and Mg, S, Cl and Mn in the leaves, demonstrating a differentiated elementary distribution. These inorganic profiles will contribute to evaluate the quality control of the Brazilian herbaceous trade and also will assist to identify which parts of the medicinal plants has greater therapeutic effect.

  13. Specialization and interaction strength in a tropical plant-frugivore network differ among forest strata.

    PubMed

    Schleuning, Matthias; Blüthgen, Nico; Flörchinger, Martina; Braun, Julius; Schaefer, H Martin; Böhning-Gaese, Katrin

    2011-01-01

    The degree of interdependence and potential for shared coevolutionary history of frugivorous animals and fleshy-fruited plants are contentious topics. Recently, network analyses revealed that mutualistic relationships between fleshy-fruited plants and frugivores are mostly built upon generalized associations. However, little is known about the determinants of network structure, especially from tropical forests where plants' dependence on animal seed dispersal is particularly high. Here, we present an in-depth analysis of specialization and interaction strength in a plant-frugivore network from a Kenyan rain forest. We recorded fruit removal from 33 plant species in different forest strata (canopy, midstory, understory) and habitats (primary and secondary forest) with a standardized sampling design (3447 interactions in 924 observation hours). We classified the 88 frugivore species into guilds according to dietary specialization (14 obligate, 28 partial, 46 opportunistic frugivores) and forest dependence (50 forest species, 38 visitors). Overall, complementary specialization was similar to that in other plant-frugivore networks. However, the plant-frugivore interactions in the canopy stratum were less specialized than in the mid- and understory, whereas primary and secondary forest did not differ. Plant specialization on frugivores decreased with plant height, and obligate and partial frugivores were less specialized than opportunistic frugivores. The overall impact of a frugivore increased with the number of visits and the specialization on specific plants. Moreover, interaction strength of frugivores differed among forest strata. Obligate frugivores foraged in the canopy where fruit resources were abundant, whereas partial and opportunistic frugivores were more common on mid- and understory plants, respectively. We conclude that the vertical stratification of the frugivore community into obligate and opportunistic feeding guilds structures this plant

  14. Carbon pools recover more quickly than plant biodiversity in tropical secondary forests

    PubMed Central

    Martin, Philip A.; Newton, Adrian C.; Bullock, James M.

    2013-01-01

    Although increasing efforts are being made to restore tropical forests, little information is available regarding the time scales required for carbon and plant biodiversity to recover to the values associated with undisturbed forests. To address this knowledge gap, we carried out a meta-analysis comparing data from more than 600 secondary tropical forest sites with nearby undisturbed reference forests. Above-ground biomass approached equivalence to reference values within 80 years since last disturbance, whereas below-ground biomass took longer to recover. Soil carbon content showed little relationship with time since disturbance. Tree species richness recovered after about 50 years. By contrast, epiphyte richness did not reach equivalence to undisturbed forests. The proportion of undisturbed forest trees and epiphyte species found in secondary forests was low and changed little over time. Our results indicate that carbon pools and biodiversity show different recovery rates under passive, secondary succession and that colonization by undisturbed forest plant species is slow. Initiatives such as the Convention on Biological Diversity and REDD+ should therefore encourage active management to help to achieve their aims of restoring both carbon and biodiversity in tropical forests. PMID:24197410

  15. Extraction of high-quality DNA from ethanol-preserved tropical plant tissues

    PubMed Central

    2014-01-01

    Background Proper conservation of plant samples, especially during remote field collection, is essential to assure quality of extracted DNA. Tropical plant species contain considerable amounts of secondary compounds, such as polysaccharides, phenols, and latex, which affect DNA quality during extraction. The suitability of ethanol (96% v/v) as a preservative solution prior to DNA extraction was evaluated using leaves of Jatropha curcas and other tropical species. Results Total DNA extracted from leaf samples stored in liquid nitrogen or ethanol from J. curcas and other tropical species (Theobroma cacao, Coffea arabica, Ricinus communis, Saccharum spp., and Solanum lycopersicon) was similar in quality, with high-molecular-weight DNA visualized by gel electrophoresis. DNA quality was confirmed by digestion with EcoRI or HindIII and by amplification of the ribosomal gene internal transcribed spacer region. Leaf tissue of J. curcas was analyzed by light and transmission electron microscopy before and after exposure to ethanol. Our results indicate that leaf samples can be successfully preserved in ethanol for long periods (30 days) as a viable method for fixation and conservation of DNA from leaves. The success of this technique is likely due to reduction or inactivation of secondary metabolites that could contaminate or degrade genomic DNA. Conclusions Tissue conservation in 96% ethanol represents an attractive low-cost alternative to commonly used methods for preservation of samples for DNA extraction. This technique yields DNA of equivalent quality to that obtained from fresh or frozen tissue. PMID:24761774

  16. Draft Genome Sequence of Plant Growth-Promoting Drought-Tolerant Bacillus sp. Strain CMAA 1363 Isolated from the Brazilian Caatinga Biome

    PubMed Central

    Santos, Suikinai Nobre; Taketani, Rodrigo Gouvêa; Vasconcellos, Rafael Leandro Figueiredo; Melo, Itamar Soares

    2017-01-01

    ABSTRACT The strain of Bacillus sp. CMAA 1363 was isolated from the Brazilian Caatinga biome and showed plant growth-promoting traits and ability to promote maize growth under drought stress. Sequencing revealed genes involved in stress response and plant growth promotion. These genomic features might aid in the protection of plants against the negative effects imposed by drought. PMID:28153893

  17. Draft Genome Sequence of Plant Growth-Promoting Drought-Tolerant Bacillus sp. Strain CMAA 1363 Isolated from the Brazilian Caatinga Biome.

    PubMed

    Kavamura, Vanessa Nessner; Santos, Suikinai Nobre; Taketani, Rodrigo Gouvêa; Vasconcellos, Rafael Leandro Figueiredo; Melo, Itamar Soares

    2017-02-02

    The strain of Bacillus sp. CMAA 1363 was isolated from the Brazilian Caatinga biome and showed plant growth-promoting traits and ability to promote maize growth under drought stress. Sequencing revealed genes involved in stress response and plant growth promotion. These genomic features might aid in the protection of plants against the negative effects imposed by drought.

  18. Insecticide dissipation from soil and plant surfaces in tropical horticulture of southern Benin, West Africa.

    PubMed

    Rosendahl, Ingrid; Laabs, Volker; Atcha-Ahowé, Cyrien; James, Braima; Amelung, Wulf

    2009-06-01

    In Sub-Saharan Africa, horticulture provides livelihood opportunities for millions of people, especially in urban and peri-urban areas. Although the vegetable agroecosystems are often characterized by intensive pesticide use, risks resulting therefrom are largely unknown under tropical horticultural conditions. The objective of this study therefore was to study the fate of pesticides in two representative horticultural soils (Acrisol and Arenosol) and plants (Solanum macrocarpon L.) after field application and thus to gain first insight on environmental persistence and dispersion of typical insecticides used in vegetable horticulture in Benin, West Africa. On plant surfaces, dissipation was rapid with half lives ranging from 2 to 87 h (alpha-endosulfan < beta-endosulfan < deltamethrin). Soil dissipation was considerably slower than dissipation from plant surfaces with half-lives ranging from 3 (diazinon) to 74 d (total endosulfan), but persistence of pesticides in soil was still reduced compared to temperate climates. Nevertheless, for deltamethrin and endosulfan, a tendency for mid-term accumulation in soil upon repeated applications was observed. The soil and plant surface concentrations of the metabolite endosulfan sulfate increased during the entire trial period, indicating that this compound is a potential long-term pollutant even in tropical environments.

  19. Evolutionary conservation of a core root microbiome across plant phyla along a tropical soil chronosequence.

    PubMed

    Yeoh, Yun Kit; Dennis, Paul G; Paungfoo-Lonhienne, Chanyarat; Weber, Lui; Brackin, Richard; Ragan, Mark A; Schmidt, Susanne; Hugenholtz, Philip

    2017-08-09

    Culture-independent molecular surveys of plant root microbiomes indicate that soil type generally has a stronger influence on microbial communities than host phylogeny. However, these studies have mostly focussed on model plants and crops. Here, we examine the root microbiomes of multiple plant phyla including lycopods, ferns, gymnosperms, and angiosperms across a soil chronosequence using 16S rRNA gene amplicon profiling. We confirm that soil type is the primary determinant of root-associated bacterial community composition, but also observe a significant correlation with plant phylogeny. A total of 47 bacterial genera are associated with roots relative to bulk soil microbial communities, including well-recognized plant-associated genera such as Bradyrhizobium, Rhizobium, and Burkholderia, and major uncharacterized lineages such as WPS-2, Ellin329, and FW68. We suggest that these taxa collectively constitute an evolutionarily conserved core root microbiome at this site. This lends support to the inference that a core root microbiome has evolved with terrestrial plants over their 400 million year history.Yeoh et al. study root microbiomes of different plant phyla across a tropical soil chronosequence. They confirm that soil type is the primary determinant of root-associated bacterial communities, but also observe a clear correlation with plant phylogeny and define a core root microbiome at this site.

  20. Plant water resource partitioning and isotopic fractionation during transpiration in a seasonally dry tropical climate

    NASA Astrophysics Data System (ADS)

    De Wispelaere, Lien; Bodé, Samuel; Hervé-Fernández, Pedro; Hemp, Andreas; Verschuren, Dirk; Boeckx, Pascal

    2017-01-01

    Lake Chala (3°19' S, 37°42' E) is a steep-sided crater lake situated in equatorial East Africa, a tropical semiarid area with a bimodal rainfall pattern. Plants in this region are exposed to a prolonged dry season, and we investigated if (1) these plants show spatial variability and temporal shifts in their water source use; (2) seasonal differences in the isotopic composition of precipitation are reflected in xylem water; and (3) plant family, growth form, leaf phenology, habitat and season influence the xylem-to-leaf water deuterium enrichment. In this study, the δ2H and δ18O of precipitation, lake water, groundwater, plant xylem water and plant leaf water were measured across different plant species, seasons and plant habitats in the vicinity of Lake Chala. We found that plants rely mostly on water from the short rains falling from October to December (northeastern monsoon), as these recharge the soil after the long dry season. This plant-available, static water pool is only slightly replenished by the long rains falling from February to May (southeastern monsoon), in agreement with the two water worlds hypothesis, according to which plants rely on a static water pool while a mobile water pool recharges the groundwater. Spatial variability in water resource use exists in the study region, with plants at the lakeshore relying on a water source admixed with lake water. Leaf phenology does not affect water resource use. According to our results, plant species and their associated leaf phenology are the primary factors influencing the enrichment in deuterium from xylem water to leaf water (ɛl/x), with deciduous species giving the highest enrichment, while growth form and season have negligible effects. Our observations have important implications for the interpretation of δ2H of plant leaf wax n-alkanes (δ2Hwax) from paleohydrological records in tropical East Africa, given that the temporal variability in the isotopic composition of

  1. Chemical constituents and toxicological studies of leaves from Mimosa caesalpiniifolia Benth., a Brazilian honey plant

    PubMed Central

    Monção, Nayana Bruna Nery; Costa, Luciana Muratori; Arcanjo, Daniel Dias Rufino; Araújo, Bruno Quirino; Lustosa, Maria do Carmo Gomes; Rodrigues, Klinger Antônio da França; Carvalho, Fernando Aécio de Amorim; Costa, Amilton Paulo Raposo; Lopes Citó, Antônia Maria das Graças

    2014-01-01

    Background: Mimosa caesalpiniifolia Benth. (Leguminosae) is widely found in the Brazilian Northeast region and markedly contributes to production of pollen and honey, being considered an important honey plant in this region. Objective: To investigate the chemical composition of the ethanol extract of leaves from M. caesalpiniifolia by GC-MS after derivatization (silylation), as well as to evaluate the in vitro and in vivo toxicological effects and androgenic activity in rats. Materials and Methods: The ethanol extract of leaves from Mimosa caesalpiniifolia was submitted to derivatization by silylation and analyzed by gas chromatography-mass spectrometry (GC-MS) to identification of chemical constituents. In vitro toxicological evaluation was performed by MTT assay in murine macrophages and by Artemia salina lethality assay, and the in vivo acute oral toxicity and androgenic evaluation in rats. Results: Totally, 32 components were detected: Phytol-TMS (11.66%), lactic acid-2TMS (9.16%), α-tocopherol-TMS (7.34%) and β-sitosterol-TMS (6.80%) were the major constituents. At the concentrations analyzed, the ethanol extract showed low cytotoxicity against brine shrimp (Artemia salina) and murine macrophages. In addition, the extract did not exhibit any toxicological effect or androgenic activity in rats. Conclusions: The derivatization by silylation allowed a rapid identification of chemical compounds from the M. caesalpiniifolia leaves extract. Besides, this species presents a good safety profile as observed in toxicological studies, and possess a great potential in the production of herbal medicines or as for food consumption. PMID:25298660

  2. Anthropogenic disturbance reduces seed-dispersal services for myrmecochorous plants in the Brazilian Caatinga.

    PubMed

    Leal, Laura C; Andersen, Alan N; Leal, Inara R

    2014-01-01

    Anthropogenic disturbance can have important indirect effects on ecosystems by disrupting species interactions. Here we examine the effects of anthropogenic disturbance on distance dispersal by ants for the diaspores of myrmecochorous Euphorbiaceae in Brazilian Caatinga. Rates of diaspore removal and distances removed of Croton sonderianus and Jatropha mollissima were observed at 24 sites ranging from low to very high disturbance (primarily grazing by livestock, hunting and firewood collection). Despite a large number of seed-disperser ant species, there were only two species providing high-quality distance-dispersal services, Dinoponera quadriceps (40% of all observed seed removals) and Ectatomma muticum (33%). D. quadriceps was responsible for 97% of all removals >2 m, and 100% of all removals >5 m. Removal rates did not vary with disturbance for C. sonderianus (small elaiosome), but declined with increasing disturbance for J. mollissima (large elaiosome). The number of removals by Ectatomma was highest at intermediate levels of disturbance, whereas those by Dinoponera decreased systematically with increasing levels of disturbance. Mean dispersal distance was four times higher at sites experiencing low disturbance, where removals >5 m represented a third of all removal events, compared with very highly disturbed sites, where no removals >5 m were observed. Despite high overall diversity there is very limited functional redundancy in disperser ant species, resulting in low disperser resilience in relation to disturbance. This is likely to have important implications for recruitment by myrmecochorous plants, and therefore on vegetation composition and structure, at sites subject to high anthropogenic disturbance.

  3. Antibacterial, Antioxidant, and Anticholinesterase Activities of Plant Seed Extracts from Brazilian Semiarid Region

    PubMed Central

    Farias, Davi Felipe; Souza, Terezinha Maria; Viana, Martônio Ponte; Soares, Bruno Marques; Cunha, Arcelina Pacheco; Vasconcelos, Ilka Maria; Ricardo, Nágila Maria Pontes Silva; Ferreira, Paulo Michel Pinheiro; Melo, Vânia Maria Maciel; Carvalho, Ana Fontenele Urano

    2013-01-01

    The antimicrobial, antioxidant, and anticholinesterase activities of ethanolic seed extracts of twenty-one plant species from Brazilian semiarid region were investigated. The extracts were tested for antimicrobial activity against six bacteria strains and three yeasts. Six extracts presented activity against the Gram (−) organism Salmonella choleraesuis and the Gram (+) organisms Staphylococcus aureus and Bacillus subtilis. The MIC values ranged from 4.96 to 37.32 mg/mL. The Triplaris gardneriana extract presented activity against the three species, with MIC values 18.8, 13.76, and 11.15 mg/mL, respectively. Five extracts presented antioxidant activity, with EC50 values ranging from 69.73 μg/mL (T. gardneriana) to 487.51 μg/mL (Licania rigida). For the anticholinesterase activity, eleven extracts were capable of inhibiting the enzyme activity. From those, T. gardneriana, Parkia platycephala and Connarus detersus presented the best activities, with inhibition values of 76.7, 71.5, and 91.9%, respectively. The extracts that presented antimicrobial activity were tested for hemolytic assay against human A, B, and O blood types and rabbit blood. From those, only the Myracrodruon urundeuva extract presented activity (about 20% of hemolysis at the lowest tested concentration, 1.9 µg/mL). Infrared spectroscopy of six representative extracts attested the presence of tannins, polyphenols, and flavonoids, which was confirmed by a qualitative phytochemical assay. PMID:24386637

  4. Power plant fuel switching and air quality in a tropical, forested environment

    NASA Astrophysics Data System (ADS)

    Medeiros, Adan S. S.; Calderaro, Gisele; Guimarães, Patricia C.; Magalhaes, Mateus R.; Morais, Marcos V. B.; Rafee, Sameh A. A.; Ribeiro, Igor O.; Andreoli, Rita V.; Martins, Jorge A.; Martins, Leila D.; Martin, Scot T.; Souza, Rodrigo A. F.

    2017-07-01

    How a changing energy matrix for electricity production affects air quality is considered for an urban region in a tropical, forested environment. Manaus, the largest city in the central Amazon Basin of Brazil, is in the process of changing its energy matrix for electricity production from fuel oil and diesel to natural gas over an approximately 10-year period, with a minor contribution by hydropower. Three scenarios of urban air quality, specifically afternoon ozone concentrations, were simulated using the Weather Research and Forecasting (WRF-Chem) model. The first scenario used fuel oil and diesel for electricity production, which was the reality in 2008. The second scenario was based on the fuel mix from 2014, the most current year for which data were available. The third scenario considered nearly complete use of natural gas for electricity production, which is the anticipated future, possibly for 2018. For each case, inventories of anthropogenic emissions were based on electricity generation, refinery operations, and transportation. Transportation and refinery operations were held constant across the three scenarios to focus on effects of power plant fuel switching in a tropical context. The simulated NOx and CO emissions for the urban region decrease by 89 and 55 %, respectively, after the complete change in the energy matrix. The results of the simulations indicate that a change to natural gas significantly decreases maximum afternoon ozone concentrations over the population center, reducing ozone by > 70 % for the most polluted days. The sensitivity of ozone concentrations to the fuel switchover is consistent with a NOx-limited regime, as expected for a tropical forest having high emissions of biogenic volatile organic compounds, high water vapor concentrations, and abundant solar radiation. There are key differences in a shifting energy matrix in a tropical, forested environment compared to other world environments. Policies favoring the burning of

  5. Isolation and enzyme bioprospection of endophytic bacteria associated with plants of Brazilian mangrove ecosystem.

    PubMed

    Castro, Renata A; Quecine, Maria Carolina; Lacava, Paulo T; Batista, Bruna D; Luvizotto, Danice M; Marcon, Joelma; Ferreira, Anderson; Melo, Itamar S; Azevedo, João L

    2014-01-01

    The mangrove ecosystem is a coastal tropical biome located in the transition zone between land and sea that is characterized by periodic flooding, which confers unique and specific environmental conditions on this biome. In these ecosystems, the vegetation is dominated by a particular group of plant species that provide a unique environment harboring diverse groups of microorganisms, including the endophytic microorganisms that are the focus of this study. Because of their intimate association with plants, endophytic microorganisms could be explored for biotechnologically significant products, such as enzymes, proteins, antibiotics and others. Here, we isolated endophytic microorganisms from two mangrove species, Rhizophora mangle and Avicennia nitida, that are found in streams in two mangrove systems in Bertioga and Cananéia, Brazil. Bacillus was the most frequently isolated genus, comprising 42% of the species isolated from Cananéia and 28% of the species from Bertioga. However, other common endophytic genera such as Pantoea, Curtobacterium and Enterobacter were also found. After identifying the isolates, the bacterial communities were evaluated for enzyme production. Protease activity was observed in 75% of the isolates, while endoglucanase activity occurred in 62% of the isolates. Bacillus showed the highest activity rates for amylase and esterase and endoglucanase. To our knowledge, this is the first reported diversity analysis performed on endophytic bacteria obtained from the branches of mangrove trees and the first overview of the specific enzymes produced by different bacterial genera. This work contributes to our knowledge of the microorganisms and enzymes present in mangrove ecosystems.

  6. Evaluation of Antileishmanial Activity of Selected Brazilian Plants and Identification of the Active Principles

    PubMed Central

    Filho, Valdir Cechinel; Meyre-Silva, Christiane; Niero, Rivaldo; Bolda Mariano, Luisa Nathália; Gomes do Nascimento, Fabiana; Vicente Farias, Ingrid; Gazoni, Vanessa Fátima; dos Santos Silva, Bruna; Giménez, Alberto; Gutierrez-Yapu, David; Salamanca, Efrain; Malheiros, Angela

    2013-01-01

    This study evaluated extracts, fractions, and isolated compounds from some selected Brazilian medicinal plants against strains of promastigotes of Leishmania amazonensis and L. brasiliensis in vitro. The cell viability was determined, comparing the results with reference standards. The dichloromethane fractions of the roots, stems, and leaves of Allamanda schottii showed IC50 values between 14.0 and 2.0 μg/mL. Plumericin was the main active compound, with IC50 of 0.3 and 0.04 μg/mL against the two species of Leishmania analyzed. The hexane extract of Eugenia umbelliflora fruits showed IC50 of 14.3 and 5.7 μg/mL against L. amazonensis and L. brasiliensis, respectively. The methanolic extracts of the seeds of Garcinia achachairu and guttiferone A presented IC50 values of 35.9 and 10.4 μg/mL, against L. amazonensis, respectively. The ethanolic extracts of the stem barks of Rapanea ferruginea and the isolated compound, myrsinoic acid B, presented activity against L. brasiliensis with IC50 of 24.1 and 6.1 μg/mL. Chloroform fraction of Solanum sisymbriifolium exhibited IC50 of 33.8 and 20.5 μg/mL, and cilistol A was the main active principle, with IC50 of 6.6 and 3.1 μg/mL against L. amazonensis and L. brasiliensis, respectively. It is concluded that the analyzed plants are promising as new and effective antiparasitic agents. PMID:23840252

  7. Screening the Brazilian flora for antihypertensive plant species for in vitro angiotensin-I-converting enzyme inhibiting activity.

    PubMed

    Castro Braga, F; Wagner, H; Lombardi, J A; de Oliveira, A B

    2000-06-01

    The evaluation of several antihypertensive activity of Brazilian plant species was performed using in vitro inhibition of the angiotensin I-converting enzyme (ACE). Nineteen species belonging to 13 families were investigated. Plants were selected based on their use as diuretics and on a chemosystematic consideration. Extracts of the following species presented the highest ACE inhibition rate, at concentrations of 0.33 mg/ml: Ouratea semiserrata (Mart. & Nees) Engl. stems (68%), Cuphea cartagenesis (Jacq.) Macbride leaves (50%) and Mansoa hirsuta DC. leaves (54%). Some hypotheses about the nature of the compounds that may be responsible for the activity of these species are discussed in the paper.

  8. Flood Frequency Analysis Under Non-stationarity Conditions: the Case of Southern Brazilian Hydroelectric Power Plants

    NASA Astrophysics Data System (ADS)

    Bartiko, Daniel; Chaffe, Pedro; Bonumá, Nadia

    2017-04-01

    Floods may be strongly affected by climate, land-use, land-cover and water infrastructure changes. However, it is common to model this process as stationary. This approach has been questioned, especially when it involves estimate of the frequency and magnitude of extreme events for designing and maintaining hydraulic structures, as those responsible for flood control and dams safety. Brazil is the third largest producer of hydroelectricity in the world and many of the country's dams are located in the Southern Region. So, it seems appropriate to investigate the presence of non-stationarity in the affluence in these plants. In our study, we used historical flood data from the Brazilian National Grid Operator (ONS) to explore trends in annual maxima in river flow of the 38 main rivers flowing to Southern Brazilian reservoirs (records range from 43 to 84 years). In the analysis, we assumed a two-parameter log-normal distribution a linear regression model was applied in order to allow for the mean to vary with time. We computed recurrence reduction factors to characterize changes in the return period of an initially estimated 100 year-flood by a log-normal stationary model. To evaluate whether or not a particular site exhibits positive trend, we only considered data series with linear regression slope coefficients that exhibit significance levels (p<0,05). The significance level was calculated using the one-sided Student's test. The trend model residuals were analyzed using the Anderson-Darling normality test, the Durbin-Watson test for the independence and the Breusch-Pagan test for heteroscedasticity. Our results showed that 22 of the 38 data series analyzed have a significant positive trend. The trends were mainly in three large basins: Iguazu, Uruguay and Paranapanema, which suffered changes in land use and flow regularization in the last years. The calculated return period for the series that presented positive trend varied from 50 to 77 years for a 100 year

  9. Tropical plant-herbivore networks: reconstructing species interactions using DNA barcodes.

    PubMed

    García-Robledo, Carlos; Erickson, David L; Staines, Charles L; Erwin, Terry L; Kress, W John

    2013-01-01

    Plants and their associated insect herbivores, represent more than 50% of all known species on earth. The first step in understanding the mechanisms generating and maintaining this important component of biodiversity is to identify plant-herbivore associations. In this study we determined insect-host plant associations for an entire guild of insect herbivores using plant DNA extracted from insect gut contents. Over two years, in a tropical rain forest in Costa Rica (La Selva Biological Station), we recorded the full diet breadth of rolled-leaf beetles, a group of herbivores that feed on plants in the order Zingiberales. Field observations were used to determine the accuracy of diet identifications using a three-locus DNA barcode (rbcL, trnH-psbA and ITS2). Using extraction techniques for ancient DNA, we obtained high-quality sequences for two of these loci from gut contents (rbcL and ITS2). Sequences were then compared to a comprehensive DNA barcode library of the Zingiberales. The rbcL locus identified host plants to family (success/sequence = 58.8%) and genus (success/sequence = 47%). For all Zingiberales except Heliconiaceae, ITS2 successfully identified host plants to genus (success/sequence = 67.1%) and species (success/sequence = 61.6%). Kindt's sampling estimates suggest that by collecting ca. four individuals representing each plant-herbivore interaction, 99% of all host associations included in this study can be identified to genus. For plants that amplified ITS2, 99% of the hosts can be identified to species after collecting at least four individuals representing each interaction. Our study demonstrates that host plant identifications at the species-level using DNA barcodes are feasible, cost-effective, and reliable, and that reconstructing plant-herbivore networks with these methods will become the standard for a detailed understanding of these interactions.

  10. Contribution of seagrass plants to CO2 capture in a tropical seagrass meadow under experimental disturbance.

    PubMed

    Deyanova, Diana; Gullström, Martin; Lyimo, Liberatus D; Dahl, Martin; Hamisi, Mariam I; Mtolera, Matern S P; Björk, Mats

    2017-01-01

    Coastal vegetative habitats are known to be highly productive environments with a high ability to capture and store carbon. During disturbance this important function could be compromised as plant photosynthetic capacity, biomass, and/or growth are reduced. To evaluate effects of disturbance on CO2 capture in plants we performed a five-month manipulative experiment in a tropical seagrass (Thalassia hemprichii) meadow exposed to two intensity levels of shading and simulated grazing. We assessed CO2 capture potential (as net CO2 fixation) using areal productivity calculated from continuous measurements of diel photosynthetic rates, and estimates of plant morphology, biomass and productivity/respiration (P/R) ratios (from the literature). To better understand the plant capacity to coping with level of disturbance we also measured plant growth and resource allocation. We observed substantial reductions in seagrass areal productivity, biomass, and leaf area that together resulted in a negative daily carbon balance in the two shading treatments as well as in the high-intensity simulated grazing treatment. Additionally, based on the concentrations of soluble carbohydrates and starch in the rhizomes, we found that the main reserve sources for plant growth were reduced in all treatments except for the low-intensity simulated grazing treatment. If permanent, these combined adverse effects will reduce the plants' resilience and capacity to recover after disturbance. This might in turn have long-lasting and devastating effects on important ecosystem functions, including the carbon sequestration capacity of the seagrass system.

  11. Effective use of high CO2 efflux at the soil surface in a tropical understory plant

    PubMed Central

    Ishida, Atsushi; Nakano, Takashi; Adachi, Minaco; Yoshimura, Kenichi; Osada, Noriyuki; Ladpala, Phanumard; Diloksumpun, Sapit; Puangchit, Ladawan; Yoshimura, Jin

    2015-01-01

    Many terrestrial plants are C3 plants that evolved in the Mesozoic Era when atmospheric CO2 concentrations ([CO2]) were high. Given current conditions, C3 plants can no longer benefit from high ambient [CO2]. Kaempferia marginata Carey is a unique understory ginger plant in the tropical dry forests of Thailand. The plant has two large flat leaves that spread on the soil surface. We found a large difference in [CO2] between the partly closed space between the soil surface and the leaves (638 µmol mol−1) and the atmosphere at 20 cm above ground level (412 µmol mol−1). This finding indicates that the plants capture CO2 efflux from the soil. Almost all of the stomata are located on the abaxial leaf surface. When ambient air [CO2] was experimentally increased from 400 to 600 μmol mol−1, net photosynthetic rates increased by 45 to 48% under near light-saturated conditions. No significant increase was observed under low light conditions. These data demonstrate that the unique leaf structure enhances carbon gain by trapping soil CO2 efflux at stomatal sites under relatively high light conditions, suggesting that ambient air [CO2] can serve as an important selective agent for terrestrial C3 plants. PMID:25758763

  12. Effective use of high CO₂ efflux at the soil surface in a tropical understory plant.

    PubMed

    Ishida, Atsushi; Nakano, Takashi; Adachi, Minaco; Yoshimura, Kenichi; Osada, Noriyuki; Ladpala, Phanumard; Diloksumpun, Sapit; Puangchit, Ladawan; Yoshimura, Jin

    2015-03-11

    Many terrestrial plants are C3 plants that evolved in the Mesozoic Era when atmospheric CO2 concentrations ([CO2]) were high. Given current conditions, C3 plants can no longer benefit from high ambient [CO2]. Kaempferia marginata Carey is a unique understory ginger plant in the tropical dry forests of Thailand. The plant has two large flat leaves that spread on the soil surface. We found a large difference in [CO2] between the partly closed space between the soil surface and the leaves (638 µmol mol(-1)) and the atmosphere at 20 cm above ground level (412 µmol mol(-1)). This finding indicates that the plants capture CO2 efflux from the soil. Almost all of the stomata are located on the abaxial leaf surface. When ambient air [CO2] was experimentally increased from 400 to 600 μmol mol(-1), net photosynthetic rates increased by 45 to 48% under near light-saturated conditions. No significant increase was observed under low light conditions. These data demonstrate that the unique leaf structure enhances carbon gain by trapping soil CO2 efflux at stomatal sites under relatively high light conditions, suggesting that ambient air [CO2] can serve as an important selective agent for terrestrial C3 plants.

  13. Effects of Nonnative Ungulate Removal on Plant Communities and Soil Biogeochemistry in Tropical Forests

    NASA Astrophysics Data System (ADS)

    Cole, R. J.; Litton, C. M.; Giardina, C. P.; Sparks, J. P.

    2014-12-01

    Non-native ungulates have substantial impacts on native ecosystems globally, altering both plant communities and soil biogeochemistry. Across tropical and temperate ecosystems, land managers fence and remove non-native ungulates to conserve native biodiversity, a costly management action, yet long-term outcomes are not well quantified. Specifically, knowledge gaps include: (i) the magnitude and time frame of plant community recovery; (ii) the response of non-native invasive plants; and (iii) changes to soil biogeochemistry. In 2010, we established a series of paired ungulate presence vs. removal plots that span a 20 yr. chronosequence in tropical montane wet forests on the Island of Hawaii to quantify the impacts and temporal legacy of feral pig removal on plant communities and soil biogeochemistry. We also compared soil biogeochemistry in targeted areas of low and high feral pig impact. Our work shows that both native and non-native vegetation respond positively to release from top-down control following removal of feral pigs, but species of high conservation concern recover only if initially present at the time of non-native ungulate removal. Feral pig impacts on soil biogeochemistry appear to last for at least 20 years following ungulate removal. We observed that both soil physical and chemical properties changed with feral pig removal. Soil bulk density and volumetric water content decreased while extractable base cations and inorganic N increased in low vs. high feral pig impact areas. We hypothesize that altered soil biogeochemistry facilitates continued invasions by non-native plants, even decades after non-native ungulate removal. Future work will concentrate on comparisons between wet and dry forest ecosystems and test whether manipulation of soil nutrients can be used to favor native vs. non-native plant establishment.

  14. Potential of medicinal plants from the Brazilian semi-arid region (Caatinga) against Staphylococcus epidermidis planktonic and biofilm lifestyles.

    PubMed

    Trentin, Danielle da Silva; Giordani, Raquel Brandt; Zimmer, Karine Rigon; da Silva, Alexandre Gomes; da Silva, Márcia Vanusa; Correia, Maria Tereza Dos Santos; Baumvol, Israel Jacob Rabin; Macedo, Alexandre José

    2011-09-01

    Medicinal plants from the Caatinga, a Brazilian xeric shrubland, are used in folk medicine to treat infections. These ethnopharmacological data can contribute to obtaining new antimicrobial/antibiofilm extracts and natural product prototypes for the development of new drugs. The aim of this study was to investigate the antibiofilm and antibacterial activities of 45 aqueous extracts from 24 Caatinga plant species. The effect of aqueous extracts on planktonic cells and on biofilm formation by Staphylococcus epidermidis was studied by the OD(600) absorbance and by the crystal violet assay, respectively. Scanning electron microscopy (SEM) was used to generate comparative images of extract-treated and untreated biofilms. Chromatographic analyses were performed to characterize the active extracts. The in vitro screening, at 0.4 mg/mL and 4.0mg/mL, showed 20 plants effective in preventing biofilm formation and 13 plants able to inhibit planktonic bacterial growth. SEM images demonstrated distinct profiles of bacterial adhesion, matrix production and cell morphology according to different treatments and surfaces. The phytochemical analysis of the selected active extracts indicates the polyphenols, coumarins, steroids and terpenes as possible active compounds. This study describes the first antibiofilm and antibacterial screening of Caatinga plants against S. epidermidis. The evaluation presented in this study confirms several ethnopharmacological reports and can be utilized to identify new antibiofilm and antibacterial products against S. epidermidis from traditional Brazilian medicine. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  15. Response of five tropical plant species to natural solar ultraviolet-B radiation

    SciTech Connect

    Searles, P.S.; Caldwell, M.M. ); Winter, K. )

    1994-06-01

    The tropical latitudes currently receive high solar ultraviolet-B radiation (UV-B, 280-320 nm) even without ozone depletion. Thus, the influence of natural, present-day UV-B irradiance was examined for three native rainforest tree species and two economically important species on Barro Colorado Island, Panama (9[degrees] N). Solar UV-B radiation conditions were obtained using a UV-B excluding plastic film or a near-ambient UV-B transmitting film over potted plants in a small clearing. Significant differences were often exhibited as increased foliar UV-B absorbing compounds, increased leaf mass pre area, and reduced leaf blade length for plants receiving solar UV-B radiation. Plant height was typically reduced under solar UV-B, but some variation among species in response was seen. Biomass and photosystem II function were generally unaffected. The results provide evidence that tropical vegetation responds to the present level of Solar UV-B radiation. This suggests even a small increase in UV-B radiation with ozone depletion may have biological implications.

  16. Earthworm abundance and distribution pattern in contrasting plant communities within a tropical wet forest in Puerto Rico

    Treesearch

    G. Gonzalez; X. Zou; A. Sabat; N. Fetcher

    1999-01-01

    Plant communities may impose strong control on soil fauna properties. We examined the abundance and distribution pattern of earthworms in two contrasting plant communities within a tropical wet forest in Puerto Rico. The Dacryodes community occurs in well-drained soils and is dominated by Dacryodes excels, Manilkara bidentata, Guarea guidonea, and Sloanea berteriana....

  17. Extensive Overlap of Tropical Rainforest Bacterial Endophytes between Soil, Plant Parts, and Plant Species.

    PubMed

    Haruna, Emmanuel; Zin, Noraziah M; Kerfahi, Dorsaf; Adams, Jonathan M

    2017-06-22

    The extent to which distinct bacterial endophyte communities occur between different plant organs and species is poorly known and has implications for bioprospecting efforts. Using the V3 region of the bacterial 16S ribosomal RNA (rRNA) gene, we investigated the diversity patterns of bacterial endophyte communities of three rainforest plant species, comparing leaf, stem, and root endophytes plus rhizosphere soil community. There was extensive overlap in bacterial communities between plant organs, between replicate plants of the same species, between plant species, and between plant organ and rhizosphere soil, with no consistent clustering by compartment or host plant species. The non-metric multidimensional scaling (NMDS) analysis highlighted an extensively overlapping bacterial community structure, and the β-nearest taxon index (βNTI) analysis revealed dominance of stochastic processes in community assembly, suggesting that bacterial endophyte operational taxonomic units (OTUs) were randomly distributed among plant species and organs and rhizosphere soil. Percentage turnover of OTUs within pairs of samples was similar both for plant individuals of the same species and of different species at around 80-90%. Our results suggest that sampling extra individuals, extra plant organs, extra species, or use of rhizosphere soil, might be about equally effective for obtaining new OTUs for culture. These observations suggest that the plant endophyte community may be much more diverse, but less predictable, than would be expected from culturing efforts alone.

  18. Volatile isoprenoids as defense compounds during abiotic stress in tropical plants

    NASA Astrophysics Data System (ADS)

    Jardine, K.

    2015-12-01

    Emissions of volatile isoprenoids from tropical forests play central roles in atmospheric processes by fueling atmospheric chemistry resulting in modified aerosol and cloud lifecycles and their associated feedbacks with the terrestrial biosphere. However, the identities of tropical isoprenoids, their biological and environmental controls, and functions within plants and ecosystems remain highly uncertain. As part of the DOE ARM program's GoAmazon 2014/15 campaign, extensive field and laboratory observations of volatile isoprenoids are being conducted in the central Amazon. Here we report the results of our completed and ongoing activities at the ZF2 forest reserve in the central Amazon. Among the results of the research are the suprisingly high abundance of light-dependent volatile isoprenoid emissions across abundant tree genera in the Amazon in both primary and secondary forests, the discovery of highly reactive monoterpene emissions from Amazon trees, and evidence for the importance of volatile isoprenoids in protecting photosynthesis during oxidative stress under elevated temperatures including energy consumption and direct antioxidant functions and a tight connection betwen volatile isoprenoid emissions, photorespiration, and CO2 recycling within leaves. The results highlight the need to model allocation of carbon to isoprenoids during elevated temperature stress in the tropics.

  19. Seasonal dynamics in photosynthesis of woody plants at the northern limit of Asian tropics: potential role of fog in maintaining tropical rainforests and agriculture in Southwest China.

    PubMed

    Zhang, Yong-Jiang; Holbrook, N Michele; Cao, Kun-Fang

    2014-10-01

    The lowland tropical rainforests in Xishuangbanna, Southwest (SW) China, mark the northern limit of Asian tropics. Fog has been hypothesized to play a role in maintaining rainforests and tropical crop production in this region, but the physiological mechanism has not been studied. The goals of this study were to characterize the seasonal dynamics in photosynthesis and to assess the potential for fog to mitigate chilling-induced photodamage for tropical trees and crops in Xishuangbanna. We measured seasonal dynamics in light-saturated net photosynthetic rate (Aa), stomatal conductance (gs), intercellular CO2 concentration, quantum yield of Photosystem II (Fv/Fm) and maximum P700 changes (Pm; indicates the amount of active PSI complex), as well as chilling resistance and fog (light/shading) effects on low temperature-induced decline in Fv/Fm and Pm for native tree and introduced lower latitude tree or woody shrub species grown in a tropical botanical garden. Despite significant decreases in Aa, gs, Pm and Fv/Fm, most species maintained considerably high Aa during the cool season (2.51-14.6 μmol m(-2) s(-1)). Shaded leaves exposed to seasonal low temperatures had higher Fv/Fm than sun-exposed leaves in the cool season. All species could tolerate 1.4 °C in the dark, whereas a combined treatment of low temperature and high light caused a distinctly faster decline in Pm and Fv/Fm compared with low temperature treatment alone. Because fog persistence avoids or shortens the duration of high light condition in the morning when the temperatures are still low, our results provide support for the hypothesis that fog reduces chilling damage to tropical plants in this region and thus plays a role in maintaining tropical rainforests and agriculture in SW China. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  20. Forage plants as an alternative feed resource for sustainable pig production in the tropics: a review.

    PubMed

    Kambashi, B; Boudry, C; Picron, P; Bindelle, J

    2014-08-01

    Globally, pressure on concentrate feed resources is increasing, especially in the tropics where many countries are net importers of food. Forage plants are a possible alternative, but their use as feed ingredients for pigs raises several issues related to their higher fibre and plant secondary metabolites contents as well as their lower nutritive value. In this paper, the nutritive value of several forage species and the parameters that influence this nutritive value in relationship to the plant family, the physiological stage, the plant part and the preservation method (fresh, hay and silage) are reviewed. The influence of the breed and the physiological status of the animal on animal voluntary intake of fibre-rich ingredients, digestibility as related to gastrointestinal volume and transit time and growth performances are also discussed. The final section highlights the advantages and drawbacks of forage plants in pig diets and stresses the need for proper economic evaluation to conclude on the benefits of the use of forage plants in pig feed.

  1. Methyl halide fluxes from tropical plants under controlled radiation and temperature regimes

    NASA Astrophysics Data System (ADS)

    Blei, Emanuel; Yokouchi, Yoko; Saito, Takuya; Nozoe, Susumu

    2015-04-01

    Methyl halides (CH3Cl, CH3Br, CH3I) contribute significantly to the halogen burden of the atmosphere and have the potential to influence the stratospheric ozone layer through their catalytic effect in the Chapman cycle. As such they have been studied over the years, and many plants and biota have been examined for their potential to act as a source of these gases. One of the potentially largest terrestrial sources identified was tropical vegetation such as tropical ferns and Dipterocarp trees. Most of these studies concentrated on the identification and quantification of such fluxes rather than their characteristics and often the chambers used in these studies were either opaque or only partially transparent to the full solar spectrum. Therefore it is not certain to which degree emissions of methyl halides are innate to the plants and how much they might vary due to radiation or temperature conditions inside the enclosures. In a separate development it had been proposed that UV-radiation could cause live plant materials to be become emitters of methane even under non-anoxic conditions. As methane is chemically very similar to methyl halides and had been proposed to be produced from methyl-groups ubiquitously found in plant cell material there is a relatively good chance that such a production mechanism would also apply to methyl halides. To test whether radiation can affect elevated emissions of methyl halides from plant materials and to distinguish this from temperature effects caused by heat build-up in chambers a set of controlled laboratory chamber enclosures under various radiation and temperature regimes was conducted on four different tropical plant species (Magnolia grandiflora, Cinnamonum camphora, Cyathea lepifera, Angiopteris lygodiifolia), the latter two of which had previously been identified as strong methyl halide emitters. Abscised leaf samples of these species were subjected to radiation treatments such UV-B, UV-A and broad spectrum radiation

  2. In vitro antihelmintic effect of fifteen tropical plant extracts on excysted flukes of Fasciola hepatica.

    PubMed

    Alvarez-Mercado, José Manuel; Ibarra-Velarde, Froylán; Alonso-Díaz, Miguel Ángel; Vera-Montenegro, Yolanda; Avila-Acevedo, José Guillermo; García-Bores, Ana María

    2015-02-27

    Fasciolosis due to Fasciola hepatica is the most important hepatic disease in veterinary medicine. Its relevance is important because of the major economical losses to the cattle industry such as: reduction in milk, meat and wool production; miscarriages, anemia, liver condemnation and occasionally deaths, are estimated in billons of dollars. The emergence of fluke resistance due to over or under dosing of fasciolides as well as environmental damage produced by the chemicals eliminated in field have stimulated the need for alternative methods to control Fasciola hepatica. The aim of this study was to evaluate the in vitro anthelmintic effect of fifteen tropical plant extracts used in tradicional Mexican medicine, on newly excysted flukes of Fasciola hepatica. The flukes were exposed in triplicate at 500, 250 and 125 mg/L to each extract. The efficacy was assessed as the mortality rate based on the number of live and dead flukes after 24, 48 and 72 h post-exposure. The plants with anthelmintic effect were evaluated once again with a concentration of 375 mg/L in order to confirm the results and to calculate lethal concentrations at 50%, 90% and 99% (LC(50), LC(90), and LC(99)). Plant extracts of Lantana camara, Bocconia frutescens, Piper auritum, Artemisia mexicana and Cajanus cajan had an in vitro anthelmintic effect (P <0.05). The LC(50), LC(90) and LC(99) to A. mexicana, C. cajan and B. frutescens were 92.85, 210.44 and 410.04 mg/L, 382.73, 570.09 and 788.9 mg/L and 369.96, 529.94 and 710.34 mg/L, respectively. It is concluded that five tropical plant extracts had promising anthelmintic effects against F. hepatica. Further studies on toxicity and in vivo biological evaluation in ruminant models might help to determine the anthelmintic potential of these plant extracts.

  3. The diversity and antimicrobial activity of endophytic fungi associated with medicinal plant Baccharis trimera (Asteraceae) from the Brazilian savannah.

    PubMed

    Vieira, Mariana L A; Johann, Susana; Hughes, Frederic M; Rosa, Carlos A; Rosa, Luiz H

    2014-12-01

    The fungal endophyte community associated with Baccharis trimera, a Brazilian medicinal plant, was characterized and screened for its ability to present antimicrobial activity. By using molecular methods, we identified and classified the endophytic fungi obtained into 25 different taxa from the phyla Ascomycota and Basidiomycota. The most abundant species were closely related to Diaporthe phaseolorum, Pestalotiopsis sp. 1, and Preussia pseudominima. The differences observed in endophytic assemblages from different B. trimera specimens might be associated with their crude extract activities. Plants that had higher α-biodiversity were also those that contributed more to the regional (γ) diversity. All fungal isolates were cultured and their crude extracts screened to examine the antimicrobial activities. Twenty-three extracts (12.8%) displayed antimicrobial activities against at least one target microorganism. Among these extracts, those obtained from Epicoccum sp., Pestalotiopsis sp. 1, Cochliobolus lunatus, and Nigrospora sp. presented the best minimum inhibitory concentration values. Our results show that the endophytic fungal community associated with the medicinal plant B. trimera included few dominant bioactive taxa, which may represent sources of compounds with antifungal activity. Additionally, the discovery of these bioactive fungi in association with B. trimera suggests that Brazilian plants used as folk medicine may shelter a rich fungal diversity as well as taxa able to produce bioactive metabolites with antimicrobial activities.

  4. Anti‐asthmatic and anxiolytic effects of Herissantia tiubae, a Brazilian medicinal plant

    PubMed Central

    Mozzini Monteiro, Talissa; Ferrera Costa, Hermann; Carvalho Vieira, Giciane; Rodrigues Salgado, Paula Regina; da Silva Stiebbe Salvadori, Mirian Graciela; de Almeida, Reinaldo Nobrega; de Fatima Vanderlei de Souza, Maria; Neves Matias, Wemerson; Andrade Braga, Valdir; Nalivaiko, Eugene

    2016-01-01

    Abstract Herissantia tiubae (HtE) is a Brazilian plant used in folk medicine to treat inflammatory diseases. Our aim was to determine whether the HtE has anti‐inflammatory and anxiolytic effects in a murine model of asthma. Ovalbumin (OVA)‐sensitized BALB/c mice were treated with HtE (50, 100, or 200 mg/kg) or dexamethasone before each OVA challenge. After the last challenge, animals were subjected to anxiety tests and respiratory measurements. Following euthanasia, we quantified immune cells in the bronchoalveolar lavage (BAL), serum IgE titer and cytokine levels, cellular infiltration and mucus content in the lung tissues, and cellular composition of the mediastinal lymph nodes. OVA challenge in sensitized animals caused: (1) reduction of mean respiratory and dominant respiratory rate (from 398 ± 12 to 286 ± 20 cicles per minute (cpm) and from 320 ± 14 to 162 ± 15 cpm, respectively); (2) increase in behavioral markers of anxiety tests; (3) substantial pro‐inflammatory effects, including rise in OVA‐specific IgE titer (from 0 to 1:2048) and these inflammatory effect diminished the titer to 1:512 after HtE treatment; rise in plasma IL‐13 (from 13 ng/mL in saline to 227 ng/mL in OVA and HtE treatment restored to 1.29 ng/mL; rise in total BAL cell count (from 0.742 cells/mL in saline to 11.77 cells/mL in OVA), with prominent eosinophilia. H. tiubae extract affected respiratory parameters similarly to aminophylline, behavioral changes comparable to diazepam, and inflammation being as efficient as dexamethasone. H. tiubae extract (HtE) possesses both anti‐inflammatory and anxiolytic properties in the murine model of asthma. PMID:27957328

  5. Temperature-Dependent Development and Survival of Brazilian Populations of the Mediterranean Fruit Fly, Ceratitis capitata, from Tropical, Subtropical and Temperate Regions

    PubMed Central

    Ricalde, Marcelo P.; Nava, Dori E.; Loeck, Alci E.; Donatti, Michele G.

    2012-01-01

    The Mediterranean fruit fly Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) is one of the principal exotic pests affecting Brazilian production in the northeastern and southeastern regions of Brazil. In the south, it is has potential as a serious threat to temperate-climate fruit farms, since it is already found in urban and suburban communities in this region. We studied the biological characteristics of C. capitata populations from Pelotas-RS (temperate climate), Petrolina-PE (tropical), and Campinas-SP (subtropical). Ceratitis capitata biology was studied under controlled temperature (15, 20, 25, 30, and 35 ± 1 °C), 70 ± 10% RH, and 14:10 L:D photoperiod. The duration and survival rate of the egg, larval, and pupal stages were evaluated and the thermal requirements of these three populations were determined. The duration and survival of these developmental stages varied with temperature, with similar values for the three populations, except for some variation in the egg phase. Egg to adult developmental time for all three populations was inversely proportional to temperature; from 15 to 30 °C developmental time varied from 71.2 to 17.1, 70.2 to 17.1, and 68.5 to 16.9 days, respectively. Survival during development was affected at 15 to 30 °C, and differed significantly from survival at 20 to 25 °C. At 35 °C, immature stages did not develop. The basal temperature and degree-day requirement were similar for all immature stages except for the egg stage. The basal temperatures and thermal constants were 9.30 and 350, 8.47 and 341, and 9.60 °C and 328 degree-days for the Pelotas, Petrolina, and Campinas populations, respectively. Results suggested that survival and thermal requirements are similar for these tropical, subtropical, and temperate populations of C. capitata, and demonstrate the species' capacity to adapt to different climate conditions. PMID:22963468

  6. Temperature-dependent development and survival of Brazilian populations of the Mediterranean fruit fly, Ceratitis capitata, from tropical, subtropical and temperate regions.

    PubMed

    Ricalde, Marcelo P; Nava, Dori E; Loeck, Alci E; Donatti, Michele G

    2012-01-01

    The Mediterranean fruit fly Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) is one of the principal exotic pests affecting Brazilian production in the northeastern and southeastern regions of Brazil. In the south, it is has potential as a serious threat to temperate-climate fruit farms, since it is already found in urban and suburban communities in this region. We studied the biological characteristics of C. capitata populations from Pelotas-RS (temperate climate), Petrolina-PE (tropical), and Campinas-SP (subtropical). Ceratitis capitata biology was studied under controlled temperature (15, 20, 25, 30, and 35 ± 1 °C), 70 ± 10% RH, and 14:10 L:D photoperiod. The duration and survival rate of the egg, larval, and pupal stages were evaluated and the thermal requirements of these three populations were determined. The duration and survival of these developmental stages varied with temperature, with similar values for the three populations, except for some variation in the egg phase. Egg to adult developmental time for all three populations was inversely proportional to temperature; from 15 to 30 °C developmental time varied from 71.2 to 17.1, 70.2 to 17.1, and 68.5 to 16.9 days, respectively. Survival during development was affected at 15 to 30 °C, and differed significantly from survival at 20 to 25 °C. At 35 °C, immature stages did not develop. The basal temperature and degree-day requirement were similar for all immature stages except for the egg stage. The basal temperatures and thermal constants were 9.30 and 350, 8.47 and 341, and 9.60 °C and 328 degree-days for the Pelotas, Petrolina, and Campinas populations, respectively. Results suggested that survival and thermal requirements are similar for these tropical, subtropical, and temperate populations of C. capitata, and demonstrate the species' capacity to adapt to different climate conditions.

  7. Plant and microbial controls on nitrogen retention and loss in a Humid Tropical Forest

    SciTech Connect

    Templer, P.; Silver, W.; Pett-Ridge, J.; DeAngelis, K.M.; Firestone, M.K.

    2009-09-15

    Humid tropical forests are generally characterized by the lack of nitrogen (N) limitation to net primary productivity, yet paradoxically have high potential for N loss. We conducted an intensive field experiment with {sup 15}NH{sub 4} and {sup 15}NO{sub 3} additions to highly weathered tropical forest soils to determine the relative importance of N retention and loss mechanisms. Over half of all the NH{sub 4}{sup +} produced from gross mineralization was rapidly converted to NO{sub 3}{sup -} during the process of gross nitrification. During the first 24 h plant roots took up 28 % of the N mineralized, dominantly as NH{sub 4}{sup +}, and were a greater sink for N than soil microbial biomass. Soil microbes were not a significant sink for added {sup 15}NH{sub 4}{sup +} or {sup 15}NO{sub 3}{sup -} during the first 24 hr, and only for {sup 15}NH{sub 4}{sup +} after 7 d. Patterns of microbial community composition, as determined by Terminal Restriction Fragment Length Polymorphism analysis, were weakly, but significantly correlated with nitrification and denitrification to N{sub 2}O. Rates of dissimilatory NO{sub 3}{sup -} reduction to NH{sub 4}{sup +} (DNRA) were high in this forest, accounting for up to 25 % of gross mineralization and 35 % of gross nitrification. DNRA was a major sink for NO{sub 3}{sup -} which may have contributed to the lower rates of N{sub 2}O and leaching losses. Despite considerable N conservation via DNRA and plant NH{sub 4}{sup +} uptake, the fate of approximately 45% of the NO{sub 3}{sup -} produced and 22% of the NH{sub 4}{sup +} produced were not measured in our fluxes, suggesting that other important pathways for N retention and loss (e.g., denitrification to N{sub 2}) are important in this system. The high proportion of mineralized N that was rapidly nitrified and the fates of that NO{sub 3}{sup -} highlight the key role of gross nitrification as a proximate control on N retention and loss in humid tropical forest soils. Furthermore, our

  8. Cooling water of power plant creates "hot spots" for tropical fishes and parasites.

    PubMed

    Emde, Sebastian; Kochmann, Judith; Kuhn, Thomas; Dörge, Dorian D; Plath, Martin; Miesen, Friedrich W; Klimpel, Sven

    2016-01-01

    Thermally altered water bodies can function as "hot spots" where non-native species are establishing self-sustaining populations beyond their tropical and subtropical native regions. Whereas many tropical fish species have been found in these habitats, the introduction of non-native parasites often remains undetected. Here, n = 77 convict cichlids (Amatitlania nigrofasciata) were sampled by electro-fishing at two sites from a thermally altered stream in Germany and examined for parasite fauna and feeding ecology. Stomach content analysis suggests an opportunistic feeding strategy of A. nigrofasciata: while plant material dominated the diet at the warm water inlet (∼30 °C), relative contributions of insects, plants, and crustaceans were balanced 3 km downstream (∼27 °C). The most abundant non-native parasite species was the tropical nematode Camallanus cotti with P = 11.90 % and P = 80.00 % at the inlet and further downstream, respectively. Additionally, nematode larvae of Anguillicoloides crassus and one specimen of the subtropical species Bothriocephalus acheilognathi were isolated. A. nigrofasciata was also highly infected with the native parasite Acanthocephalus anguillae, which could be linked to high numbers of the parasite's intermediate host Asellus aquaticus. The aim of this study was to highlight the risk and consequences of the release and establishment of ornamental fish species for the introduction and spread of non-indigenous metazoan parasites using the convict cichlid as a model species. Furthermore, the spread of non-native parasites into adjacent fish communities needs to be addressed in the future as first evidence of Camallanus cotti in native fish species was also found.

  9. Bidirectional exchange of methyl halides between tropical plants and the atmosphere

    NASA Astrophysics Data System (ADS)

    Saito, Takuya; Yokouchi, Yoko; Phillip, Elizabeth; Okuda, Toshinori

    2013-10-01

    a stable isotope tracer technique, we studied the exchange of methyl chloride (CH3Cl) and methyl bromide (CH3Br) between plants and the atmosphere in a tropical rain forest in Malaysia. Most plant species examined showed not only production but also consumption of CH3Cl with a large net emission overall. In contrast, CH3Br consumption was comparable to its production, so the net emission was small. The rates of CH3Cl and CH3Br consumption were highly correlated with each other, and their ratio was consistent with reported values in terrestrial ecosystems, where microorganisms are responsible for the consumption. Such microorganisms might participate in the consumption we observed, as the consumption rates were faster in saplings, whose leaves were generally covered by epiphytic microorganisms, than in healthy looking leaves of mature trees.

  10. [Characteristics of canopy plant substratum in a low land humid tropical forest (Upper Orinoco, Venezuela)].

    PubMed

    Hernández-Rosas, José Ibrahin

    2004-01-01

    By international agreement (Austria-Venezuela) a tower crane was installed near Surumoni river, Upper Orinoco, for canopy research in a tropical rain forest. From the 1.5 ha crane-accessible area of the forest, an experimental plot was selected for assessment of the canopy plants' aerial substrates and to determine their relationship with spatial distribution, presence or absence of vascular plants, and some of the strategies used in their ecological space. In the middle and lower canopy strata myrmecophytic associations appear, where the conformation of the aerial substrates determines the establishment and maintenance of these associations. The high content of nutrients of these aerial substrata represents a reservoir for the forest, where the mirmecophytic activity is determining. A higher fertility of aerial substrates of the ants gardens can be related to a higher number of vascular epiphytes present in these gardens.

  11. Plant invasions in protected areas of tropical pacific islands, with special reference to Hawaii

    USGS Publications Warehouse

    R. Flint Hughes,; Jean-Yves Meyer, jean-yves.meyer@recherche.gov.pf; Loope, Lloyd L.

    2013-01-01

    Isolated tropical islands are notoriously vulnerable to plant invasions. Serious management for protection of native biodiversity in Hawaii began in the 1970s, arguably at Hawaii Volcanoes National Park. Concerted alien plant management began there in the 1980s and has in a sense become a model for protected areas throughout Hawaii and Pacific Island countries and territories. We review the relative successes of their strategies and touch upon how their experience has been applied elsewhere. Protected areas in Hawaii are fortunate in having relatively good resources for addressing plant invasions, but many invasions remain intractable, and invasions from outside the boundaries continue from a highly globalised society with a penchant for horticultural novelty. There are likely few efforts in most Pacific Islands to combat alien plant invasions in protected areas, but such areas may often have fewer plant invasions as a result of their relative remoteness and/or socio-economic development status. The greatest current needs for protected areas in this region may be for establishment of yet more protected areas, for better resources to combat invasions in Pacific Island countries and territories, for more effective control methods including biological control programme to contain intractable species, and for meaningful efforts to address prevention and early detection of potential new invaders.

  12. Life histories of hosts and pathogens predict patterns in tropical fungal plant diseases.

    PubMed

    García-Guzmán, Graciela; Heil, Martin

    2014-03-01

    Plant pathogens affect the fitness of their hosts and maintain biodiversity. However, we lack theories to predict the type and intensity of infections in wild plants. Here we demonstrate using fungal pathogens of tropical plants that an examination of the life histories of hosts and pathogens can reveal general patterns in their interactions. Fungal infections were more commonly reported for light-demanding than for shade-tolerant species and for evergreen rather than for deciduous hosts. Both patterns are consistent with classical defence theory, which predicts lower resistance in fast-growing species and suggests that the deciduous habit can reduce enemy populations. In our literature survey, necrotrophs were found mainly to infect shade-tolerant woody species whereas biotrophs dominated in light-demanding herbaceous hosts. Far-red signalling and its inhibitory effects on jasmonic acid signalling are likely to explain this phenomenon. Multiple changes between the necrotrophic and the symptomless endophytic lifestyle at the ecological and evolutionary scale indicate that endophytes should be considered when trying to understand large-scale patterns in the fungal infections of plants. Combining knowledge about the molecular mechanisms of pathogen resistance with classical defence theory enables the formulation of testable predictions concerning general patterns in the infections of wild plants by fungal pathogens. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  13. Mapping the spatial variability of plant diversity in a tropical forest: comparison of spatial interpolation methods.

    PubMed

    Hernandez-Stefanoni, J Luis; Ponce-Hernandez, Raul

    2006-06-01

    Knowledge of the spatial distribution of plant species is essential to conservation and forest managers in order to identify high priority areas such as vulnerable species and habitats, and designate areas for reserves, refuges and other protected areas. A reliable map of the diversity of plant species over the landscape is an invaluable tool for such purposes. In this study, the number of species, the exponent Shannon and the reciprocal Simpson indices, calculated from 141 quadrat sites sampled in a tropical forest were used to compare the performance of several spatial interpolation techniques used to prepare a map of plant diversity, starting from sample (point) data over the landscape. Means of mapped classes, inverse distance functions, kriging and co-kriging, both, applied over the entire studied landscape and also applied within vegetation classes, were the procedures compared. Significant differences in plant diversity indices between classes demonstrated the usefulness of boundaries between vegetation types, mapped through satellite image classification, in stratifying the variability of plant diversity over the landscape. These mapped classes, improved the accuracy of the interpolation methods when they were used as prior information for stratification of the area. Spatial interpolation by co-kriging performed among the poorest interpolators due to the poor correlation between the plant diversity variables and vegetation indices computed by remote sensing and used as covariables. This indicated that the latter are not suitable covariates of plant diversity indices. Finally, a within-class kriging interpolator yielded the most accurate estimates of plant diversity values. This interpolator not only provided the most accurate estimates by accounting for the indices' intra-class variability, but also provided additional useful interpretations of the structure of spatial variability of diversity values through the interpretation of their semi-variograms. This

  14. Allelopathic Activity of Extracts from Different Brazilian Peanut (Arachis hypogaea L.) Cultivars on Lettuce (Lactuca sativa) and Weed Plants

    PubMed Central

    Garcia, R.; Simas, N. K.

    2017-01-01

    Peanut (Arachis hypogaea L.) is the fourth most consumed oleaginous plant in the world, producing seeds with high contents of lipids, proteins, vitamins, and carbohydrates. Biological activities of different extracts of this species have already been evaluated by many researchers, including antioxidant, antitumoral, and antibacterial. In this work, the allelopathic activity of extracts from different Brazilian peanut cultivars against lettuce (Lactuca sativa) and two weed plants (Commelina benghalensis and Ipomoea nil) was studied. Aerial parts, roots, seeds, and seed coats were used for the preparation of crude extracts. Seed extract partitioning was performed with n-hexane, dichloromethane, ethyl acetate, n-butanol, and aqueous residue. Germination and growth of hypocotyls and rootlets were evaluated after one and five days of incubation with plant extracts, respectively. Crude seed extract and its dichloromethanic partition displayed highest allelopathic activity. These results contribute for the study of new potential natural herbicides. PMID:28396881

  15. Allelopathic Activity of Extracts from Different Brazilian Peanut (Arachis hypogaea L.) Cultivars on Lettuce (Lactuca sativa) and Weed Plants.

    PubMed

    Casimiro, G S; Mansur, E; Pacheco, G; Garcia, R; Leal, I C R; Simas, N K

    2017-01-01

    Peanut (Arachis hypogaea L.) is the fourth most consumed oleaginous plant in the world, producing seeds with high contents of lipids, proteins, vitamins, and carbohydrates. Biological activities of different extracts of this species have already been evaluated by many researchers, including antioxidant, antitumoral, and antibacterial. In this work, the allelopathic activity of extracts from different Brazilian peanut cultivars against lettuce (Lactuca sativa) and two weed plants (Commelina benghalensis and Ipomoea nil) was studied. Aerial parts, roots, seeds, and seed coats were used for the preparation of crude extracts. Seed extract partitioning was performed with n-hexane, dichloromethane, ethyl acetate, n-butanol, and aqueous residue. Germination and growth of hypocotyls and rootlets were evaluated after one and five days of incubation with plant extracts, respectively. Crude seed extract and its dichloromethanic partition displayed highest allelopathic activity. These results contribute for the study of new potential natural herbicides.

  16. Contribution of aboveground plant respiration to carbon cycling in a Bornean tropical rainforet

    NASA Astrophysics Data System (ADS)

    Katayama, Ayumi; Tanaka, Kenzo; Ichie, Tomoaki; Kume, Tomonori; Matsumoto, Kazuho; Ohashi, Mizue; Kumagai, Tomo'omi

    2014-05-01

    Bornean tropical rainforests have a different characteristic from Amazonian tropical rainforests, that is, larger aboveground biomass caused by higher stand density of large trees. Larger biomass may cause different carbon cycling and allocation pattern. However, there are fewer studies on carbon allocation and each component in Bornean tropical rainforests, especially for aboveground plant respiration, compared to Amazonian forests. In this study, we measured woody tissue respiration and leaf respiration, and estimated those in ecosystem scale in a Bornean tropical rainforest. Then, we examined carbon allocation using the data of soil respiration and aboveground net primary production obtained from our previous studies. Woody tissue respiration rate was positively correlated with diameter at breast height (dbh) and stem growth rate. Using the relationships and biomass data, we estimated woody tissue respiration in ecosystem scale though methods of scaling resulted in different estimates values (4.52 - 9.33 MgC ha-1 yr-1). Woody tissue respiration based on surface area (8.88 MgC ha-1 yr-1) was larger than those in Amazon because of large aboveground biomass (563.0 Mg ha-1). Leaf respiration rate was positively correlated with height. Using the relationship and leaf area density data at each 5-m height, leaf respiration in ecosystem scale was estimated (9.46 MgC ha-1 yr-1), which was similar to those in Amazon because of comparable LAI (5.8 m2 m-2). Gross primary production estimated from biometric measurements (44.81 MgC ha-1 yr-1) was much higher than those in Amazon, and more carbon was allocated to woody tissue respiration and total belowground carbon flux. Large tree with dbh > 60cm accounted for about half of aboveground biomass and aboveground biomass increment. Soil respiration was also related to position of large trees, resulting in high soil respiration rate in this study site. Photosynthesis ability of top canopy for large trees was high and leaves for

  17. Nephropathy associated with animal, plant, and chemical toxins in the tropics.

    PubMed

    Jha, Vivekanand; Chugh, Kirpal S

    2003-01-01

    Widespread human exposure to a variety of drugs, chemicals, and biologic products and recent awareness of their toxic manifestations has led to the recognition of toxic nephropathy as an important segment of renal disease in the tropical countries. Tropical nephrotoxins are distinctly different from those seen in the rest of the world and are derived from local fauna and flora or plant and chemical sources. The spectrum of exposure varies from country to country and even from community to community, depending on variations in the distribution of local plants and animal species and prevalent social practices. Acute renal failure (ARF), either alone or in association with liver failure, neurologic abnormalities, metabolic acidosis, disseminated intravascular coagulation, or pulmonary infections is the most common form of presentation. Traditional medicines prescribed by witch doctors (traditional healers) constitute a special class of nephrotoxins among several communities in Africa and Asia. The prevalence of nephropathy caused by traditional medicines is directly related to a combination of ignorance, poverty, lack of medical facilities, lax legislation, and widespread belief in indigenous systems of medicine in rural areas. These medicines are a mix of herbs and unknown chemicals administered orally or as enemas. Clustering of cases after exposure to a particular agent suggests the possibility of a toxic insult. Common animal nephrotoxins are venoms of viper snakes, sea snakes, stinging insects, and raw gallbladder and bile of carp and sheep. Botanical nephrotoxins are encountered both in common edible plants (djenkol beans, mushrooms) and medicinal herbs (impila, cat's claw). Mistaken identification of medicinal herbs by untrained workers and even deliberate trials of toxic substitutes derived from plants frequently lead to renal disease, the most commonly reported being the Chinese herbal nephropathy. Nephrotoxicity caused by chemicals can be secondary to

  18. Genetic structure in a tropical lek-breeding bird, the blue manakin (Chiroxiphia caudata) in the Brazilian Atlantic Forest.

    PubMed

    Francisco, Mercival R; Gibbs, H Lisle; Galetti, Mauro; Lunardi, Vitor O; Galetti, Pedro M

    2007-12-01

    Determining the genetic structure of tropical bird populations is important for assessing potential genetic effects of future habitat fragmentation and for testing hypotheses about evolutionary mechanisms promoting diversification. Here we used 10 microsatellite DNA loci to describe levels of genetic differentiation for five populations of the lek-mating blue manakin (Chiroxiphia caudata), sampled along a 414-km transect within the largest remaining continuous tract of the highly endangered Atlantic Forest habitat in southeast Brazil. We found small but significant levels of differentiation between most populations. F(ST) values varied from 0.0 to 0.023 (overall F(ST)=0.012) that conformed to a strong isolation by distance relationship, suggesting that observed levels of differentiation are a result of migration-drift equilibrium. N(e)m values estimated using a coalescent-based method were small (tropical bird in continuous habitat in the absence of geographical barriers possibly due to behavioural features of the species.

  19. Why do people use exotic plants in their local medical systems? A systematic review based on Brazilian local communities.

    PubMed

    Medeiros, Patrícia Muniz de; Ferreira Júnior, Washington Soares; Ramos, Marcelo Alves; Silva, Taline Cristina da; Ladio, Ana Haydée; Albuquerque, Ulysses Paulino

    2017-01-01

    Efforts have been made to understand the processes that lead to the introduction of exotic species into local pharmacopoeias. Among those efforts, the diversification hypothesis predicts that exotic plants are introduced in local medical systems to amplify the repertoire of knowledge related to the treatment of diseases, filling blanks that were not occupied by native species. Based on such hypothesis, this study aimed to contribute to this discussion using the context of local Brazilian populations. We performed a systematic review of Brazilian studies up to 2011 involving medicinal plants, excluding those studies that presented a high risk of bias (because of sampling or plant identification problems). An analysis of similarities (ANOSIM) was conducted in different scales to test for differences in the repertoire of therapeutic indications treated using native and exotic species. We have found that although there is some overlap between native and exotic plants regarding their therapeutic indications and the body systems (BSs) that they treat, there are clear gaps present, that is, there are therapeutic indications and BSs treated that are exclusive to exotic species. This scenario enables the postulation of two alternative unfoldings of the diversification hypothesis, namely, (1) exotic species are initially introduced to fill gaps and undergo subsequent expansion of their use for medical purposes already addressed using native species and (2) exotic species are initially introduced to address problems already addressed using native species to diversify the repertoire of medicinal plants and to increase the resilience of medical systems. The reasons why exotic species may have a competitive advantage over the native ones, the implications of the introduction of exotic species for the resilience of medical systems, and the contexts in which autochthonous plants can gain strength to remain in pharmacopoeias are also discussed.

  20. Tree shrew lavatories: a novel nitrogen sequestration strategy in a tropical pitcher plant

    PubMed Central

    Clarke, Charles M.; Bauer, Ulrike; Lee, Ch'ien C.; Tuen, Andrew A.; Rembold, Katja; Moran, Jonathan A.

    2009-01-01

    Nepenthes pitcher plants are typically carnivorous, producing pitchers with varying combinations of epicuticular wax crystals, viscoelastic fluids and slippery peristomes to trap arthropod prey, especially ants. However, ant densities are low in tropical montane habitats, thereby limiting the potential benefits of the carnivorous syndrome. Nepenthes lowii, a montane species from Borneo, produces two types of pitchers that differ greatly in form and function. Pitchers produced by immature plants conform to the ‘typical’ Nepenthes pattern, catching arthropod prey. However, pitchers produced by mature N. lowii plants lack the features associated with carnivory and are instead visited by tree shrews, which defaecate into them after feeding on exudates that accumulate on the pitcher lid. We tested the hypothesis that tree shrew faeces represent a significant nitrogen (N) source for N. lowii, finding that it accounts for between 57 and 100 per cent of foliar N in mature N. lowii plants. Thus, N. lowii employs a diversified N sequestration strategy, gaining access to a N source that is not available to sympatric congeners. The interaction between N. lowii and tree shrews appears to be a mutualism based on the exchange of food sources that are scarce in their montane habitat. PMID:19515656

  1. Emission of volatile organic compounds (VOC) from tropical plant species in India.

    PubMed

    Padhy, P K; Varshney, C K

    2005-06-01

    Foliar emission of volatile organic compounds (VOC) from common Indian plant species was measured. Dynamic flow enclosure technique was used and the gas samples were collected onto Tenax-GC/Carboseive cartridges. The Tenax-GC/Carboseive cartridges were attached to the thermal disorber sample injection system and the gas sample was analysed using gas chromatography (GC) with flame ionisation detection (FID). Fifty-one local plant species were screened, out of which 36 species were found to emit VOC (4 high emitter; 28 moderate emitter; and 4 low-emitter), while in the remaining 15 species no VOC emission was detected or the levels of emission were below detection limit (BDL). VOC emission was found to vary from one species to another. There was a marked seasonal and diurnal variation in VOC emission. The minimum and maximum VOC emission values were < 0.1 and 87 microgg(-1) dry leaf h(-1) in Ficus infectoria and Lantana camara respectively. Out of the 51 plant species studied, 13 species are reported here for the first time. Among the nine tree species (which were selected for detailed study), the highest average hourly emission (9.69+/-8.39 microgg(-1) dry leaf) was observed in Eucalyptus species and the minimum in Syzygium jambolanum (1.89+/-2.48 microgg(-1) dry leaf). An attempt has been made to compare VOC emission from different plant species between present study and the literature (tropical and other regions).

  2. Antioxidant, Metal Chelating, Anti-glucosidase Activities and Phytochemical Analysis of Selected Tropical Medicinal Plants

    PubMed Central

    Wong, Fai-Chu; Yong, Ann-Li; Ting, Evon Peir-Shan; Khoo, Sim-Chyi; Ong, Hean-Chooi; Chai, Tsun-Thai

    2014-01-01

    The purpose of this investigation was to determine the antioxidant potentials and anti-glucosidase activities of six tropical medicinal plants. The levels of phenolic constituents in these medicinal plants were also quantified and compared. Antioxidation potentials were determined colorimetrically for scavenging activities against DPPH and NO radicals. Metal chelating assay was based on the measurement of iron-ferrozine absorbance at 562 nm. Anti-diabetic potentials were measured by using α-glucosidase as target enzyme. Medicinal plants’ total phenolic, total flavonoid and hydroxycinnamic acid contents were determined using spectrophotometric methods, by comparison to standard plots prepared using gallic acid, quercetin and caffeic acid standards, respectively. Radical scavenging and metal chelating activities were detected in all medicinal plants, in concentration-dependent manners. Among the six plants tested, C. nutans, C. formosana and H. diffusa were found to possess α-glucosidase inhibitory activities. Spectrophotometric analysis indicated that the total phenolic, total flavonoid and hydroxycinnamic acid contents ranged from 12.13-21.39 mg GAE per g of dry sample, 1.83-9.86 mg QE per g of dry sample, and 0.91-2.74 mg CAE per g of dry sample, respectively. Our results suggested that C. nutans and C. formosana could potentially be used for the isolation of potent antioxidants and anti-diabetic compounds. To the best of our knowledge, this study represents the first time that C. nutans (Acanthaceae family) was reported in literature with glucosidase inhibition activity. PMID:25587331

  3. Tree shrew lavatories: a novel nitrogen sequestration strategy in a tropical pitcher plant.

    PubMed

    Clarke, Charles M; Bauer, Ulrike; Lee, Ch'ien C; Tuen, Andrew A; Rembold, Katja; Moran, Jonathan A

    2009-10-23

    Nepenthes pitcher plants are typically carnivorous, producing pitchers with varying combinations of epicuticular wax crystals, viscoelastic fluids and slippery peristomes to trap arthropod prey, especially ants. However, ant densities are low in tropical montane habitats, thereby limiting the potential benefits of the carnivorous syndrome. Nepenthes lowii, a montane species from Borneo, produces two types of pitchers that differ greatly in form and function. Pitchers produced by immature plants conform to the 'typical' Nepenthes pattern, catching arthropod prey. However, pitchers produced by mature N. lowii plants lack the features associated with carnivory and are instead visited by tree shrews, which defaecate into them after feeding on exudates that accumulate on the pitcher lid. We tested the hypothesis that tree shrew faeces represent a significant nitrogen (N) source for N. lowii, finding that it accounts for between 57 and 100 per cent of foliar N in mature N. lowii plants. Thus, N. lowii employs a diversified N sequestration strategy, gaining access to a N source that is not available to sympatric congeners. The interaction between N. lowii and tree shrews appears to be a mutualism based on the exchange of food sources that are scarce in their montane habitat.

  4. Total phenolic compounds, flavonoids, and radical scavenging activity of 21 selected tropical plants.

    PubMed

    Mustafa, R A; Abdul Hamid, A; Mohamed, S; Bakar, F Abu

    2010-01-01

    Free radical scavenging activity of 21 tropical plant extracts was evaluated using 1,1-diphenyl-2-picrylhydrazyl assay (DPPH). Total phenolic compounds and flavonoids were determined using Folin-Ciocalteu and HPLC, respectively. Results of the study revealed that all the plants tested exhibited excellent antioxidant activity with IC(50) in the range of 21.3 to 89.6 microg/mL. The most potent activity was demonstrated by Cosmos caudatus (21.3 microg/mL) and Piper betle (23.0 microg/mL) that are not significantly different than that of -tocopherol or BHA. L. inermis extract was found to consist of the highest concentration of phenolics, catechin, epicatechin, and naringenin. High content of quercetin, myricetin, and kaempferol were identified in Vitex negundo, Centella asiatica, and Sesbania grandiflora extracts, respectively. Luteolin and apigenin, on the other hand, were found in Premna cordifolia and Kaempferia galanga extracts. Strong correlation (R = 0.8613) between total phenolic compounds and total flavonoids (R = 0.8430) and that of antioxidant activity of the extracts were observed. The study revealed that phenolic, in particular flavonoids, may be the main contributors to the antioxidant activity exhibited by the plants. Potent antioxidant from natural sources is of great interest to replace the use of synthetic antioxidants. In addition, some of the plants have great potential to be used in the development of functional ingredients/foods that are currently in demand for the health benefits associated with their use.

  5. Negative plant-soil feedback predicts tree-species relative abundance in a tropical forest.

    PubMed

    Mangan, Scott A; Schnitzer, Stefan A; Herre, Edward A; Mack, Keenan M L; Valencia, Mariana C; Sanchez, Evelyn I; Bever, James D

    2010-08-05

    The accumulation of species-specific enemies around adults is hypothesized to maintain plant diversity by limiting the recruitment of conspecific seedlings relative to heterospecific seedlings. Although previous studies in forested ecosystems have documented patterns consistent with the process of negative feedback, these studies are unable to address which classes of enemies (for example, pathogens, invertebrates, mammals) exhibit species-specific effects strong enough to generate negative feedback, and whether negative feedback at the level of the individual tree is sufficient to influence community-wide forest composition. Here we use fully reciprocal shade-house and field experiments to test whether the performance of conspecific tree seedlings (relative to heterospecific seedlings) is reduced when grown in the presence of enemies associated with adult trees. Both experiments provide strong evidence for negative plant-soil feedback mediated by soil biota. In contrast, above-ground enemies (mammals, foliar herbivores and foliar pathogens) contributed little to negative feedback observed in the field. In both experiments, we found that tree species that showed stronger negative feedback were less common as adults in the forest community, indicating that susceptibility to soil biota may determine species relative abundance in these tropical forests. Finally, our simulation models confirm that the strength of local negative feedback that we measured is sufficient to produce the observed community-wide patterns in tree-species relative abundance. Our findings indicate that plant-soil feedback is an important mechanism that can maintain species diversity and explain patterns of tree-species relative abundance in tropical forests.

  6. Climate-Dependence of Plant-Soil 15N/14N Interactions Across Tropical Rainforests

    NASA Astrophysics Data System (ADS)

    Houlton, B. Z.; Sigman, D. M.; Hedin, L. O.

    2005-12-01

    soils and plants across these tropical rainforests. We also show that these interactions are climate-dependent.

  7. 75 FR 81793 - Endangered and Threatened Wildlife and Plants; Listing Seven Brazilian Bird Species as Endangered...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-28

    ...We, the U.S. Fish and Wildlife Service (Service), determine endangered status for the following seven Brazilian bird species and subspecies (collectively referred to as ``species'' for purposes of this rule) under the Endangered Species Act of 1973, as amended (Act) (16 U.S.C. 1531 et seq.): Black-hooded antwren (Formicivora erythronotos), Brazilian merganser (Mergus octosetaceus), cherry- throated tanager (Nemosia rourei), fringe-backed fire-eye (Pyriglena atra), Kaempfer's tody-tyrant (Hemitriccus kaempferi), Margaretta's hermit hummingbird (Phaethornis malaris margarettae), and southeastern rufous-vented ground-cuckoo (Neomorphus geoffroyi dulcis).

  8. Malaria in the State of Amazonas: a typical Brazilian tropical disease influenced by waves of economic development.

    PubMed

    Sampaio, Vanderson Souza; Siqueira, André Machado; Alecrim, Maria das Graças Costa; Mourão, Maria Paula Gomes; Marchesini, Paola Barbosa; Albuquerque, Bernardino Cláudio; Nascimento, Joabi; Figueira, Élder Augusto Guimarães; Alecrim, Wilson Duarte; Monteiro, Wuelton Marcelo; Lacerda, Marcus Vinícius Guimarães

    2015-01-01

    In Brazil, more than 99% of malaria cases are reported in the Amazon, and the State of Amazonas accounts for 40% of this total. However, the accumulated experience and challenges in controlling malaria in this region in recent decades have not been reported. Throughout the first economic cycle during the rubber boom (1879 to 1912), malaria was recorded in the entire state, with the highest incidence in the villages near the Madeira River in the Southern part of the State of Amazonas. In the 1970s, during the second economic development cycle, the economy turned to the industrial sector and demanded a large labor force, resulting in a large migratory influx to the capital Manaus. Over time, a gradual increase in malaria transmission was observed in peri-urban areas. In the 1990s, the stimulation of agroforestry, particularly fish farming, led to the formation of permanent Anopheline breeding sites and increased malaria in settlements. The estimation of environmental impacts and the planning of measures to mitigate them, as seen in the construction of the Coari-Manaus gas pipeline, proved effective. Considering the changes occurred since the Amsterdam Conference in 1992, disease control has been based on early diagnosis and treatment, but the development of parasites that are resistant to major antimalarial drugs in Brazilian Amazon has posed a new challenge. Despite the decreased lethality and the gradual decrease in the number of malaria cases, disease elimination, which should be associated with government programs for economic development in the region, continues to be a challenge.

  9. Diversity and microdistribution of black fly (Diptera: Simuliidae) assemblages in the tropical savanna streams of the Brazilian cerrado.

    PubMed

    Figueiró, Ronaldo; Gil-Azevedo, Leonardo Henrique; Maia-Herzog, Marilza; Monteiro, Ricardo Ferreira

    2012-05-01

    We describe the abiotic factors affecting the distribution of black flies at a microhabitat scale, rather than at the regional scale usually present in the literature on the Neotropics. Black fly larvae were sampled from the Tocantins River and three tributaries, located in the Brazilian savanna (state of Tocantins, Brazil) during six bi-monthly sampling periods from October 2004-August 2005. At each sampling site, 15 random quadrats (30 x 30 cm) were sampled each period and for each quadrat were determined mean water velocity, predominant substrate type (rocks, riffle litter or riparian vegetation) and depth detrended correspondence analysis (DCA) was used to determine associations with current velocity, whereas correspondence analysis (CA) was used to estimate site specific current velocity associations. Canonical correspondence analysis (CCA) was used to identify general microhabitat associations. The CCA showed that most species had a trend towards riffle litter, except for Simulium nigrimanum associated with rocky substrate and Simulium cuasiexiguum associated with riparian vegetation. The DCA showed a well defined pattern of water velocity associations. The CA revealed that the species showed different speed associations from one site to another, suggesting different competitive pressures resulting in the occurrence of different realized niches.

  10. Occurrence of triclosan in the tropical rivers receiving the effluents from the hospital wastewater treatment plant.

    PubMed

    Yang, Gordon C C; Tsai, Hsin-Jen; Chang, Fu-Kuei

    2015-03-01

    The objective of this study was to determine the occurrence of triclosan in the tropical rivers where received the effluents from a hospital wastewater treatment plant (HWWTP) in southern Taiwan. Three and ten sampling sites were selected at the Jiaosu River (S0-S2) and Dian-Bao River (S3-S12), respectively. The samples of the HWWTP influent, effluent and receiving river water and sediment were collected and analyzed using ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/ MS). Results showed that the triclosan level in surface water of the Jiaosu River and Dian-Bao River ranged from 3 to 68 ng/L and ranged from <2.7 to 51 ng/L, respectively. The hospital did contribute a loading of triclosan to the neighboring river. The mean value of triclosan concentration in the downstream surface water of the Jiaosu River (S1 20.2 ng/L) was approximately three times higher than that of the background level (S0 6.0 ng/L) (p = 0.011). The concentrations of triclosan in two surface water samples were over the predicted no effect concentration (PNEC) of 50 ng/L for algae. In addition, significant seasonal differences of triclosan in surface water of Jiaosu River (p = 0.020) and the HWWTP effluents (p = 0.302) were also observed. The concentrations of triclosan in sediments of these two rivers seemed stable. On average, triclosan was detected in 86 % of the sediment samples with a range from <1.1 to 13 ng/g. Triclosan in surface water and sediments of the tropical rivers might be rapidly photolyzed due to plenty of sunshine. It is worth to further investigate the occurrence and fate of triclosan photoproduct in the aquatic environment of the tropics.

  11. Soil and biomass carbon pools in model communities of tropical plants under elevated CO2.

    PubMed

    Arnone, J A; Körner, Ch

    1995-09-01

    The experimental data presented here relate to the question of whether terrestrial ecosystems will sequester more C in their soils, litter and biomass as atmospheric CO2 concentrations rise. Similar to our previous study with relatively fertile growth conditions (Körner and Arnone 1992), we constructed four rather nutrient-limited model communities of moist tropical plant species in greenhouses (approximately 7 m(2) each). Plant communities were composed of seven species (77 individuals per community) representing major taxonomic groups and various life forms found in the moist tropics. Two ecosystems were exposed to 340 μl CO2 l(-1) and two to 610 μl l(-1) for 530 days of humid tropical growth conditions. In order to permit precise determination of C deposition in the soil, plant communities were initially established in C-free unwashed quartz sand. Soils were then amended with known amounts of organic matter (containing C and nutrients). Mineral nutrients were also supplied over the course of the experiment as timed-release full-balance fertilizer pellets. Soils represented by far the largest repositories for fixed C in all ecosystems. Almost 5 times more C (ca. 80% of net C fixation) was sequestered in the soil than in the biomass, but this did not differ between CO2 treatments. In addition, at the whole-ecosystem level we found a remarkably small and statistically non-significant increase in C sequestration (+4%; the sum of C accretion in the soil, biomass, litter and necromass). Total community biomass more than quadrupled during the experiment, but at harvest was, on average, only 8% greater (i.e. 6% per year; n.s.) under elevated CO2, mainly due to increased root biomass (+15%, P=0.12). Time courses of leaf area index of all ecosystems suggested that canopy expansion was approaching steady state by the time systems were harvested. Net primary productivity (NPP) of all ecosystems-i.e. annual accumulation of biomass, necromass, and leaf litter (but not

  12. Fire alters ecosystem carbon and nutrients but not plant nutrient stoichiometry or composition in tropical savanna.

    PubMed

    Pellegrini, Adam F A; Hedin, Lars O; Staver, A Carla; Govender, Navashni

    2015-05-01

    Fire and nutrients interact to influence the global distribution and dynamics of the savanna biome, but the results of these interactions are both complex and poorly known. A critical but unresolved question is whether short-term losses of carbon and nutrients caused by fire can trigger long-term and potentially compensatory responses in the nutrient stoichiometry of plants, or in the abundance of dinitrogen-fixing trees. There is disagreement in the literature about the potential role of fire on savanna nutrients, and, in turn, on plant stoichiometry and composition. A major limitation has been the lack of fire manipulations over time scales sufficiently long for these interactions to emerge. We use a 58-year, replicated, large-scale, fire manipulation experiment in Kruger National Park (South Africa) in savanna to quantify the effect of fire on (1) distributions of carbon, nitrogen, and phosphorus at the ecosystem scale; (2) carbon: nitrogen: phosphorus stoichiometry of above- and belowground tissues of plant species; and (3) abundance of plant functional groups including nitrogen fixers. Our results show dramatic effects of fire on the relative distribution of nutrients in soils, but that individual plant stoichiometry and plant community composition remained unexpectedly resilient. Moreover, measures of nutrients and carbon stable isotopes allowed us to discount the role of tree cover change in favor of the turnover of herbaceous biomass as the primary mechanism that mediates a transition from low to high 'soil carbon and nutrients in the absence of fire. We conclude that, in contrast to extra-tropical grasslands or closed-canopy forests, vegetation in the savanna biome may be uniquely adapted to nutrient losses caused by recurring fire.

  13. Plant diversity in live fences and pastures, two examples from the Mexican humid tropics.

    PubMed

    Ruiz-Guerra, Betsabé; Rosas, Noé Velázquez; López-Acosta, Juan Carlos

    2014-09-01

    This study analyzes the potential uses of live fences and pastures as reservoirs of plant diversity for two regions with different management histories, Los Tuxtlas (LT) and Uxpanapa (UX), Veracruz, México. We studied two habitats, live fences and pastures, analyzed their species richness, diversity, structure and plant composition and classified species according to plant regeneration modes (light-demanding and shade tolerant), seed dispersal syndrome and their local uses. We recorded 62 species of trees at LT and 48 at UX. Live fences were more diverse than pastures in both regions. The LT site showed to analyze the relationship a higher diversity of plants in regeneration stages than the one at UX. However, UX had higher diversity of adult plants in the pastures than LT. Composition and structure of live fences were different between regions, as well as within live fences and pastures, 53 % of species were light-demanding and 40 % were shade tolerant; 70 % of the species were dispersed by birds. Differences between sites are associated with the modifications in live fences structure, which changed according to managerial practices and the use of local species; this may influence plant regeneration modes as well as the visits of avian dispersal agents. In LT, all species found in live fences were useful to humans, whereas in UX, less than half were used by the local population. Our results underline the importance of live fences and isolated trees in pasture habitats as potential sites to host native and useful species from tropical rain forests in livestock landscapes.

  14. Plant Diversity in Live Fences and Pastures, Two Examples from the Mexican Humid Tropics

    NASA Astrophysics Data System (ADS)

    Ruiz-Guerra, Betsabé; Rosas, Noé Velázquez; López-Acosta, Juan Carlos

    2014-09-01

    This study analyzes the potential uses of live fences and pastures as reservoirs of plant diversity for two regions with different management histories, Los Tuxtlas (LT) and Uxpanapa (UX), Veracruz, México. We studied two habitats, live fences and pastures, analyzed their species richness, diversity, structure and plant composition and classified species according to plant regeneration modes (light-demanding and shade tolerant), seed dispersal syndrome and their local uses. We recorded 62 species of trees at LT and 48 at UX. Live fences were more diverse than pastures in both regions. The LT site showed to analyze the relationship a higher diversity of plants in regeneration stages than the one at UX. However, UX had higher diversity of adult plants in the pastures than LT. Composition and structure of live fences were different between regions, as well as within live fences and pastures, 53 % of species were light-demanding and 40 % were shade tolerant; 70 % of the species were dispersed by birds. Differences between sites are associated with the modifications in live fences structure, which changed according to managerial practices and the use of local species; this may influence plant regeneration modes as well as the visits of avian dispersal agents. In LT, all species found in live fences were useful to humans, whereas in UX, less than half were used by the local population. Our results underline the importance of live fences and isolated trees in pasture habitats as potential sites to host native and useful species from tropical rain forests in livestock landscapes.

  15. Carbon and Nitrogen Metabolism in Mycorrhizal Networks and Mycoheterotrophic Plants of Tropical Forests: A Stable Isotope Analysis1[W

    PubMed Central

    Courty, Pierre-Emmanuel; Walder, Florian; Boller, Thomas; Ineichen, Kurt; Wiemken, Andres; Rousteau, Alain; Selosse, Marc-André

    2011-01-01

    Most achlorophyllous mycoheterotrophic (MH) plants obtain carbon (C) from mycorrhizal networks and indirectly exploit nearby autotrophic plants. We compared overlooked tropical rainforest MH plants associating with arbuscular mycorrhizal fungi (AMF) to well-reported temperate MH plants associating with ectomycorrhizal basidiomycetes. We investigated 13C and 15N abundances of MH plants, green plants, and AMF spores in Caribbean rainforests. Whereas temperate MH plants and fungi have higher δ13C than canopy trees, these organisms displayed similar δ13C values in rainforests, suggesting differences in C exchanges. Although temperate green and MH plants differ in δ15N, they display similar 15N abundances, and likely nitrogen (N) sources, in rainforests. Contrasting with the high N concentrations shared by temperate MH plants and their fungi, rainforest MH plants had lower N concentrations than AMF, suggesting differences in C/N of exchanged nutrients. We provide a framework for isotopic studies on AMF networks and suggest that MH plants in tropical and temperate regions evolved different physiologies to adapt in diverging environments. PMID:21527422

  16. Land-use intensification effects on functional properties in tropical plant communities.

    PubMed

    Carreño-Rocabado, Geovana; Peña-Claros, Marielos; Bongers, Frans; Díaz, Sandra; Quetier, Fabien; Chuviña, José; Poorter, Lourens

    2016-01-01

    There is consensus that plant diversity and ecosystem processes are negatively affected by land-use intensification (LUI), but, at the same time, there is empirical evidence that a large heterogeneity can be found in the responses. This heterogeneity is especially poorly understood in tropical ecosystems. We evaluated changes in community functional properties across five common land-use types in the wet tropics with different land-use intensity: mature forest, logged forest, secondary forest, agricultural land, and pastureland, located in the lowlands of Bolivia. For the dominant plant species, we measured 12 functional response traits related to their life history, acquisition and conservation of resources, plant domestication, and breeding. We used three single-trait metrics to describe community functional properties: community abundance-weighted mean (CWM) traits values, coefficient of variation, and kurtosis of distribution. The CWM of all 12 traits clearly responded to LUI. Overall, we found that an increase in LUI resulted in communities dominated by plants with acquisitive leaf trait values. However, contrary to our expectations, secondary forests had more conservative trait values (i.e., lower specific leaf area) than mature and logged forest, probably because they were dominated by palm species. Functional variation peaked at intermediate land-use intensity (high coefficient of variation and low kurtosis), which included secondary forest but, unexpectedly, also agricultural land, which is an intensely managed system. The high functional variation of these systems is due to a combination of how response traits (and species) are filtered out by biophysical filters and how management practices introduced a range of exotic species and their trait values into the local species pool. Our results showed that, at local scales and depending on prevailing environmental and management practices, LUI does not necessarily result in communities with more acquisitive

  17. Tropical Glaciers

    NASA Astrophysics Data System (ADS)

    Fountain, Andrew

    The term "tropical glacier" calls to mind balmy nights and palm trees on one hand and cold, blue ice on the other. Certainly author Gabriel Garcia Marqez exploited this contrast in One Hundred Years of Solitude. We know that tropical fish live in warm, Sun-kissed waters and tropical plants provide lush, dense foliage populated by colorful tropical birds. So how do tropical glaciers fit into this scene? Like glaciers everywhere, tropical glaciers form where mass accumulation—usually winter snow—exceeds mass loss, which is generally summer melt. Thus, tropical glaciers exist at high elevations where precipitation can occur as snowfall exceeds melt and sublimation losses, such as the Rwenzori Mountains in east Africa and the Maoke Range of Irian Jaya.

  18. Seasonal and altitudinal variations of legacy and current-use pesticides in the Brazilian tropical and subtropical mountains

    NASA Astrophysics Data System (ADS)

    Meire, Rodrigo Ornellas; Lee, Sum Chi; Yao, Yuan; Targino, Admir C.; Torres, João Paulo M.; Harner, Tom

    2012-11-01

    Polyurethane foam (PUF) disk passive air samplers were deployed over summer (December-March) and winter (June-August) periods in 2007-2008 along altitudinal gradients in Brazilian southeastern and southern mountain regions. As part of the Global Atmospheric Passive Sampling (GAPS) Network, this work was initiated to address the lack of knowledge on the fate of legacy and current-use pesticides in South America, particularly in mountainous regions. Of the pesticides measured, concentrations in air were dominated by the current-use pesticides (CUPs) endosulfan (and its metabolite, endosulfan sulphate (EndoSO4)) and chlorpyrifos. Other pesticides that were regularly detected included α- and γ-hexachlorocyclohexanes (HCHs), dieldrin, heptachlor epoxide and p,p‧-DDE. Highest air concentrations were observed for total endosulfan (Endo I + Endo II + EndoSO4) (100s-1000s pg m-3), followed by chlorpyrifos, ΣDDT (mainly o,p‧-DDT + p,p‧-DDE), ΣHCH (α-HCH + γ-HCH), dieldrin and heptachlor epoxide. Seasonal variations did not show any clear trends for pesticides, except for endosulfan which reached concentration values one order of magnitude higher during summer at all sites compared to levels during winter. Along the altitudinal gradients, some pesticides showed higher atmospheric concentrations at sites above 1500 m which may indicate efficient high-altitude transport from regional sources. Northerly and southerly air back trajectories appeared to be the main continental influences at the two highest-altitude sites in both mountain regions. These trajectories travelled over extended crop areas from central Brazil to Argentina. A strong, positive correlation between air concentration and altitude was observed (Spearman's correlation, p < 0.05) for endosulfan, consistent with previous studies of endosulfan in mountainous regions in South America.

  19. Plant delta 15N correlates with the transpiration efficiency of nitrogen acquisition in tropical trees.

    PubMed

    Cernusak, Lucas A; Winter, Klaus; Turner, Benjamin L

    2009-11-01

    Based upon considerations of a theoretical model of (15)N/(14)N fractionation during steady-state nitrate uptake from soil, we hypothesized that, for plants grown in a common soil environment, whole-plant delta(15)N (deltaP) should vary as a function of the transpiration efficiency of nitrogen acquisition (F(N)/v) and the difference between deltaP and root delta(15)N (deltaP - deltaR). We tested these hypotheses with measurements of several tropical tree and liana species. Consistent with theoretical expectations, both F(N)/v and deltaP - deltaR were significant sources of variation in deltaP, and the relationship between deltaP and F(N)/v differed between non-N(2)-fixing and N(2)-fixing species. We interpret the correlation between deltaP and F(N)/v as resulting from variation in mineral nitrogen efflux-to-influx ratios across plasma membranes of root cells. These results provide a simple explanation of variation in delta(15)N of terrestrial plants and have implications for understanding nitrogen cycling in ecosystems.

  20. Plant phylogeny as a window on the evolution of hyperdiversity in the tropical rainforest biome.

    PubMed

    Eiserhardt, Wolf L; Couvreur, Thomas L P; Baker, William J

    2017-03-09

    I. II. III. IV. V. VI. VII. VIII. IX. References SUMMARY: Tropical rainforest (TRF) is the most species-rich terrestrial biome on Earth, harbouring just under half of the world's plant species in c. 7% of the land surface. Phylogenetic trees provide important insights into mechanisms underpinning TRF hyperdiversity that are complementary to those obtained from the fossil record. Phylogenetic studies of TRF plant diversity have mainly focused on whether this biome is an evolutionary 'cradle' or 'museum', emphasizing speciation and extinction rates. However, other explanations, such as biome age, immigration and ecological limits, must also be considered. We present a conceptual framework for addressing the drivers of TRF diversity, and review plant studies that have tested them with phylogenetic data. Although surprisingly few in number, these studies point to old age of TRF, low extinction and high speciation rates as credible drivers of TRF hyperdiversity. There is less evidence for immigration and ecological limits, but these cannot be dismissed owing to the limited number of studies. Rapid methodological developments in DNA sequencing, macroevolutionary analysis and the integration of phylogenetics with other disciplines may improve our grasp of TRF hyperdiversity in the future. However, such advances are critically dependent on fundamental systematic research, yielding numerous, additional, well-sampled phylogenies of TRF lineages.

  1. β-Diversity of Functional Groups of Woody Plants in a Tropical Dry Forest in Yucatan

    PubMed Central

    López-Martínez, Jorge Omar; Sanaphre-Villanueva, Lucía; Dupuy, Juan Manuel; Hernández-Stefanoni, José Luis; Meave, Jorge Arturo; Gallardo-Cruz, José Alberto

    2013-01-01

    Two main theories have attempted to explain variation in plant species composition (β-diversity). Niche theory proposes that most of the variation is related to environment (environmental filtering), whereas neutral theory posits that dispersal limitation is the main driver of β-diversity. In this study, we first explored how α- and β-diversity of plant functional groups defined by growth form (trees, shrubs and lianas, which represent different strategies of resource partitioning), and dispersal syndrome (autochory, anemochory and zoochory, which represent differences in dispersal limitation) vary with successional age and topographic position in a tropical dry forest. Second, we examined the effects of environmental, spatial, and spatially-structured environmental factors on β-diversity of functional groups; we used the spatial structure of sampling sites as a proxy for dispersal limitation, and elevation, soil properties and forest stand age as indicators of environmental filtering. We recorded 200 species and 22,245 individuals in 276 plots; 120 species were trees, 41 shrubs and 39 lianas. We found that β-diversity was highest for shrubs, intermediate for lianas and lowest for trees, and was slightly higher for zoochorous than for autochorous and anemochorous species. All three dispersal syndromes, trees and shrubs varied in composition among vegetation classes (successional age and topographic position), whilst lianas did not. β-diversity was influenced mostly by proxies of environmental filtering, except for shrubs, for which the influence of dispersal limitation was more important. Stand age and topography significantly influenced α-diversity across functional groups, but showed a low influence on β-diversity –possibly due to the counterbalancing effect of resprouting on plant distribution and composition. Our results show that considering different plant functional groups reveals important differences in both α- and β-diversity patterns and

  2. β-Diversity of functional groups of woody plants in a tropical dry forest in Yucatan.

    PubMed

    López-Martínez, Jorge Omar; Sanaphre-Villanueva, Lucía; Dupuy, Juan Manuel; Hernández-Stefanoni, José Luis; Meave, Jorge Arturo; Gallardo-Cruz, José Alberto

    2013-01-01

    Two main theories have attempted to explain variation in plant species composition (β-diversity). Niche theory proposes that most of the variation is related to environment (environmental filtering), whereas neutral theory posits that dispersal limitation is the main driver of β-diversity. In this study, we first explored how α- and β-diversity of plant functional groups defined by growth form (trees, shrubs and lianas, which represent different strategies of resource partitioning), and dispersal syndrome (autochory, anemochory and zoochory, which represent differences in dispersal limitation) vary with successional age and topographic position in a tropical dry forest. Second, we examined the effects of environmental, spatial, and spatially-structured environmental factors on β-diversity of functional groups; we used the spatial structure of sampling sites as a proxy for dispersal limitation, and elevation, soil properties and forest stand age as indicators of environmental filtering. We recorded 200 species and 22,245 individuals in 276 plots; 120 species were trees, 41 shrubs and 39 lianas. We found that β-diversity was highest for shrubs, intermediate for lianas and lowest for trees, and was slightly higher for zoochorous than for autochorous and anemochorous species. All three dispersal syndromes, trees and shrubs varied in composition among vegetation classes (successional age and topographic position), whilst lianas did not. β-diversity was influenced mostly by proxies of environmental filtering, except for shrubs, for which the influence of dispersal limitation was more important. Stand age and topography significantly influenced α-diversity across functional groups, but showed a low influence on β-diversity -possibly due to the counterbalancing effect of resprouting on plant distribution and composition. Our results show that considering different plant functional groups reveals important differences in both α- and β-diversity patterns and

  3. Nectar-living yeasts of a tropical host plant community: diversity and effects on community-wide floral nectar traits

    PubMed Central

    2017-01-01

    We characterize the diversity of nectar-living yeasts of a tropical host plant community at different hierarchical sampling levels, measure the associations between yeasts and nectariferous plants, and measure the effect of yeasts on nectar traits. Using a series of hierarchically nested sampling units, we extracted nectar from an assemblage of host plants that were representative of the diversity of life forms, flower shapes, and pollinator types in the tropical area of Yucatan, Mexico. Yeasts were isolated from single nectar samples; their DNA was identified, the yeast cell density was estimated, and the sugar composition and concentration of nectar were quantified using HPLC. In contrast to previous studies from temperate regions, the diversity of nectar-living yeasts in the plant community was characterized by a relatively high number of equally common species with low dominance. Analyses predict highly diverse nectar yeast communities in a relatively narrow range of tropical vegetation, suggesting that the diversity of yeasts will increase as the number of sampling units increases at the level of the species, genera, and botanical families of the hosts. Significant associations between specific yeast species and host plants were also detected; the interaction between yeasts and host plants impacted the effect of yeast cell density on nectar sugars. This study provides an overall picture of the diversity of nectar-living yeasts in tropical host plants and suggests that the key factor that affects the community-wide patterns of nectar traits is not nectar chemistry, but rather the type of yeasts interacting with host plants. PMID:28717591

  4. Nectar-living yeasts of a tropical host plant community: diversity and effects on community-wide floral nectar traits.

    PubMed

    Canto, Azucena; Herrera, Carlos M; Rodriguez, Rosalina

    2017-01-01

    We characterize the diversity of nectar-living yeasts of a tropical host plant community at different hierarchical sampling levels, measure the associations between yeasts and nectariferous plants, and measure the effect of yeasts on nectar traits. Using a series of hierarchically nested sampling units, we extracted nectar from an assemblage of host plants that were representative of the diversity of life forms, flower shapes, and pollinator types in the tropical area of Yucatan, Mexico. Yeasts were isolated from single nectar samples; their DNA was identified, the yeast cell density was estimated, and the sugar composition and concentration of nectar were quantified using HPLC. In contrast to previous studies from temperate regions, the diversity of nectar-living yeasts in the plant community was characterized by a relatively high number of equally common species with low dominance. Analyses predict highly diverse nectar yeast communities in a relatively narrow range of tropical vegetation, suggesting that the diversity of yeasts will increase as the number of sampling units increases at the level of the species, genera, and botanical families of the hosts. Significant associations between specific yeast species and host plants were also detected; the interaction between yeasts and host plants impacted the effect of yeast cell density on nectar sugars. This study provides an overall picture of the diversity of nectar-living yeasts in tropical host plants and suggests that the key factor that affects the community-wide patterns of nectar traits is not nectar chemistry, but rather the type of yeasts interacting with host plants.

  5. Transgenic plants for tropical regions: Some considerations about their development and their transfer to the small farmer

    PubMed Central

    Herrera-Estrella, Luis

    1999-01-01

    Biotechnological applications, especially transgenic plants, probably hold the most promise in augmenting agricultural production in the first decades of the next millennium. However, the application of these technologies to the agriculture of tropical regions where the largest areas of low productivity are located, and where they are most needed, remains a major challenge. In this paper, some of the important issues that need to be considered to ensure that plant biotechnology is effectively transferred to the developing world are discussed. PMID:10339527

  6. Plant zonation in a tropical irregular estuary: can large occurrence zones be explained by a tradeoff model?

    PubMed

    Ribeiro, J P N; Matsumoto, R S; Takao, L K; Lima, M I S

    2015-08-01

    Estuaries present an environmental gradient that ranges from almost fresh water conditions to almost marine conditions. Salinity and flooding are the main abiotic drivers for plants. Therefore, plant zonation in estuaries is closely related to the tidal cycles. It is expected that the competitive abilities of plants would be inversely related to the tolerance toward environmental stress (tradeoff). Thus, in estuaries, plant zonation tends to be controlled by the environment near the sandbar and by competition away from it. This zonation pattern has been proposed for regular non-tropical estuaries. For tropical estuaries, the relative importance of rain is higher, and it is not clear to what extent this model can be extrapolated. We measured the tidal influence along the environmental gradient of a tropical irregular estuary and quantified the relative importance of the environment and the co-occurrence degree. Contrary to the narrow occurrence zone that would be expected for regular estuaries, plants presented large occurrence zones. However, the relative importance of the environment and competition followed the same patterns proposed for regular estuaries. The environmental conditions allow plants to occur in larger zones, but these zones arise from smaller and infrequent patches distributed across a larger area, and most species populations are concentrated in relatively narrow zones. Thus, we concluded that the zonation pattern in the Massaguaçu River estuary agrees with the tradeoff model.

  7. Clinical and laboratory features of HTLV-I asymptomatic carriers and patients with HTLV-I-associated myelopathy/tropical spastic paraparesis from the Brazilian Amazon.

    PubMed

    Takatani, Massanobu; Crispim, Myuki Esashika; Fraiji, Nelson; Stefani, Mariane Martins Araujo; Kiesslich, Dagmar

    2017-04-03

    Clinical and laboratory parameters including blood and cerebrospinal fluid (CSF) neopterin were investigated in human-T-lymphotropic-virus-type-I associated-myelopathy/tropical-spastic-paraparesis-HAM/TSP and in HTLV-I carriers. HAM/TSP (n = 11, 2 males/9 females, median age = 48 years), recently diagnosed HTLV-I carriers (n = 21, 15 females/6 males, median age = 44 years), healthy individuals (n = 20, 10 males/10 females, median age = 34.6 years) from the Brazilian Amazon (Manaus, Amazonas State) were investigated. Neopterin was measured (IBL ELISA Neopterin, Germany) in serum samples of all the participants, in CSF of 9 HAM/TSP patients as well as in 6 carriers. In HAM/TSP patients, CSF cell counts, protein and glucose were measured, the Osame's motor-disability-score/OMDS was determined, and brain/spinal cord magnetic-resonance-imaging (MRI) was performed. HAM/TSP patients had normal CSF glucose, leukocyte counts; and normal protein levels predominated. Brain-MRI showed white-matter lesions in 7 out of 11 HAM/TSP patients. OMDS varied from 2-8: 9 were able to walk, 2 were wheel-chair-users. The median serum neopterin concentration in HAM/TSP patients was 6.6 nmol/ L; min. 2.8- max. 12.5 nmol/ L); was lower in carriers (4.3 nmol/L; min. 2.7- max. 7.2 nmol/ L) as well as in healthy participants (4.7 nmol/ L; min. 2.7- max. 8.0 nmol/ L) (p < 0.05). CSF neopterin concentrations in HAM/TSP patients were higher than in serum samples, and higher compared to carriers (p < 0.05). Carriers had similar serum-CSF neopterin concentrations compared to healthy participants. Variable clinical and laboratory profiles were seen in HAM/TSP patients, however our results support the neopterin measurement as a potential biomarker of disease activity.

  8. The Brazilian developments on the Regional Atmospheric Modeling System (BRAMS 5.2): an integrated environmental model tuned for tropical areas

    NASA Astrophysics Data System (ADS)

    Freitas, Saulo R.; Panetta, Jairo; Longo, Karla M.; Rodrigues, Luiz F.; Moreira, Demerval S.; Rosário, Nilton E.; Silva Dias, Pedro L.; Silva Dias, Maria A. F.; Souza, Enio P.; Freitas, Edmilson D.; Longo, Marcos; Frassoni, Ariane; Fazenda, Alvaro L.; Silva, Cláudio M. Santos e.; Pavani, Cláudio A. B.; Eiras, Denis; França, Daniela A.; Massaru, Daniel; Silva, Fernanda B.; Santos, Fernando C.; Pereira, Gabriel; Camponogara, Gláuber; Ferrada, Gonzalo A.; Campos Velho, Haroldo F.; Menezes, Isilda; Freire, Julliana L.; Alonso, Marcelo F.; Gácita, Madeleine S.; Zarzur, Maurício; Fonseca, Rafael M.; Lima, Rafael S.; Siqueira, Ricardo A.; Braz, Rodrigo; Tomita, Simone; Oliveira, Valter; Martins, Leila D.

    2017-01-01

    We present a new version of the Brazilian developments on the Regional Atmospheric Modeling System (BRAMS), in which different previous versions for weather, chemistry, and carbon cycle were unified in a single integrated modeling system software. This new version also has a new set of state-of-the-art physical parameterizations and greater computational parallel and memory usage efficiency. The description of the main model features includes several examples illustrating the quality of the transport scheme for scalars, radiative fluxes on surface, and model simulation of rainfall systems over South America at different spatial resolutions using a scale aware convective parameterization. Additionally, the simulation of the diurnal cycle of the convection and carbon dioxide concentration over the Amazon Basin, as well as carbon dioxide fluxes from biogenic processes over a large portion of South America, are shown. Atmospheric chemistry examples show the model performance in simulating near-surface carbon monoxide and ozone in the Amazon Basin and the megacity of Rio de Janeiro. For tracer transport and dispersion, the model capabilities to simulate the volcanic ash 3-D redistribution associated with the eruption of a Chilean volcano are demonstrated. The gain of computational efficiency is described in some detail. BRAMS has been applied for research and operational forecasting mainly in South America. Model results from the operational weather forecast of BRAMS on 5 km grid spacing in the Center for Weather Forecasting and Climate Studies, INPE/Brazil, since 2013 are used to quantify the model skill of near-surface variables and rainfall. The scores show the reliability of BRAMS for the tropical and subtropical areas of South America. Requirements for keeping this modeling system competitive regarding both its functionalities and skills are discussed. Finally, we highlight the relevant contribution of this work to building a South American community of model

  9. Experimental defoliation affects male but not female reproductive performance of the tropical monoecious plant Croton suberosus (Euphorbiaceae)

    PubMed Central

    Narbona, Eduardo; Dirzo, Rodolfo

    2010-01-01

    Background and Aims Monoecious plants have the capacity to allocate resources separately to male and female functions more easily than hermaphrodites. This can be advantageous against environmental stresses such as leaf herbivory. However, studies showing effects of herbivory on male and female functions and on the interaction with the plant's pollinators are limited, particularly in tropical plants. Here, the effects of experimental defoliation were examined in the monoecious shrub Croton suberosus (Euphorbiaceae), a wasp-pollinated species from a Mexican tropical dry forest. Methods Three defoliation treatments were applied: 0 % (control), 25 % (low) or 75 % (high) of plant leaf area removed. Vegetative (production of new leaves) and reproductive (pistillate and staminate flower production, pollen viability, nectar production, fruit set, and seed set) performance variables, and the abundance and activity of floral visitors were examined. Key Results Defoliated plants overcompensated for tissue loss by producing more new leaves than control plants. Production of staminate flowers gradually decreased with increasing defoliation and the floral sex ratio (staminate : pistillate flowers) was drastically reduced in high-defoliation plants. In contrast, female reproductive performance (pistillate flower production, fruit set and seed set) and pollinator visitation and abundance were not impacted by defoliation. Conclusions The asymmetrical effects of defoliation on male and female traits of C. suberosus may be due to the temporal and spatial flexibility in the allocation of resources deployed by monoecious plants. We posit that this helps to maintain the plant's pollination success in the face of leaf herbivory stress. PMID:20519239

  10. Brazilian medicinal plants to treat upper respiratory tract and bronchial illness: systematic review and meta-analyses—study protocol

    PubMed Central

    Lopes, Luciane C; Silva, Maria Carolina O; Motta, Cristiane Bergamashi; Macho Quirós, Antonio; Biavatti, Maique Weber; de Oliveira, Jardel Corrêa; Guyatt, Gordon

    2014-01-01

    Introduction Respiratory illness, often associated with cough and sputum, is frequent. In Brazil, herbal medicines are often recommended as a first-line treatment for respiratory illness. There exists uncertainty regarding the effectiveness of these treatments. No systematic review has evaluated Brazilian medicinal plants (BMP) to treat upper respiratory tract and bronchial illness (URTI). Methods and analysis We will conduct a systematic review and, if appropriate, a series of meta-analyses evaluating the safety and effectiveness of BMP for URTI. Eligible randomised controlled trials and observational studies will enrol adult or paediatric patients presenting with URTI treated by BMP approved by the Brazilian Health Surveillance Agency compared with placebo, no treatment or an alternative therapy. Our search will include the Cochrane Central Register of Controlled Trials (CENTRAL), which contains the Cochrane Acute Respiratory Illness Group's Specialized Register; MEDLINE; EMBASE; CINAHL (Cumulative Index to Nursing and Allied Health Literature); Web of Science; AMED; LILACS; CAB abstracts; clinical trial.gov; the WHO Trial Register and the Brazilian thesis database (CAPES) without any language restrictions. Outcomes of interest are time to resolution of clinical symptoms and/or signs (cough, sputum production or activity limitations), severity of symptoms prior to resolution and major/minor adverse events. Teams of reviewers will, independently and in duplicate, screen titles and abstracts and the complete full text to determine eligibility. For eligible studies, reviewers will perform data abstraction and assess risk of bias of eligible trials. When appropriate, we will conduct meta-analyses. We will also assess the quality of body of evidence (confidence in estimates of effect) for each of the outcomes using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Ethics and dissemination The systematic review will be published in

  11. Nutrient resorption patterns of plant functional groups in a tropical savanna: variation and functional significance.

    PubMed

    Ratnam, Jayashree; Sankaran, Mahesh; Hanan, Niall P; Grant, Rina C; Zambatis, Nick

    2008-08-01

    Green and senesced leaf nitrogen (N) and phosphorus (P) concentrations of different plant functional groups in savanna communities of Kruger National Park, South Africa were analyzed to determine if nutrient resorption was regulated by plant nutritional status and foliar N:P ratios. The N and P concentrations in green leaves and the N concentrations in senesced leaves differed significantly between the dominant plant functional groups in these savannas: fine-leaved trees, broad-leaved trees and grasses. However, all three functional groups reduced P to comparable and very low levels in senesced leaves, suggesting that P was tightly conserved in this tropical semi-arid savanna ecosystem. Across all functional groups, there was evidence for nutritional control of resorption in this system, with both N and P resorption efficiencies decreasing as green leaf nutrient concentrations increased. However, specific patterns of resorption and the functional relationships between nutrient concentrations in green and senesced leaves varied by nutrient and plant functional group. Functional relationships between N concentrations in green and senesced leaves were indistinguishable between the dominant groups, suggesting that variation in N resorption efficiency was largely the result of inter-life form differences in green leaf N concentrations. In contrast, observed differences in P resorption efficiencies between life forms appear to be the result of both differences in green leaf P concentrations as well as inherent differences between life forms in the fraction of green leaf P resorbed from senescing leaves. Our results indicate that foliar N:P ratios are poor predictors of resorption efficiency in this ecosystem, in contrast to N and P resorption proficiencies, which are more responsive to foliar N:P ratios.

  12. Stable carbon, oxygen, and nitrogen, isotope analysis of plants from a South Asian tropical forest: Implications for primatology.

    PubMed

    Roberts, Patrick; Blumenthal, Scott A; Dittus, Wolfgang; Wedage, Oshan; Lee-Thorp, Julia A

    2017-03-27

    Stable isotope analysis of primate tissues in tropical forest contexts is an increasingly popular means of obtaining information about niche distinctions among sympatric species, including preferences in feeding height, forest canopy density, plant parts, and trophism. However, issues of equifinality mean that feeding height, canopy density, as well as the plant parts and plant species consumed, may produce similar or confounding effects. With a few exceptions, researchers have so far relied largely on general principles and/or limited plant data from the study area as references for deducing the predominant drivers of primate isotope variation. Here, we explore variation in the stable carbon (δ(13) C), nitrogen (δ(15) N), and oxygen (δ(18) O) isotope ratios of 288 plant samples identified as important to the three primate species from the Polonnaruwa Nature Sanctuary, Sri Lanka, relative to plant part, season, and canopy height. Our results show that plant part and height have the greatest effect on the δ(13) C and δ(18) O measurements of plants of immediate relevance to the primates, Macaca sinica, Semnopithecus priam thersites, and Trachypithecus vetulus, living in this monsoonal tropical forest. We find no influence of plant part, height or season on the δ(15) N of measured plants. While the plant part effect is particularly pronounced in δ(13) C between fruits and leaves, differential feeding height, and plant taxonomy influence plant δ(13) C and δ(18) O differences in addition to plant organ. Given that species composition in different regions and forest types will differ, the results urge caution in extrapolating general isotopic trends without substantial local baselines studies.

  13. Tropical trees: Are they good alternatives for biomonitoring the atmospheric level of potential toxic elements near to the Brazilian Atlantic Rainforest?

    PubMed

    Nakazato, Ricardo K; Rinaldi, Mirian C S; Domingos, Marisa

    2016-12-01

    The foliar accumulation and enrichment factor for 36 elements were studied in Psidium guajava 'Paluma' (fruit tropical tree) and Tibouchina pulchra Cogn. (native tree of the Atlantic rainforest) plants exposed around the city of Cubatão/Brazil, to propose a biomonitoring species in the Atlantic rainforest. The field experiments were conducted in six sites from November/2009 to April/2011. Parallel exposures of plants to filtered air in open-top chambers were performed to determine the background leaf concentrations of all elements. Both plants were enriched with elements (Ni, La, Fe, Ba, Al, Co, Pb, Hg and Mn) that characterize the industrial area of Cubatão, Brazil. P. guajava is a better option for biomonitoring toxic elements in Cubatão, since it was able to enrich higher metal levels than T. pulchra. Furthermore, P. guajava showed a better spatial and temporal variations in metal levels Cubatão. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Persistent bill and corolla matching despite shifting temporal resources in tropical hummingbird-plant interactions.

    PubMed

    Weinstein, Ben G; Graham, Catherine H

    2017-03-01

    By specialising on specific resources, species evolve advantageous morphologies to increase the efficiency of nutrient acquisition. However, many specialists face variation in resource availability and composition. Whether specialists respond to these changes depends on the composition of the resource pulses, the cost of foraging on poorly matched resources, and the strength of interspecific competition. We studied hummingbird bill and plant corolla matching during seasonal variation in flower availability and morphology. Using a hierarchical Bayesian model, we accounted for the detectability and spatial overlap of hummingbird-plant interactions. We found that despite seasonal pulses of flowers with short-corollas, hummingbirds consistently foraged on well-matched flowers, leading to low niche overlap. This behaviour suggests that the costs of searching for rare and more specialised resources are lower than the benefit of switching to super-abundant resources. Our results highlight the trade-off between foraging efficiency and interspecific competition, and underline niche partitioning in maintaining tropical diversity. © 2017 John Wiley & Sons Ltd/CNRS.

  15. Diversity of the endophytic fungi associated with the ancient and narrowly endemic neotropical plant Vellozia gigantea from the endangered Brazilian rupestrian grasslands

    USDA-ARS?s Scientific Manuscript database

    The diversity of cultivable endophytic fungal community associated with the rare, ancient and narrowly endemic Neotropical plant Vellozia gigantea present in the Brazilian Rupestrian Grasslands was assessed. Two hundred and eighty-five fungal isolates obtained were identified into 27 genera and 87 t...

  16. Selection of sugar cane families by using BLUP and multi-diverse analyses for planting in the Brazilian savannah.

    PubMed

    Barbosa, M H P; Ferreira, A; Peixoto, L A; Resende, M D V; Nascimento, M; Silva, F F

    2014-03-12

    This study evaluated different strategies to select sugar cane families and obtain clones adapted to the conditions of the Brazilian savannah. Specifically, 7 experiments were conducted, with 10 full sib families, and 2 witnesses in common to all experiments, in each experiment. The plants were grown in random blocks, with witnesses in common (incomplete blocks), and 6 repetitions of each experiment. The data were analyzed through the methodology of mixed patterns, in which the matrices of kinship between the families were identified by the method of restricted maximum likelihood. The characteristics that were evaluated included soluble solids content (BRIX), BRIX ton/ha, average mass of a culm, number of culms/m, and tons of culms/ha. A multi-diverse alternative based on the analysis of groupings by using the UPGMA method was used to identify the most viable families for selection, when considering the genotypic effects on all characteristics. This method appeared suitable for the selection of families, with 5 family groups being formed. The families that formed Group 2 appeared superior to all other families for all the evaluated characteristics. It is recommended that the families in Group 2 are preferentially used in sugar cane improvement programs to obtain varieties optimally adapted to the conditions of the Brazilian savannah.

  17. In vitro investigation of Brazilian Cerrado plant extract activity against Plasmodium falciparum, Trypanosoma cruzi and T. brucei gambiense.

    PubMed

    Charneau, Sébastien; de Mesquita, Mariana Laundry; Bastos, Izabela Marques Dourado; Santana, Jaime Martins; de Paula, José Elias; Grellier, Philippe; Espindola, Laila Salmen

    2016-06-01

    The threatened Brazilian Cerrado biome is an important biodiversity hotspot but still few explored that constitutes a potential reservoir of molecules to treat infectious diseases. We selected eight Cerrado plant species for screening against the erythrocytic stages of Plasmodium falciparum, human intracellular stages of Trypanosoma cruzi and bloodstream forms of T. brucei gambiense, and for their cytotoxicity upon the rat L6-myoblast cell line. Bioassays were performed with 37 hexane, ethyl acetate and ethanol extracts prepared from different plant organs. Activities against parasites were observed for 24 extracts: 9 with anti-P. falciparum, 4 with anti-T. cruzi and 11 with anti-T. brucei gambiense activities. High anti-protozoal activity (IC50 values < 10 μg/mL) without obvious cytotoxicity to L6 cells was observed for eight extracts from plants: Connarus suberosus, Blepharocalyx salicifolius, Psidium laruotteanum and Myrsine guianensis. Overall, studies of plant extracts will contribute to increase the biodiversity knowledge essential for Cerrado conservation and sustainable development.

  18. Alien and endangered plants in the Brazilian Cerrado exhibit contrasting relationships with vegetation biomass and N : P stoichiometry.

    PubMed

    Lannes, Luciola S; Bustamante, Mercedes M C; Edwards, Peter J; Venterink, Harry Olde

    2012-11-01

    Although endangered and alien invasive plants are commonly assumed to persist under different environmental conditions, surprisingly few studies have investigated whether this is the case. We examined how endangered and alien species are distributed in relation to community biomass and N : P ratio in the above-ground community biomass in savanna vegetation in the Brazilian Cerrado. For 60 plots, we related the occurrence of endangered (Red List) and alien invasive species to plant species richness, vegetation biomass and N : P ratio, and soil variables. Endangered plants occurred mainly in plots with relatively low above-ground biomass and high N : P ratios, whereas alien invasive species occurred in plots with intermediate to high biomass and low N : P ratios. Occurrences of endangered or alien plants were unrelated to extractable N and P concentrations in the soil. These contrasting distributions in the Cerrado imply that alien species only pose a threat to endangered species if they are able to invade sites occupied by these species and increase the above-ground biomass and/or decrease the N : P ratio of the vegetation. We found some evidence that alien species do increase above-ground community biomass in the Cerrado, but their possible effect on N : P stoichiometry requires further study.

  19. Long-term patterns in tropical reforestation: plant community composition and aboveground biomass accumulation.

    PubMed

    Marín-Spiotta, E; Ostertag, R; Silver, W L

    2007-04-01

    Primary tropical forests are renowned for their high biodiversity and carbon storage, and considerable research has documented both species and carbon losses with deforestation and agricultural land uses. Economic drivers are now leading to the abandonment of agricultural lands, and the area in secondary forests is increasing. We know little about how long it takes for these ecosystems to achieve the structural and compositional characteristics of primary forests. In this study, we examine changes in plant species composition and aboveground biomass during eight decades of tropical secondary succession in Puerto Rico, and compare these patterns with primary forests. Using a well-replicated chronosequence approach, we sampled primary forests and secondary forests established 10, 20, 30, 60, and 80 years ago on abandoned pastures. Tree species composition in all secondary forests was different from that of primary forests and could be divided into early (10-, 20-, and 30-year) vs. late (60- and 80-year) successional phases. The highest rates of aboveground biomass accumulation occurred in the first 20 years, with rates of C sequestration peaking at 6.7 +/- 0.5 Mg C x ha(-1) x yr(-1). Reforestation of pastures resulted in an accumulation of 125 Mg C/ha in aboveground standing live biomass over 80 years. The 80 year-old secondary forests had greater biomass than the primary forests, due to the replacement of woody species by palms in the primary forests. Our results show that these new ecosystems have different species composition, but similar species richness, and significant potential for carbon sequestration, compared to remnant primary forests.

  20. Partitioning of water resources among plants of a lowland tropical forest.

    PubMed

    Jackson, P C; Cavelier, J; Goldstein, G; Meinzer, F C; Holbrook, N M

    1995-02-01

    Source water used by plants of several species in a semi-evergreen lowland tropical forest on Barro Colorado Island, Panama, was assessed by comparing the relative abundance of deuterium, D, versus hydrogen, H (stable hydrogen isotope composition, δD) in xylem sap and in soil water at different depths, during the dry season of 1992. Ecological correlates of source water were examined by comparing xylem water δD values with leaf phenology, leaf water status determined with a pressure chamber, and rates of water use determined as mass flow of sap using the stem heat balance method. Soil water δD values decreased sharply to 30 cm, then remained relatively constant with increasing depth. Average δD values were-13‰, for 0-30 cm depth and-36.7‰ for 30-100 cm depth. Soil water δD values were negatively associated with soil water content and soil water potential. Concurrent analyses of xylem water revealed a high degree of partitioning of water resources among species of this tropical forest. Xylem water δD of deciduous trees (average=-25.3±1.4‰) was higher than that of evergreen trees (average=-36.3±3.5‰), indicating that evergreen species had access to the more abundant soil water at greater depth than deciduous species. In evergreen shade-tolerant and high-light requiring shrubs and small trees, δD of xylem water was negatively correlated with transpiration rate and leaf water potential indicating that species using deeper, more abundant water resources had both higher rates of water use and more favorable leaf water status.

  1. Yeasts from native Brazilian Cerrado plants: Occurrence, diversity and use in the biocontrol of citrus green mould.

    PubMed

    Sperandio, Eugenio Miranda; do Vale, Helson Mario Martins; Moreira, Geisianny Augusta Monteiro

    2015-11-01

    Yeasts are some of the most important postharvest biocontrol agents. Postharvest oranges frequently deteriorate due to green mould (Penicillium digitatum), which causes significant losses. The aims of this study were to determine the composition and diversity of yeasts on plants of the Brazilian Cerrado and to explore their potential for inhibiting citrus green mould. Leaves and fruit of Byrsonima crassifolia and Eugenia dysenterica were collected from Cerrado conservation areas, and thirty-five yeasts were isolated and identified by sequencing the D1-D2 domain of the rDNA large subunit (26S). The isolates represented the Aureobasidium, Meyerozyma, Candida, and Pichia genera. Three isolates identified as Aureobasidium pullulans exhibited potential for the control of P. digitatum in both in vitro and in vivo tests; these isolates reduced the incidence of disease and increased the storage time of fruit. Aureobasidium. pullulans has immense potential for the biological control of filamentous fungi.

  2. Magnetic Nanosystem for Cancer Therapy Using Oncocalyxone A, an Antitomour Secondary Metabolite Isolated from a Brazilian Plant

    PubMed Central

    Barreto, Antônio C. H.; Santiago, Vivian R.; Freire, Rafael M.; Mazzetto, Selma E.; Denardin, Juliano C.; Mele, Giuseppe; Cavalcante, Igor M.; Ribeiro, Maria E. N. P.; Ricardo, Nágila M. P. S.; Gonçalves, Tamara; Carbone, Luigi; Lemos, Telma L. G.; Pessoa, Otília D. L.; Fechine, Pierre B. A.

    2013-01-01

    This paper describes the investigation and development of a novel magnetic drug delivery nanosystem (labeled as MO-20) for cancer therapy. The drug employed was oncocalyxone A (onco A), which was isolated from Auxemma oncocalyx, an endemic Brazilian plant. It has a series of pharmacological properties: antioxidant, cytotoxic, analgesic, anti-inflammatory, antitumor and antiplatelet. Onco A was associated with magnetite nanoparticles in order to obtain magnetic properties. The components of MO-20 were characterized by XRD, FTIR, TGA, TEM and Magnetization curves. The MO-20 presented a size of about 30 nm and globular morphology. In addition, drug releasing experiments were performed, where it was observed the presence of the anomalous transport. The results found in this work showed the potential of onco A for future applications of the MO-20 as a new magnetic drug release nanosystem for cancer treatment. PMID:24013376

  3. DNA barcode for the identification of the sand fly Lutzomyia longipalpis plant feeding preferences in a tropical urban environment

    PubMed Central

    Lima, Leonardo H. G. de M.; Mesquita, Marcelo R.; Skrip, Laura; de Souza Freitas, Moisés T.; Silva, Vladimir C.; Kirstein, Oscar D.; Abassi, Ibrahim; Warburg, Alon; Balbino, Valdir de Q.; Costa, Carlos H. N.

    2016-01-01

    Little is known about the feeding behavior of hematophagous insects that require plant sugar to complete their life cycles. We studied plant feeding of Lutzomyia longipalpis sand flies, known vectors of Leishmania infantum/chagasi parasites, in a Brazilian city endemic with visceral leishmaniasis. The DNA barcode technique was applied to identify plant food source of wild-caught L. longipalpis using specific primers for a locus from the chloroplast genome, ribulose diphosphate carboxylase. DNA from all trees or shrubs within a 100-meter radius from the trap were collected to build a barcode reference library. While plants from the Anacardiaceae and Meliaceae families were the most abundant at the sampling site (25.4% and 12.7% of the local plant population, respectively), DNA from these plant families was found in few flies; in contrast, despite its low abundance (2.9%), DNA from the Fabaceae family was detected in 94.7% of the sand flies. The proportion of sand flies testing positive for DNA from a given plant family was not significantly associated with abundance, distance from the trap, or average crown expansion of plants from that family. The data suggest that there may indeed be a feeding preference of L. longipalpis for plants in the Fabaceae family. PMID:27435430

  4. Recruitment of invasive plant species in the Sundarbans following tropical Cyclone Aila

    NASA Astrophysics Data System (ADS)

    Rahman, M. M.; Vacik, H.

    2016-02-01

    The Sundarbans is the largest mangrove forest in the world. Two-thirds of the forest (62%) is in the southwest corner of Bangladesh while the rest is in the West Bengal of India. The out flow of water from Bangladesh is the third highest in the world, next to the Amazonia and Congo basin. Major rivers of Bangladesh flow from north to south, silting up the mangroves delta and draining into the Bay of Bengal. The mangroves delta is also a region of transition between the freshwater of the rivers originating from the Ganges and the saline water of the Bay of Bengal. The ecosystems as well as the luxuriant biodiversity of Sundarbans have strong interactions with marine environments. The environmental parameters with the direct influences on Sundarbans in terms of global climate change are sea-level rise, natural calamities like cyclones, salinity and drought. Almost 26 percent frequency of cyclones was increased over past 120 years in the Bay of Bengal. Five disastrous tropical cyclones originated in the Bay of Bengal since 2006 - Sidr, Nargis, Bijli, Aila and Mahasen. Cyclones impact Sundarbans through four primary mechanisms: wind damage, storm surge, sedimentation and colonization of invasive species. Many researches were carried out to investigate the wind damages. The invasions of plant species were not documented; this study is the first attempt to do so in a scientific manner. The study area in the Chandpai Range of Sundarbans was classified as `less affected' (LAA) and `high affected' (HAA) areas due to the tropical cyclone `Aila'. In total 23 invasive plant species were identified in the Chandpai Range of Sundarbans, out of them 19 species are indigenous and the rest are alien. All species were found in the HAA, where only 09 species were found in the LAA. The abundance, diversity and rate of invasion were higher in the HAA than that of LAA. Proper management must be adopted to control the invasion to protect the endemic species. Key words: Mangrove, Marine

  5. Aspergillus and Penicillium (Eurotiales: Trichocomaceae) in soils of the Brazilian tropical dry forest: diversity in an area of environmental preservation.

    PubMed

    Barbosa, Renan do Nascimento; Bezerra, Jadson Diogo Pereira; Costa, Phelipe Manoel Oller; de Lima-Júnior, Nelson Correia; Alves de Souza Galvão, Ivana Roberta Gomes; Alves dos Santos-Júnior, Anthony; Fernandes, Maria José; de Souza-Motta, Cristina Maria; Oliveira, Neiva Tinti

    2016-03-01

    Soil is a complex biological system that plays a key role for plants and animals, especially in dry forests such as the Caatinga. Fungi from soils, such as Aspergillus and Penicillium, can be used as bioindica- tors for biodiversity conservation. The aim of this study was to isolate and identify species of Aspergillus and Penicillium in soil, from the municipalities of Tupanatinga and Ibimirim, with dry forests, in the Catimbau National Park. Five collections were performed in each area during the drought season of 2012, totaling 25 soil samples per area. Fungi were isolated by suspending soil samples in sterile distilled water and plating on Sabouraud Agar media plus Chloramphenicol and Rose Bengal, and Glycerol Dicloran Agar. Isolates were identified by morphological taxonomy in the Culture Collection Laboratory and confirmed by sequencing of the Internal Transcribed Spacer of rDNA. A total of 42 species were identified, of which 22 belong to the genus Aspergillus and 20 to Penicillium. Penicillium isolates showed uniform distribution from the collecting area in Tupanatinga, and the evenness indices found were 0.92 and 0.88 in Tupanatinga and Ibimirim, respectively. Among isolates of Aspergillus evenness, the value found in Tupanatinga (0.85) was very close to that found in Ibimirim (0.86). High diversity and low dominance of fungi in soil samples was observed. These results con- tributed to the estimation of fungal diversity in dry environments of the Caatinga, where diversity is decreasing in soils that have undergone disturbance.

  6. Plant litter dynamics in the forest-stream interface: precipitation is a major control across tropical biomes.

    PubMed

    Tonin, Alan M; Gonçalves, José F; Bambi, Paulino; Couceiro, Sheyla R M; Feitoza, Lorrane A M; Fontana, Lucas E; Hamada, Neusa; Hepp, Luiz U; Lezan-Kowalczuk, Vânia G; Leite, Gustavo F M; Lemes-Silva, Aurea L; Lisboa, Leonardo K; Loureiro, Rafael C; Martins, Renato T; Medeiros, Adriana O; Morais, Paula B; Moretto, Yara; Oliveria, Patrícia C A; Pereira, Evelyn B; Ferreira, Lidiane P; Pérez, Javier; Petrucio, Mauricio M; Reis, Deusiano F; S Rezende, Renan; Roque, Nadia; Santos, Luiz E P; Siegloch, Ana E; Tonello, Gabriela; Boyero, Luz

    2017-09-07

    Riparian plant litter is a major energy source for forested streams across the world and its decomposition has repercussions on nutrient cycling, food webs and ecosystem functioning. However, we know little about plant litter dynamics in tropical streams, even though the tropics occupy 40% of the Earth's land surface. Here we investigated spatial and temporal (along a year cycle) patterns of litter inputs and storage in multiple streams of three tropical biomes in Brazil (Atlantic forest, Amazon forest and Cerrado savanna), predicting major differences among biomes in relation to temperature and precipitation regimes. Precipitation explained most of litter inputs and storage, which were generally higher in more humid biomes (litterfall: 384, 422 and 308 g m(-2) y(-1), storage: 55, 113 and 38 g m(-2), on average in Atlantic forest, Amazon and Cerrado, respectively). Temporal dynamics varied across biomes in relation to precipitation and temperature, with uniform litter inputs but seasonal storage in Atlantic forest streams, seasonal inputs in Amazon and Cerrado streams, and aseasonal storage in Amazon streams. Our findings suggest that litter dynamics vary greatly within the tropics, but point to the major role of precipitation, which contrasts with the main influence of temperature in temperate areas.

  7. Crab spiders (Araneae: Thomisidae) in flowering plants in a Brazilian "Cerrado" ecosystem.

    PubMed

    Rocha-Filho, L C; Rinaldi, I M P

    2011-05-01

    Although crab spiders are common in flowering plants, their relations with plant species and its floral traits have been poorly known in the Neotropics. Observations regarding plant habits, floral visitors and also floral characteristics such as anthesis, odour, shape, colour and floral resources were recorded in flowering plant species of an area of "Cerrado" on a 2 km long trail. Misumenops argenteus and Misumenops pallens accounted for 62.86% of the spiders captured on 22 flowering plant species. The plants Senna rugosa (Fabaceae), Styrax ferrugineus (Styracaceae) and Banisteriopsis campestris (Malpighiaceae), hosted, each one, about 10 to 17% of the total spiders collected and these plants had diurnal anthesis, bee-attractive flower colours such as yellow (S. rugosa), white (S. ferrugineus), and pink (B. campestris), poricidal anthers as well as being visited by bees which evidenced bee-pollination syndrome. This study is the first survey regarding crab spiders and their associations with plant species of the "Cerrado".

  8. Clinical and laboratory features of HTLV-I asymptomatic carriers and patients with HTLV-I-associated myelopathy/tropical spastic paraparesis from the Brazilian Amazon

    PubMed Central

    Takatani, Massanobu; Crispim, Myuki Esashika; Fraiji, Nelson; Stefani, Mariane Martins Araujo; Kiesslich, Dagmar

    2017-01-01

    ABSTRACT Clinical and laboratory parameters including blood and cerebrospinal fluid (CSF) neopterin were investigated in human-T-lymphotropic-virus-type-I associated-myelopathy/tropical-spastic-paraparesis-HAM/TSP and in HTLV-I carriers. HAM/TSP (n = 11, 2 males/9 females, median age = 48 years), recently diagnosed HTLV-I carriers (n = 21, 15 females/6 males, median age = 44 years), healthy individuals (n = 20, 10 males/10 females, median age = 34.6 years) from the Brazilian Amazon (Manaus, Amazonas State) were investigated. Neopterin was measured (IBL ELISA Neopterin, Germany) in serum samples of all the participants, in CSF of 9 HAM/TSP patients as well as in 6 carriers. In HAM/TSP patients, CSF cell counts, protein and glucose were measured, the Osame’s motor-disability-score/OMDS was determined, and brain/spinal cord magnetic-resonance-imaging (MRI) was performed. HAM/TSP patients had normal CSF glucose, leukocyte counts; and normal protein levels predominated. Brain-MRI showed white-matter lesions in 7 out of 11 HAM/TSP patients. OMDS varied from 2-8: 9 were able to walk, 2 were wheel-chair-users. The median serum neopterin concentration in HAM/TSP patients was 6.6 nmol/ L; min. 2.8- max. 12.5 nmol/ L); was lower in carriers (4.3 nmol/L; min. 2.7- max. 7.2 nmol/ L) as well as in healthy participants (4.7 nmol/ L; min. 2.7- max. 8.0 nmol/ L) (p < 0.05). CSF neopterin concentrations in HAM/TSP patients were higher than in serum samples, and higher compared to carriers (p < 0.05). Carriers had similar serum-CSF neopterin concentrations compared to healthy participants. Variable clinical and laboratory profiles were seen in HAM/TSP patients, however our results support the neopterin measurement as a potential biomarker of disease activity. PMID:28380116

  9. Effect of logging on rodent scatter-hoarding dynamics in tropical forests: implications for plant recruitment.

    PubMed

    Gutiérrez-Granados, Gabriel

    2011-06-01

    The present study tested the hypothesis that logging affects the scatter-hoarding behavior of rodents, which, in turn, negatively affects the quantity and quality of Pouteria campechiana (Sapotaceae) seed dispersal. A series of seed stations was established in logged and unlogged forests of ejido Señor, Yucatan Peninsula, and comparisons were made between logged and unlogged forests in terms of: (i) seed removal; (ii) number of seeds hoarded; (iii) hoarding distance; and (iv) the number of recruits and the survival of hoarded seeds. The number of both hoarded and removed seeds was significantly higher in unlogged sites. Furthermore, the mean distance of hoarding was greater in unlogged compared with logged sites. Although recruitment and survival were present in both logged and unlogged sites, there were more surviving seedlings in unlogged sites. The data indicate that both the quantity and quality of seed dispersal are negatively affected by logging because of a change in the rodent scatter-hoarding dynamics. These changes suggest that plant-animal interactions are crucial to the understanding of the ecology and conservation of managed tropical forests.

  10. The insulin-releasing activity of the tropical plant momordica charantia.

    PubMed

    Welihinda, J; Arvidson, G; Gylfe, E; Hellman, B; Karlsson, E

    1982-01-01

    An aqueous extract from the unripe fruits of the tropical plant Momordica charantia was found to be a potent stimulator of insulin release from beta-cell-rich pancreatic islets isolated from obese-hyperglycemic mice. The stimulation of insulin release was partially reversible. It differed from that of D-glucose and other commonly employed insulin secretagogues in not being suppressed by L-epinephrine and in even being potentiated by the removal of Ca2+. This anomalous behaviour was not associated with general effects on the metabolism of the beta-cells as indicated by an unaltered oxidation of D-glucose. Studies of 45Ca fluxes suggest that the insulin-releasing action is the result of perturbations of membrane functions. In support for the idea of direct effects on membrane lipids, the action of the extract was found to mimic that of saponin in inhibiting the Ca2+/H+ exchange mediated by the ionophore A23187 in isolated chromaffin granules and release Ca2+ from preloaded liposomes.

  11. Flavonoids from Eight Tropical Plant Species That Inhibit the Multidrug Resistance Transporter ABCG2

    PubMed Central

    Versiani, Muhammad Ali; Diyabalanage, Thushara; Ratnayake, Ranjala; Henrich, Curtis J.; Bates, Susan E.; McMahon, James B.; Gustafson, Kirk R.

    2013-01-01

    Overexpression of ABCG2, a membrane-bound multidrug transporter, can make tumor cells resistant to treatment with conventional chemotherapeutic agents. A high-throughput screening effort with the NCI repository of natural product extracts revealed that eight tropical plant extracts significantly inhibited the function of ABCG2. This activity was tracked throughout the extract fractionation process to a series of ABCG2 inhibitory flavonoids (1–13). Their structures were identified by a combination of NMR, mass spectrometry, and circular dichroism studies, and this resulted in the elucidation of (2S)-5,7,3′-trihydroxy-4′-methoxy-8-(3″-methylbut-2″-enyl)-flavonone (1), (2S)-5,7,3′,5′-tetrahydroxy-8-[3″,8″ -dimethylocta-2″(E),7″-dienyl]flavonone (3), and 5,7,3′-trihydroxy-3,5′-dimethoxy-2′-(3′-methylbut-2-enyl)flavone (12) as new compounds. PMID:21275386

  12. Evaluation of tropical plants containing tannin on in vitro methanogenesis and fermentation parameters using rumen fluid.

    PubMed

    Hariadi, Bambang Tjahyono; Santoso, Budi

    2010-02-01

    Methane (CH(4)) produced during ruminal fermentation represents a loss of 10-11% of gross energy intake. The use of browse species containing tannin as feed supplement for ruminants tends to increase in order to reduce CH(4) production. The present study was conducted to evaluate some tropical plants containing tannin as feed supplement (200 g kg(-1)) on in vitro CH(4) production and fermentation parameters. The crude protein (CP) content ranged from 87 to 390 g kg(-1) dry matter (DM) and was highest in Sesbania grandiflora (L.) Poiret. The neutral detergent fibre (NDF) concentration was highest in Pennisetum purpureum Schumach (725 g kg(-1) DM) and lowest in S. grandiflora (330 g kg(-1) DM). The ranking order of plants based on their total tannin content was Acacia mangium Willd. > Biophytum petersianum Klotzch > Jatropa curcas Linnaeus > Psidium guajava Linnaeus > Phaleria papuana > Persea americana Mill. > S. grandiflora. Methane gas production after 48 h of incubation was significantly (P < 0.05) lower with inclusion of A. mangium (PP + AM), B. petersianum (PP + BP), J. curcas (PP + JC) or P. guajava (PP + PG) as compared to control feed (PP). There was negative correlation between total tannin content and CH(4) production at 48 h of incubation (r = - 0.76). Concentration NH(3)-N was significantly (P < 0.01) higher with inclusion of S. glandiflora. Inclusion of P. guajava significantly (P < 0.05) suppressed protozoa population by 49.7% relative to control feed (PP). It was concluded that A. mangium, B. petersianum, J. curcas and P. guajava have potential to be used as a feed supplement to reduce CH(4) production in ruminants.

  13. Overstory structure and soil nutrients effect on plant diversity in unmanaged moist tropical forest

    NASA Astrophysics Data System (ADS)

    Gautam, Mukesh Kumar; Manhas, Rajesh Kumar; Tripathi, Ashutosh Kumar

    2016-08-01

    Forests with intensive management past are kept unmanaged to restore diversity and ecosystem functioning. Before perpetuating abandonment after protracted restitution, understanding its effect on forest vegetation is desirable. We studied plant diversity and its relation with environmental variables and stand structure in northern Indian unmanaged tropical moist deciduous forest. We hypothesized that post-abandonment species richness would have increased, and the structure of contemporary forest would be heterogeneous. Vegetation structure, composition, and diversity were recorded, in forty 0.1 ha plots selected randomly in four forest ranges. Three soil samples per 0.1 ha were assessed for physicochemistry, fine sand, and clay mineralogy. Contemporary forest had less species richness than pre-abandonment reference period. Fourteen species were recorded as either seedling or sapling, suggesting reappearance or immigration. For most species, regeneration was either absent or impaired. Ordination and multiple regression results showed that exchangeable base cations and phosphorous affected maximum tree diversity and structure variables. Significant correlations between soil moisture and temperature, and shrub layer was observed, besides tree layer correspondence with shrub richness, suggesting that dense overstory resulting from abandonment through its effect on soil conditions, is responsible for dense shrub layer. Herb layer diversity was negatively associated with tree layer and shrub overgrowth (i.e. Mallotus spp.). Protracted abandonment may not reinforce species richness and heterogeneity; perhaps result in high tree and shrub density in moist deciduous forests, which can impede immigrating or reappearing plant species establishment. This can be overcome by density/basal area reduction strategies, albeit for both tree and shrub layer.

  14. Evaluation of two Brazilian indigenous plants for phytostabilization and phytoremediation of copper-contaminated soils.

    PubMed

    Andreazza, R; Bortolon, L; Pieniz, S; Bento, F M; Camargo, F A O

    2015-11-01

    Indigenous plants have been grown naturally and vigorously in copper contaminated soils. Thus, the aim of this study was to evaluate the phytoremediation ability of two indigenous plants naturally grown in two vineyard soils copper contaminated, and in a copper mining waste. However, it was evaluated the macro and micronutrient uptake and the potential of phytoremediation. So, a greenhouse study was carried out with Bidens pilosa and Plantago lanceolata in samples of vineyard soils (Inceptisol and Mollisol) copper contaminated, and in a copper mining waste. Plant growth, macro and micronutrient up take, tolerance index (TI), translocation factor (TF), metal extraction ratio (MER), bioaccumulation factor (BCF), plant effective number of the shoots (PENs), and plant effective number of the total plant (PENt) were analyzed. Both plants grown in vineyard soils showed high phytomass production and TI. P. lanceolata plants cultivated in the Inceptisol showed the highest copper concentrations in the shoots (142 mg kg-1), roots (964 mg kg-1) and entire plants (1,106 mg kg-1). High levels of copper were phytoaccumulated from the Inceptisol by B. pilosa and P. lanceolata with 3,500 and 2,200 g ha-1 respectively. Both B. pilosa and P. lanceolata plants showed characteristics of high copper hyperaccumulator. Results showed that both species play an important role in the natural copper phytoaccumulation in both vineyard soils contaminated with copper, being important to its phytoremediation.

  15. Evaluation of two Brazilian indigenous plants for phytostabilization and phytoremediation of copper-contaminated soils.

    PubMed

    Andreazza, R; Bortolon, L; Pieniz, S; Bento, F M; Camargo, F A O

    2015-11-10

    AbstractIndigenous plants have been grown naturally and vigorously in copper contaminated soils. Thus, the aim of this study was to evaluate the phytoremediation ability of two indigenous plants naturally grown in two vineyard soils copper contaminated, and in a copper mining waste. However, it was evaluated the macro and micronutrient uptake and the potential of phytoremediation. So, a greenhouse study was carried out with Bidens pilosa and Plantago lanceolata in samples of vineyard soils (Inceptisol and Mollisol) copper contaminated, and in a copper mining waste. Plant growth, macro and micronutrient up take, tolerance index (TI), translocation factor (TF), metal extraction ratio (MER), bioaccumulation factor (BCF), plant effective number of the shoots (PENs), and plant effective number of the total plant (PENt) were analyzed. Both plants grown in vineyard soils showed high phytomass production and TI. P. lanceolata plants cultivated in the Inceptisol showed the highest copper concentrations in the shoots (142 mg kg-1), roots (964 mg kg-1) and entire plants (1,106 mg kg-1). High levels of copper were phytoaccumulated from the Inceptisol by B. pilosa and P. lanceolata with 3,500 and 2,200 g ha-1 respectively. Both B. pilosa and P. lanceolata plants showed characteristics of high copper hyperaccumulator. Results showed that both species play an important role in the natural copper phytoaccumulation in both vineyard soils contaminated with copper, being important to its phytoremediation.

  16. Edge effect and phenology in Erythroxylum tortuosum (Erythroxylaceae), a typical plant of the Brazilian Cerrado.

    PubMed

    Ishino, M N; De Sibio, P R; Rossi, M N

    2012-08-01

    The edge of a forest fragment can be considered a zone of transition between the interior of the fragment and the surrounding habitat matrix. Plants along the edge are more exposed to disturbance and microclimate variation than interior plants, resulting in the so-called edge effect. In this study, we compared leaf area, fluctuating asymmetry and chemical (water, nitrogen and tannins) leaf traits between Erythroxylum tortuosum plants inhabiting the edge with those growing in the interior of a cerrado fragment in Brazil. We also describe the temporal variation in the vegetative and reproductive phenological events of E. tortuosum plants throughout the season. Nitrogen, leaf area and fluctuating asymmetry did not differ between the two plant groups. Young leaves of the edge plants had significantly higher levels of tannins and lower levels of water than those of interior plants. We suggest that differences in leaf chemical concentrations between edge and interior plants may occur due to factors such as light intensity, wind, temperature and leaf age rather than plant stress. With respect to plant phenology, most reproductive events occurred during the spring. Leaf buds and young leaves prevailed during the rainy season. In the dry season, however, the vegetative events decreased due to leaf senescence followed by leaf abscission.

  17. Photosynthetic responses to leaf surface wetness in tropical plant species of Costa Rica with varying leaf traits

    NASA Astrophysics Data System (ADS)

    Aparecido, L. M. T.; Moore, G. W.; Miller, G. R.; Cahill, A. T.

    2015-12-01

    Wet tropical forests are some of the environments with the greatest annual precipitation, but are also considered as the world's major carbon sink; however, literature postulates that phothsynthesis rates are inhibited while leaves are wet. Yet measurements of photosynthesis during wet conditions are challenging to obtain due to equipment limitations and the extreme complexity of canopy-atmosphere interactions in tropical environments. The objective of this study was to evaluate tropical species reactions to simulated leaf wetness and test the hypothesis that leaf wetness reduces rates of photosynthesis. In a central Costa Rica site with an average 4200 mm annual rainfall, we selected six tropical species with distinct leaf traits in which five sun-exposed leaf replicates from each species were subjected to gas exchange measurements using a LI-6400 IRGA (LICOR Inc., Lincoln, NE) under dry and wet/misted leaf conditions. Relationships between photosynthesis (As) and stomatal conductance (gs) with leaf to air temperature difference (DT), VPD, and relative humidity were evaluated using linear regression analysis. We found that the responses varied greatly among species, but all plants maintained a baseline of activity under wet leaf conditions, suggesting that abaxial leaf As was a significant percentage of total leaf As. Stachytarpheta jamaicens had an 18.7% reduction in As, while others, like Zamia skinneri, had a 7% increase in As. Tibouchina heteromalla showed a rapid stomatal recovery of 2 mins, while Carapa guianensis was slower with 7 mins. This variability between species suggests that leaf traits, such as presence or absence of trichomes, water repellency, vein distribution and size and leaf angle variation, may be critical for optimizing photosynthesis under wet conditions. Relative humidity and leaf temperature were the strongest secondary influences on As and gs under wet leaf conditions. While tropical vegetation-atmosphere interactions are complex, such

  18. Evapotranspiration from subsurface horizontal flow wetlands planted with Phragmites australis in sub-tropical Australia.

    PubMed

    Headley, T R; Davison, L; Huett, D O; Müller, R

    2012-02-01

    The balance between evapotranspiration (ET) loss and rainfall ingress in treatment wetlands (TWs) can affect their suitability for certain applications. The aim of this paper was to investigate the water balance and seasonal dynamics in ET of subsurface horizontal flow (HF) TWs in a sub-tropical climate. Monthly water balances were compiled for four pilot-scale HF TWs receiving horticultural runoff over a two year period (Sep. 1999-Aug. 2001) on the sub-tropical east-coast of Australia. The mean annual wetland ET rate increased from 7.0 mm/day in the first year to 10.6 mm/day in the second, in response to the development of the reed (Phragmites australis) population. Consequently, the annual crop coefficients (ratio of wetland ET to pan evaporation) increased from 1.9 in the first year to 2.6 in the second. The mean monthly ET rates were generally greater and more variable than the Class-A pan evaporation rates, indicating that transpiration is an important contributor to ET in HF TWs. Evapotranspiration rates were generally highest in the summer and autumn months, and corresponded with the times of peak standing biomass of P. australis. It is likely that ET from the relatively small 1 m wide by 4 m long HF TWs was enhanced by advection through so-called "clothesline" and "oasis" effects, which contributed to the high crop coefficients. For the second year, when the reed population was well established, the annual net loss to the atmosphere (taking into account rainfall inputs) accounted for 6.1-9.6 % of the influent hydraulic load, which is considered negligible. However, the net loss is likely to be higher in arid regions with lower rainfall. The Water Use Efficiency (WUE) of the wetlands in the second year of operation was 1.3 g of above-ground biomass produced per kilogram of water consumed, which is low compared to agricultural crops. It is proposed that system level WUE provides a useful metric for selecting wetland plant species and TW design alternatives to

  19. Brazilian medicinal plants to treat upper respiratory tract and bronchial illness: systematic review and meta-analyses-study protocol.

    PubMed

    Lopes, Luciane C; Silva, Maria Carolina O; Motta, Cristiane Bergamashi; Macho Quirós, Antonio; Biavatti, Maique Weber; de Oliveira, Jardel Corrêa; Guyatt, Gordon

    2014-07-23

    Respiratory illness, often associated with cough and sputum, is frequent. In Brazil, herbal medicines are often recommended as a first-line treatment for respiratory illness. There exists uncertainty regarding the effectiveness of these treatments. No systematic review has evaluated Brazilian medicinal plants (BMP) to treat upper respiratory tract and bronchial illness (URTI). We will conduct a systematic review and, if appropriate, a series of meta-analyses evaluating the safety and effectiveness of BMP for URTI. Eligible randomised controlled trials and observational studies will enrol adult or paediatric patients presenting with URTI treated by BMP approved by the Brazilian Health Surveillance Agency compared with placebo, no treatment or an alternative therapy. Our search will include the Cochrane Central Register of Controlled Trials (CENTRAL), which contains the Cochrane Acute Respiratory Illness Group's Specialized Register; MEDLINE; EMBASE; CINAHL (Cumulative Index to Nursing and Allied Health Literature); Web of Science; AMED; LILACS; CAB abstracts; clinical trial.gov; the WHO Trial Register and the Brazilian thesis database (CAPES) without any language restrictions. Outcomes of interest are time to resolution of clinical symptoms and/or signs (cough, sputum production or activity limitations), severity of symptoms prior to resolution and major/minor adverse events. Teams of reviewers will, independently and in duplicate, screen titles and abstracts and the complete full text to determine eligibility. For eligible studies, reviewers will perform data abstraction and assess risk of bias of eligible trials. When appropriate, we will conduct meta-analyses. We will also assess the quality of body of evidence (confidence in estimates of effect) for each of the outcomes using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. The systematic review will be published in a peer-reviewed journal. Brief reports of review findings

  20. An ethnobotanical study of anti-malarial plants among indigenous people on the upper Negro River in the Brazilian Amazon.

    PubMed

    Frausin, Gina; Hidalgo, Ari de Freitas; Lima, Renata Braga Souza; Kinupp, Valdely Ferreira; Ming, Lin Chau; Pohlit, Adrian Martin; Milliken, William

    2015-11-04

    In this article we present the plants used for the treatment of malaria and associated symptoms in Santa Isabel do Rio Negro in the Brazilian Amazon. The region has important biological and cultural diversities including more than twenty indigenous ethnic groups and a strong history in traditional medicine. The aims of this study are to survey information in the Baniwa, Baré, Desana, Piratapuia, Tariana, Tukano, Tuyuca and Yanomami ethnic communities and among caboclos (mixed-ethnicity) on (a) plant species used for the treatment of malaria and associated symptoms, (b) dosage forms and (c) distribution of these anti-malarial plants in the Amazon. Information was obtained through classical ethnobotanical and ethnopharmacological methods from interviews with 146 informants in Santa Isabel municipality on the upper Negro River, Brazil. Fifty-five mainly native neotropical plant species from 34 families were in use. The detailed uses of these plants were documented. The result was 187 records (64.5%) of plants for the specific treatment of malaria, 51 records (17.6%) of plants used in the treatment of liver problems and 29 records (10.0%) of plants used in the control of fevers associated with malaria. Other uses described were blood fortification ('dar sangue'), headache and prophylaxis. Most of the therapeutic preparations were decoctions and infusions based on stem bark, root bark and leaves. These were administered by mouth. In some cases, remedies were prepared with up to three different plant species. Also, plants were used together with other ingredients such as insects, mammals, gunpowder and milk. This is the first study on the anti-malarial plants from this region of the Amazon. Aspidosperma spp. and Ampelozizyphus amazonicus Ducke were the most cited species in the communities surveyed. These species have experimental proof supporting their anti-malarial efficacy. The dosage of the therapeutic preparations depends on the kind of plant, quantity of plant

  1. CARBON SEQUESTRATION AND PLANT COMMUNITY DYNAMICS FOLLOWING REFORESTATION OF TROPICAL PASTURE.

    Treesearch

    WHENDEE L. SILVER; LARA M. KUEPPERS; ARIEL E. LUGO; REBECCA OSTERTAG; VIRGINIA MATZEK

    2004-01-01

    Conversion of abandoned cattle pastures to secondary forests and plantations in the tropics has been proposed as a means to increase rates of carbon (C) sequestration from the atmosphere and enhance local biodiversity. We used a long-term tropical reforestation project (55–61 yr) to estimate rates of above- and belowground C sequestration and to investigate the impact...

  2. Anti-Streptococcal activity of Brazilian Amazon Rain Forest plant extracts presents potential for preventive strategies against dental caries.

    PubMed

    Silva, Juliana Paola Correa da; Castilho, Adriana Lígia de; Saraceni, Cíntia Helena Couri; Díaz, Ingrit Elida Collantes; Paciencia, Mateus Luís Barradas; Suffredini, Ivana Barbosa

    2014-04-01

    Caries is a global public health problem, whose control requires the introduction of low-cost treatments, such as strong prevention strategies, minimally invasive techniques and chemical prevention agents. Nature plays an important role as a source of new antibacterial substances that can be used in the prevention of caries, and Brazil is the richest country in terms of biodiversity. In this study, the disk diffusion method (DDM) was used to screen over 2,000 Brazilian Amazon plant extracts against Streptococcus mutans. Seventeen active plant extracts were identified and fractionated. Extracts and their fractions, obtained by liquid-liquid partition, were tested in the DDM assay and in the microdilution broth assay (MBA) to determine their minimal inhibitory concentrations (MICs) and minimal bactericidal concentrations (MBCs). The extracts were also subjected to antioxidant analysis by thin layer chromatography. EB271, obtained from Casearia spruceana, showed significant activity against the bacterium in the DDM assay (20.67±0.52 mm), as did EB1129, obtained from Psychotria sp. (Rubiaceae) (15.04±2.29 mm). EB1493, obtained from Ipomoea alba, was the only extract to show strong activity against Streptococcus mutans (0.08 mg/mL

  3. New Pesticidal Diterpenoids from Vellozia gigantea (Velloziaceae), an Endemic Neotropical Plant Living in the Endangered Brazilian Biome Rupestrian Grasslands.

    PubMed

    Ferreira, Mariana C; Cantrell, Charles L; Duke, Stephen O; Ali, Abbas; Rosa, Luiz H

    2017-01-21

    Vellozia gigantea is a rare, ancient, and endemic neotropical plant present in the Brazilian Rupestrian grasslands. The dichloromethane extract of V. gigantea adventitious roots was phytotoxic against Lactuca sativa, Agrostis stolonifera, and Lemna paucicostata, and showed larvicidal activity against Aedes aegypti. Phytotoxicity bioassay-directed fractionation of the extract revealed one new isopimaradiene, 8(9),15-isopimaradien-1,3,7,11-tetraone, and three new cleistanthane diterpenoids, 7-oxo-8,11,13-cleistanthatrien-3-ol, 3,20-epoxy-7-oxo-8,11,13-cleistanthatrien-3-ol, and 20-nor-3,7-dioxo-1,8,11,13-cleistanthatetraen-10-ol. These new structures are proposed based on interpretation of ¹H, (13)C, COSY, NOESY, HSQC, and HMBC NMR data. 8(9),15-isopimaradien-1,3,7,11-tetraone was especially phytotoxic with an IC50 value (30 μM) comparable to those of commercial herbicides clomazone, EPTC, and naptalam. In addition, 7-oxo-8,11,13-cleistanthatrien-3-ol provided 100% mortality at a concentration of 125 ppm against one-day-old Ae. aegypti larvae. Our results show that ancient and unique plants, like the endangered narrowly endemic neotropical species V. gigantea present in the Rupestrian grasslands, should also be protected because they can be sources of new bioactive compounds.

  4. Concepts of Plants Held by Young Brazilian Children: An Exploratory Study

    ERIC Educational Resources Information Center

    Bartoszeck, Amauri Betini; Cosmo, Claudete Rosa; da Silva, Bernadete Rocha; Tunnicliffe, Sue Dale

    2015-01-01

    Children from southern and northern Brazil have a basic knowledge of plants, which they observe during their everyday life. Children ages between 3 to 10 years old (kindergarten & primary school), but the majority of them in the age group of 4-5 (total 145) were asked to draw what they think is a plant (total sample = 332). Afterwards, a equal…

  5. A new species of Japanagromyza Sasakawa (Diptera: Agromyzidae) from the Brazilian Amazon with notes on biology.

    PubMed

    Monteiro, Nilton Juvencio Santiago; Carvalho-Filho, Fernando Da Silva; Esposito, Maria Cristina

    2015-02-18

    Japanagromyza sasakawai sp. n. is described from the Brazilian Amazon, based on the male, female, third instar larva and puparium. This species is a leaf-miner of Terminalia catappa L. (Combretaceae), which is an introduced plant from the Old World tropics used in Brazil as an ornamental. The male aedeagus of J. sasakawai sp. n. differs from other species mainly in having the mesophallus covered with many spine-like processes. This is the third record of Japanagromyza Sasakawa in Brazil and first in the Brazilian Amazon. The key to Neotropical species of Japanagromyza by Sousa & Couri (2014) is modified to include this new species.

  6. Diversity in plant hydraulic traits explains seasonal and inter-annual variations of vegetation dynamics in seasonally dry tropical forests.

    PubMed

    Xu, Xiangtao; Medvigy, David; Powers, Jennifer S; Becknell, Justin M; Guan, Kaiyu

    2016-10-01

    We assessed whether diversity in plant hydraulic traits can explain the observed diversity in plant responses to water stress in seasonally dry tropical forests (SDTFs). The Ecosystem Demography model 2 (ED2) was updated with a trait-driven mechanistic plant hydraulic module, as well as novel drought-phenology and plant water stress schemes. Four plant functional types were parameterized on the basis of meta-analysis of plant hydraulic traits. Simulations from both the original and the updated ED2 were evaluated against 5 yr of field data from a Costa Rican SDTF site and remote-sensing data over Central America. The updated model generated realistic plant hydraulic dynamics, such as leaf water potential and stem sap flow. Compared with the original ED2, predictions from our novel trait-driven model matched better with observed growth, phenology and their variations among functional groups. Most notably, the original ED2 produced unrealistically small leaf area index (LAI) and underestimated cumulative leaf litter. Both of these biases were corrected by the updated model. The updated model was also better able to simulate spatial patterns of LAI dynamics in Central America. Plant hydraulic traits are intercorrelated in SDTFs. Mechanistic incorporation of plant hydraulic traits is necessary for the simulation of spatiotemporal patterns of vegetation dynamics in SDTFs in vegetation models. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  7. Multiple soil nutrient competition between plants, microbes, and mineral surfaces: model development, parameterization, and example applications in several tropical forests

    NASA Astrophysics Data System (ADS)

    Zhu, Q.; Riley, W. J.; Tang, J.; Koven, C. D.

    2015-03-01

    Soil is a complex system where biotic (e.g., plant roots, micro-organisms) and abiotic (e.g., mineral surfaces) consumers compete for resources necessary for life (e.g., nitrogen, phosphorus). This competition is ecologically significant, since it regulates the dynamics of soil nutrients and controls aboveground plant productivity. Here we develop, calibrate, and test a nutrient competition model that accounts for multiple soil nutrients interacting with multiple biotic and abiotic consumers. As applied here for tropical forests, the Nutrient COMpetition model (N-COM) includes three primary soil nutrients (NH4+, NO3-, and POx (representing the sum of PO43-, HPO42-, and H2PO4-)) and five potential competitors (plant roots, decomposing microbes, nitrifiers, denitrifiers, and mineral surfaces). The competition is formulated with a quasi-steady-state chemical equilibrium approximation to account for substrate (multiple substrates share one consumer) and consumer (multiple consumers compete for one substrate) effects. N-COM successfully reproduced observed soil heterotrophic respiration, N2O emissions, free phosphorus, sorbed phosphorus, and free NH4+ at a tropical forest site (Tapajos). The overall model posterior uncertainty was moderately well constrained. Our sensitivity analysis revealed that soil nutrient competition was primarily regulated by consumer-substrate affinity rather than environmental factors such as soil temperature or soil moisture. Our results imply that the competitiveness (from most to least competitive) followed this order: (1) for NH4+, nitrifiers ~ decomposing microbes > plant roots, (2) for NO3-, denitrifiers ~ decomposing microbes > plant roots, (3) for POx, mineral surfaces > decomposing microbes ~ plant roots. Although smaller, plant relative competitiveness is of the same order of magnitude as microbes. We then applied the N-COM model to analyze field nitrogen and phosphorus perturbation experiments in two tropical forest sites (in Hawaii

  8. Effects of indiscriminate foraging by tropical hummingbirds on pollination and plant reproductive success: experiments with two tropical treelets (Rubiaceae).

    PubMed

    Feinsinger, Peter; Busby, William H; Tiebout, Hary M

    1988-08-01

    In cloud forest at Monteverde, Costa Rica, two common treelets (Palicourea lasiorrachis and Cephaelis elata, both Rubiaceae) depend simultaneously on one hummingbird population (Lampornis calolaema) for pollination. Both species are distylous and self-incompatible. In laboratory experiments, we examined possible effects of indiscriminate foraging by hummingbirds among flowers of both species, as observed in the field, on pollination of Palicourea. In each of 35 trials, captive L. calolaema probed 2 flowers from pin plants of Palicourea followed by 20 thrum flowers of the same species, with either 0, 2, or 10 Cephaelis flowers intervening. We assessed pollen transfer by staining and counting pin pollen tubes growing in thrum styles; counts of 0, 1, or ≥2 pollen tubes relate directly to seed output (0, 1, or 2 seeds per fruit, respectively). Intervening Cephaelis flowers sharply reduced pollen receipt by thrum flowers of Palicourea and reduced some aspects of pollen dispersal from pins as well, thereby curtailing maternal and paternal reproductive potential of Palicourea. Such effects of interspecific pollen loss on reproductive output may lead to strong competition among some, though not all, combinations of plant species pollinated by L. calolaema or of other plant combinations that share animal pollinators.

  9. Global diversification of a tropical plant growth form: environmental correlates and historical contingencies in climbing palms

    PubMed Central

    Couvreur, Thomas L. P.; Kissling, W. Daniel; Condamine, Fabien L.; Svenning, Jens-Christian; Rowe, Nick P.; Baker, William J.

    2015-01-01

    Tropical rain forests (TRF) are the most diverse terrestrial biome on Earth, but the diversification dynamics of their constituent growth forms remain largely unexplored. Climbing plants contribute significantly to species diversity and ecosystem processes in TRF. We investigate the broad-scale patterns and drivers of species richness as well as the diversification history of climbing and non-climbing palms (Arecaceae). We quantify to what extent macroecological diversity patterns are related to contemporary climate, forest canopy height, and paleoclimatic changes. We test whether diversification rates are higher for climbing than non-climbing palms and estimate the origin of the climbing habit. Climbers account for 22% of global palm species diversity, mostly concentrated in Southeast Asia. Global variation in climbing palm species richness can be partly explained by past and present-day climate and rain forest canopy height, but regional differences in residual species richness after accounting for current and past differences in environment suggest a strong role of historical contingencies in climbing palm diversification. Climbing palms show a higher net diversification rate than non-climbers. Diversification analyses of palms detected a diversification rate increase along the branches leading to the most species-rich clade of climbers. Ancestral character reconstructions revealed that the climbing habit originated between early Eocene and Miocene. These results imply that changes from non-climbing to climbing habits may have played an important role in palm diversification, resulting in the origin of one fifth of all palm species. We suggest that, in addition to current climate and paleoclimatic changes after the late Neogene, present-day diversity of climbing palms can be explained by morpho-anatomical innovations, the biogeographic history of Southeast Asia, and/or ecological opportunities due to the diversification of high-stature dipterocarps in Asian TRFs

  10. Bacilliform DNA-containing plant viruses in the tropics: commonalities within a genetically diverse group.

    PubMed

    Borah, Basanta K; Sharma, Shweta; Kant, Ravi; Johnson, A M Anthony; Saigopal, Divi Venkata Ramana; Dasgupta, Indranil

    2013-10-01

    Plant viruses, possessing a bacilliform shape and containing double-stranded DNA, are emerging as important pathogens in a number of agricultural and horticultural crops in the tropics. They have been reported from a large number of countries in African and Asian continents, as well as from islands from the Pacific region. The viruses, belonging to two genera, Badnavirus and Tungrovirus, within the family Caulimoviridae, have genomes displaying a common plan, yet are highly variable, sometimes even between isolates of the same virus. In this article, we summarize the current knowledge with a view to revealing the common features embedded within the genetic diversity of this group of viruses. Virus; order Unassigned; family Caulimoviridae; genera Badnavirus and Tungrovirus; species Banana streak viruses, Bougainvillea spectabilis chlorotic vein banding virus, Cacao swollen shoot virus, Citrus yellow mosaic badnavirus, Dioscorea bacilliform viruses, Rice tungro bacilliform virus, Sugarcane bacilliform viruses and Taro bacilliform virus. Bacilliform in shape; length, 60-900 nm; width, 35-50 nm; circular double-stranded DNA of approximately 7.5 kbp with one or more single-stranded discontinuities. Each virus generally limited to its own host, including banana, bougainvillea, black pepper, cacao, citrus species, Dioscorea alata, rice, sugarcane and taro. Foliar streaking in banana and sugarcane, swelling of shoots in cacao, yellow mosaic in leaves and stems in citrus, brown spot in the tubers in yam and yellow-orange discoloration and stunting in rice. http://www.dpvweb.net. 2013 BSPP and JOHN WILEY & SONS LTD

  11. Global diversification of a tropical plant growth form: environmental correlates and historical contingencies in climbing palms.

    PubMed

    Couvreur, Thomas L P; Kissling, W Daniel; Condamine, Fabien L; Svenning, Jens-Christian; Rowe, Nick P; Baker, William J

    2014-01-01

    Tropical rain forests (TRF) are the most diverse terrestrial biome on Earth, but the diversification dynamics of their constituent growth forms remain largely unexplored. Climbing plants contribute significantly to species diversity and ecosystem processes in TRF. We investigate the broad-scale patterns and drivers of species richness as well as the diversification history of climbing and non-climbing palms (Arecaceae). We quantify to what extent macroecological diversity patterns are related to contemporary climate, forest canopy height, and paleoclimatic changes. We test whether diversification rates are higher for climbing than non-climbing palms and estimate the origin of the climbing habit. Climbers account for 22% of global palm species diversity, mostly concentrated in Southeast Asia. Global variation in climbing palm species richness can be partly explained by past and present-day climate and rain forest canopy height, but regional differences in residual species richness after accounting for current and past differences in environment suggest a strong role of historical contingencies in climbing palm diversification. Climbing palms show a higher net diversification rate than non-climbers. Diversification analyses of palms detected a diversification rate increase along the branches leading to the most species-rich clade of climbers. Ancestral character reconstructions revealed that the climbing habit originated between early Eocene and Miocene. These results imply that changes from non-climbing to climbing habits may have played an important role in palm diversification, resulting in the origin of one fifth of all palm species. We suggest that, in addition to current climate and paleoclimatic changes after the late Neogene, present-day diversity of climbing palms can be explained by morpho-anatomical innovations, the biogeographic history of Southeast Asia, and/or ecological opportunities due to the diversification of high-stature dipterocarps in Asian TRFs.

  12. Molecular marker-based genetic diversity analysis of scantly studied Brazilian accessions of a medicinal plant, Morinda citrifolia L. (noni).

    PubMed

    Bordallo, P N; Monteiro, A M R; Sousa, J A; Aragão, F A S

    2017-02-23

    Morinda citrifolia L., commonly known as noni, has been used for the treatment of various diseases for over two centuries. It was introduced and widely disseminated in Brazil because of its high market value and ease of adaptation to the soil and climatic conditions of the country. The aim of this study was to estimate the genetic variability of noni accessions from the collection of Embrapa Agroindústria Tropical in Brazil. We evaluated 36 plants of the 13 accessions of noni from the germplasm collection of M. citrifolia. Several methods of DNA extraction were tested. After definition of the method, the DNA of each sample was subjected to polymerase chain reactions using 20 random amplified polymorphic DNA primers. The band patterns on agarose gel were converted into a binary data matrix, which was used to estimate the genetic distances between the plants and to perform the cluster analyses. Of the total number of markers used in this study, 125 (81.1%) were polymorphic. The genetic distances between the genotypes ranged from 0.04 to 0.49. Regardless of the high number of polymorphic bands, the genetic variability of the noni plants evaluated was low since most of the genotypes belonged to the same cluster as shown by the dendrogram and Tocher's cluster analysis. The low genetic diversity among the studied noni individuals indicates that additional variability should be introduced in the germplasm collection of noni by gathering new individuals and/or by hybridizing contrasting individuals.

  13. Arbuscular and Ectomycorrhizal Fungi Associated with the Invasive Brazilian Pepper Tree (Schinus terebinthifolius) and Two Native Plants in South Florida

    PubMed Central

    Dawkins, Karim; Esiobu, Nwadiuto

    2017-01-01

    The potential role of soil fungi in the invasion of the Brazilian pepper tree (Schinus terebinthifolius—BP) in Florida is not known; although the low biotic resistance of Florida soils is often invoked to explain the prevalence of many invasive species. To gain an initial insight into BP's mycorrhizal associations, this study examined the rhizobiome of BP and two native plants (Hamelia patens and Bidens alba) across six locations. Arbuscular mycorrhizal fungi (AMF) associated with the roots of the target plants and bulk soil was characterized by spore morphotyping. Sequence analysis of metagenomic DNA from lateral roots/rhizosphere of BP (n = 52) and a native shrub H. patens (n = 37) on the same parcel yielded other fungal associates. Overall, the total population of AMF associated with BP was about two folds greater than that of the two native plants (p = 0.0001) growing on the same site. The dominant AMF under Schinus were members of the common Glomus and Rhizophagus spp. By contrast, the most prevalent AMF in the bulk soil and rhizosphere of the two Florida native plants, Acaulospora spp (29%) was sharply diminished (9%) under BP rhizosphere. Analysis of the ITS2 sequences also showed that Schinus rhizosphere had a high relative abundance of ectomycorrhizal fungi (76.5%) compared to the native H. patens (2.6%), with the species Lactifluus hygrophoroides (Basidiomycota) being the most prevalent at 61.5% (p < 0.05). Unlike the native plants where pathogenic fungi like Phyllosticta sp., Phoma sp., and Neofusicoccum andium were present (8.1% for H. patens), only one potentially pathogenic fungal taxon was detected (3.9%) under BP. The striking disparity in the relative abundance of AMF and other fungal types between BP and the native species is quite significant. Fungal symbionts could aide plant invasion via resource-use efficiency and other poorly defined mechanisms of protection from pathogens in their invaded range. This report exposes a potentially

  14. Arbuscular and Ectomycorrhizal Fungi Associated with the Invasive Brazilian Pepper Tree (Schinus terebinthifolius) and Two Native Plants in South Florida.

    PubMed

    Dawkins, Karim; Esiobu, Nwadiuto

    2017-01-01

    The potential role of soil fungi in the invasion of the Brazilian pepper tree (Schinus terebinthifolius-BP) in Florida is not known; although the low biotic resistance of Florida soils is often invoked to explain the prevalence of many invasive species. To gain an initial insight into BP's mycorrhizal associations, this study examined the rhizobiome of BP and two native plants (Hamelia patens and Bidens alba) across six locations. Arbuscular mycorrhizal fungi (AMF) associated with the roots of the target plants and bulk soil was characterized by spore morphotyping. Sequence analysis of metagenomic DNA from lateral roots/rhizosphere of BP (n = 52) and a native shrub H. patens (n = 37) on the same parcel yielded other fungal associates. Overall, the total population of AMF associated with BP was about two folds greater than that of the two native plants (p = 0.0001) growing on the same site. The dominant AMF under Schinus were members of the common Glomus and Rhizophagus spp. By contrast, the most prevalent AMF in the bulk soil and rhizosphere of the two Florida native plants, Acaulospora spp (29%) was sharply diminished (9%) under BP rhizosphere. Analysis of the ITS2 sequences also showed that Schinus rhizosphere had a high relative abundance of ectomycorrhizal fungi (76.5%) compared to the native H. patens (2.6%), with the species Lactifluus hygrophoroides (Basidiomycota) being the most prevalent at 61.5% (p < 0.05). Unlike the native plants where pathogenic fungi like Phyllosticta sp., Phoma sp., and Neofusicoccum andium were present (8.1% for H. patens), only one potentially pathogenic fungal taxon was detected (3.9%) under BP. The striking disparity in the relative abundance of AMF and other fungal types between BP and the native species is quite significant. Fungal symbionts could aide plant invasion via resource-use efficiency and other poorly defined mechanisms of protection from pathogens in their invaded range. This report exposes a potentially significant

  15. Basic Research and Development Effort to Design a Micro Nuclear Power Plant for Brazilian Space Applications

    NASA Astrophysics Data System (ADS)

    Guimares, L. N. F.; Camillo, G. P.; Placco, G. M.; Barrios, G., A., Jr.; Do Nascimento, J. A.; Borges, E. M.; De Castro Lobo, P. D.

    For some years the Nuclear Energy Division of the Institute for Advanced Studies is conducting the TERRA (Portuguese abbreviation for advanced fast reactor technology) project. This project aims at research and development of the key issues related with nuclear energy applied to space technology. The purpose of this development is to allow future Brazilian space explorers the access of a good and reliable heat, power and/or propulsion system based on nuclear energy. Efforts are being made in fuel and nuclear core design, designing and building a closed Brayton cycle loop for energy conversion, heat pipe systems research for passive space heat rejection, developing computational programs for thermal loop safety analysis and other technology that may be used to improve efficiency and operation. Currently there is no specific mission that requires these technology development efforts; therefore, there is a certain degree of freedom in the organization and development efforts. This paper will present what has been achieved so far, what is the current development status, where efforts are heading and a proposed time table to meet development objectives.

  16. Genetic Diversity of Colletotrichum spp. an Endophytic Fungi in a Medicinal Plant, Brazilian Pepper Tree

    PubMed Central

    Lima, J. S.; Figueiredo, J. G.; Gomes, R. G.; Stringari, D.; Goulin, E. H.; Adamoski, D.; Kava-Cordeiro, V.; Galli-Terasawa, L. V.; Glienke, C.

    2012-01-01

    In this study, we reported thirty-nine endophytic fungi identified as Colletotrichum spp. associated with Brazilian pepper tree or aroeira (Schinus terebinthifolius Raddi. Anacardiaceae) in Paraná state, Brazil. These endophytes were identified by morphological and molecular methods, using PCR taxon-specific with CaInt/ITS4, CgInt/ITS4, and Col1/ITS4 primers, which amplify specific bands in C. acutatum, C. gloeosporioides lato sensu, and Colletotrichum boninensis, respectively, and by DNA sequence analysis of the nrDNA internal transcribed spacer region (ITS1, 5.8S, ITS2). We also assayed the presence of dsRNA particles in Colletotrichum spp. isolates. Combining both morphological characters and molecular data, we identified the species C. gloeosporioides, C. boninense, and C. simmondsii. However, we found a high genetic variability intraspecific in C. gloeosporioides which suggests the existence of several other species. Bands of double-stranded RNA (dsRNA) were detected in three of thirty-nine isolates. Identity of these bands was confirmed by RNAse, DNAse, and S1 nuclease treatments for the isolates LGMF633, LGMF726, and LGMF729. This is the first study reporting these particles of dsRNA in C. gloeosporioides. PMID:23724319

  17. The Multiple Impacts of Tropical Forest Fragmentation on Arthropod Biodiversity and on their Patterns of Interactions with Host Plants

    PubMed Central

    Benítez-Malvido, Julieta; Dáttilo, Wesley; Martínez-Falcón, Ana Paola; Durán-Barrón, César; Valenzuela, Jorge; López, Sara; Lombera, Rafael

    2016-01-01

    Tropical rain forest fragmentation affects biotic interactions in distinct ways. Little is known, however, about how fragmentation affects animal trophic guilds and their patterns of interactions with host plants. In this study, we analyzed changes in biotic interactions in forest fragments by using a multitrophic approach. For this, we classified arthropods associated with Heliconia aurantiaca herbs into broad trophic guilds (omnivores, herbivores and predators) and assessed the topological structure of intrapopulation plant-arthropod networks in fragments and continuous forests. Habitat type influenced arthropod species abundance, diversity and composition with greater abundance in fragments but greater diversity in continuous forest. According to trophic guilds, coleopteran herbivores were more abundant in continuous forest and overall omnivores in fragments. Continuous forest showed a greater diversity of interactions than fragments. Only in fragments, however, did the arthropod community associated with H aurantiaca show a nested structure, suggesting novel and/or opportunistic host-arthropod associations. Plants, omnivores and predators contributed more to nestedness than herbivores. Therefore, Heliconia-arthropod network properties do not appear to be maintained in fragments mainly caused by the decrease of herbivores. Our study contributes to the understanding of the impact of fragmentation on the structure and dynamics of multitrophic arthropod communities associated with a particular plant species of the highly biodiverse tropical forests. Nevertheless, further replication of study sites is needed to strengthen the conclusion that forest fragmentation negatively affects arthropod assemblages. PMID:26731271

  18. The Multiple Impacts of Tropical Forest Fragmentation on Arthropod Biodiversity and on their Patterns of Interactions with Host Plants.

    PubMed

    Benítez-Malvido, Julieta; Dáttilo, Wesley; Martínez-Falcón, Ana Paola; Durán-Barrón, César; Valenzuela, Jorge; López, Sara; Lombera, Rafael

    2016-01-01

    Tropical rain forest fragmentation affects biotic interactions in distinct ways. Little is known, however, about how fragmentation affects animal trophic guilds and their patterns of interactions with host plants. In this study, we analyzed changes in biotic interactions in forest fragments by using a multitrophic approach. For this, we classified arthropods associated with Heliconia aurantiaca herbs into broad trophic guilds (omnivores, herbivores and predators) and assessed the topological structure of intrapopulation plant-arthropod networks in fragments and continuous forests. Habitat type influenced arthropod species abundance, diversity and composition with greater abundance in fragments but greater diversity in continuous forest. According to trophic guilds, coleopteran herbivores were more abundant in continuous forest and overall omnivores in fragments. Continuous forest showed a greater diversity of interactions than fragments. Only in fragments, however, did the arthropod community associated with H aurantiaca show a nested structure, suggesting novel and/or opportunistic host-arthropod associations. Plants, omnivores and predators contributed more to nestedness than herbivores. Therefore, Heliconia-arthropod network properties do not appear to be maintained in fragments mainly caused by the decrease of herbivores. Our study contributes to the understanding of the impact of fragmentation on the structure and dynamics of multitrophic arthropod communities associated with a particular plant species of the highly biodiverse tropical forests. Nevertheless, further replication of study sites is needed to strengthen the conclusion that forest fragmentation negatively affects arthropod assemblages.

  19. Convergence beyond flower morphology? Reproductive biology of hummingbird-pollinated plants in the Brazilian Cerrado.

    PubMed

    Ferreira, C; Maruyama, P K; Oliveira, P E

    2016-03-01

    Convergent reproductive traits in non-related plants may be the result of similar environmental conditions and/or specialised interactions with pollinators. Here, we documented the pollination and reproductive biology of Bionia coriacea (Fabaceae), Esterhazya splendida (Orobanchaceae) and Ananas ananassoides (Bromeliaceae) as case studies in the context of hummingbird pollination in Cerrado, the Neotropical savanna of Central South America. We combined our results with a survey of hummingbird pollination studies in the region to investigate the recently suggested association of hummingbird pollination and self-compatibility. Plant species studied here differed in their specialisation for ornithophily, from more generalist A. ananassoides to somewhat specialist B. coriacea and E. splendida. This continuum of specialisation in floral traits also translated into floral visitor composition. Amazilia fimbriata was the most frequent pollinator for all species, and the differences in floral display and nectar energy availability among plant species affect hummingbirds' behaviour. Most of the hummingbird-pollinated Cerrado plants (60.0%, n = 20), including those studied here, were self-incompatible, in contrast to other biomes in the Neotropics. Association to more generalist, often territorial, hummingbirds, and resulting reduced pollen flow in open savanna areas may explain predominance of self-incompatibility. But it is possible that mating system is more associated with the predominance of woody hummingbird plants in the Cerrado plant assemblage than to the pollination system itself. © 2015 German Botanical Society and The Royal Botanical Society of the Netherlands.

  20. Plant Traits Demonstrate That Temperate and Tropical Giant Eucalypt Forests Are Ecologically Convergent with Rainforest Not Savanna

    PubMed Central

    Tng, David Y. P.; Jordan, Greg J.; Bowman, David M. J. S.

    2013-01-01

    Ecological theory differentiates rainforest and open vegetation in many regions as functionally divergent alternative stable states with transitional (ecotonal) vegetation between the two forming transient unstable states. This transitional vegetation is of considerable significance, not only as a test case for theories of vegetation dynamics, but also because this type of vegetation is of major economic importance, and is home to a suite of species of conservation significance, including the world’s tallest flowering plants. We therefore created predictions of patterns in plant functional traits that would test the alternative stable states model of these systems. We measured functional traits of 128 trees and shrubs across tropical and temperate rainforest – open vegetation transitions in Australia, with giant eucalypt forests situated between these vegetation types. We analysed a set of functional traits: leaf carbon isotopes, leaf area, leaf mass per area, leaf slenderness, wood density, maximum height and bark thickness, using univariate and multivariate methods. For most traits, giant eucalypt forest was similar to rainforest, while rainforest, particularly tropical rainforest, was significantly different from the open vegetation. In multivariate analyses, tropical and temperate rainforest diverged functionally, and both segregated from open vegetation. Furthermore, the giant eucalypt forests overlapped in function with their respective rainforests. The two types of giant eucalypt forests also exhibited greater overall functional similarity to each other than to any of the open vegetation types. We conclude that tropical and temperate giant eucalypt forests are ecologically and functionally convergent. The lack of clear functional differentiation from rainforest suggests that giant eucalypt forests are unstable states within the basin of attraction of rainforest. Our results have important implications for giant eucalypt forest management. PMID:24358359

  1. Plant traits demonstrate that temperate and tropical giant eucalypt forests are ecologically convergent with rainforest not savanna.

    PubMed

    Tng, David Y P; Jordan, Greg J; Bowman, David M J S

    2013-01-01

    Ecological theory differentiates rainforest and open vegetation in many regions as functionally divergent alternative stable states with transitional (ecotonal) vegetation between the two forming transient unstable states. This transitional vegetation is of considerable significance, not only as a test case for theories of vegetation dynamics, but also because this type of vegetation is of major economic importance, and is home to a suite of species of conservation significance, including the world's tallest flowering plants. We therefore created predictions of patterns in plant functional traits that would test the alternative stable states model of these systems. We measured functional traits of 128 trees and shrubs across tropical and temperate rainforest - open vegetation transitions in Australia, with giant eucalypt forests situated between these vegetation types. We analysed a set of functional traits: leaf carbon isotopes, leaf area, leaf mass per area, leaf slenderness, wood density, maximum height and bark thickness, using univariate and multivariate methods. For most traits, giant eucalypt forest was similar to rainforest, while rainforest, particularly tropical rainforest, was significantly different from the open vegetation. In multivariate analyses, tropical and temperate rainforest diverged functionally, and both segregated from open vegetation. Furthermore, the giant eucalypt forests overlapped in function with their respective rainforests. The two types of giant eucalypt forests also exhibited greater overall functional similarity to each other than to any of the open vegetation types. We conclude that tropical and temperate giant eucalypt forests are ecologically and functionally convergent. The lack of clear functional differentiation from rainforest suggests that giant eucalypt forests are unstable states within the basin of attraction of rainforest. Our results have important implications for giant eucalypt forest management.

  2. Brazilian Consensus on Photoprotection

    PubMed Central

    Schalka, Sérgio; Steiner, Denise; Ravelli, Flávia Naranjo; Steiner, Tatiana; Terena, Aripuanã Cobério; Marçon, Carolina Reato; Ayres, Eloisa Leis; Addor, Flávia Alvim Sant'anna; Miot, Helio Amante; Ponzio, Humberto; Duarte, Ida; Neffá, Jane; da Cunha, José Antônio Jabur; Boza, Juliana Catucci; Samorano, Luciana de Paula; Corrêa, Marcelo de Paula; Maia, Marcus; Nasser, Nilton; Leite, Olga Maria Rodrigues Ribeiro; Lopes, Otávio Sergio; Oliveira, Pedro Dantas; Meyer, Renata Leal Bregunci; Cestari, Tânia; dos Reis, Vitor Manoel Silva; Rego, Vitória Regina Pedreira de Almeida

    2014-01-01

    Brazil is a country of continental dimensions with a large heterogeneity of climates and massive mixing of the population. Almost the entire national territory is located between the Equator and the Tropic of Capricorn, and the Earth axial tilt to the south certainly makes Brazil one of the countries of the world with greater extent of land in proximity to the sun. The Brazilian coastline, where most of its population lives, is more than 8,500 km long. Due to geographic characteristics and cultural trends, Brazilians are among the peoples with the highest annual exposure to the sun. Epidemiological data show a continuing increase in the incidence of non-melanoma and melanoma skin cancers. Photoprotection can be understood as a set of measures aimed at reducing sun exposure and at preventing the development of acute and chronic actinic damage. Due to the peculiarities of Brazilian territory and culture, it would not be advisable to replicate the concepts of photoprotection from other developed countries, places with completely different climates and populations. Thus the Brazilian Society of Dermatology has developed the Brazilian Consensus on Photoprotection, the first official document on photoprotection developed in Brazil for Brazilians, with recommendations on matters involving photoprotection. PMID:25761256

  3. Brazilian consensus on photoprotection.

    PubMed

    Schalka, Sérgio; Steiner, Denise; Ravelli, Flávia Naranjo; Steiner, Tatiana; Terena, Aripuanã Cobério; Marçon, Carolina Reato; Ayres, Eloisa Leis; Addor, Flávia Alvim Sant'anna; Miot, Helio Amante; Ponzio, Humberto; Duarte, Ida; Neffá, Jane; Cunha, José Antônio Jabur da; Boza, Juliana Catucci; Samorano, Luciana de Paula; Corrêa, Marcelo de Paula; Maia, Marcus; Nasser, Nilton; Leite, Olga Maria Rodrigues Ribeiro; Lopes, Otávio Sergio; Oliveira, Pedro Dantas; Meyer, Renata Leal Bregunci; Cestari, Tânia; Reis, Vitor Manoel Silva dos; Rego, Vitória Regina Pedreira de Almeida

    2014-01-01

    Brazil is a country of continental dimensions with a large heterogeneity of climates and massive mixing of the population. Almost the entire national territory is located between the Equator and the Tropic of Capricorn, and the Earth axial tilt to the south certainly makes Brazil one of the countries of the world with greater extent of land in proximity to the sun. The Brazilian coastline, where most of its population lives, is more than 8,500 km long. Due to geographic characteristics and cultural trends, Brazilians are among the peoples with the highest annual exposure to the sun. Epidemiological data show a continuing increase in the incidence of non-melanoma and melanoma skin cancers. Photoprotection can be understood as a set of measures aimed at reducing sun exposure and at preventing the development of acute and chronic actinic damage. Due to the peculiarities of Brazilian territory and culture, it would not be advisable to replicate the concepts of photoprotection from other developed countries, places with completely different climates and populations. Thus the Brazilian Society of Dermatology has developed the Brazilian Consensus on Photoprotection, the first official document on photoprotection developed in Brazil for Brazilians, with recommendations on matters involving photoprotection.

  4. Antimalarial drug discovery: screening of Brazilian medicinal plants and purified compounds.

    PubMed

    Krettli, Antoniana Ursine

    2009-02-01

    Malaria is the most important parasitic disease and its control depends on specific chemotherapy, now complicated by Plasmodium falciparum that has become resistant to most commonly available antimalarials. Treatment of the disease requires quinine or drug combinations of artemisinin derivatives and other antimalarials. Further drug resistance is expected. New active compounds need to be discovered. To find new antimalarials from medicinal and randomly collected plants, crude extracts are screened against P. falciparum in cultures and in malaria animal models, following bioassays of purified fractions, and cytotoxicity tests. For antimalarial research, screening medicinal plants is more efficient than screening randomly chosen plants. Biomonitored fractionation allows selection of new active molecules identified as potential antimalarials in multidisciplinary projects in Brazil; no new molecule is available for human testing. The advantages of projects based on ethnopharmacology are discussed.

  5. Polychlorinated biphenyls and polybrominated diphenylethers in soils from planted forests and adjacent natural forests on a tropical island.

    PubMed

    Liu, Xin; Wang, Shuai; Jiang, Yishan; Sun, Yingtao; Li, Jun; Zhang, Gan

    2017-08-01

    Transformation from natural forests to planted forests in tropical regions is an expanding global phenomenon causing major modifications of land cover and soil properties, e.g. soil organic carbon (SOC). This study investigated accumulations of POPs in soils under eucalyptus and rubber forests as compared with adjacent natural forests on Hainan Island, China. Results showed that due to the greater forest filter effect and the higher SOC, the natural forest have accumulated larger amounts of POPs in the top 20 cm soil. Based on correlation and air-soil equilibrium analysis, we highlighted the importance of SOC in the distribution of POPs. It is assumed that the elevated mobility of POPs in the planted forests was caused by greater loss of SOC and extensive leaching in the soil profile. This suggests that a better understanding of global POPs fate should take into consideration the role of planted forests. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Chemical Composition and Larvicidal Activity of Essential Oils Extracted from Brazilian Legal Amazon Plants against Aedes aegypti L. (Diptera: Culicidae)

    PubMed Central

    Dias, Clarice Noleto; Alves, Luciana Patrícia Lima; Rodrigues, Klinger Antonio da Franca; Brito, Maria Cristiane Aranha; Rosa, Carliane dos Santos; do Amaral, Flavia Maria Mendonça; Monteiro, Odair dos Santos; Andrade, Eloisa Helena de Aguiar; Maia, José Guilherme Soares; Moraes, Denise Fernandes Coutinho

    2015-01-01

    The mosquito Aedes aegypti L. (Diptera: Culicidae) is the major vector of dengue and chikungunya fever. The lack of effective therapies and vaccines for these diseases highlights the need for alternative strategies to control the spread of virus. Therefore, this study investigated the larvicidal potential of essential oils from common plant species obtained from the Chapada das Mesas National Park, Brazil, against third instar A. aegypti larvae. The chemical composition of these oils was determined by gas chromatography coupled to mass spectrometry. The essential oils of Eugenia piauhiensis Vellaff., Myrcia erythroxylon O. Berg, Psidium myrsinites DC., and Siparuna camporum (Tul.) A. DC. were observed to be mainly composed of sesquiterpene hydrocarbons. The essential oil of Lippia gracilis Schauer was composed of oxygenated monoterpenes. Four of the five tested oils were effective against the A. aegypti larvae, with the lethal concentration (LC50) ranging from 230 to 292 mg/L after 24 h of exposure. Overall, this work demonstrated the possibility of developing larvicidal products against A. aegypti by using essential oils from the flora of the Brazilian Legal Amazon. This in turn demonstrates the potential of using natural resources for the control of disease vectors. PMID:25949264

  7. Endophytic Actinobacteria from the Brazilian Medicinal Plant Lychnophora ericoides Mart. and the Biological Potential of Their Secondary Metabolites.

    PubMed

    Conti, Raphael; Chagas, Fernanda Oliveira; Caraballo-Rodriguez, Andrés Mauricio; Melo, Weilan Gomes da Paixão; do Nascimento, Andréa Mendes; Cavalcanti, Bruno Coêlho; de Moraes, Manoel Odorico; Pessoa, Cláudia; Costa-Lotufo, Letícia Veras; Krogh, Renata; Andricopulo, Adriano Defini; Lopes, Norberto Peporine; Pupo, Mônica Tallarico

    2016-06-01

    Endophytic actinobacteria from the Brazilian medicinal plant Lychnophora ericoides were isolated for the first time, and the biological potential of their secondary metabolites was evaluated. A phylogenic analysis of isolated actinobacteria was accomplished with 16S rRNA gene sequencing, and the predominance of the genus Streptomyces was observed. All strains were cultured on solid rice medium, and ethanol extracts were evaluated with antimicrobial and cytotoxic assays against cancer cell lines. As a result, 92% of the extracts showed a high or moderate activity against at least one pathogenic microbial strain or cancer cell line. Based on the biological and chemical analyses of crude extracts, three endophytic strains were selected for further investigation of their chemical profiles. Sixteen compounds were isolated, and 3-hydroxy-4-methoxybenzamide (9) and 2,3-dihydro-2,2-dimethyl-4(1H)-quinazolinone (15) are reported as natural products for the first time in this study. The biological activity of the pure compounds was also assessed. Compound 15 displayed potent cytotoxic activity against all four tested cancer cell lines. Nocardamine (2) was only moderately active against two cancer cell lines but showed strong activity against Trypanosoma cruzi. Our results show that endophytic actinobacteria from L. ericoides are a promising source of bioactive compounds.

  8. Antifungal activity of Brazilian medicinal plants involved in popular treatment of mycoses.

    PubMed

    Cruz, M C S; Santos, P O; Barbosa, A M; de Mélo, D L F M; Alviano, C S; Antoniolli, A R; Alviano, D S; Trindade, R C

    2007-05-04

    A survey of medicinal plants used to treat common mycoses was done in the Curituba district, Sergipe State, Brazil. One hundred inhabitants were interviewed by health agents and traditional healers. Four different plants were the most cited (more than 50% of the citations): Ziziphus joazeiro, Caesalpinia pyramidalis, Bumelia sartorum and Hymenea courbaril. The aqueous extracts obtained following traditional methods and using different parts of these plants, were submitted to drop agar diffusion tests for primary antimicrobial screening. Only the water infusion extract of Ziziphus joazeiro and Caesalpinea pyramidalis presented a significant antifungal activity against Trichophyton rubrum, Candida guilliermondii, Candida albicans, Cryptococcus neoformans and Fonsecaea pedrosoi, when compared to the antifungal agent amphotericin B. The minimal inhibitory concentration (MIC) of the bioactive extracts was evaluated by the microdilution method. Best activity with a MIC of 6.5 microg/ml for both extracts was observed against Trichophyton rubrum and Candida guilliermondii. Ziziphus joazeiro and Caesalpinea pyramidalis extracts presented also low acute toxicity in murine models. The present study validates the folk use of these plant extracts and indicates that they can be effective potential candidates for the development of new strategies to treat fungal infections.

  9. In vitro and in vivo anti-malarial activity of plants from the Brazilian Amazon.

    PubMed

    Lima, Renata B S; Rocha e Silva, Luiz F; Melo, Marcia R S; Costa, Jaqueline S; Picanço, Neila S; Lima, Emerson S; Vasconcellos, Marne C; Boleti, Ana Paula A; Santos, Jakeline M P; Amorim, Rodrigo C N; Chaves, Francisco C M; Coutinho, Julia P; Tadei, Wanderli P; Krettli, Antoniana U; Pohlit, Adrian M

    2015-12-18

    The anti-malarials quinine and artemisinin were isolated from traditionally used plants (Cinchona spp. and Artemisia annua, respectively). The synthetic quinoline anti-malarials (e.g. chloroquine) and semi-synthetic artemisinin derivatives (e.g. artesunate) were developed based on these natural products. Malaria is endemic to the Amazon region where Plasmodium falciparum and Plasmodium vivax drug-resistance is of concern. There is an urgent need for new anti-malarials. Traditionally used Amazonian plants may provide new treatments for drug-resistant P. vivax and P. falciparum. Herein, the in vitro and in vivo antiplasmodial activity and cytotoxicity of medicinal plant extracts were investigated. Sixty-nine extracts from 11 plant species were prepared and screened for in vitro activity against P. falciparum K1 strain and for cytotoxicity against human fibroblasts and two melanoma cell lines. Median inhibitory concentrations (IC50) were established against chloroquine-resistant P. falciparum W2 clone using monoclonal anti-HRPII (histidine-rich protein II) antibodies in an enzyme-linked immunosorbent assay. Extracts were evaluated for toxicity against murine macrophages (IC50) and selectivity indices (SI) were determined. Three extracts were also evaluated orally in Plasmodium berghei-infected mice. High in vitro antiplasmodial activity (IC50 = 6.4-9.9 µg/mL) was observed for Andropogon leucostachyus aerial part methanol extracts, Croton cajucara red variety leaf chloroform extracts, Miconia nervosa leaf methanol extracts, and Xylopia amazonica leaf chloroform and branch ethanol extracts. Paullinia cupana branch chloroform extracts and Croton cajucara red variety leaf ethanol extracts were toxic to fibroblasts and or melanoma cells. Xylopia amazonica branch ethanol extracts and Zanthoxylum djalma-batistae branch chloroform extracts were toxic to macrophages (IC50 = 6.9 and 24.7 µg/mL, respectively). Andropogon leucostachyus extracts were the most selective (SI >28

  10. Isolation, Diversity, and Antimicrobial Activity of Rare Actinobacteria from Medicinal Plants of Tropical Rain Forests in Xishuangbanna, China▿ †

    PubMed Central

    Qin, Sheng; Li, Jie; Chen, Hua-Hong; Zhao, Guo-Zhen; Zhu, Wen-Yong; Jiang, Cheng-Lin; Xu, Li-Hua; Li, Wen-Jun

    2009-01-01

    Endophytic actinobacteria are relatively unexplored as potential sources of novel species and novel natural products for medical and commercial exploitation. Xishuangbanna is recognized throughout the world for its diverse flora, especially the rain forest plants, many of which have indigenous pharmaceutical histories. However, little is known about the endophytic actinobacteria of this tropical area. In this work, we studied the diversity of actinobacteria isolated from medicinal plants collected from tropical rain forests in Xishuangbanna. By the use of different selective isolation media and methods, a total of 2,174 actinobacteria were isolated. Forty-six isolates were selected on the basis of their morphologies on different media and were further characterized by 16S rRNA gene sequencing. The results showed an unexpected level of diversity, with 32 different genera. To our knowledge, this is the first report describing the isolation of Saccharopolyspora, Dietzia, Blastococcus, Dactylosporangium, Promicromonospora, Oerskovia, Actinocorallia, and Jiangella species from endophytic environments. At least 19 isolates are considered novel taxa by our current research. In addition, all 46 isolates were tested for antimicrobial activity and were screened for the presence of genes encoding polyketide synthetases and nonribosomal peptide synthetases. The results confirm that the medicinal plants of Xishuangbanna represent an extremely rich reservoir for the isolation of a significant diversity of actinobacteria, including novel species, that are potential sources for the discovery of biologically active compounds. PMID:19648362

  11. Anti-Streptococcal activity of Brazilian Amazon Rain Forest plant extracts presents potential for preventive strategies against dental caries

    PubMed Central

    da SILVA, Juliana Paola Corrêa; de CASTILHO, Adriana Lígia; SARACENI, Cíntia Helena Couri; DÍAZ, Ingrit Elida Collantes; PACIÊNCIA, Mateus Luís Barradas; SUFFREDINI, Ivana Barbosa

    2014-01-01

    Caries is a global public health problem, whose control requires the introduction of low-cost treatments, such as strong prevention strategies, minimally invasive techniques and chemical prevention agents. Nature plays an important role as a source of new antibacterial substances that can be used in the prevention of caries, and Brazil is the richest country in terms of biodiversity. Objective In this study, the disk diffusion method (DDM) was used to screen over 2,000 Brazilian Amazon plant extracts against Streptococcus mutans. Material and Methods Seventeen active plant extracts were identified and fractionated. Extracts and their fractions, obtained by liquid-liquid partition, were tested in the DDM assay and in the microdilution broth assay (MBA) to determine their minimal inhibitory concentrations (MICs) and minimal bactericidal concentrations (MBCs). The extracts were also subjected to antioxidant analysis by thin layer chromatography. Results EB271, obtained from Casearia spruceana, showed significant activity against the bacterium in the DDM assay (20.67±0.52 mm), as did EB1129, obtained from Psychotria sp. (Rubiaceae) (15.04±2.29 mm). EB1493, obtained from Ipomoea alba, was the only extract to show strong activity against Streptococcus mutans (0.08 mg/mL

  12. Antifungal activity of extracts of some plants used in Brazilian traditional medicine against the pathogenic fungus Paracoccidioides brasiliensis.

    PubMed

    Johann, Susana; Cisalpino, Patricia Silva; Watanabe, Gisele Almeida; Cota, Betania Barros; de Siqueira, Ezequias Pessoa; Pizzolatti, Moacir Geraldo; Zani, Carlos Leomar; de Resende, Maria Aparecida

    2010-04-01

    Paracoccidioidomycosis (PCM) is a systemic granulomatous disease caused by Paracoccidioides brasiliensis Almeida (Onygenales) that requires 1-2 years of treatment. In the absence of drug therapy, the disease is usually fatal, highlighting the need for the identification of safer, novel, and more effective antifungal compounds. With this need in mind, several plants employed in Brazilian traditional medicine were assayed on P. brasiliensis and murine macrophages. Extracts were prepared from 10 plant species: Inga spp. Mill. (Leguminosae), Schinus terebinthifolius Raddi (Anacardiaceae), Punica granatum L. (Punicaceae), Alternanthera brasiliana Kuntze (Amaranthaceae), Piper regnellii CDC. (Piperaceae), P. abutiloides Kunth (Piperaceae), Herissantia crispa L. Briz. (Malvaceae), Rubus urticaefolius Poir (Rosaceae), Rumex acetosa L. (Polygonaceae), and Baccharis dracunculifolia DC. (Asteraceae). Hexane fractions from hydroalcoholic extracts of Piper regnellii and Baccharis dracunculifolia were the most active against the fungus, displaying minimum inhibitory concentration (MIC) values of 7.8 microg/mL and 7.8-30 mug/mL, respectively. Additionally, neither of the extracts exhibited any apparent cytotoxic effects on murine macrophages at 20 microg/mL. Analyses of these fractions using gas chromatography-mass spectrometry (GC-MS) showed that the major components of B. dracunculifolia were ethyl hydrocinnamate (14.35%) and spathulenol (16.02%), while the major components of the hexane fraction of Piper regnellii were 1-methoxy-4-(1-propenyl) benzene (21.94%) and apiol (21.29%). The activities of these fractions against P. brasiliensis without evidence of cytotoxicity to macrophages justify their investigation as a potential source of new chemical agents for the treatment of PCM.

  13. Differential responses of C3 and CAM native Brazilian plant species to a SO2- and SPMFe-contaminated Restinga.

    PubMed

    da Silva, Luzimar Campos; de Araújo, Talita Oliveira; Martinez, Carlos Alberto; de Almeida Lobo, Francisco; Azevedo, Aristéa Alves; Oliva, Marco Antonio

    2015-09-01

    Aiming to evaluate responses in terms of growth rates, physiological parameters, and degree of sensitivity to SO2 and SPMFe in Eugenia uniflora L. (Myrtaceae, a C3 species) and Clusia hilariana Schlecht (Clusiaceae, a CAM species); saplings were exposed to emissions from a pelletizing factory for 7 months. The species were distributed along a transect (200, 500, 800, 1400, and 1700 m away from the emission source), and analyses were performed after 71, 118, and 211 days of exposure to the pollutants. E. uniflora received higher superficial deposition of particulate iron. The highest total iron foliar contents were observed 200 m away from the emission source in both plant species, while the highest total sulfur foliar contents were observed 200 m away in C. hilariana and 800 m away in E. uniflora. E. uniflora presented decreased values of height growth rate, number of necrotic leaves, chlorophyll analysis (SPAD index) and transpiration, in relation to the distances from the emission source. C. hilariana showed decreased values of height growth rate, number of leaves, number of necrotic leaves, total ionic permeability, stomatal conductance, transpiration, net CO2 assimilation, and total dry matter, in relation to distances from the emission source. In relation to the days of exposure, both species presented increased number of necrotic leaves and foliar phytotoxicity index, and decreased values in the chlorophyll analysis. The two native plant species, both of which occur in the Brazilian Restinga, showed damage when exposed to emissions from an iron ore pelletizing factory. C. hilariana was considered the most sensitive species due to the decreased values in a higher number of variables after exposition.

  14. Higher β-diversity observed for herbs over woody plants is driven by stronger habitat filtering in a tropical understory.

    PubMed

    Murphy, Stephen J; Salpeter, Kara; Comita, Liza S

    2016-08-01

    Herbaceous plants are a key component of tropical forests. Previous work indicates that herbs contribute substantially to the species richness of tropical plant communities. However, the processes structuring tropical herb diversity, and how they contrast with woody communities, have been underexplored. Within the understory of a 50-ha forest dynamics plot in central Panama, we compared the diversity, distribution, and abundance of vascular herbaceous plants with woody seedlings (i.e., tree and lianas <1 cm DBH and ≥20 cm tall). Beta-diversity was calculated for each community using a null model approach. We then assessed the similarity in alpha and beta-diversity among herbs, tree seedlings, and liana seedlings. Strengths of habitat associations were measured using permutational ANOVA among topographic habitat-types. Variance partitioning was then used to quantify the amount of variation in species richness and composition explained by spatial and environmental variables (i.e., topography, soils, and shade) for each growth form. Species richness and diversity were highest for tree seedlings, followed by liana seedlings and then herbs. In contrast, beta-diversity was 16-127% higher for herbs compared to woody seedlings, indicating higher spatial variation in this stratum. We observed no correlation between local richness or compositional uniqueness of herbs and woody seedlings across sites, indicating that different processes control the spatial patterns of woody and herbaceous diversity and composition. Habitat associations were strongest for herbs, as indicated by greater compositional dissimilarity among habitat types. Likewise, environmental variables explained a larger proportion of the variation in species richness and composition for herbs than for woody seedlings (richness = 25%, 14%, 12%; composition = 25%, 9%, 6%, for herbs, trees, and lianas, respectively). These differences between strata did not appear to be due to differences in lifespan alone

  15. Antioxidant activity of five Brazilian plants used as traditional medicines and food in Brazil

    PubMed Central

    Santos, Allana K. L.; Costa, José G. M.; Menezes, Irwin R. A.; Cansanção, Isaac F.; Santos, Karla K. A.; Matias, Edinardo F. F.; Coutinho, Henrique D. M.

    2010-01-01

    Background: This study evaluates the radical-scavenging activity of five plants used as food and medicines in the northeastern region of Brazil. Materials and Methods: Spectrophotometric analysis of the plants’ ethanol extracts was carried out. The antioxidant activity was determined by the DPPH (2,2-diphenyl-1 picrylhydrazyl) test. The antioxidant capacity was measured using ascorbic acid as a positive control. Results: All tested plant extracts showed an antioxidant activity, but the highest activity was observed with the extracts of Momordica charantia and Eugenia jambolana. Conclusions: Therefore, these species must be studied as a putative source of products for use in the prevention and treatment of diseases in which oxidants or free radicals are implicated. PMID:21120039

  16. Do Epigeal Termite Mounds Increase the Diversity of Plant Habitats in a Tropical Rain Forest in Peninsular Malaysia?

    PubMed Central

    Beaudrot, Lydia; Du, Yanjun; Rahman Kassim, Abdul; Rejmánek, Marcel; Harrison, Rhett D.

    2011-01-01

    The extent to which environmental heterogeneity can account for tree species coexistence in diverse ecosystems, such as tropical rainforests, is hotly debated, although the importance of spatial variability in contributing to species co-existence is well recognized. Termites contribute to the micro-topographical and nutrient spatial heterogeneity of tropical forests. We therefore investigated whether epigeal termite mounds could contribute to the coexistence of plant species within a 50 ha plot at Pasoh Forest Reserve, Malaysia. Overall, stem density was significantly higher on mounds than in their immediate surroundings, but tree species diversity was significantly lower. Canonical correspondence analysis showed that location on or off mounds significantly influenced species distribution when stems were characterized by basal area. Like studies of termite mounds in other ecosystems, our results suggest that epigeal termite mounds provide a specific microhabitat for the enhanced growth and survival of certain species in these species-rich tropical forests. However, the extent to which epigeal termite mounds facilitate species coexistence warrants further investigation. PMID:21625558

  17. Do epigeal termite mounds increase the diversity of plant habitats in a tropical rain forest in peninsular Malaysia?

    PubMed

    Beaudrot, Lydia; Du, Yanjun; Rahman Kassim, Abdul; Rejmánek, Marcel; Harrison, Rhett D

    2011-01-01

    The extent to which environmental heterogeneity can account for tree species coexistence in diverse ecosystems, such as tropical rainforests, is hotly debated, although the importance of spatial variability in contributing to species co-existence is well recognized. Termites contribute to the micro-topographical and nutrient spatial heterogeneity of tropical forests. We therefore investigated whether epigeal termite mounds could contribute to the coexistence of plant species within a 50 ha plot at Pasoh Forest Reserve, Malaysia. Overall, stem density was significantly higher on mounds than in their immediate surroundings, but tree species diversity was significantly lower. Canonical correspondence analysis showed that location on or off mounds significantly influenced species distribution when stems were characterized by basal area. Like studies of termite mounds in other ecosystems, our results suggest that epigeal termite mounds provide a specific microhabitat for the enhanced growth and survival of certain species in these species-rich tropical forests. However, the extent to which epigeal termite mounds facilitate species coexistence warrants further investigation.

  18. Bitter plants used as substitute of Cinchona spp. (quina) in Brazilian traditional medicine.

    PubMed

    Cosenza, Gustavo P; Somavilla, Nádia S; Fagg, Christopher W; Brandão, Maria G L

    2013-10-07

    Bitter tasting plant species are used as tonics and have been previously used to treat intermittent fevers in Brazil, the principal symptom of malaria. Many of these species were named quina and were used as substitutes of Cinchona spp., the source of quinine. To present data on these bitter species named quina and to discuss their potential as sources of bioactive substances. Data about the plants were obtained from a survey of the literature and documents written by early naturalists and clinical doctors living in the 18th and 19th centuries in Brazil. Correlated pharmacological studies were obtained from different scientific databases. A total of 29 species were recorded. The largest number of species belonged to the Rubiaceae family (14), being Remijia ferruginea (A. St.-Hil) DC. the most representative. Strychnos pseudoquina A. St.-Hil. (Loganiaceae), Hortia brasiliana Vand. ex DC. (Rutaceae) and Solanum pseudoquina A. St.-Hil. (Solanaceae) were also frequently mentioned in the historical bibliography. Pharmacological studies have shown the presence of bitter bioactive substances useful to treat digestive disorders and/or with antimalarial activities, in all of the recorded botanic families. This study shows that several bitter species named quina were used in the past as substitute of Cinchona spp. and studying these plants can lead to the development of new products. © 2013 Elsevier Ireland Ltd. All rights reserved.

  19. Arbuscular mycorrhizal associations and occurrence of dark septate endophytes in the roots of Brazilian weed plants.

    PubMed

    Massenssini, André Marcos; Bonduki, Víctor Hugo Araújo; Tótola, Marcos Rogério; Ferreira, Francisco Affonso; Costa, Maurício Dutra

    2014-02-01

    The ecology of weed plants includes their interactions with soil microorganisms, such as mutualistic partners that may contribute to their adaptation and competitive success in the agricultural fields. Despite the importance of microorganisms to plant growth, knowledge on weed-symbiont associations is still incipient compared to crops. Thus, a survey for the presence of arbuscular mycorrhiza (AM) and dark septate endophyte (DSE) associations in the roots of 50 weed species was done in three distinct areas during the dry and rainy seasons. We found that 41 and 29 out of the 50 species were associated with AM fungi and DSE, respectively, and 27 species presented both associations. All the plant species not forming AM belong to families thought to be nonmycorrhizal, such as Amaranthaceae, Commelinaceae, Brassicaceae, and Cyperaceae. The most common morphotype of AM observed was the Arum-type. No significant differences were found in root length colonization between the areas or seasons. For 19 species surveyed, this is the first report on their mycorrhizal status.

  20. Insect herbivory in model tropical plant communities after 1. 5 years exposure to elevated CO[sub 2

    SciTech Connect

    Arnone, J.A. III; Zaller, J.G.; Korner, C.; Ziegler, C.; Zandt, H. )

    1994-06-01

    Insect herbivores have been observed to practice compensatory feeding when providing leaves from plants grown under elevated atmospheric CO[sub 2]. This has been attributed to reductions in leaf quality (e.g. increased C:N ratio) occurring at high CO[sub 2]. However, no data are available on feeding patterns in plant communications exposed to high CO[sub 2], where insects can choose among species and canopy layers. We introduced 100 Spodoptera eridania larvae to each of four identically-planted communities of moist tropical species (80 plants, 7 spp.) after 1.5 years exposure to either ambient (340 [mu]l l[sup [minus]1]) or elevated (610 [mu]l l[sup [minus]1]) CO[sub 2]. Species representing contrasting life forms were installed in 6.7 m[sup 2] closed ecosystems, each with a common soil. Larvae actively fed in all communities, but the total amount of leaf area and leaf biomass consumed was similar at both CO[sub 2] levels. Elevated CO[sub 2] did alter herbivore plant-species preference. For example, 62.8% of the total leaf area consumed was represented by Cecropia peltata in communities exposed to ambient CO[sub 2], versus 44.1% under elevated CO[sub 2]. Our results indicate that compensatory feeding may not occur in natural plant communities in a CO[sub 2]-rich world.

  1. Germination, survival and growth of three vascular plants on biological soil crusts from a Mexican tropical desert.

    PubMed

    Godínez-Alvarez, H; Morín, C; Rivera-Aguilar, V

    2012-01-01

    Information about the effects of biological soil crusts (BSC) on germination, seedling survival and growth of vascular plants is controversial because they can have positive, neutral or negative effects. This controversy may be because most studies conducted until now have just analysed one or two recruitment stages independently. To understand the BSC effects on vascular plants, it is necessary to consider each stage of the recruitment process and synthesise all this information. The goal of this study was twofold. First, we analyse germination, seedling survival and growth of three vascular plants (Agave marmorata, Prosopis laevigata and Neobuxbaumia tetetzo) on BSC (cyanobacteria and mixed crust) from a tropical desert region of south-central México. Second, we synthesise the information to determine the total effect of BSC on plant species performance. We conducted experiments under controlled conditions to evaluate the proportion of germinated seeds, proportion of surviving seedlings and seedling dry weight in BSC and bare soil. Results showed that BSC have different effects on germination, seedling survival and growth of plant species. Plant species performance was qualitatively higher on BSC than bare soil. The highest performance of A. marmorata and P. laevigata was observed on cyanobacteria and mixed crusts, respectively. The highest performance of N. tetetzo was on both crust types.

  2. Medicinal plants at Rio Jauaperi, Brazilian Amazon: Ethnobotanical survey and environmental conservation.

    PubMed

    Pedrollo, Camilo Tomazini; Kinupp, Valdely Ferreira; Shepard, Glenn; Heinrich, Michael

    2016-06-20

    The Amazon basin is a mosaic of different environments. Flooded riparian and upland forests play a significant role for the establishment of human settlements. Riparian communities in the Amazon have evolved depending on the use of plants applied for therapeutic purposes, thus developing important knowledge about their management and preparation. This paper describes and analyzes the use and management of medicinal plants in order to establish links to environmental conservation. The categorization of habitats of occurrence and categories of diseases were held in five riparian communities at Rio Jauaperi, in the border between Roraima and Amazonas states in Brazil. The study sight is poorly investigated in terms of scientific research. Quantitative and qualitative ethnobotanical field inquiries and analytical methods including observations, individual and focus group discussions, individual interviews, preference ranking by free listing tasks, guided tours and community mapping were applied. Sutrop's cognitive salience index was applied in order to check the most important ethnospecies and diseases. The survey was conducted from February to December 2012. A total of 62 informants were interviewed, resulting in 119 botanical species documented. The most salient medicinal species are usually wide distributed and recognized transculturally. Arboreal habit was the most important corresponding to 47% of total species used. The most frequent accessed environments were terra-firme (upland forest), vargeado (flooded forest), poultry (regenerating forest) and restinga (seasonally flooded forest) which together provides 59% of the total medicinal plant species. Exotic species played a secondary role with only 20% of the total. Thirty seven percent of the species were cultivated. Plants at homegardens are usually associated with children's or women's disease. Xixuaú is the community with improved ability to environmental preservation using more forestry species. The most

  3. Community-wide assessment of pollen limitation in hummingbird-pollinated plants of a tropical montane rain forest.

    PubMed

    Wolowski, Marina; Ashman, Tia-Lynn; Freitas, Leandro

    2013-09-01

    Although pollen limitation of reproduction (PL) has been widely studied, our understanding of its occurrence in tropical communities, especially for bird-pollinated plants, is underdeveloped. In addition, inclusion of both quantity and quality aspects in studies of PL are generally lacking. Within hummingbird-pollinated plants, a prediction was made for higher PL for the quality than quantity aspects and a minor effect of temporal variation because hummingbirds are constant and efficient pollen vectors but they may transfer low quality pollen. Field hand and open pollination experiments were conducted on 21 species in a tropical montane rain forest over 2 years. The quantity (fruit set and seeds per fruit) and quality (seed weight and germination) aspects of reproduction were assessed as the response to open pollination relative to outcross hand pollination. The relationships between the effect size of quantity and quality aspects of reproduction and predictive plant features (self-incompatibility, autogamy, density and pollinator specialization level) were assessed with phylogenetic generalized linear models. Just over half of all the species expressed PL for one or more response variables. On average, the severity of PL was strong for one quality variable (seed germination; 0·83), but insignificant for another (seed weight; -0·03), and low to moderate for quantity variables (0·31 for seeds per fruit and 0·39 for fruit set). There was only a minor contribution of temporal variation to PL within the studied species. Common predictors of PL, i.e. phylogenetic relatedness, self-incompatibility, autogamy, plant density and pollinator specialization level, did not adequately explain variation in PL within this community. Despite the measurable degree of PL within these hummingbird-pollinated plants, the causes of pollen quality and quantity insufficiency are not clear. Variables other than those tested may contribute to PL or causes of PL may vary among species and

  4. Plant extracts, isolated phytochemicals, and plant-derived agents which are lethal to arthropod vectors of human tropical diseases--a review.

    PubMed

    Pohlit, Adrian Martin; Rezende, Alex Ribeiro; Lopes Baldin, Edson Luiz; Lopes, Norberto Peporine; Neto, Valter Ferreira de Andrade

    2011-04-01

    The recent scientific literature on plant-derived agents with potential or effective use in the control of the arthropod vectors of human tropical diseases is reviewed. Arthropod-borne tropical diseases include: amebiasis, Chagas disease (American trypanosomiasis), cholera, cryptosporidiosis, dengue (hemorrhagic fever), epidemic typhus (Brill-Zinsser disease), filariasis (elephantiasis), giardia (giardiasis), human African trypanosomiasis (sleeping sickness), isosporiasis, leishmaniasis, Lyme disease (lyme borreliosis), malaria, onchocerciasis, plague, recurrent fever, sarcocystosis, scabies (mites as causal agents), spotted fever, toxoplasmosis, West Nile fever, and yellow fever. Thus, coverage was given to work describing plant-derived extracts, essential oils (EOs), and isolated chemicals with toxic or noxious effects on filth bugs (mechanical vectors), such as common houseflies (Musca domestica Linnaeus), American and German cockroaches (Periplaneta americana Linnaeus, Blatella germanica Linnaeus), and oriental latrine/blowflies (Chrysomya megacephala Fabricius) as well as biting, blood-sucking arthropods such as blackflies (Simulium Latreille spp.), fleas (Xenopsylla cheopis Rothschild), kissing bugs (Rhodnius Stål spp., Triatoma infestans Klug), body and head lice (Pediculus humanus humanus Linnaeus, P. humanus capitis De Geer), mosquitoes (Aedes Meigen, Anopheles Meigen, Culex L., and Ochlerotatus Lynch Arribálzaga spp.), sandflies (Lutzomyia longipalpis Lutz & Neiva, Phlebotomus Loew spp.), scabies mites (Sarcoptes scabiei De Geer, S. scabiei var hominis, S. scabiei var canis, S. scabiei var suis), and ticks (Ixodes Latreille, Amblyomma Koch, Dermacentor Koch, and Rhipicephalus Koch spp.). Examples of plant extracts, EOs, and isolated chemicals exhibiting noxious or toxic activity comparable or superior to the synthetic control agents of choice (pyrethroids, organophosphorous compounds, etc.) are provided in the text for many arthropod vectors of tropical

  5. Rethinking plant functional types in Earth System Models: pan-tropical analysis of tree survival across environmental gradients

    NASA Astrophysics Data System (ADS)

    Johnson, D. J.; Needham, J.; Xu, C.; Davies, S. J.; Bunyavejchewin, S.; Giardina, C. P.; Condit, R.; Cordell, S.; Litton, C. M.; Hubbell, S.; Kassim, A. R. B.; Shawn, L. K. Y.; Nasardin, M. B.; Ong, P.; Ostertag, R.; Sack, L.; Tan, S. K. S.; Yap, S.; McDowell, N. G.; McMahon, S.

    2016-12-01

    Terrestrial carbon cycling is a function of the growth and survival of trees. Current model representations of tree growth and survival at a global scale rely on coarse plant functional traits that are parameterized very generally. In view of the large biodiversity in the tropical forests, it is important that we account for the functional diversity in order to better predict tropical forest responses to future climate changes. Several next generation Earth System Models are moving towards a size-structured, trait-based approach to modelling vegetation globally, but the challenge of which and how many traits are necessary to capture forest complexity remains. Additionally, the challenge of collecting sufficient trait data to describe the vast species richness of tropical forests is enormous. We propose a more fundamental approach to these problems by characterizing forests by their patterns of survival. We expect our approach to distill real-world tree survival into a reasonable number of functional types. Using 10 large-area tropical forest plots that span geographic, edaphic and climatic gradients, we model tree survival as a function of tree size for hundreds of species. We found surprisingly few categories of size-survival functions emerge. This indicates some fundamental strategies at play across diverse forests to constrain the range of possible size-survival functions. Initial cluster analysis indicates that four to eight functional forms are necessary to describe variation in size-survival relations. Temporal variation in size-survival functions can be related to local environmental variation, allowing us to parameterize how demographically similar groups of species respond to perturbations in the ecosystem. We believe this methodology will yield a synthetic approach to classifying forest systems that will greatly reduce uncertainty and complexity in global vegetation models.

  6. Disentangling the roles of plant diversity and precipitation in structuring microbial community composition and function in a tropical rain forest

    NASA Astrophysics Data System (ADS)

    McGuire, Krista; Treseder, Kathleen; Fierer, Noah; Turner, Benjamin

    2010-05-01

    Shifting frequency and intensity of precipitation events is expected to impact soil fungi through a variety of complex feedbacks, although the general patterns and mechanisms are not fully understood. Precipitation and plant diversity often covary, and disentangling the relative contribution of each is important for predicting changes in global C and N fluxes. In order to test the relative contributions of plant diversity and precipitation in shaping fungal community structure and function, soil samples (0-10cm) from six established 1-ha plots across a natural precipitation gradient on the isthmus of Panama were collected. These plots co-vary in mean annual precipitation and plant diversity. Fungal DNA was sequenced using general fungal primers for the 18S region and 454 pyrosequencing. We found that total fungal taxa significantly increased with increasing mean annual precipitation, but not with plant diversity. Activity for some extracellular enzymes increased, whereas as others decreased with mean annual precipitation, indicating that the effect of shifting precipitation on nutrient transformations may be process-specific. To directly test for effects of plant species richness on fungal diversity and function, we experimentally re-created litter diversity gradients in nylon, 2 mm screen litter bags with 1, 25, and 50 species of plant leaf litter. After six months, we found a significant effect of plant litter diversity on decomposition rate, but only after the increase from one to 25 species of leaf litter. Total fungal taxa as determined by 454 sequencing and extracellular enzyme activity did not track plant species richness, suggesting that precipitation may be a more important factor than plant diversity in structuring soil fungi in tropical rain forests.

  7. Cytotoxicity of Brazilian plant extracts against oral microorganisms of interest to dentistry

    PubMed Central

    2013-01-01

    Background With the emergence of strains resistant to conventional antibiotics, it is important to carry studies using alternative methods to control these microorganisms causing important infections, such as the use of products of plant origin that has demonstrated effective antimicrobial activity besides biocompatibility. Therefore, this study aimed to evaluate the antimicrobial activity of plant extracts of Equisetum arvense L., Glycyrrhiza glabra L., Punica granatum L. and Stryphnodendron barbatimam Mart. against Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus mutans, Candida albicans, Candida tropicalis, and Candida glabrata, and to analyze the cytotoxicity of these extracts in cultured murine macrophages (RAW 264.7). Methods Antimicrobial activity of plant extracts was evaluated by microdilution method based on Clinical and Laboratory Standards Institute (CLSI), M7-A6 and M27-A2 standards. The cytotoxicity of concentrations that eliminated the microorganisms was evaluated by MTT colorimetric method and by quantification of proinflammatory cytokines (IL-1β and TNF-α) using ELISA. Results In determining the minimum microbicidal concentration, E. arvense L., P. granatum L., and S. barbatimam Mart. extracts at a concentration of 50 mg/mL and G. glabra L. extract at a concentration of 100 mg/mL, were effective against all microorganisms tested. Regarding cell viability, values were 48% for E. arvense L., 76% for P. granatum L, 86% for S. barbatimam Mart. and 79% for G. glabra L. at the same concentrations. About cytokine production after stimulation with the most effective concentrations of the extracts, there was a significant increase of IL-1β in macrophage cultures treated with S. barbatimam Mart. (3.98 pg/mL) and P. granatum L. (7.72 pg/mL) compared to control (2.20 pg/mL) and a significant decrease of TNF-α was observed in cultures treated with G. glabra L. (4.92 pg/mL), S. barbatimam Mart. (0.85 pg/mL), E. arvense L. (0.83 pg/mL), and P

  8. Cytotoxicity of Brazilian plant extracts against oral microorganisms of interest to dentistry.

    PubMed

    de Oliveira, Jonatas Rafael; de Castro, Vinicius Carlos; das Graças Figueiredo Vilela, Polyana; Camargo, Samira Esteves Afonso; Carvalho, Cláudio Antonio Talge; Jorge, Antonio Olavo Cardoso; de Oliveira, Luciane Dias

    2013-08-15

    With the emergence of strains resistant to conventional antibiotics, it is important to carry studies using alternative methods to control these microorganisms causing important infections, such as the use of products of plant origin that has demonstrated effective antimicrobial activity besides biocompatibility. Therefore, this study aimed to evaluate the antimicrobial activity of plant extracts of Equisetum arvense L., Glycyrrhiza glabra L., Punica granatum L. and Stryphnodendron barbatimam Mart. against Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus mutans, Candida albicans, Candida tropicalis, and Candida glabrata, and to analyze the cytotoxicity of these extracts in cultured murine macrophages (RAW 264.7). Antimicrobial activity of plant extracts was evaluated by microdilution method based on Clinical and Laboratory Standards Institute (CLSI), M7-A6 and M27-A2 standards. The cytotoxicity of concentrations that eliminated the microorganisms was evaluated by MTT colorimetric method and by quantification of proinflammatory cytokines (IL-1β and TNF-α) using ELISA. In determining the minimum microbicidal concentration, E. arvense L., P. granatum L., and S. barbatimam Mart. extracts at a concentration of 50 mg/mL and G. glabra L. extract at a concentration of 100 mg/mL, were effective against all microorganisms tested. Regarding cell viability, values were 48% for E. arvense L., 76% for P. granatum L, 86% for S. barbatimam Mart. and 79% for G. glabra L. at the same concentrations. About cytokine production after stimulation with the most effective concentrations of the extracts, there was a significant increase of IL-1β in macrophage cultures treated with S. barbatimam Mart. (3.98 pg/mL) and P. granatum L. (7.72 pg/mL) compared to control (2.20 pg/mL) and a significant decrease of TNF-α was observed in cultures treated with G. glabra L. (4.92 pg/mL), S. barbatimam Mart. (0.85 pg/mL), E. arvense L. (0.83 pg/mL), and P. granatum L. (0.00 pg

  9. Activities of some Brazilian plants against larvae of the mosquito Aedes aegypti.

    PubMed

    de Mendonça, Fernando A C; da Silva, K F S; dos Santos, K K; Ribeiro Júnior, K A L; Sant'Ana, A E G

    2005-12-01

    The insecticidal activities of extracts and oils of seventeen medicinal plants of Brazil have been determined using an Aedes aegypti larvicidal bioassay. Oils from Anacardium occidentalis, Copaifera langsdorffii, Carapa guianensis, Cymbopogon winterianus and Ageratum conyzoides showed high activities with LC50 values of 14.5, 41, 57, 98 and 148 microg/l, respectively. The most active ethanolic extract tested was that from the stem of Annona glabra which presented an LC50 value of 27 microg/l. The potential application of cashew nut oil, an industrial by-product with low commercial value, in the control of the vector of dengue and yellow fever, may be proposed.

  10. Snake Venom PLA2s Inhibitors Isolated from Brazilian Plants: Synthetic and Natural Molecules

    PubMed Central

    Carvalho, B. M. A.; Santos, J. D. L.; Xavier, B. M.; Almeida, J. R.; Resende, L. M.; Martins, W.; Marcussi, S.; Marangoni, S.; Stábeli, R. G.; Calderon, L. A.; Soares, A. M.; Da Silva, S. L.; Marchi-Salvador, D. P.

    2013-01-01

    Ophidian envenomation is an important health problem in Brazil and other South American countries. In folk medicine, especially in developing countries, several vegetal species are employed for the treatment of snakebites in communities that lack prompt access to serum therapy. However, the identification and characterization of the effects of several new plants or their isolated compounds, which are able to inhibit the activities of snake venom, are extremely important and such studies are imperative. Snake venom contains several organic and inorganic compounds; phospholipases A2 (PLA2s) are one of the principal toxic components of venom. PLA2s display a wide variety of pharmacological activities, such as neurotoxicity, myotoxicity, cardiotoxicity, anticoagulant, hemorrhagic, and edema-inducing effects. PLA2 inhibition is of pharmacological and therapeutic interests as these enzymes are involved in several inflammatory diseases. This review describes the results of several studies of plant extracts and their isolated active principles, when used against crude snake venoms or their toxic fractions. Isolated inhibitors, such as steroids, terpenoids, and phenolic compounds, are able to inhibit PLA2s from different snake venoms. The design of specific inhibitors of PLA2s might help in the development of new pharmaceutical drugs, more specific antivenom, or even as alternative approaches for treating snakebites. PMID:24171158

  11. Biofilm-producing ability of Listeria monocytogenes isolates from Brazilian cheese processing plants.

    PubMed

    In Lee, Sarah Hwa; Barancelli, Giovana Verginia; de Camargo, Tarsila Mendes; Corassin, Carlos Humberto; Rosim, Roice Eliana; da Cruz, Adriano Gomes; Cappato, Leandro Pereira; de Oliveira, Carlos Augusto Fernandes

    2017-01-01

    The persistence of Listeria monocytogenes in food industry environments has been associated to the ability of specific isolates to produce biofilms. This study aimed to evaluate the biofilm production of 85 L. monocytogenes strains previously isolated from samples of cheese, brine and the environment of two cheese processing plants located in São Paulo, Brazil. The L. monocytogenes isolates belonged to serotypes 4b, 1/2b and 1/2c, yielded 30 different pulsotypes by pulsed-field gel electrophoresis (PFGE), and were submitted to biofilm-formation assays on polystyrene microplates and stainless steel coupons incubated statically at 35±0.5°C for 48h. All isolates from different sources showed ability to produce biofilms on polystyrene microplates, from which 21 (24.7%) also produced biofilms on stainless steel. Four isolates (4.7%) belonging to four different pulsotypes were classified as strong biofilms-producers on polystyrene microplates, while isolates belonging to four pulsotypes previously evaluated as persistent had weak or moderate ability to produce biofilms on polystyrene microplates. No relationship between the serotypes or pulsotypes and their biofilm-forming ability was observed. This study highlights the high variability in the biofilm production among L. monocytogenes strains collected from cheese and cheese-production environment, also indicating that strong biofilm-formation ability is not a key factor for persistence of specific isolates in cheese processing plants.

  12. Multiple soil nutrient competition between plants, microbes, and mineral surfaces: model development, parameterization, and example applications in several tropical forests

    NASA Astrophysics Data System (ADS)

    Zhu, Q.; Riley, W. J.; Tang, J.; Koven, C. D.

    2016-01-01

    Soil is a complex system where biotic (e.g., plant roots, micro-organisms) and abiotic (e.g., mineral surfaces) consumers compete for resources necessary for life (e.g., nitrogen, phosphorus). This competition is ecologically significant, since it regulates the dynamics of soil nutrients and controls aboveground plant productivity. Here we develop, calibrate and test a nutrient competition model that accounts for multiple soil nutrients interacting with multiple biotic and abiotic consumers. As applied here for tropical forests, the Nutrient COMpetition model (N-COM) includes three primary soil nutrients (NH4+, NO3- and POx; representing the sum of PO43-, HPO42- and H2PO4-) and five potential competitors (plant roots, decomposing microbes, nitrifiers, denitrifiers and mineral surfaces). The competition is formulated with a quasi-steady-state chemical equilibrium approximation to account for substrate (multiple substrates share one consumer) and consumer (multiple consumers compete for one substrate) effects. N-COM successfully reproduced observed soil heterotrophic respiration, N2O emissions, free phosphorus, sorbed phosphorus and NH4+ pools at a tropical forest site (Tapajos). The overall model uncertainty was moderately well constrained. Our sensitivity analysis revealed that soil nutrient competition was primarily regulated by consumer-substrate affinity rather than environmental factors such as soil temperature or soil moisture. Our results also imply that under strong nutrient limitation, relative competitiveness depends strongly on the competitor functional traits (affinity and nutrient carrier enzyme abundance). We then applied the N-COM model to analyze field nitrogen and phosphorus perturbation experiments in two tropical forest sites (in Hawaii and Puerto Rico) not used in model development or calibration. Under soil inorganic nitrogen and phosphorus elevated conditions, the model accurately

  13. Long-term patterns in tropical reforestation: plant community composition and aboveground biomass accumulation.

    Treesearch

    E. Mar¡n-Spiotta; R. Ostertag; Silver W. L.

    2007-01-01

    Primary tropical forests are renowned for their high biodiversity and carbon storage, and considerable research has documented both species and carbon losses with deforestation and agricultural land uses. Economic drivers are now leading to the abandonment of agricultural lands, and the area in secondary forests is increasing. We know little about how long it takes for...

  14. Long-term, patterns in tropical reforestation: plant community composition and aboveground biomass accumulation.

    Treesearch

    E. MARIN-SPIOTTA; R. OSTERTAG; SILVER W. L.

    2007-01-01

    Primary tropical forests are renowned for their high biodiversity and carbon storage, and considerable research has documented both species and carbon losses with deforestation and agricultural land uses. Economic drivers are now leading to the abandonment of agricultural lands, and the area in secondary forests is increasing. We know little about how long it takes for...

  15. Roles of host plants in boll weevil range expansion beyond tropical Mesoamerica

    USDA-ARS?s Scientific Manuscript database

    New findings on boll weevil, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), biology and ecology have had repercussions on the current level of understanding about short- and long-range boll weevil dispersal, and range expansion from its original tropical Mesoamerican habitat. The w...

  16. Plant available nitrogen from anaerobically digested sludge and septic tank sludge applied to crops grown in the tropics.

    PubMed

    Sripanomtanakorn, S; Polprasert, C

    2002-04-01

    Agricultural land is an attractive alternative for the disposal of biosolids since it utilises the recyclable nutrients in the production of crops. In Thailand and other tropical regions, limited field-study information exists on the effect of biosolids management strategies on crop N utilisation and plant available N (PAN) of biosolids. A field study was conducted to quantify the PAN of the applied biosolids, and to evaluate the N uptake rates of some tropical crops. Sunflower (Helianthus annuus) and tomato (Lycopersicon esculentum) were chosen in this study. Two types of biosolids used were: anaerobically digested sludge and septic tank sludge. The soil is acid sulfate and is classified as Sulfic Tropaquepts with heavy clay in texture. The anaerobically digested sludge applied rates were: 0, 156 and 312 kg N ha(-1) for the sunflower plots, and 0, 586, and 1172 kg N ha(-1) for the tomato plots. The septic tank sludge applied rates were: 0, 95 and 190 kg N ha(-1) for the sunflower plots, and 0, 354 and 708 kg N ha(-1) for the tomato plots, respectively. The results indicated the feasibility of applying biosolids to grow tropical crops. The applications of the anaerobically digested sludge and the septic tank sludge resulted in the yields of sunflower seeds and tomato fruits and the plant N uptakes comparable or better than that applied with only the chemical fertiliser. The estimated PAN of the anaerobically digested sludge was about 27-42% of the sludge organic N during the growing season. For the septic tank sludge, the PAN was about 15-58% of the sludge organic N. It is interesting to observe that an increase of the rate of septic tank sludge incorporated into this heavy clay soil under the cropping system resulted in the decrease of N mineralisation rate. This situation could cause the reduction of yield and N uptake of crops.

  17. Indigenous knowledge informing management of tropical forests: the link between rhythms in plant secondary chemistry and lunar cycles.

    PubMed

    Vogt, Kristiina A; Beard, Karen H; Hammann, Shira; Palmiotto, Jennifer O'Hara; Vogt, Daniel J; Scatena, Frederick N; Hecht, Brooke P

    2002-09-01

    This research used knowledge of the indigenous practice of timing nontimber forest product harvest with the full moon to demonstrate that chemicals controlling the decomposition rate of foliage fluctuate with the lunar cycle and may have developed as a result of plant-herbivore interactions. Indigenous knowledge suggests that leaves harvested during the full moon are more durable. Palm leaves harvested during the full moon had higher total C, hemicellulose, complex C and lower Ca concentrations. These chemical changes should make palm leaves less susceptible to herbivory and more durable when harvested during the full moon. This study proposes a mechanism by which plants in the tropics minimize foliage herbivory and influence the decomposition rates of senesced leaves and their durability, especially during the full moon. This research supports the need to use natural life cycles in managing forests and provides a scientific basis for an indigenous community's harvesting practice.

  18. Biochemical responses in tree foliage exposed to coal-fired power plant emission in seasonally dry tropical environment.

    PubMed

    Sharma, Atul Prakash; Tripathi, B D

    2009-11-01

    A biomonitoring study was conducted to investigate the responses of plants exposed to power plant emission in a dry tropical environment. For this purpose, five sampling sites were selected in the prevailing wind direction (NE) at different distance to thermal power plant (TPP) within 8.0 km range and a reference site was selected in eastern direction at a distance of 22.0 km. The two most common tree species, Ficus benghalensis L. (Evergreen tree) and Dalbergia sisso Roxb. (deciduous tree) were selected as test plants. Ambient sulphur dioxide (SO(2)), nitrogen dioxide (NO(2)), suspended particulate matter (SPM), respirable suspended particulate matter (RSPM), dust-fall rate (DFR) and plant responses such as leaf pigments (chlorophyll a, chlorophyll b and carotenoids), ascorbic acid, sugar and sulphate-sulphur (SO4(2-)-S) contents were measured. Ambient SO(2), NO(2), SPM, RSPM and DFR showed significant spatial and temporal variation at different sites. Considerable reduction in pigment (chlorophyll a, chlorophyll b and carotenoids) and sugar contents were observed at sites receiving higher pollution load. Ascorbic acid exhibited significant positive correlation with pollution load. Accumulation of SO4(2-)-S in leaf tissue showed significant positive correlation with ambient SO(2) concentration at all the sites. At the same time, SO4(2-)-S showed significant negative correlation with pigment and sugar content. D. sisso Roxb. tree was found to be more sensitive as compared to F. benghalensis L. tree.

  19. Phenolic compounds, organic acids and antioxidant activity of grape juices produced from new Brazilian varieties planted in the Northeast Region of Brazil.

    PubMed

    Lima, Marcos Dos Santos; Silani, Igor de Souza Veras; Toaldo, Isabela Maia; Corrêa, Luiz Claudio; Biasoto, Aline Camarão Telles; Pereira, Giuliano Elias; Bordignon-Luiz, Marilde T; Ninow, Jorge Luiz

    2014-10-15

    The phenolic compounds, organic acids and the antioxidant activity were determined for grape juice samples from new Brazilian varieties grown in the Sub-middle São Francisco Valley in the Northeast Region of Brazil. The results showed that the Brazilian grape juices have high antioxidant activity, which was significantly correlated with the phenolic compounds catechin, epicatechin gallate, procyanidin B1, rutin, gallic acid, caffeic acid, p-coumaric acid, pelargonidin-3-glucoside, cyanidin-3-glucoside, cyaniding-3,5-diglucoside and delphinidin-3-glucoside. The produced juice samples showed higher concentrations of trans-resveratrol than those observed in juices made from different varieties of grapes from traditional growing regions. Organic acids concentrations were similar to those of juices produced from other classical varieties. It was demonstrated that it is possible to prepare juices from grapes of new varieties grown in the Northeast of Brazil containing a high content of bioactive compounds and typical characteristics of the tropical viticulture practised in the Sub-middle São Francisco Valley. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Cellulose δ18O is an index of leaf-to-air vapor pressure difference (VPD) in tropical plants

    PubMed Central

    Kahmen, Ansgar; Sachse, Dirk; Arndt, Stefan K.; Tu, Kevin P.; Farrington, Heraldo; Vitousek, Peter M.; Dawson, Todd E.

    2011-01-01

    Cellulose in plants contains oxygen that derives in most cases from precipitation. Because the stable oxygen isotope composition, δ18O, of precipitation is associated with environmental conditions, cellulose δ18O should be as well. However, plant physiological models using δ18O suggest that cellulose δ18O is influenced by a complex mix of both climatic and physiological drivers. This influence complicates the interpretation of cellulose δ18O values in a paleo-context. Here, we combined empirical data analyses with mechanistic model simulations to i) quantify the impacts that the primary climatic drivers humidity (ea) and air temperature (Tair) have on cellulose δ18O values in different tropical ecosystems and ii) determine which environmental signal is dominating cellulose δ18O values. Our results revealed that ea and Tair equally influence cellulose δ18O values and that distinguishing which of these factors dominates the δ18O values of cellulose cannot be accomplished in the absence of additional environmental information. However, the individual impacts of ea and Tair on the δ18O values of cellulose can be integrated into a single index of plant-experienced atmospheric vapor demand: the leaf-to-air vapor pressure difference (VPD). We found a robust relationship between VPD and cellulose δ18O values in both empirical and modeled data in all ecosystems that we investigated. Our analysis revealed therefore that δ18O values in plant cellulose can be used as a proxy for VPD in tropical ecosystems. As VPD is an essential variable that determines the biogeochemical dynamics of ecosystems, our study has applications in ecological-, climate-, or forensic-sciences. PMID:21245322

  1. Larvicidal activity of essential oils from Brazilian plants against Aedes aegypti L.

    PubMed

    Cavalcanti, Eveline Solon Barreira; Morais, Selene Maia de; Lima, Michele Ashley A; Santana, Eddie William Pinho

    2004-08-01

    Aedes aegypti L. is the major vector of dengue fever, an endemic disease in Brazil. In an effort to find effective and affordable ways to control this mosquito, the larvicidal activities of essential oils from nine plants widely found in the Northeast of Brazil were analyzed by measurement of their LC50. The essential oils were extracted by steam distillation and their chemical composition determined by GL-chromatography coupled to mass spectroscopy. The essential oils from Cymbopogon citratus and Lippia sidoides, reported in the literature to have larvicidal properties against A. aegypti, were used for activity comparison. The results show that Ocimum americanum and Ocimum gratissimum have LC50 of 67 ppm and 60 ppm respectively, compared to 63 ppm for L. sidoides and 69 ppm for C. citratus. These results suggest a potential utilization of the essential oil of these two Ocimum species for the control of A. aegypti.

  2. Transcriptional profile of Paracoccidioides induced by oenothein B, a potential antifungal agent from the Brazilian Cerrado plant Eugenia uniflora

    PubMed Central

    2013-01-01

    Background The compound oenothein B (OenB), which is isolated from the leaves of Eugenia uniflora, a Brazilian Cerrado plant, interferes with Paracoccidioides yeast cell morphology and inhibits 1,3-β-D-glucan synthase (PbFKS1) transcript accumulation, which is involved in cell wall synthesis. In this work we examined the gene expression changes in Paracoccidioides yeast cells following OenB treatment in order to investigate the adaptive cellular responses to drug stress. Results We constructed differential gene expression libraries using Representational Difference Analysis (RDA) of Paracoccidioides yeast cells treated with OenB for 90 and 180 min. Treatment for 90 min resulted in the identification of 463 up-regulated expressed sequences tags (ESTs) and 104 down-regulated ESTs. For the 180 min treatment 301 up-regulated ESTs and 143 down-regulated were identified. Genes involved in the cell wall biosynthesis, such as GLN1, KRE6 and FKS1, were found to be regulated by OenB. Infection experiments in macrophages corroborated the in vitro results. Fluorescence microscopy showed increased levels of chitin in cells treated with OenB. The carbohydrate polymer content of the cell wall of the fungus was also evaluated, and the results corroborated with the transcriptional data. Several other genes, such as those involved in a variety of important cellular processes (i.e., membrane maintenance, stress and virulence) were found to be up-regulated in response to OenB treatment. Conclusions The exposure of Paracoccidioides to OenB resulted in a complex altered gene expression profile. Some of the changes may represent specific adaptive responses to this compound in this important pathogenic fungus. PMID:24119145

  3. Land Use Dynamics in the Brazilian Amazon

    Treesearch

    Robert Walker

    1996-01-01

    The articles presented in this special issue of Ecological Economics address the important theme of land use dynamics as it pertains to the Brazilian Amazon. Much environmental change is an ecological artifact of human agency, and such agency is often manifested in land use impacts, particularly in tropical areas. The critical problem of tropical deforestation is but...

  4. Impacts of hydroelectric dams on alluvial riparian plant communities in Eastern Brazilian Amazonian.

    PubMed

    Ferreira, Leandro Valle; Cunha, Denise A; Chaves, Priscilla P; Matos, Darley C L; Parolin, Pia

    2013-09-01

    The major rivers of the Amazon River basin and their biota are threatened by the planned construction of large hydroelectric dams that are expected to have strong impacts on floodplain plant communities. The present study presents forest inventories from three floodplain sites colonized by alluvial riparian vegetation in the Tapajós, Xingu and Tocantins River basins in eastern Amazonian. Results indicate that tree species of the highly specialized alluvial riparian vegetation are clearly distinct among the three river basins, although they are not very distinct from each other and environmental constraints are very similar. With only 6 of 74 species occurring in all three inventories, most tree and shrub species are restricted to only one of the rivers, indicating a high degree of local distribution. Different species occupy similar environmental niches, making these fragile riparian formations highly valuable. Conservation plans must consider species complementarily when decisions are made on where to place floodplain forest conservation units to avoid the irreversible loss of unique alluvial riparian vegetation biodiversity.

  5. Phenolic composition and antiparasitic activity of plants from the Brazilian Northeast "Cerrado".

    PubMed

    Calixto Júnior, João Tavares; de Morais, Selene Maia; Gomez, Celeste Vega; Molas, Cathia Coronel; Rolon, Miriam; Boligon, Aline Augusti; Athayde, Margareth Linde; de Morais Oliveira, Cícera Datiane; Tintino, Saulo Relison; Henrique Douglas, Melo Coutinho

    2016-05-01

    This work describes the antiparasitic and cytotoxic activities of three plant species from the Cerrado biome, Northeastern Brazil. Significant antiparasitic inhibition was observed against Trypanosoma cruzi (63.86%), Leishmania brasiliensis (92.20%) and Leishmania infantum (95.23%) when using ethanol extract from leaves of Guazuma ulmifolia Lam. (Malvaceae), at a concentration of 500 μg/mL. However, low levels of inhibition were observed when assessing leishmanicidal and trypanocidal (Clone CL-B5) activities of crude ethanol extracts from leaves and bast tissue of Luehea paniculata (Malvaceae) and leaves and bark of Prockia crucis (Salicaceae) at a concentration of 500 μg/mL. The extracts revealed the presence of phenolic acids such as gallic acid, chlorogenic acid, caffeic acid and rosmarinic acid, as well as flavonoids such as rutin, luteolin, apigenin and quercetin - the latter detected only in G. ulmifolia. G. ulmifolia extract displayed higher leishmanicidal activity probably due to the presence of quercetin, a potent known leishmanicidal compound. A cytotoxicity test indicated values over 50% at the highest concentration (1000 μg/mL) for all natural products, which were considered cytotoxic. This points out the need for further tests to enable future in vivo trials, including antineoplastic activity on human tumor cells.

  6. Activity of essential oils from Brazilian medicinal plants on Escherichia coli.

    PubMed

    Duarte, Marta Cristina Teixeira; Leme, Ewerton Eduardo; Delarmelina, Camila; Soares, Andressa Almeida; Figueira, Glyn Mara; Sartoratto, Adilson

    2007-05-04

    Essential oils obtained from leaves of 29 medicinal plants commonly used in Brazil were screened against 13 different Escherichia coli serotypes. The oils were obtained by water-distillation using a Clevenger-type system and their minimal inhibitory concentration (MIC) were determined by microdilution method. Essential oil from Cymbopogon martinii exhibited a broad inhibition spectrum, presenting strong activity (MIC between 100 and 500 microg/mL) against 10 out of 13 Escherichia coli serotypes: three enterotoxigenic, two enteropathogenic, three enteroinvasive and two shiga-toxin producers. C. winterianus inhibited strongly two enterotoxigenic, one enteropathogenic, one enteroinvasive and one shiga-toxin producer serotypes. Aloysia triphylla also shows good potential to kill Escherichia coli with moderate to strong inhibition. Other essential oils showed antimicrobial properties, however with a more restricted action against the serotypes studied. Chemical analysis of Cymbopogon martinii essential oil performed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC-MS) showed the presence of compounds with known antimicrobial activity, including geraniol, geranyl acetate and trans-cariophyllene, which tested separately, indicated geraniol as antimicrobial active compound. The significant antibacterial activity of Cymbopogon martinii oil suggests that they could serve as a source for compounds with therapeutic potential.

  7. Phenolic composition and antiparasitic activity of plants from the Brazilian Northeast “Cerrado”

    PubMed Central

    Calixto Júnior, João Tavares; de Morais, Selene Maia; Gomez, Celeste Vega; Molas, Cathia Coronel; Rolon, Miriam; Boligon, Aline Augusti; Athayde, Margareth Linde; de Morais Oliveira, Cícera Datiane; Tintino, Saulo Relison; Henrique Douglas, Melo Coutinho

    2015-01-01

    This work describes the antiparasitic and cytotoxic activities of three plant species from the Cerrado biome, Northeastern Brazil. Significant antiparasitic inhibition was observed against Trypanosoma cruzi (63.86%), Leishmania brasiliensis (92.20%) and Leishmania infantum (95.23%) when using ethanol extract from leaves of Guazuma ulmifolia Lam. (Malvaceae), at a concentration of 500 μg/mL. However, low levels of inhibition were observed when assessing leishmanicidal and trypanocidal (Clone CL-B5) activities of crude ethanol extracts from leaves and bast tissue of Luehea paniculata (Malvaceae) and leaves and bark of Prockia crucis (Salicaceae) at a concentration of 500 μg/mL. The extracts revealed the presence of phenolic acids such as gallic acid, chlorogenic acid, caffeic acid and rosmarinic acid, as well as flavonoids such as rutin, luteolin, apigenin and quercetin – the latter detected only in G. ulmifolia. G. ulmifolia extract displayed higher leishmanicidal activity probably due to the presence of quercetin, a potent known leishmanicidal compound. A cytotoxicity test indicated values over 50% at the highest concentration (1000 μg/mL) for all natural products, which were considered cytotoxic. This points out the need for further tests to enable future in vivo trials, including antineoplastic activity on human tumor cells. PMID:27081371

  8. Multiple soil nutrient competition between plants, microbes, and mineral surfaces: model development, parameterization, and example applications in several tropical forests

    DOE PAGES

    Zhu, Q.; Riley, W. J.; Tang, J.; ...

    2016-01-18

    Soil is a complex system where biotic (e.g., plant roots, micro-organisms) and abiotic (e.g., mineral surfaces) consumers compete for resources necessary for life (e.g., nitrogen, phosphorus). This competition is ecologically significant, since it regulates the dynamics of soil nutrients and controls aboveground plant productivity. Here we develop, calibrate and test a nutrient competition model that accounts for multiple soil nutrients interacting with multiple biotic and abiotic consumers. As applied here for tropical forests, the Nutrient COMpetition model (N-COM) includes three primary soil nutrients (NH4+, NO3− and POx; representing the sum of PO43−, HPO42− and H2PO4−) and five potential competitors (plantmore » roots, decomposing microbes, nitrifiers, denitrifiers and mineral surfaces). The competition is formulated with a quasi-steady-state chemical equilibrium approximation to account for substrate (multiple substrates share one consumer) and consumer (multiple consumers compete for one substrate) effects. N-COM successfully reproduced observed soil heterotrophic respiration, N2O emissions, free phosphorus, sorbed phosphorus and NH4+ pools at a tropical forest site (Tapajos). The overall model uncertainty was moderately well constrained. Our sensitivity analysis revealed that soil nutrient competition was primarily regulated by consumer–substrate affinity rather than environmental factors such as soil temperature or soil moisture. Our results also imply that under strong nutrient limitation, relative competitiveness depends strongly on the competitor functional traits (affinity and nutrient carrier enzyme abundance). We then applied the N-COM model to analyze field nitrogen and phosphorus perturbation experiments in two tropical forest sites (in Hawaii and Puerto Rico) not used in model development or calibration. Under soil inorganic nitrogen and phosphorus elevated conditions, the model accurately replicated the experimentally observed

  9. Micro-organisms behind the pollination scenes: microbial imprint on floral nectar sugar variation in a tropical plant community

    PubMed Central

    Canto, A.; Herrera, C. M.

    2012-01-01

    Background and Aims Variation in the composition of floral nectar reflects intrinsic plant characteristics as well as the action of extrinsic factors. Micro-organisms, particularly yeasts, represent one extrinsic factor that inhabit the nectar of animal-pollinated flowers worldwide. In this study a ‘microbial imprint hypothesis’ is formulated and tested, in which it is proposed that natural community-wide variation in nectar sugar composition will partly depend on the presence of yeasts in flowers. Methods Occurrence and density of yeasts were studied microscopically in single-flower nectar samples of 22 animal-pollinated species from coastal xeric and sub-humid tropical habitats of the Yucatán Peninsula, Mexico. Nectar sugar concentration and composition were concurrently determined on the same samples using high-performance liquid chromatography (HPLC) methods. Key Results Microscopical examination of nectar samples revealed the presence of yeasts in nearly all plant species (21 out of 22 species) and in about half of the samples examined (51·8 % of total, all species combined). Plant species and individuals differed significantly in nectar sugar concentration and composition, and also in the incidence of nectar yeasts. After statistically controlling for differences between plant species and individuals, nectar yeasts still accounted for a significant fraction of community-wide variance in all nectar sugar parameters considered. Significant yeast × species interactions on sugar parameters revealed that plant species differed in the nectar sugar correlates of variation in yeast incidence. Conclusions The results support the hypothesis that nectar yeasts impose a detectable imprint on community-wide variation in nectar sugar composition and concentration. Since nectar sugar features influence pollinator attraction and plant reproduction, future nectar studies should control for yeast presence and examine the extent to which microbial signatures on nectar

  10. Micro-organisms behind the pollination scenes: microbial imprint on floral nectar sugar variation in a tropical plant community.

    PubMed

    Canto, A; Herrera, C M

    2012-11-01

    Variation in the composition of floral nectar reflects intrinsic plant characteristics as well as the action of extrinsic factors. Micro-organisms, particularly yeasts, represent one extrinsic factor that inhabit the nectar of animal-pollinated flowers worldwide. In this study a 'microbial imprint hypothesis' is formulated and tested, in which it is proposed that natural community-wide variation in nectar sugar composition will partly depend on the presence of yeasts in flowers. Occurrence and density of yeasts were studied microscopically in single-flower nectar samples of 22 animal-pollinated species from coastal xeric and sub-humid tropical habitats of the Yucatán Peninsula, Mexico. Nectar sugar concentration and composition were concurrently determined on the same samples using high-performance liquid chromatography (HPLC) methods. Microscopical examination of nectar samples revealed the presence of yeasts in nearly all plant species (21 out of 22 species) and in about half of the samples examined (51·8 % of total, all species combined). Plant species and individuals differed significantly in nectar sugar concentration and composition, and also in the incidence of nectar yeasts. After statistically controlling for differences between plant species and individuals, nectar yeasts still accounted for a significant fraction of community-wide variance in all nectar sugar parameters considered. Significant yeast × species interactions on sugar parameters revealed that plant species differed in the nectar sugar correlates of variation in yeast incidence. The results support the hypothesis that nectar yeasts impose a detectable imprint on community-wide variation in nectar sugar composition and concentration. Since nectar sugar features influence pollinator attraction and plant reproduction, future nectar studies should control for yeast presence and examine the extent to which microbial signatures on nectar characteristics ultimately have some influence on

  11. Radiation preservation of foods of plant origin. III. Tropical fruits: bananas, mangoes, and papayas

    SciTech Connect

    Thomas, P.

    1986-01-01

    The current status of research on the use of ionizing radiation for shelf life improvement and disinfestation of fresh tropical fruits like bananas, mangoes, and papayas are reviewed. The aspects covered are influence of maturity and physiological state of the fruits on delayed ripening and tolerance to radiation; varietal responses; changes in chemical constituents, volatiles, respiration, and ethylene evolution; biochemical mechanisms of delayed ripening and browning of irradiated fruits; and organoleptic quality. The efficacy of the combination of hot water dip and radiation treatments for control of postharvest fungal diseases are considered. The immediate potential of radiation as a quarantine treatment, in place of the currently used chemical fumigants, for disinfestation of fruit flies and mango seed weevil are discussed. Future prospects for irradiation of tropical fruits are discussed in the light of experience gained from studies conducted in different countries.146 references.

  12. Plant DNA barcodes, taxonomic management, and species discovery in tropical forests.

    PubMed

    Dick, Christopher W; Webb, Campbell O

    2012-01-01

    DNA barcodes have great potential for species identification and taxonomic discovery in tropical forests. This use of DNA barcodes requires a reference DNA library of known taxa with which to match DNA from unidentified specimens. At an even more basic level, it presupposes that the species in the regional species pool have Latin binomials. This is not the case in species-rich tropical forests in which many species are new to science or members of poorly circumscribed species complexes. This chapter describes a workflow geared toward taxonomic discovery, which includes the discovery of new species, distribution records, and hybrid forms, and to management of taxonomic entities in forest inventory plots. It outlines the roles of laboratory technicians, field workers and herbarium-based taxonomists, and concludes with a discussion of potential multilocus nuclear DNA approaches for identifying species in recently evolved clades.

  13. Planting seedlings in tree islands versus plantations as a large-scale tropical forest restoration strategy

    Treesearch

    K. D. Holl; R. A. Zahawi; R. J. Cole; R. Ostertag; S. Cordell

    2010-01-01

    Planting tree seedlings in small patches (islands) has been proposed as a method to facilitate forest recovery that is less expensive than planting large areas and better simulates the nucleation process of recovery. We planted seedlings of four tree species at 12 formerly agricultural sites in southern Costa Rica in two designs: plantation (entire 50 × 50 m area...

  14. Anthelmintic efficacy of five tropical native Australian plants against Haemonchus contortus and Trichostrongylus colubriformis in experimentally infected goats (Capra hircus).

    PubMed

    Moreno, F C; Gordon, I J; Knox, M R; Summer, P M; Skerrat, L F; Benvenutti, M A; Saumell, C A

    2012-06-08

    The study of the anthelmintic properties of plants rich in plant secondary metabolites can provide ecologically sound methods for the treatment of parasites on grazing animals. The purpose of the present study was to evaluate the anthelmintic effect of five tropical native Australian plant species rich in plant secondary metabolites on adult Haemonchus contortus and Trichostrongylus colubriformis in experimentally infected goats. Thirty young, nematode-free goats were infected with 2500 H. contortus and 5000 T. colubriformis infective larvae thrice weekly for a week (day 1-7 of the experiment). On day 27 after first infection, the goats were allocated into six groups of five animals per group. From day 28 to day 35, fresh leaves from Acacia salicina, Acacia nilotica, Eucalyptus corymbia, Casuarina cunninghamiana and Eucalyptus drepanophylla were included in the goats diet. Five groups were offered leaves from one of these plant species and one group, the untreated control, received only the basal diet formulated with 20% Medicago sativa and 80% Avena sativa. Following plant material administration, the goats were monitored daily until day 40 and then slaughtered on day 41. Total faecal worm egg output, total production of larvae recovered from faecal cultures, total post-mortem worm burdens and the per capita fecundity of female worms were estimated. The toxicity of the plant species for the goats was measured by histopathological analyses of liver and kidney samples. Results showed that goats feeding on the plant material rich in plant secondary metabolites had significantly lower egg output compared to the control goats (P<0.05). A similar response was found for larval production in both H. contortus and T. colubriformis supporting that egg output was affected in both species. Although the total worm burdens were not affected by the plant material (P>0.05), the per capita fecundity was significantly reduced by E. corymbia, A. nilotica and A. salicina (P<0.05). No

  15. Local Plant Physiological Responses to Increasing CO2 Contribute to a Zonally Asymmetric Pattern of Precipitation Change over Tropical Forests

    NASA Astrophysics Data System (ADS)

    Kooperman, G. J.; Randerson, J. T.; Chen, Y.; Swann, A. L. S.; Koven, C.; Hoffman, F. M.; Lindsay, K. T.; Pritchard, M. S.

    2016-12-01

    Understanding how anthropogenic CO2 emissions may impact future precipitation patterns is a critical question for earth science and society, especially over tropical forests where changes affect drought conditions, ecosystem health, and the availability of freshwater. While there remains significant uncertainty about how tropical precipitation will change in the future, CMIP5 models robustly project a consistent zonally asymmetric pattern over land, amplifying differences between the Maritime Continent and Amazon. This pattern cannot be explained by mechanisms describing zonal mean changes to the hydrological cycle (e.g. Hadley strength, ITCZ shift, or wet-get-wetter response). Here we show, in CESM1(BGC), that the pattern is largely controlled by plant physiological responses to increased CO2, which setup local dynamic anomalies over each continent, rather than global-scale radiative forcing. Regional precipitation and associated circulation changes that manifest with global CO2 increases are also captured when CO2 increases are isolated to the land-surfaces of individual continents. Increased CO2 throttles stomatal conductance, reducing local transpiration and increasing sensible heating and surface temperature. Changes in heating over land drive regional circulations that influence vertical mixing and moisture fluxes over each continent, leading to greater moisture transport into the upper atmosphere and more precipitation over Indonesia, Central Africa and the west coast of South America, and less precipitation over the Amazon.

  16. Patterns of plant functional variation and specialization along secondary succession and topography in a tropical dry forest

    NASA Astrophysics Data System (ADS)

    Sanaphre-Villanueva, Lucía; Dupuy, Juan Manuel; Andrade, José Luis; Reyes-García, Casandra; Jackson, Paula C.; Paz, Horacio

    2017-05-01

    Long-term human disturbance of tropical forests may favor generalist plant species leading to biotic homogenization. We aimed to a) assess if generalist species dominate across different successional ages and topographical positions in a tropical dry forest with a long history of human disturbance, b) to characterize functional traits associated with generalist and specialist species, and c) to assess if a predominance of generalists leads to a homogeneous functional structure across the landscape. We used a multinomial model of relative abundances to classify 118 woody species according to their successional/topographic habitat. Three species were classified as secondary-forest specialists, five as mature-forest specialists, 35 as generalists, and 75 as too rare to classify. According to topography, six species were hill specialists, eight flat-site specialists, 35 generalists, and 70 too rare. Generalists dominated across the landscape. Analysis of 14 functional traits from 65 dominant species indicated that generalists varied from acquisitive strategies of light and water early in succession to conservative strategies in older forests and on hills. Long-term human disturbance may have favored generalist species, but this did not result in functional homogenization. Further analyses considering other functional traits, and temporal and fine-scale microenvironmental variation are needed to better understand community assembly.

  17. Contribution of Ebullition to Methane and Carbon Dioxide Emission from Water between Plant Rows in a Tropical Rice Paddy Field

    PubMed Central

    Komiya, Shujiro; Noborio, Kosuke; Katano, Kentaro; Pakoktom, Tiwa; Siangliw, Meechai; Toojinda, Theerayut

    2015-01-01

    Although bubble ebullition through water in rice paddy fields dominates direct methane (CH4) emissions from paddy soil to the atmosphere in tropical regions, the temporal changes and regulating factors of this ebullition are poorly understood. Bubbles in a submerged paddy soil also contain high concentrations of carbon dioxide (CO2), implying that CO2 ebullition may occur in addition to CH4 ebullition. We investigated the dynamics of CH4 and CO2 ebullition in tropical rice paddy fields using an automated closed chamber installed between rice plants. Abrupt increases in CH4 concentrations occurred by bubble ebullition. The CO2 concentration in the chamber air suddenly increased at the same time, which indicated that CO2 ebullition was also occurring. The CH4 and CO2 emissions by bubble ebullition were correlated with falling atmospheric pressure and increasing soil surface temperature. The relative contribution of CH4 and CO2 ebullitions to the daily total emissions was 95–97% and 13–35%, respectively. PMID:27347533

  18. Contribution of Ebullition to Methane and Carbon Dioxide Emission from Water between Plant Rows in a Tropical Rice Paddy Field.

    PubMed

    Komiya, Shujiro; Noborio, Kosuke; Katano, Kentaro; Pakoktom, Tiwa; Siangliw, Meechai; Toojinda, Theerayut

    2015-01-01

    Although bubble ebullition through water in rice paddy fields dominates direct methane (CH4) emissions from paddy soil to the atmosphere in tropical regions, the temporal changes and regulating factors of this ebullition are poorly understood. Bubbles in a submerged paddy soil also contain high concentrations of carbon dioxide (CO2), implying that CO2 ebullition may occur in addition to CH4 ebullition. We investigated the dynamics of CH4 and CO2 ebullition in tropical rice paddy fields using an automated closed chamber installed between rice plants. Abrupt increases in CH4 concentrations occurred by bubble ebullition. The CO2 concentration in the chamber air suddenly increased at the same time, which indicated that CO2 ebullition was also occurring. The CH4 and CO2 emissions by bubble ebullition were correlated with falling atmospheric pressure and increasing soil surface temperature. The relative contribution of CH4 and CO2 ebullitions to the daily total emissions was 95-97% and 13-35%, respectively.

  19. Community-wide assessment of pollen limitation in hummingbird-pollinated plants of a tropical montane rain forest

    PubMed Central

    Wolowski, Marina; Ashman, Tia-Lynn; Freitas, Leandro

    2013-01-01

    Background and Aims Although pollen limitation of reproduction (PL) has been widely studied, our understanding of its occurrence in tropical communities, especially for bird-pollinated plants, is underdeveloped. In addition, inclusion of both quantity and quality aspects in studies of PL are generally lacking. Within hummingbird-pollinated plants, a prediction was made for higher PL for the quality than quantity aspects and a minor effect of temporal variation because hummingbirds are constant and efficient pollen vectors but they may transfer low quality pollen. Methods Field hand and open pollination experiments were conducted on 21 species in a tropical montane rain forest over 2 years. The quantity (fruit set and seeds per fruit) and quality (seed weight and germination) aspects of reproduction were assessed as the response to open pollination relative to outcross hand pollination. The relationships between the effect size of quantity and quality aspects of reproduction and predictive plant features (self-incompatibility, autogamy, density and pollinator specialization level) were assessed with phylogenetic generalized linear models. Key Results Just over half of all the species expressed PL for one or more response variables. On average, the severity of PL was strong for one quality variable (seed germination; 0·83), but insignificant for another (seed weight; –0·03), and low to moderate for quantity variables (0·31 for seeds per fruit and 0·39 for fruit set). There was only a minor contribution of temporal variation to PL within the studied species. Common predictors of PL, i.e. phylogenetic relatedness, self-incompatibility, autogamy, plant density and pollinator specialization level, did not adequately explain variation in PL within this community. Conclusions Despite the measurable degree of PL within these hummingbird-pollinated plants, the causes of pollen quality and quantity insufficiency are not clear. Variables other than those tested may

  20. Production of prodigiosin and chitinases by tropical Serratia marcescens strains with potential to control plant pathogens.

    PubMed

    Gutiérrez-Román, Martha Ingrid; Holguín-Meléndez, Francisco; Bello-Mendoza, Ricardo; Guillén-Navarro, Karina; Dunn, Michael F; Huerta-Palacios, Graciela

    2012-01-01

    The potential of three Serratia marcescens strains (CFFSUR-B2, CFFSUR-B3 and CFFSUR-B4) isolated from tropical regions in Mexico to inhibit the mycelial growth and conidial germination of Colletotrichum gloeosporioides, causal agent of fruit anthracnose, was evaluated. The ability of these strains to produce prodigiosin and chitinases when cultivated in oil seed-based media (peanut, sesame, soybean and castor bean) and in Luria-Bertani medium was determined. All of the strains exhibited similar fungal antagonistic activities and inhibited myceliar growth by more than 40% while inhibiting conidial germination by 81-89% (P = 0.01). The highest level of prodigiosin (40 μg/ml) was produced in the peanut-based medium while growth in soybean-based medium allowed the highest production of chitinases (56 units/ml), independent of the strain used. Strain CFFSUR-B2 grown in peanut medium was used to evaluate the effect of inoculum density and initial pH on metabolite production. The amount of prodigiosin produced increased with greater inoculum densities, with an initial density of 1 × 10(12) resulting in the highest production (60 μg/ml). Prodigiosin production was not affected by pH. The strains studied have the advantage of being adapted to tropical climates and are able to produce chitinases in the absence of chitin induction in vitro. These characteristics suggest their potential as biocontrol agents for fungal pathogens in tropical regions of the world.

  1. Plant δ15N Correlates with the Transpiration Efficiency of Nitrogen Acquisition in Tropical Trees1[OA

    PubMed Central

    Cernusak, Lucas A.; Winter, Klaus; Turner, Benjamin L.

    2009-01-01

    Based upon considerations of a theoretical model of 15N/14N fractionation during steady-state nitrate uptake from soil, we hypothesized that, for plants grown in a common soil environment, whole-plant δ15N (δP) should vary as a function of the transpiration efficiency of nitrogen acquisition (FN/v) and the difference between δP and root δ15N (δP − δR). We tested these hypotheses with measurements of several tropical tree and liana species. Consistent with theoretical expectations, both FN/v and δP − δR were significant sources of variation in δP, and the relationship between δP and FN/v differed between non-N2-fixing and N2-fixing species. We interpret the correlation between δP and FN/v as resulting from variation in mineral nitrogen efflux-to-influx ratios across plasma membranes of root cells. These results provide a simple explanation of variation in δ15N of terrestrial plants and have implications for understanding nitrogen cycling in ecosystems. PMID:19726571

  2. Testing the stress-gradient hypothesis during the restoration of tropical degraded land using the shrub Rhodomyrtus tomentosa as a nurse plant

    Treesearch

    Nan Liu; Hai Ren; Sufen Yuan; Qinfeng Guo; Long Yang

    2013-01-01

    The relative importance of facilitation and competition between pairwise plants across abiotic stress gradients as predicted by the stress-gradient hypothesis has been confirmed in arid and temperate ecosystems, but the hypothesis has rarely been tested in tropical systems, particularly across nutrient gradients. The current research examines the interactions between a...

  3. Scatter hoarding of seeds confers survival advantages and disadvantages to large-seeded tropical plants at different life stages.

    PubMed

    Kuprewicz, Erin K

    2015-01-01

    Scatter hoarding of seeds by animals contributes significantly to forest-level processes, including plant recruitment and forest community composition. However, the potential positive and negative effects of caching on seed survival, germination success, and seedling survival have rarely been assessed through experimental studies. Here, I tested the hypothesis that seed burial mimicking caches made by scatter hoarding Central American agoutis (Dasyprocta punctate) enhances seed survival, germination, and growth by protecting seeds from seed predators and providing favorable microhabitats for germination. In a series of experiments, I used simulated agouti seed caches to assess how hoarding affects seed predation by ground-dwelling invertebrates and vertebrates for four plant species. I tracked germination and seedling growth of intact and beetle-infested seeds and, using exclosures, monitored the effects of mammals on seedling survival through time. All experiments were conducted over three years in a lowland wet forest in Costa Rica. The majority of hoarded palm seeds escaped predation by both invertebrates and vertebrates while exposed seeds suffered high levels of infestation and removal. Hoarding had no effect on infestation rates of D. panamensis, but burial negatively affected germination success by preventing endocarp dehiscence. Non-infested palm seeds had higher germination success and produced larger seedlings than infested seeds. Seedlings of A. alatum and I. deltoidea suffered high mortality by seed-eating mammals. Hoarding protected most seeds from predators and enhanced germination success (except for D. panamensis) and seedling growth, although mammals killed many seedlings of two plant species; all seedling deaths were due to seed removal from the plant base. Using experimental caches, this study shows that scatter hoarding is beneficial to most seeds and may positively affect plant propagation in tropical forests, although tradeoffs in seed

  4. Scatter Hoarding of Seeds Confers Survival Advantages and Disadvantages to Large-Seeded Tropical Plants at Different Life Stages

    PubMed Central

    Kuprewicz, Erin K.

    2015-01-01

    Scatter hoarding of seeds by animals contributes significantly to forest-level processes, including plant recruitment and forest community composition. However, the potential positive and negative effects of caching on seed survival, germination success, and seedling survival have rarely been assessed through experimental studies. Here, I tested the hypothesis that seed burial mimicking caches made by scatter hoarding Central American agoutis (Dasyprocta punctate) enhances seed survival, germination, and growth by protecting seeds from seed predators and providing favorable microhabitats for germination. In a series of experiments, I used simulated agouti seed caches to assess how hoarding affects seed predation by ground-dwelling invertebrates and vertebrates for four plant species. I tracked germination and seedling growth of intact and beetle-infested seeds and, using exclosures, monitored the effects of mammals on seedling survival through time. All experiments were conducted over three years in a lowland wet forest in Costa Rica. The majority of hoarded palm seeds escaped predation by both invertebrates and vertebrates while exposed seeds suffered high levels of infestation and removal. Hoarding had no effect on infestation rates of D. panamensis, but burial negatively affected germination success by preventing endocarp dehiscence. Non-infested palm seeds had higher germination success and produced larger seedlings than infested seeds. Seedlings of A. alatum and I. deltoidea suffered high mortality by seed-eating mammals. Hoarding protected most seeds from predators and enhanced germination success (except for D. panamensis) and seedling growth, although mammals killed many seedlings of two plant species; all seedling deaths were due to seed removal from the plant base. Using experimental caches, this study shows that scatter hoarding is beneficial to most seeds and may positively affect plant propagation in tropical forests, although tradeoffs in seed

  5. A physiologically-based plant hydraulics scheme for ESMs: impacts of hydraulic trait variability for tropical forests under drought

    NASA Astrophysics Data System (ADS)

    Christoffersen, B. O.; Xu, C.; Fisher, R.; Fyllas, N.; Gloor, M.; Fauset, S.; Galbraith, D.; Koven, C.; Knox, R. G.; Kueppers, L. M.; Chambers, J. Q.; Meir, P.; McDowell, N. G.

    2016-12-01

    A major challenge of Earth System Models (ESMs) is to capture the diversity of individual-level responses to changes in water availability. Yet, decades of research in plant physiological ecology have given us a means to quantify central tendencies and variances of plant hydraulic traits. If ESMs possessed the relevant hydrodynamic process structure, these traits could be incorporated into improved predictions of community- and ecosystem-level processes such as tree mortality. We present a model of plant hydraulics in which all parameters are biologically-interpretable and measurable traits, such as turgor loss point πtlp, bulk elastic modulus ɛ, hydraulic capacitance Cft, xylem hydraulic conductivity ks,max, water potential at 50 % loss of conductivity for both xylem (P50,x) and stomata (P50,gs). We applied this scheme to tropical forests by incorporating it into both an individual-based model `Trait Forest Simulator' (TFS) and the `Functionally Assembled Terrestrial Ecosystem Simulator' (FATES; derived from CLM(ED)), and explore the consequences of variability in plant hydraulic traits on simulated leaf water potential, a potentially powerful predictor of tree mortality. We show that, independent of the difference between P50,gs and P50,x, or the hydraulic safety margin (HSM), diversity in hydraulic traits can increase or decrease whole-ecosystem resistance to hydraulic failure, and thus ecosystem-level responses to drought. Key uncertainties remaining concern how coordination and trade-offs in hydraulic traits are parameterized. We conclude that inclusion of such a physiologically-based plant hydraulics scheme in ESMs will greatly improve the capability of ESMs to predict functional trait filtering within ecosystems in responding to environmental change.

  6. Coevolutionary arms race versus host defense chase in a tropical herbivore-plant system.

    PubMed

    Endara, María-José; Coley, Phyllis D; Ghabash, Gabrielle; Nicholls, James A; Dexter, Kyle G; Donoso, David A; Stone, Graham N; Pennington, R Toby; Kursar, Thomas A

    2017-09-05

    Coevolutionary models suggest that herbivores drive diversification and community composition in plants. For herbivores, many questions remain regarding how plant defenses shape host choice and community structure. We addressed these questions using the tree genus Inga and its lepidopteran herbivores in the Amazon. We constructed phylogenies for both plants and insects and quantified host associations and plant defenses. We found that similarity in herbivore assemblages between Inga species was correlated with similarity in defenses. There was no correlation with phylogeny, a result consistent with our observations that the expression of defenses in Inga is independent of phylogeny. Furthermore, host defensive traits explained 40% of herbivore community similarity. Analyses at finer taxonomic scales showed that different lepidopteran clades select hosts based on different defenses, suggesting taxon-specific histories of herbivore-host plant interactions. Finally, we compared the phylogeny and defenses of Inga to phylogenies for the major lepidopteran clades. We found that closely related herbivores fed on Inga with similar defenses rather than on closely related plants. Together, these results suggest that plant defenses might be more evolutionarily labile than the herbivore traits related to host association. Hence, there is an apparent asymmetry in the evolutionary interactions between Inga and its herbivores. Although plants may evolve under selection by herbivores, we hypothesize that herbivores may not show coevolutionary adaptations, but instead "chase" hosts based on the herbivore's own traits at the time that they encounter a new host, a pattern more consistent with resource tracking than with the arms race model of coevolution.

  7. Transcriptome profiling of low temperature-treated cassava apical shoots showed dynamic responses of tropical plant to cold stress

    PubMed Central

    2012-01-01

    Background Cassava is an important tropical root crop adapted to a wide range of environmental stimuli such as drought and acid soils. Nevertheless, it is an extremely cold-sensitive tropical species. Thus far, there is limited information about gene regulation and signalling pathways related to the cold stress response in cassava. The development of microarray technology has accelerated the study of global transcription profiling under certain conditions. Results A 60-mer oligonucleotide microarray representing 20,840 genes was used to perform transcriptome profiling in apical shoots of cassava subjected to cold at 7°C for 0, 4 and 9 h. A total of 508 transcripts were identified as early cold-responsive genes in which 319 sequences had functional descriptions when aligned with Arabidopsis proteins. Gene ontology annotation analysis identified many cold-relevant categories, including 'Response to abiotic and biotic stimulus', 'Response to stress', 'Transcription factor activity', and 'Chloroplast'. Various stress-associated genes with a wide range of biological functions were found, such as signal transduction components (e.g., MAP kinase 4), transcription factors (TFs, e.g., RAP2.11), and reactive oxygen species (ROS) scavenging enzymes (e.g., catalase 2), as well as photosynthesis-related genes (e.g., PsaL). Seventeen major TF families including many well-studied members (e.g., AP2-EREBP) were also involved in the early response to cold stress. Meanwhile, KEGG pathway analysis uncovered many important pathways, such as 'Plant hormone signal transduction' and 'Starch and sucrose metabolism'. Furthermore, the expression changes of 32 genes under cold and other abiotic stress conditions were validated by real-time RT-PCR. Importantly, most of the tested stress-responsive genes were primarily expressed in mature leaves, stem cambia, and fibrous roots rather than apical buds and young leaves. As a response to cold stress in cassava, an increase in transcripts and

  8. Constructed tropical wetlands with integrated submergent-emergent plants for sustainable water quality management.

    PubMed

    Tanaka, Norio; Jinadasa, K B S N; Werellagama, D R I B; Mowjood, M I M; Ng, W J

    2006-01-01

    Improvement of primary effluent quality by using an integrated system of emergent plants (Scirpus grossus in the leading subsurface flow arrangement) and submergent plants (Hydrilla verticillata in a subsequent channel) was investigated. The primary effluent was drawn from a septic tank treating domestic sewage from a student dormitory at the University of Peradeniya, Sri Lanka. Influent and effluent samples were collected once every 2 weeks from May 2004 through July 2005 and analyzed to determine water quality parameters. Both the emergent and submergent plants were harvested at predetermined intervals. The results suggested that harvesting prolonged the usefulness of the system and the generation of a renewable biomass with potential economic value. The mean overall pollutant removal efficiencies of the integrated emergent and submergent plant system were biological oxygen demand (BOD5), 65.7%; chemical oxygen demand (COD), 40.8%; ammonium (NH4+-N), 74.8%; nitrate (NO3--N), 38.8%; phosphate (PO43-), 61.2%; total suspended solids (TSS), 65.8%; and fecal coliforms, 94.8%. The submergent plant subsystem improved removal of nutrients that survived the emergent subsystem operated at low hydraulic retention times. The significant improvement in effluent quality following treatment by the submergent plant system indicates the value of incorporating such plants in wetland systems.

  9. Dynamic Carboniferous tropical forests: new views of plant function and potential for physiological forcing of climate.

    PubMed

    Wilson, Jonathan P; Montañez, Isabel P; White, Joseph D; DiMichele, William A; McElwain, Jennifer C; Poulsen, Christopher J; Hren, Michael T

    2017-09-01

    Contents 1333 I. 1334 II. 1335 III. 1339 IV. 1344 V. 1347 VI. 1347 1348 1348 References 1348 SUMMARY: The Carboniferous, the time of Earth's penultimate icehouse and widespread coal formation, was dominated by extinct lineages of early-diverging vascular plants. Studies of nearest living relatives of key Carboniferous plants suggest that their physiologies and growth forms differed substantially from most types of modern vegetation, particularly forests. It remains a matter of debate precisely how differently and to what degree these long-extinct plants influenced the environment. Integrating biophysical analysis of stomatal and vascular conductivity with geochemical analysis of fossilized tissues and process-based ecosystem-scale modeling yields a dynamic and unique perspective on these paleoforests. This integrated approach indicates that key Carboniferous plants were capable of growth and transpiration rates that approach values found in extant crown-group angiosperms, differing greatly from comparatively modest rates found in their closest living relatives. Ecosystem modeling suggests that divergent stomatal conductance, leaf sizes and stem life span between dominant clades would have shifted the balance of soil-atmosphere water fluxes, and thus surface runoff flux, during repeated, climate-driven, vegetation turnovers. This synthesis highlights the importance of 'whole plant' physiological reconstruction of extinct plants and the potential of vascular plants to have influenced the Earth system hundreds of millions of years ago through vegetation-climate feedbacks. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  10. Preliminary measurements of spectral signatures of tropical and temperate plants in the thermal infrared

    NASA Technical Reports Server (NTRS)

    Salisbury, John W.; Milton, N. M.

    1987-01-01

    Spectral reflectance measurements of seven tropical species and six deciduous species were carried out in thermal infrared to establish the species-dependent spectral characteristics and to investigate the effect on spectral signatures of environmental variables, such as leaf maturity, drought, and metal stress. Seasonal variations of spectral signatures occurred between spring and summer leaves, but such variations were minimal during summer and early fall. Overall reflectance of senescent leaves was higher than that of young leaves, as was the reflectance of leaves from trees growing in metal-enriched soils, as compared with leaves from the control area. However, the characteristic spectral features were not changed in either case. It was also found that water stress did not have any effect on the infrared signatures: trees grown during a drought season maintained their characteristic spectral signatures.

  11. Preliminary measurements of spectral signatures of tropical and temperate plants in the thermal infrared

    NASA Technical Reports Server (NTRS)

    Salisbury, John W.; Milton, N. M.

    1987-01-01

    Spectral reflectance measurements of seven tropical species and six deciduous species were carried out in thermal infrared to establish the species-dependent spectral characteristics and to investigate the effect on spectral signatures of environmental variables, such as leaf maturity, drought, and metal stress. Seasonal variations of spectral signatures occurred between spring and summer leaves, but such variations were minimal during summer and early fall. Overall reflectance of senescent leaves was higher than that of young leaves, as was the reflectance of leaves from trees growing in metal-enriched soils, as compared with leaves from the control area. However, the characteristic spectral features were not changed in either case. It was also found that water stress did not have any effect on the infrared signatures: trees grown during a drought season maintained their characteristic spectral signatures.

  12. [Native plant resources to optimize the performances of forest rehabilitation in Mediterranean and tropical environment: some examples of nursing plant species that improve the soil mycorrhizal potential].

    PubMed

    Duponnois, Robin; Ramanankierana, Heriniaina; Hafidi, Mohamed; Baohanta, Rondro; Baudoin, Ezékiel; Thioulouse, Jean; Sanguin, Hervé; Bâ, Amadou; Galiana, Antoine; Bally, René; Lebrun, Michel; Prin, Yves

    2013-01-01

    The overexploitation of natural resources, resulting in an increased need for arable lands by local populations, causes a serious dysfunction in the soil's biological functioning (mineral deficiency, salt stress, etc.). This dysfunction, worsened by the climatic conditions (drought), requires the implementation of ecological engineering strategies allowing the rehabilitation of degraded areas through the restoration of essential ecological services. The first symptoms of weathering processes of soil quality in tropical and Mediterranean environments result in an alteration of the plant cover structure with, in particular, the pauperization of plant species diversity and abundance. This degradation is accompanied by a weakening of soils and an increase of the impact of erosion on the surface layer resulting in reduced fertility of soils in terms of their physicochemical characteristics as well as their biological ones (e.g., soil microbes). Among the microbial components particularly sensitive to erosion, symbiotic microorganisms (rhizobia, Frankia, mycorrhizal fungi) are known to be key components in the main terrestrial biogeochemical cycles (C, N and P). Many studies have shown the importance of the management of these symbiotic microorganisms in rehabilitation and revegetation strategies of degraded environments, but also in improving the productivity of agrosystems. In particular, the selection of symbionts and their inoculation into the soil were strongly encouraged in recent decades. These inoculants were selected not only for their impact on the plant, but also for their ability to persist in the soil at the expense of the residual native microflora. The performance of this technique was thus evaluated on the plant cover, but its impact on soil microbial characteristics was totally ignored. The role of microbial diversity on productivity and stability (resistance, resilience, etc.) of eco- and agrosystems has been identified relatively recently and has led

  13. Predictive Models of Primary Tropical Forest Structure from Geomorphometric Variables Based on SRTM in the Tapajós Region, Brazilian Amazon

    PubMed Central

    Bispo, Polyanna da Conceição; dos Santos, João Roberto; Valeriano, Márcio de Morisson; Graça, Paulo Maurício Lima de Alencastro; Balzter, Heiko; França, Helena; Bispo, Pitágoras da Conceição

    2016-01-01

    Surveying primary tropical forest over large regions is challenging. Indirect methods of relating terrain information or other external spatial datasets to forest biophysical parameters can provide forest structural maps at large scales but the inherent uncertainties need to be evaluated fully. The goal of the present study was to evaluate relief characteristics, measured through geomorphometric variables, as predictors of forest structural characteristics such as average tree basal area (BA) and height (H) and average percentage canopy openness (CO). Our hypothesis is that geomorphometric variables are good predictors of the structure of primary tropical forest, even in areas, with low altitude variation. The study was performed at the Tapajós National Forest, located in the Western State of Pará, Brazil. Forty-three plots were sampled. Predictive models for BA, H and CO were parameterized based on geomorphometric variables using multiple linear regression. Validation of the models with nine independent sample plots revealed a Root Mean Square Error (RMSE) of 3.73 m2/ha (20%) for BA, 1.70 m (12%) for H, and 1.78% (21%) for CO. The coefficient of determination between observed and predicted values were r2 = 0.32 for CO, r2 = 0.26 for H and r2 = 0.52 for BA. The models obtained were able to adequately estimate BA and CO. In summary, it can be concluded that relief variables are good predictors of vegetation structure and enable the creation of forest structure maps in primary tropical rainforest with an acceptable uncertainty. PMID:27089013

  14. ACC deaminase and IAA producing growth promoting bacteria from the rhizosphere soil of tropical rice plants.

    PubMed

    Bal, Himadri Bhusan; Das, Subhasis; Dangar, Tushar K; Adhya, Tapan K

    2013-12-01

    Beneficial plant-associated bacteria play a key role in supporting and/or promoting plant growth and health. Plant growth promoting bacteria present in the rhizosphere of crop plants can directly affect plant metabolism or modulate phytohormone production or degradation. We isolated 355 bacteria from the rhizosphere of rice plants grown in the farmers' fields in the coastal rice field soil from five different locations of the Ganjam district of Odisha, India. Six bacteria producing both ACC deaminase (ranging from 603.94 to 1350.02 nmol α-ketobutyrate mg(-1)  h(-1) ) and indole acetic acid (IAA; ranging from 10.54 to 37.65 μM ml(-1) ) in pure cultures were further identified using polyphasic taxonomy including BIOLOG((R)) , FAME analysis and the 16S rRNA gene sequencing. Phylogenetic analyses of the isolates resulted into five major clusters to include members of the genera Bacillus, Microbacterium, Methylophaga, Agromyces, and Paenibacillus. Seed inoculation of rice (cv. Naveen) by the six individual PGPR isolates had a considerable impact on different growth parameters including root elongation that was positively correlated with ACC deaminase activity and IAA production. The cultures also had other plant growth attributes including ammonia production and at least two isolates produced siderophores. Study indicates that presence of diverse rhizobacteria with effective growth-promoting traits, in the rice rhizosphere, may be exploited for a sustainable crop management under field conditions. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Draft genome sequence of bitter gourd (Momordica charantia), a vegetable and medicinal plant in tropical and subtropical regions

    PubMed Central

    Urasaki, Naoya; Takagi, Hiroki; Natsume, Satoshi; Uemura, Aiko; Taniai, Naoki; Miyagi, Norimichi; Fukushima, Mai; Suzuki, Shouta; Tarora, Kazuhiko; Tamaki, Moritoshi; Sakamoto, Moriaki; Terauchi, Ryohei

    2017-01-01

    Abstract Bitter gourd (Momordica charantia) is an important vegetable and medicinal plant in tropical and subtropical regions globally. In this study, the draft genome sequence of a monoecious bitter gourd inbred line, OHB3-1, was analyzed. Through Illumina sequencing and de novo assembly, scaffolds of 285.5 Mb in length were generated, corresponding to ∼84% of the estimated genome size of bitter gourd (339 Mb). In this draft genome sequence, 45,859 protein-coding gene loci were identified, and transposable elements accounted for 15.3% of the whole genome. According to synteny mapping and phylogenetic analysis of conserved genes, bitter gourd was more related to watermelon (Citrullus lanatus) than to cucumber (Cucumis sativus) or melon (C. melo). Using RAD-seq analysis, 1507 marker loci were genotyped in an F2 progeny of two bitter gourd lines, resulting in an improved linkage map, comprising 11 linkage groups. By anchoring RAD tag markers, 255 scaffolds were assigned to the linkage map. Comparative analysis of genome sequences and predicted genes determined that putative trypsin-inhibitor and ribosome-inactivating genes were distinctive in the bitter gourd genome. These genes could characterize the bitter gourd as a medicinal plant. PMID:28028039

  16. Draft genome sequence of bitter gourd (Momordica charantia), a vegetable and medicinal plant in tropical and subtropical regions.

    PubMed

    Urasaki, Naoya; Takagi, Hiroki; Natsume, Satoshi; Uemura, Aiko; Taniai, Naoki; Miyagi, Norimichi; Fukushima, Mai; Suzuki, Shouta; Tarora, Kazuhiko; Tamaki, Moritoshi; Sakamoto, Moriaki; Terauchi, Ryohei; Matsumura, Hideo

    2017-02-01

    Bitter gourd (Momordica charantia) is an important vegetable and medicinal plant in tropical and subtropical regions globally. In this study, the draft genome sequence of a monoecious bitter gourd inbred line, OHB3-1, was analyzed. Through Illumina sequencing and de novo assembly, scaffolds of 285.5 Mb in length were generated, corresponding to ∼84% of the estimated genome size of bitter gourd (339 Mb). In this draft genome sequence, 45,859 protein-coding gene loci were identified, and transposable elements accounted for 15.3% of the whole genome. According to synteny mapping and phylogenetic analysis of conserved genes, bitter gourd was more related to watermelon (Citrullus lanatus) than to cucumber (Cucumis sativus) or melon (C. melo). Using RAD-seq analysis, 1507 marker loci were genotyped in an F2 progeny of two bitter gourd lines, resulting in an improved linkage map, comprising 11 linkage groups. By anchoring RAD tag markers, 255 scaffolds were assigned to the linkage map. Comparative analysis of genome sequences and predicted genes determined that putative trypsin-inhibitor and ribosome-inactivating genes were distinctive in the bitter gourd genome. These genes could characterize the bitter gourd as a medicinal plant.

  17. Influence of crop types and soil properties on radionuclide soil-to-plant transfer factors in tropical and subtropical environments.

    PubMed

    Velasco, H; Ayub, J Juri; Sansone, U

    2009-09-01

    This paper presents a descriptive statistical analysis of radionuclide soil-to-plant transfer factors (Fv) for tropical and subtropical environments. These values were collected from previous databases and standard publications with the objective of contributing to the IAEA Technical Report Series: Handbook of parameter values for the prediction of radionuclide transfer to humans in terrestrial and freshwater environments. More than 2200 Fv values of different radionuclides were gathered and arranged into specific databases, detailing relevant information regarding the environments where this parameter was calculated. This study explores the dependence of Fv values to crop types, and soil properties. The wide variability and uncertainty observed in calculated Fv values were considerably reduced when the data was independently grouped into clusters containing the same radionuclide/plant group/soil type combinations. For each cluster the principal statistical quantities were determined. Using these quantities, the Fv distributions of each data set was explored. Fv probability distribution is discussed to clarify the use of this empirical parameter in radioecological and radiological assessment models.

  18. AFLP marker analysis revealing genetic structure of the tree Parapiptadenia rigida (Benth.) Brenan (Leguminosae-Mimosoideae) in the southern Brazilian Tropical Rainforest.

    PubMed

    de Souza, Laís Bérgamo; Ruas, Eduardo A; Rodrigues, Luana A; Ruas, Claudete F; Ruas, Paulo M

    2013-12-01

    Parapiptadenia rigida is a tropical early secondary succession tree characteristic of the Tropical Atlantic Rainforest. This species is of great ecological importance in the recovery of degraded areas. In this study we investigated the variability and population genetic structure of eight populations of P. rigida. Five AFLP primer combinations were used in a sample of 159 individuals representing these eight populations, rendering a total of 126 polymorphic fragments. The averages of percentage of polymorphic loci, gene diversity, and Shannon index were 60.45%, 0.217, and 0.322, respectively. A significant correlation between the population genetic variability and the population sizes was observed. The genetic variability within populations (72.20%) was higher than between these (22.80%). No perfect correlation was observed between geographic and genetic distances, which might be explained by differences in deforestation intensities that occurred in these areas. A dendrogram constructed by the UPGMA method revealed the formation of two clusters, these also confirmed by Bayesian analysis for the number of K cluster. These results show that it is necessary to develop urgent management strategies for the conservation of certain populations of P. rigida, while other populations still preserve reasonably high levels of genetic variability.

  19. AFLP marker analysis revealing genetic structure of the tree Parapiptadenia rigida (Benth.) Brenan (Leguminosae-Mimosoideae) in the southern Brazilian Tropical Rainforest

    PubMed Central

    de Souza, Laís Bérgamo; Ruas, Eduardo A.; Rodrigues, Luana A.; Ruas, Claudete F.; Ruas, Paulo M.

    2013-01-01

    Parapiptadenia rigida is a tropical early secondary succession tree characteristic of the Tropical Atlantic Rainforest. This species is of great ecological importance in the recovery of degraded areas. In this study we investigated the variability and population genetic structure of eight populations of P. rigida. Five AFLP primer combinations were used in a sample of 159 individuals representing these eight populations, rendering a total of 126 polymorphic fragments. The averages of percentage of polymorphic loci, gene diversity, and Shannon index were 60.45%, 0.217, and 0.322, respectively. A significant correlation between the population genetic variability and the population sizes was observed. The genetic variability within populations (72.20%) was higher than between these (22.80%). No perfect correlation was observed between geographic and genetic distances, which might be explained by differences in deforestation intensities that occurred in these areas. A dendrogram constructed by the UPGMA method revealed the formation of two clusters, these also confirmed by Bayesian analysis for the number of K cluster. These results show that it is necessary to develop urgent management strategies for the conservation of certain populations of P. rigida, while other populations still preserve reasonably high levels of genetic variability. PMID:24385857

  20. Water use in four model tropical plant associations established in the lowlands of Costa Rica.

    PubMed

    Gutiérrez-Soto, Marco V; Ewel, John J

    2008-12-01

    We examined soil water use patterns of four model plant associations established in the North Caribbean lowlands of Costa Rica by comparing the stable hydrogen isotope composition, deltaD, in xylem sap and in soil water at different depths, under rainy and dry conditions. Four 5-year-old model plant associations composed of 2 tree species (Hyeronima alchorneoides and Cedrela odorata) having different architecture and phenology were studied. Average tree height was 8.9 and 7.6 m, respectively. Each tree species was grown in monoculture and in polyculture with 2 perennial monocotyledons (Euterpe oleracea and Heliconia imbricata). Maximum rooting depth at the time of 6D determination was approximately 2 m for almost all species. Most roots of all species were concentrated in the upper soil layers. Stomatal conductance to water vapor (gS) was higher in the deciduous C. odorata than in the evergreen H. alchorneoides; within each species, g, did not differ when the trees were grown in mono or in polyculture. During the rainy season, gradients in soil water 6D were not observed. Average rainy season xylem sap deltaD did not differ among members of the plant combinations tested (-30% per thousand), and was more similar to deltaD values of shallow soil water. Under dry conditions, volumetric soil water content declined from 50 to approximately 35%, and modest gradients in soil water deltaD were observed. Xylem sap deltaD obtained during dry conditions was significantly lower than rainy season values. Xylem sap deltaD of plants growing in the four associations varied between -9 and -22% per hundred, indicating that shallow water was predominantly absorbed during the dry period too. Differences in xylem sap deltaD of trees and monocots were also detected, but no significant patterns emerged. The results suggest that: (a) the plant associations examined extracted water predominantly from shallow soil layers (<1 m), (b) the natural isotopic variation in soil and plant water at

  1. Hydrolysis of Selected Tropical Plant Wastes Catalyzed by a Magnetic Carbonaceous Acid with Microwave

    PubMed Central

    Su, Tong-Chao; Fang, Zhen; Zhang, Fan; Luo, Jia; Li, Xing-Kang

    2015-01-01

    In this study, magnetic carbonaceous acids were synthesized by pyrolysis of the homogeneous mixtures of glucose and magnetic Fe3O4 nanoparticles, and subsequent sulfonation. The synthesis conditions were optimized to obtain a catalyst with both high acid density (0.75 mmol g−1) and strong magnetism [magnetic saturation, Ms = 19.5 Am2 kg−1]. The screened catalyst (C-SO3H/Fe3O4) was used to hydrolyze ball-milled cellulose in a microwave reactor with total reducing sugar (TRS) yield of 25.3% under the best conditions at 190 °C for 3.5 h. It was cycled for at least seven times with high catalyst recovery rate (92.8%), acid density (0.63 mmol g−1) and magnetism (Ms = 12.9 Am2 kg−1), as well as high TRS yield (20.1%) from the hydrolysis of ball-milled cellulose. The catalyst was further successfully tested for the hydrolysis of tropical biomass with high TRS and glucose yields of 79.8% and 58.3% for bagasse, 47.2% and 35.6% for Jatropha hulls, as well as 54.4% and 35.8% for Plukenetia hulls. PMID:26648414

  2. Hydrolysis of Selected Tropical Plant Wastes Catalyzed by a Magnetic Carbonaceous Acid with Microwave

    NASA Astrophysics Data System (ADS)

    Su, Tong-Chao; Fang, Zhen; Zhang, Fan; Luo, Jia; Li, Xing-Kang

    2015-12-01

    In this study, magnetic carbonaceous acids were synthesized by pyrolysis of the homogeneous mixtures of glucose and magnetic Fe3O4 nanoparticles, and subsequent sulfonation. The synthesis conditions were optimized to obtain a catalyst with both high acid density (0.75 mmol g-1) and strong magnetism [magnetic saturation, Ms = 19.5 Am2 kg-1]. The screened catalyst (C-SO3H/Fe3O4) was used to hydrolyze ball-milled cellulose in a microwave reactor with total reducing sugar (TRS) yield of 25.3% under the best conditions at 190 °C for 3.5 h. It was cycled for at least seven times with high catalyst recovery rate (92.8%), acid density (0.63 mmol g-1) and magnetism (Ms = 12.9 Am2 kg-1), as well as high TRS yield (20.1%) from the hydrolysis of ball-milled cellulose. The catalyst was further successfully tested for the hydrolysis of tropical biomass with high TRS and glucose yields of 79.8% and 58.3% for bagasse, 47.2% and 35.6% for Jatropha hulls, as well as 54.4% and 35.8% for Plukenetia hulls.

  3. Organic matter dynamics control plant species coexistence in a tropical peat swamp forest.

    PubMed

    Shimamura, Tetsuya; Momose, Kuniyasu

    2005-07-22

    We studied the relationship between the coexistence of tree species and the dynamics of organic matter in forests. A tropical peat swamp forest was selected as a model ecosystem, where abiotic factors, such as geological topography or parent rock types, are homogeneous and only biological processes create habitat heterogeneity. The temporal or spatial variation of the ground elevation of peat soils is mainly caused by changes in the balance between organic matter inputs to soils and decomposition, which is affected by the growth and death of influential trees. To clarify the processes of elevation dynamics, we measured the microtopography around some tree groups, estimated organic matter (in the form of litter and roots) in soils under three kinds of microtopographic conditions, measured decomposition rates and detected dominant species' shifting distribution patterns in different stages of growth in relation to the locations of tree groups creating specific microtopographic conditions. We found that growth or death of buttressed trees has the greatest effects on the rising or sinking of ground surfaces through changes in litter supply and root production. We discuss here the possibility of extending our model to other forest types.

  4. SPECIES AND ROTATION FREQUENCY INFLUENCE SOIL NITROGEN IN SIMPLIFIED TROPICAL PLANT COMMUNITIES

    Treesearch

    JOHN J. EWEL

    2006-01-01

    Among the many factors that potentially influence the rate at which nitrogen (N) becomes available to plants in terrestrial ecosystems are the identity and diversity of species composition, frequency of disturbance or stand turnover, and time. Replicated suites of investigator-designed communities afforded an opportunity to examine the effects of those factors on net N...

  5. Soil fauna and plant litter decomposition in tropical and subalpine forests

    Treesearch

    G. Gonzalez; T.R. Seastedt

    2001-01-01

    The decomposition of plant residues is influenced by their chemical composition, the physical-chemical environment, and the decomposer organisms. Most studies interested in latitudinal gradients of decomposition have focused on substrate quality and climate effects on decomposition, and have excluded explicit recognition of the soil organisms involved in the process....

  6. A temporary social parasite of tropical plant-ants improves the fitness of a myrmecophyte

    NASA Astrophysics Data System (ADS)

    Dejean, Alain; Leroy, Céline; Corbara, Bruno; Céréghino, Régis; Roux, Olivier; Hérault, Bruno; Rossi, Vivien; Guerrero, Roberto J.; Delabie, Jacques H. C.; Orivel, Jérôme; Boulay, Raphaël

    2010-10-01

    Myrmecophytes offer plant-ants a nesting place in exchange for protection from their enemies, particularly defoliators. These obligate ant-plant mutualisms are common model systems for studying factors that allow horizontally transmitted mutualisms to persist since parasites of ant-myrmecophyte mutualisms exploit the rewards provided by host plants whilst providing no protection in return. In pioneer formations in French Guiana, Azteca alfari and Azteca ovaticeps are known to be mutualists of myrmecophytic Cecropia ( Cecropia ants). Here, we show that Azteca andreae, whose colonies build carton nests on myrmecophytic Cecropia, is not a parasite of Azteca- Cecropia mutualisms nor is it a temporary social parasite of A. alfari; it is, however, a temporary social parasite of A. ovaticeps. Contrarily to the two mutualistic Azteca species that are only occasional predators feeding mostly on hemipteran honeydew and food bodies provided by the host trees, A. andreae workers, which also attend hemipterans, do not exploit the food bodies. Rather, they employ an effective hunting technique where the leaf margins are fringed with ambushing workers, waiting for insects to alight. As a result, the host trees’ fitness is not affected as A. andreae colonies protect their foliage better than do mutualistic Azteca species resulting in greater fruit production. Yet, contrarily to mutualistic Azteca, when host tree development does not keep pace with colony growth, A. andreae workers forage on surrounding plants; the colonies can even move to a non- Cecropia tree.

  7. Effect of initial soil properties on six-year growth of 15 tree species in tropical restoration plantings.

    PubMed

    Martínez-Garza, Cristina; Campo, Julio; Ricker, Martin; Tobón, Wolke

    2016-12-01

    In restoration plantings in degraded pastures, initial soil nutrient status may lead to differential growth of tropical tree species with diverse life history attributes and capacity for N2 fixation. In 2006, we planted 1,440 seedlings of 15 native tree species in 16 fenced plots (30 × 30 m) in a 60-year-old pasture in Los Tuxtlas, Veracruz, Mexico, in two planting combinations. In the first year, we evaluated bulk density, pH, the concentration of organic carbon (C), total nitrogen (N), ammonia (NO3-), nitrate (NH4+), and total phosphorus (P) in the upper soil profile (0-20 cm in depth) of all plots. The first two axes of two principal component analyses explained more than 60% of the variation in soil variables: The axes were related to increasing bulk density, NO3-, NH4+, total N concentration, and pH. Average relative growth rates in diameter at the stem base of the juvenile trees after 6 years were higher for pioneer (45.7%) and N2-fixing species (47.6%) than for nonpioneer (34.7%) and nonfixing species (36.2%). Most N2-fixing species and those with the slowest growth rates did not respond to soil attributes. Tree species benefited from higher pH levels and existing litter biomass. The pioneers Ficus yoponensis, Cecropia obtusifolia, and Heliocarpus appendiculatus, and the N2-fixing nonpioneers Cojoba arborea, Inga sinacae, and Platymiscium dimorphandrum were promising for forest restoration on our site, given their high growth rates.

  8. Does secondary plant metabolism provide a mechanism for plant defenses in the tropical soda apple Solanum viarum (Solanales: Solanaceae) against the beet armyworm Spodoptera exigua and southern armyworm S. eridania?

    USDA-ARS?s Scientific Manuscript database

    Survival assays were conducted with beet armyworm Spodoptera exigua and southern armyworm S. eridania with tropical soda apple Solanum viarum a relative of tomato. In addition, polyphenol oxidase (PPO) enzyme assays were conducted to determine if secondary plant defense compounds are being produce...

  9. Are we filling the data void? An assessment of the amount and extent of plant collection records and census data available for tropical South America.

    PubMed

    Feeley, Kenneth

    2015-01-01

    Large-scale studies are needed to increase our understanding of how large-scale conservation threats, such as climate change and deforestation, are impacting diverse tropical ecosystems. These types of studies rely fundamentally on access to extensive and representative datasets (i.e., "big data"). In this study, I asses the availability of plant species occurrence records through the Global Biodiversity Information Facility (GBIF) and the distribution of networked vegetation census plots in tropical South America. I analyze how the amount of available data has changed through time and the consequent changes in taxonomic, spatial, habitat, and climatic representativeness. I show that there are large and growing amounts of data available for tropical South America. Specifically, there are almost 2,000,000 unique geo-referenced collection records representing more than 50,000 species of plants in tropical South America and over 1,500 census plots. However, there is still a gaping "data void" such that many species and many habitats remain so poorly represented in either of the databases as to be functionally invisible for most studies. It is important that we support efforts to increase the availability of data, and the representativeness of these data, so that we can better predict and mitigate the impacts of anthropogenic disturbances.

  10. Are We Filling the Data Void? An Assessment of the Amount and Extent of Plant Collection Records and Census Data Available for Tropical South America

    PubMed Central

    Feeley, Kenneth

    2015-01-01

    Large-scale studies are needed to increase our understanding of how large-scale conservation threats, such as climate change and deforestation, are impacting diverse tropical ecosystems. These types of studies rely fundamentally on access to extensive and representative datasets (i.e., “big data”). In this study, I asses the availability of plant species occurrence records through the Global Biodiversity Information Facility (GBIF) and the distribution of networked vegetation census plots in tropical South America. I analyze how the amount of available data has changed through time and the consequent changes in taxonomic, spatial, habitat, and climatic representativeness. I show that there are large and growing amounts of data available for tropical South America. Specifically, there are almost 2,000,000 unique geo-referenced collection records representing more than 50,000 species of plants in tropical South America and over 1,500 census plots. However, there is still a gaping “data void” such that many species and many habitats remain so poorly represented in either of the databases as to be functionally invisible for most studies. It is important that we support efforts to increase the availability of data, and the representativeness of these data, so that we can better predict and mitigate the impacts of anthropogenic disturbances. PMID:25927831

  11. Plant DNA barcodes and a community phylogeny of a tropical forest dynamics plot in Panama

    PubMed Central

    Kress, W. John; Erickson, David L.; Jones, F. Andrew; Swenson, Nathan G.; Perez, Rolando; Sanjur, Oris; Bermingham, Eldredge

    2009-01-01

    The assembly of DNA barcode libraries is particularly relevant within species-rich natural communities for which accurate species identifications will enable detailed ecological forensic studies. In addition, well-resolved molecular phylogenies derived from these DNA barcode sequences have the potential to improve investigations of the mechanisms underlying community assembly and functional trait evolution. To date, no studies have effectively applied DNA barcodes sensu strictu in this manner. In this report, we demonstrate that a three-locus DNA barcode when applied to 296 species of woody trees, shrubs, and palms found within the 50-ha Forest Dynamics Plot on Barro Colorado Island (BCI), Panama, resulted in >98% correct identifications. These DNA barcode sequences are also used to reconstruct a robust community phylogeny employing a supermatrix method for 281 of the 296 plant species in the plot. The three-locus barcode data were sufficient to reliably reconstruct evolutionary relationships among the plant taxa in the plot that are congruent with the broadly accepted phylogeny of flowering plants (APG II). Earlier work on the phylogenetic structure of the BCI forest dynamics plot employing less resolved phylogenies reveals significant differences in evolutionary and ecological inferences compared with our data and suggests that unresolved community phylogenies may have increased type I and type II errors. These results illustrate how highly resolved phylogenies based on DNA barcode sequence data will enhance research focused on the interface between community ecology and evolution. PMID:19841276

  12. Plant DNA barcodes and a community phylogeny of a tropical forest dynamics plot in Panama.

    PubMed

    Kress, W John; Erickson, David L; Jones, F Andrew; Swenson, Nathan G; Perez, Rolando; Sanjur, Oris; Bermingham, Eldredge

    2009-11-03

    The assembly of DNA barcode libraries is particularly relevant within species-rich natural communities for which accurate species identifications will enable detailed ecological forensic studies. In addition, well-resolved molecular phylogenies derived from these DNA barcode sequences have the potential to improve investigations of the mechanisms underlying community assembly and functional trait evolution. To date, no studies have effectively applied DNA barcodes sensu strictu in this manner. In this report, we demonstrate that a three-locus DNA barcode when applied to 296 species of woody trees, shrubs, and palms found within the 50-ha Forest Dynamics Plot on Barro Colorado Island (BCI), Panama, resulted in >98% correct identifications. These DNA barcode sequences are also used to reconstruct a robust community phylogeny employing a supermatrix method for 281 of the 296 plant species in the plot. The three-locus barcode data were sufficient to reliably reconstruct evolutionary relationships among the plant taxa in the plot that are congruent with the broadly accepted phylogeny of flowering plants (APG II). Earlier work on the phylogenetic structure of the BCI forest dynamics plot employing less resolved phylogenies reveals significant differences in evolutionary and ecological inferences compared with our data and suggests that unresolved community phylogenies may have increased type I and type II errors. These results illustrate how highly resolved phylogenies based on DNA barcode sequence data will enhance research focused on the interface between community ecology and evolution.

  13. Greenhouse Gas Emissions from Brazilian Sugarcane Soils

    NASA Astrophysics Data System (ADS)

    Carmo, J.; Pitombo, L.; Cantarella, H.; Rosseto, R.; Andrade, C.; Martinelli, L.; Gava, G.; Vargas, V.; Sousa-Neto, E.; Zotelli, L.; Filoso, S.; Neto, A. E.

    2012-04-01

    Bioethanol from sugarcane is increasingly seen as a sustainable alternative energy source. Besides having high photosynthetic efficiency, sugarcane is a perennial tropical grass crop that can re-grow up to five or more years after being planted. Brazil is the largest producer of sugarcane in the world and management practices commonly used in the country lead to lower rates of inorganic N fertilizer application than sugarcane grown elsewhere, or in comparison to other feedstocks such as corn. Therefore, Brazilian sugarcane ethanol potentially promotes greenhouse gas savings. For that reason, several recent studies have attempted to assess emissions of greenhouse gases (GHG) during sugarcane production in the tropics. However, estimates have been mainly based on models due to a general lack of field data. In this study, we present data from in situ experiments on emission of three GHG (CO2, N2O, and CH4) in sugarcane fields in Brazil. Emissions are provided for sugarcane in different phases of the crop life cycle and under different management practices. Our results show that the use of nitrogen fertilizer in sugarcane crops resulted in an emission factor for N2O similar to those predicted by IPCC (1%), ranging from 0.59% in ratoon cane to 1.11% in plant cane. However, when vinasse was applied in addition to mineralN fertilizer, emissions of GHG increased in comparison to those from the use of mineral N fertilizer alone. Emissions increased significantly when experiments mimicked the accumulation of cane trash on the soil surface with 14 tons ha-1and 21 tons ha-1, which emission factor were 1.89% and 3.03%, respectively. This study is representative of Brazilian sugarcane systems under specific conditions for key factors affecting GHG emissions from soils. Nevertheless, the data provided will improve estimates of GHG from Brazilian sugarcane, and efforts to assess sugarcane ethanol sustainability and energy balance. Funding provided by the São Paulo Research

  14. In vitro antiplasmodial activity of extract and constituents from Esenbeckia febrifuga, a plant traditionally used to treat malaria in the Brazilian Amazon.

    PubMed

    Dolabela, Maria Fâni; Oliveira, Salma G; Nascimento, José Maria; Peres, José Maria; Wagner, Hildebert; Póvoa, Marinete Marins; de Oliveira, Alaíde Braga

    2008-05-01

    Esenbeckia febrifuga (Rutaceae) is a plant traditionally used to treat malaria in the Brazilian Amazon region. Ethanol extract of stems displayed a good antiplasmodial activity against Plasmodium falciparum strains W-2 (IC(50) 15.5+/-0.71 microg/ml) and 3 D7 (IC(50) 21.0+/-1.4 microg/ml). Two coumarins (bergaptene 1 and isopimpinellin 2), five alkaloids (flindersiamine 3, kokusaginine 4, skimmiamine 5, gamma-fagarine 6 and 1-hydroxy-3-methoxy-N-methylacridone, 7), besides a limonoid (rutaevine 8), have been isolated for the first time from this species. Antiplasmodial activity of compounds 3, 5-8 has been evaluated in vitro against P. falciparum strains (W-2 and 3D7) and the furoquinolines 5 and 6 were the most potent displaying IC(50) values <50 microg/ml; flindersiamine (3) showed a weak activity while alkaloid 7 and rutaevine (8) were inactive (IC(50)>100 microg/ml).

  15. Evaluation of ash from some tropical plants of Nigeria for the control of Sclerotium rolfsii Sacc. on wheat (Triticum aestivum L.).

    PubMed

    Enikuomehin, O A; Ikotun, T; Ekpo, E J

    1998-01-01

    Eleven ash samples, from organs of nine tropical plants, were screened for their abilities to inhibit mycelial growth and sclerotial germination of a Nigerian isolate of Sclerotium rolfsii on agar and in the soil. Ten ash samples showed some activity against mycelial growth of S. rolfsii in vitro. Ash samples from Delonix regia stem wood, Mangifera indica leaf and Vernonia amygdalina leaf were most effective as each totally inhibited mycelial growth of S. rolfsii in vitro. Ocimum gratissimum leaf ash, D. regia wood ash and Musa paradisiaca flower bract ash inhibited sclerotial germination on agar. Nine ash samples protected seeds against pre-emergence rot. Ash from M. indica leaf, V. amygdalina leaf and Azadirachta indica leaf protected seedlings against post-emergence infection. Eichornia crassipes ash, which was ineffective in vitro, offered some protection to seeds in soil against pre-emergence rot. The study demonstrates potentials of ash samples from tropical plants in control of S. rolfsii on wheat.

  16. The tropic response of plant roots to oxygen: oxytropism in Pisum sativum L.

    PubMed

    Porterfield, D M; Musgrave, M E

    1998-09-01

    Plant roots are known to orient growth through the soil by gravitropism, hydrotropism, and thigmotropism. Recent observations of plant roots that developed in a microgravity environment in space suggested that plant roots may also orient their growth toward oxygen (oxytropism). Using garden pea (Pisum sativum L. cv. Weibul's Apollo) and an agravitropic mutant (cv. Ageotropum), root oxytropism was studied in the controlled environment of a microrhizotron. A series of channels in the microrhizotron allowed establishment of an oxygen gradient of 0.8 mmol mol-1 mm-1. Curvature of seedling roots was determined prior to freezing the roots for subsequent spectrophotometric determinations of alcohol dehydrogenase activity. Oxytropic curvature was observed all along the gradient in both cultivars of pea. The normal gravitropic cultivar showed a maximal curvature of 45 degrees after 48 h, while the agravitropic mutant curved to 90 degrees. In each cultivar, the amount of curvature declined as the oxygen concentration decreased, and was linearly related to the root elongation rate. Since oxytropic curvature occurred in roots exposed to oxygen concentrations that were not low enough to induce the hypoxically responsive protein alcohol dehydrogenase, we suspect that the oxygen sensor associated with oxytropism does not control the induction of hypoxic metabolism. Our results indicate that oxygen can play a critical role in determining root orientation as well as impacting root metabolic status. Oxytropism allows roots to avoid oxygen-deprived soil strata and may also be the basis of an auto-avoidance mechanism, decreasing the competition between roots for water and nutrients as well as oxygen.

  17. The tropic response of plant roots to oxygen: oxytropism in Pisum sativum L

    NASA Technical Reports Server (NTRS)

    Porterfield, D. M.; Musgrave, M. E.

    1998-01-01

    Plant roots are known to orient growth through the soil by gravitropism, hydrotropism, and thigmotropism. Recent observations of plant roots that developed in a microgravity environment in space suggested that plant roots may also orient their growth toward oxygen (oxytropism). Using garden pea (Pisum sativum L. cv. Weibul's Apollo) and an agravitropic mutant (cv. Ageotropum), root oxytropism was studied in the controlled environment of a microrhizotron. A series of channels in the microrhizotron allowed establishment of an oxygen gradient of 0.8 mmol mol-1 mm-1. Curvature of seedling roots was determined prior to freezing the roots for subsequent spectrophotometric determinations of alcohol dehydrogenase activity. Oxytropic curvature was observed all along the gradient in both cultivars of pea. The normal gravitropic cultivar showed a maximal curvature of 45 degrees after 48 h, while the agravitropic mutant curved to 90 degrees. In each cultivar, the amount of curvature declined as the oxygen concentration decreased, and was linearly related to the root elongation rate. Since oxytropic curvature occurred in roots exposed to oxygen concentrations that were not low enough to induce the hypoxically responsive protein alcohol dehydrogenase, we suspect that the oxygen sensor associated with oxytropism does not control the induction of hypoxic metabolism. Our results indicate that oxygen can play a critical role in determining root orientation as well as impacting root metabolic status. Oxytropism allows roots to avoid oxygen-deprived soil strata and may also be the basis of an auto-avoidance mechanism, decreasing the competition between roots for water and nutrients as well as oxygen.

  18. The tropic response of plant roots to oxygen: oxytropism in Pisum sativum L

    NASA Technical Reports Server (NTRS)

    Porterfield, D. M.; Musgrave, M. E.

    1998-01-01

    Plant roots are known to orient growth through the soil by gravitropism, hydrotropism, and thigmotropism. Recent observations of plant roots that developed in a microgravity environment in space suggested that plant roots may also orient their growth toward oxygen (oxytropism). Using garden pea (Pisum sativum L. cv. Weibul's Apollo) and an agravitropic mutant (cv. Ageotropum), root oxytropism was studied in the controlled environment of a microrhizotron. A series of channels in the microrhizotron allowed establishment of an oxygen gradient of 0.8 mmol mol-1 mm-1. Curvature of seedling roots was determined prior to freezing the roots for subsequent spectrophotometric determinations of alcohol dehydrogenase activity. Oxytropic curvature was observed all along the gradient in both cultivars of pea. The normal gravitropic cultivar showed a maximal curvature of 45 degrees after 48 h, while the agravitropic mutant curved to 90 degrees. In each cultivar, the amount of curvature declined as the oxygen concentration decreased, and was linearly related to the root elongation rate. Since oxytropic curvature occurred in roots exposed to oxygen concentrations that were not low enough to induce the hypoxically responsive protein alcohol dehydrogenase, we suspect that the oxygen sensor associated with oxytropism does not control the induction of hypoxic metabolism. Our results indicate that oxygen can play a critical role in determining root orientation as well as impacting root metabolic status. Oxytropism allows roots to avoid oxygen-deprived soil strata and may also be the basis of an auto-avoidance mechanism, decreasing the competition between roots for water and nutrients as well as oxygen.

  19. Radiation induced a supra-additive cytotoxic effect in head and neck carcinoma cell lines when combined with plant extracts from Brazilian Cerrado biome.

    PubMed

    Elias, Silvia T; Borges, Gabriel A; Amorim, Danilo A; Rêgo, Daniela F; Simeoni, Luiz A; Silveira, Dâmaris; Fonseca-Bazzo, Yris Maria; Paula, José E; Fagg, Christopher William; Barros, Ivelone M C; Abreu, Wenzel C; Pinto-Júnior, Décio S; Magalhães, Pérola O; Neves, Francisco A R; Lofrano-Porto, Adriana; Guerra, Eliete N S

    2015-04-01

    Antineoplastic effects of molecules derived from plants have recently gained increasing attention as an additive to traditional therapies. The aim of this study was to evaluate the cytotoxic activity of plant extracts from the Brazilian Cerrado biome associated with radiotherapy in head and neck carcinoma cells (HNSCC). Fifteen extracts derived from five Cerrado plants were tested in HNSCC cell lines (SCC-25, SCC-9, FaDu) and keratinocyte cells (HaCat). Cell cytotoxicity of extracts and association extract/radiation (2Gy/min) was assessed by MTT assay. Cisplatin (50 μg/mL) was used as a positive control. Extracts with the major cytotoxic activity were selected and their IC50 concentrations were defined. Apoptosis was assessed using flow cytometric analysis. Ten isolated extracts resulted in moderate cytotoxicity (>20 and ≤ 50 % of viable cells), while three extracts induced severe cytotoxic effects (≤ 20 % of viable cells). Plant extracts treatment improved radiotherapy cytotoxicity in all cell lines. Although plant extracts are not as potent as cisplatin plus radiation, in FaDu cells, seven extracts associated with irradiation showed cytotoxic activity similar or better than the association of cisplatin and radiation. Hexanic extract of Erythroxylum daphinites could induce apoptosis in oral cancer cells; however, necrosis was the prevalent kind of death in FaDu cells treated with hexanic extract of Erythroxylum suberosum. Pre-treatment of HNSCC cells with the extract derived from Cerrado plants followed by irradiation induced a supra-additive cytotoxic effect. This study highlights the potential biological relevance of the Cerrado biome when associated with traditional therapy for cancer.

  20. Species and rotation frequency influence soil nitrogen in simplified tropical plant communities.

    PubMed

    Ewel, John J

    2006-04-01

    Among the many factors that potentially influence the rate at which nitrogen (N) becomes available to plants in terrestrial ecosystems are the identity and diversity of species composition, frequency of disturbance or stand turnover, and time. Replicated suites of investigator-designed communities afforded an opportunity to examine the effects of those factors on net N mineralization over a 12-year period. The communities consisted of large-stature perennial plants, comprising three tree species (Hyeronima alchorneoides, Cedrela odorata, and Cordia alliodora), a palm (Euterpe oleracea), and a large, perennial herb (Heliconia imbricata). Trees were grown in monoculture and in combination with the other two life-forms; tree monocultures were subjected to rotations of one or four years, or like the three-life-form systems, left uncut. The work was conducted on fertile soil in the humid lowlands of Costa Rica, a site with few abiotic constraints to plant growth. Rates of net N mineralization and nitrification were high, typically in the range of 0.2-0.8 microg x g(1) x d(-1), with net nitrification slightly higher than net mineralization, indicating preferential uptake of ammonium (NH4+) by plants and microbes. Net rates of N mineralization were about 30% lower in stands of one of the three tree species, Hyeronima, than in stands of the other two. Contrary to expectations, short-rotation management (one or four years) resulted in higher net rates of N mineralization than in uncut stands, whether the latter were composed of a single tree species or a combination of life-forms. Neither additional species richness nor replenishment of leached N augmented mineralization rates. The net rate at which N was supplied tended to be lowest in stands where demand for N was highest. Careful choice of species, coupled with low frequency of disturbance, can lead to maintenance of N within biomass and steady rates of within-system circulation, whereas pulses, whether caused by cutting

  1. Assessing the Chemical Composition and Antimicrobial Activity of Essential Oils from Brazilian Plants-Eremanthus erythropappus (Asteraceae), Plectrantuns barbatus, and P. amboinicus (Lamiaceae).

    PubMed

    Santos, Nara O Dos; Mariane, Bruna; Lago, João Henrique G; Sartorelli, Patricia; Rosa, Welton; Soares, Marisi G; da Silva, Adalberto M; Lorenzi, Harri; Vallim, Marcelo A; Pascon, Renata C

    2015-05-11

    The chemical composition and antimicrobial activity of essential oils obtained from three Brazilian plant species-leaves and branches of Eremanthus erythropappus (Asteraceae), leaves of Plectranthus barbatus, and leaves of P. amboinicus (Lamiaceae)-were determined. Analysis by GC/MS and determination of Kovats indexes both indicated δ-elemene (leaves-42.61% and branches-23.41%) as well as (-)-α-bisabolol (leaves-24.80% and stem bark-66.16%) as major constituents of E. erythropappus essential oils. The main components of leaves of P. barbatus were identified as (Z)-caryophyllene (17.98%), germacrene D (17.35%), and viridiflorol (14.13%); whereas those of leaves of P. amboinicus were characterized as p-cymene (12.01%), γ-terpinene (14.74%), carvacrol (37.70%), and (Z)-caryophyllene (14.07%). The antimicrobial activity against yeasts and bacteria was assessed in broth microdilution assays to determine the minimum inhibitory concentration (MIC) necessary to inhibit microbial growth. In addition, the crude oil of branches of E. erythropappus was subjected to chromatographic separation procedures to afford purified (-)-α-bisabolol. This compound displayed biological activity against pathogenic yeasts, thus suggesting that the antimicrobial effect observed with crude oils of E. erythropappus leaves and branches may be related to the occurrence of (-)-α-bisabolol as their main component. Our results showed that crude oils of Brazilian plants, specifically E. erythropappus, P. barbatus, and P. amboinicus and its components, could be used as a tool for the developing novel and more efficacious antimicrobial agents.

  2. In vitro larval migration and kinetics of exsheathment of Haemonchus contortus larvae exposed to four tropical tanniniferous plant extracts.

    PubMed

    Alonso-Díaz, M A; Torres-Acosta, J F J; Sandoval-Castro, C A; Aguilar-Caballero, A J; Hoste, H

    2008-05-31

    As for some temperate forage, some tropical tanniniferous plants (TTP) from browsing might represent an alternative to chemical anthelmintic. The anthelmintic effect of four TTP (Acacia pennatula, Lysiloma latisiliquum, Piscidia piscipula, Leucaena leucocephala) on Haemonchus contortus was measured using two in vitro assays. First, the effects of increasing concentrations of lyophilized extracts (150, 300, 600, 1200 microg/ml PBS) were tested on H. contortus larvae (L(3)) using the larval migration inhibition (LMI) test. An inhibitor of tannin, polyvinyl polypyrrolidone (PVPP), was used to verify whether tannins were responsible for the AH effect. Secondly, the effects of extracts on larval exsheathment were examined. Larvae (L(3)) were in contact with extracts (1200 microg/ml) for 3h, and then were exposed to an artificial exsheathment procedure with observations of the process at 10 min intervals. A general lineal model (GLM) test was used to determine the dose effect in the LMI test and the difference of the percentage of exsheathed larvae between the control and the treatment groups. A Kruskal Wallis test was used to determine the effect of PVPP on LMI results. The LMI test showed a dose-dependent anthelmintic effect for A. pennatula, L. latisiliquum and L. leucocephala (P<0.01), which disappeared after PVPP addition, confirming the role of tannins. No effect was found for P. piscipula on H. contortus in the LMI test. However, all four plant extracts interfered with the process of L(3) exsheathment which might be involved as a mechanism of action of tannins on H. contortus larvae. A. pennatula, L. latisiliquum and L. leucocephala could be used as an anthelmintic for the control of H. contortus after confirmation based on in vivo studies.

  3. Responses of seedlings of tropical woody plants to environmental stresses with emphasis on Theobroma cacao and Hevea brasiliensis

    SciTech Connect

    Sena Gomes, A.R.

    1987-01-01

    Relative humidity, flooding, temperature, wind, and SO/sub 2/ variously influenced physiological processes and growth of tropical woody plants, with emphasis on three Theobroma cacao varieties and three Hevea brasiliensis families. Stomata were smaller and more numerous in Theobroma than in Hevea. In Theobroma, but not Heavea, stomatal frequency decreased from the leaf base to the apex and from the midrib outward. Stomata of Theobroma cacao var. Catongo opened in high relative humidity (RH) and closed in low RH. The more open stomata in high RH were associated with high rates of photosynthesis, low leaf water potential, high water use efficiency (WUE), and low transpiration rate (TR). Variations in TR and WUE were correlated with changes in vapor pressure deficit. Other responses included stomatal closure, decreased chlorophyll content, leaf epinasty, production of hypertrophied lenticels and adventitious roots, and acceleration of ethylene production. Responses to flooding varied with species, Theobroma varieties and Hevea families. Effects of temperature regimes on growth varied with species, varieties and families, plant parts, growth parameters, and time of harvesting. Optimal temperatures for dry weight increase of stems or roots of Theobroma cacao var. Comum were 22.2 C; and 33.3 C for dry weight increase or relative growth rates of leaves or seedlings. Optimal temperatures for growth varied for Hevea families. Wind injured leaves of Theobroma cacao, with more injury by wind of 6.0 than 3.0 m s/sup -1/. Stomata were more open on windy than on calm days, but tended to close at high wind speeds. Wind lowered transpiration rate but the reduction was not correlated with leaf dehydration. SO/sub 2/ at 0.5, 1.0, or 1.5 ppm for 24 h did not injure Theobroma leaves but reduced dry weight increment of leaves of var. Catongo but not Catongo/Sial.

  4. Exposure-plant response of ambient ozone over the tropical Indian region

    NASA Astrophysics Data System (ADS)

    Roy, S.; Beig, G.; Ghude, S.

    2009-02-01

    A high resolution regional chemistry-transport model has been used to study the distribution of exposure-plant response index (AOT40, Accumulated exposure Over a Threshold of 40 ppb, expressed as ppb h) over the Indian geographical region for the year 2003 as case study. The directives on ozone pollution in ambient air provided by United Nations Economic Commission for Europe (UNECE) and World Health Organization (WHO) for vegetation protection (AOT40) have been used to assess the air quality. A substantial temporal and spatial variation in AOT40 values has been observed across the Indian region. Large areas of India show ozone values above the AOT40 threshold limit (3000 ppb h for 3 months). Simulated AOT40 values are found to be substantially higher throughout the year over the most fertile Indo-Gangetic plains than the other regions of India, which can have an adverse effect on plants and vegetation in this region. The observed monthly AOT40 values reported from an Indian station, agree reasonably well with model simulated results. We find that the simulated AOT40 target values for protection of vegetation is exceeded even in individual months, especially during November and April. Necessary and effective emission reduction strategies are therefore required to be developed in order to curb the surface level ozone pollution to protect the vegetation from further damage in India whose economy is highly dependent on agricultural sector and may influence the global balance.

  5. Abundant and diverse endophytic actinobacteria associated with medicinal plant Maytenus austroyunnanensis in Xishuangbanna tropical rainforest revealed by culture-dependent and culture-independent methods.

    PubMed

    Qin, Sheng; Chen, Hua-Hong; Zhao, Guo-Zhen; Li, Jie; Zhu, Wen-Yong; Xu, Li-Hua; Jiang, Ji-Hong; Li, Wen-Jun

    2012-10-01

    Endophytes are now considered as an important component of biodiversity. However, the diversity of endophytic actinobacteria associated with tropical rainforest native medicinal plants is essentially unknown. In this study, the diversity of endophytic actinobacteria residing in root, stem and leaf tissues of medicinal plant Maytenus austroyunnanensis collected from tropical rainforest in Xishuangbanna, China was investigated with a combination of cultivation and culture-independent analysis on the basis of 16S rRNA gene sequencing. By using different selective isolation media and methods, a total of 312 actinobacteria were obtained, and they were affiliated with the order Actinomycetales (distributed into 21 genera). Based on a protocol for endophytes enrichment, three 16S rRNA gene clone libraries were constructed and 84 distinct operational taxonomic units were identified and they distributed among the orders Actinomycetales and Acidimicrobiales, including eight suborders and at least 38 genera with a number of rare actinobacteria genera. Phylogenetic analysis showed that 32% of the clones in the libraries had lower than 97% similarities with related type strains. Interestingly, six genera from the order Actinomycetales and uncultured clones from Acidimicrobiales have not, to our knowledge, been previously reported as endophytes. Our study confirms abundant endophytic actinobacterial consortium in tropical rainforest native plant and suggests that this special habitat represents an underexplored reservoir of diverse and novel actinobacteria of potential interest for bioactive compounds discovery. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

  6. Stable carbon isotope ratio of methyl chloride emitted from glasshouse-grown tropical plants and its implication for the global methyl chloride budget

    NASA Astrophysics Data System (ADS)

    Saito, Takuya; Yokouchi, Yoko

    2008-04-01

    Stable carbon isotope ratios of methyl chloride (CH3Cl) were measured in foliar emissions from 14 species of tropical plants growing in a glasshouse. The isotopic ratio of CH3Cl (arithmetic mean: -83.2 +/- 15.2‰) ranged from -56‰ to -114‰ that from dipterocarp trees (-87.4 +/- 12.3‰) was on average more depleted in 13C than that from tree ferns (-61.9 +/- 9.7‰). The isotopic ratio was lower than that of CH3Cl produced by other known sources (e.g., biomass burning and salt marshes), with the exception of that by dead leaves. Using the distinctive isotope ratio of CH3Cl emitted from tropical plants together with previously reported isotopic data of CH3Cl sources and sinks to an isotopic mass balance calculation, global CH3Cl emission by tropical plants was estimated to be approximately 1500-3000 Gg yr-1 with uncertainties of 30-60%, which could account for 30-50% of the global emission.

  7. Root strength of tropical plants - An investigation in the Western Ghats of Kerala, India

    NASA Astrophysics Data System (ADS)

    Lukose Kuriakose, S.; van Beek, L. P. H.; van Westen, C. J.

    2009-04-01

    Earlier research on debris flows in the Tikovil River basin of the Western Ghats concluded that root cohesion is significant in maintaining the overall stability of the region. In this paper we present the most recent results (December 2008) of root tensile strength tests conducted on nine species of plants that are commonly found in the region. They are 1) Rubber (Hevea Brasiliensis), 2) Coconut Palm (Cocos nucifera), 3) Jackfruit trees (Artocarpus heterophyllus), 4) Teak (Tectona grandis), 5) Mango trees (Mangifera indica), 6) Lemon grass (Cymbopogon citratus), 7) A variety of Tamarind (Garcinia gummigutta), 8) Coffee (Coffea Arabica) and Tea (Camellia sinensis). About 1500 samples were collected of which only 380 could be tested (in the laboratory) due to breakage of roots during the tests. In the successful tests roots failed in tension. Roots having diameters between 2 mm and 12 mm were tested. Each sample tested has a length of 15 cm. Results indicate that the roots of Coffee, Tamarind, Lemon grass and Jackfruit are the strongest of the nine plant types tested whereas Tea and Teak plants had the most fragile roots. Coconut roots behaved atypical to the others, as the bark of the roots was crushed and slipped from the clamp when tested whereas its internal fiber was the strongest of all tested. Root tensile strength decreases with increasing diameters, Rubber showing more ductile behaviour than Coffee and Tamarind that behaved more brittle, root tensile strength increasing exponentially for finer roots. Teak and Tea showed almost a constant root tensile strength over the range of diameters tested and little variability. Jack fruit and mango trees showed the largest variability, which may be explained by the presence of root nodules, preventing the derivation of an unequivocal relationship between root diameters and tensile strength. This results in uncertainty of root strength estimates that are applicable. These results provide important information to

  8. Monitoring the HTLV-1 proviral load in the peripheral blood of asymptomatic carriers and patients with HTLV-associated myelopathy/tropical spastic paraparesis from a Brazilian cohort: ROC curve analysis to establish the threshold for risk disease.

    PubMed

    Furtado, Marina dos Santos Brito Silva; Andrade, Rafaela Gomes; Romanelli, Luiz Cláudio Ferreira; Ribeiro, Maisa Aparecida; Ribas, João Gabriel; Torres, Elídio Barbosa; Barbosa-Stancioli, Edel Figueiredo; Proietti, Anna Bárbara de Freitas Carneiro; Martins, Marina Lobato

    2012-04-01

    Human T-lymphotropic virus 1 (HTLV-1) infection is associated with HTLV-associated myelopathy/tropical spastic paraparesis (HAM/TSP), which affects approximately 5% of carriers. High proviral load is a risk marker for HAM/TSP, although there is an overlap of proviral load levels in peripheral blood between asymptomatic carriers and HAM/TSP patients. In this study, receiver operating characteristic curve analysis was used to define a set point of HTLV-1 proviral load that better indicates an increased risk for HAM/TSP. Proviral load was quantified in 75 asymptomatic carriers and 78 HAM/TSP patients in a Brazilian cohort. The cut-off of proviral load was defined as 114 copies/10(4)  cells, with 78.2% sensitivity to identify true HAM/TSP patients. The mean proviral load levels were not significantly different between males and females with the same clinical status, and there was no significant correlation between proviral load and age at blood sampling, age at the onset of illness, or duration of disease. In HAM/TSP patients, proviral load was significantly higher in wheelchair-bound patients than in individuals able to walk without support and in those with the worst spinal cord injuries. Follow-up of HTLV-1-infected individuals showed that proviral load was more stable in asymptomatic carriers than in HAM/TSP patients. In a cohort study, periodically quantifying proviral load in asymptomatic carriers is necessary to identify those at risk for developing neurological disease, and it is necessary for HAM/TSP patients to monitor spinal injury and progression to walking disability. The measure of proviral load in clinical practice implicates the definition of the cut-off of proviral load and its validation during follow-up. Copyright © 2012 Wiley Periodicals, Inc.

  9. The use of light in prey capture by the tropical pitcher plant Nepenthes aristolochioides.

    PubMed

    Moran, Jonathan A; Clarke, Charles; Gowen, Brent E

    2012-08-01

    Nepenthes pitcher plants deploy tube-shaped pitchers to catch invertebrate prey; those of Nepenthes aristolochioides possess an unusual translucent dome. The hypothesis was tested that N. aristolochioides pitchers operate as light traps, by quantifying prey capture under three shade treatments. Flies are red-blind, with visual sensitivity maxima in the UV, blue, and green wavebands. Red celluloid filters were used to reduce the transmission of these wavebands into the interior of the pitchers. Those that were shaded at the rear showed a 3-fold reduction in Drosophila caught, relative to either unshaded control pitchers, or pitchers that were shaded at the front. Thus, light transmitted through the translucent dome is a fundamental component of N. aristolochioides' trapping mechanism.

  10. Osteoporotic fracture healing: potential use of medicinal plants from the tropics.

    PubMed

    Abdul Jalil, Mohd Azri; Shuid, Ahmad Nazrun; Muhammad, Norliza

    2013-12-01

    With improvements in living standards and healthcare, life expectancy has been increasing dramatically in most parts of the world. These situations lead to the increase in the reported cases of geriatrics-related diseases such as hypogonadal osteoporosis with skeletal fracture being the ultimate outcome, which eventually causes significant morbidity and mortality. The deficient gonadal hormones, which are the main cause of hypogonadal osteoporosis, could be substituted with hormone replacement therapy to hinder bone loss. However, the artificial hormonal therapy has been linked to grievous conditions such as breast and prostate cancers. In view of the various adverse effects associated with conventional treatment, many researchers are now focusing on finding alternative remedies from nature. This article explores the possibilities of certain medicinal plants native to Malaysia that possess androgenic and antioxidant properties to potentially be used in the treatment of fracture due to osteoporosis in ageing people.

  11. Exposure-plant response of ambient ozone over the tropical Indian region

    NASA Astrophysics Data System (ADS)

    Roy, S. Deb; Beig, G.; Ghude, Sachin D.

    2009-07-01

    A high resolution regional chemistry-transport model has been used to study the distribution of exposure-plant response index (AOT40, Accumulated exposure Over a Threshold of 40 ppb, expressed as ppb h) over the Indian geographical region for the year 2003 as case study. The directives on ozone pollution in ambient air provided by United Nations Economic Commission for Europe (UNECE) and World Health Organization (WHO) for vegetation protection (AOT40) have been used to assess the air quality. A substantial temporal and spatial variation in AOT40 values has been observed across the Indian region. Large areas of India show ozone values above the AOT40 threshold limit (3000 ppb h for 3 months). Simulated AOT40 values are found to be substantially higher throughout the year over the most fertile Indo-Gangetic plains than the other regions of India, which can have an adverse effect on plants and vegetation in this region. The observed monthly AOT40 values reported from an Indian station, agree reasonably well with model simulated results. There is an underestimation of AOT40 in the model results during the periods of highest ozone concentration from December to March. We find that the simulated AOT40 target values for protection of vegetation is exceeded even in individual months, especially during November to April. Necessary and effective emission reduction strategies are therefore required to be developed in order to curb the surface level ozone pollution to protect the vegetation from further damage in India whose economy is highly dependent on agricultural sector and may influence the global balance.

  12. Does plant architectural complexity increase with increasing habitat complexity? A test with a pioneer shrub in the Brazilian Cerrado.

    PubMed

    Silveira, F A O; Oliveira, E G

    2013-05-01

    Understanding variation in plant traits in heterogeneous habitats is important to predict responses to changing environments, but trait-environment associations are poorly known along ecological gradients. We tested the hypothesis that plant architectural complexity increases with habitat complexity along a soil fertility gradient in a Cerrado (Neotropical savanna) area in southeastern Brazil. Plant architecture and productivity (estimated as the total number of healthy infructescences) of Miconia albicans (SW.) Triana were examined in three types of vegetation which together form a natural gradient of increasing soil fertility, tree density and canopy cover: grasslands (campo sujo, CS), shrublands (cerrado sensu strico, CE) and woodlands (cerradão, CD). As expected, plants growing at the CS were shorter and had a lower branching pattern, whereas plants at the CD were the tallest. Unexpectedly, however, CD plants did not show higher architectural complexity compared to CE plants. Higher architectural similarity between CE and CD plants compared to similarity between CS and CE plants suggests reduced expression of functional architectural traits under shade. Plants growing at the CE produced more quaternary shoots, leading to a larger number of infructescences. This higher plant productivity in CE indicates that trait variation in ecological gradients is more complex than previously thought. Nematode-induced galls accounted for fruit destruction in 76.5% infructescences across physiognomies, but percentage of attack was poorly related to architectural variables. Our data suggest shade-induced limitation in M. albicans architecture, and point to complex phenotypic variation in heterogeneous habitats in Neotropical savannas.

  13. Detecting subcanopy invasive plant species in tropical rainforest by integrating optical and microwave (InSAR/PolInSAR) remote sensing data, and a decision tree algorithm

    NASA Astrophysics Data System (ADS)

    Ghulam, Abduwasit; Porton, Ingrid; Freeman, Karen

    2014-02-01

    In this paper, we propose a decision tree algorithm to characterize spatial extent and spectral features of invasive plant species (i.e., guava, Madagascar cardamom, and Molucca raspberry) in tropical rainforests by integrating datasets from passive and active remote sensing sensors. The decision tree algorithm is based on a number of input variables including matching score and infeasibility images from Mixture Tuned Matched Filtering (MTMF), land-cover maps, tree height information derived from high resolution stereo imagery, polarimetric feature images, Radar Forest Degradation Index (RFDI), polarimetric and InSAR coherence and phase difference images. Spatial distributions of the study organisms are mapped using pixel-based Winner-Takes-All (WTA) algorithm, object oriented feature extraction, spectral unmixing, and compared with the newly developed decision tree approach. Our results show that the InSAR phase difference and PolInSAR HH-VV coherence images of L-band PALSAR data are the most important variables following the MTMF outputs in mapping subcanopy invasive plant species in tropical rainforest. We also show that the three types of invasive plants alone occupy about 17.6% of the Betampona Nature Reserve (BNR) while mixed forest, shrubland and grassland areas are summed to 11.9% of the reserve. This work presents the first systematic attempt to evaluate forest degradation, habitat quality and invasive plant statistics in the BNR, and provides significant insights as to management strategies for the control of invasive plants and conversation in the reserve.

  14. Tropical forages: morphoanatomy of plants grown in areas with the death of pasture syndrome.

    PubMed

    Ribeiro-Júnior, N G; Fagundes, O S; Benevenuti, A S; Yamashita, O M; Rossi, A A B; Carvalho, M A C; Silva, I V

    2017-11-01

    Roots and leaves of Panicum maximum Tanzânia, Mombaça and Massai; Urochloa brizantha Piatã, Marandu and Xaraés; Urochloa humidicola Llanero; Urochloa ruziziensis Ruzizienses; Urochloa hybrida Mulato II and Cynodon nlemfuensis Estrela-roxa were analyzed, seeking to identify characters for better adaptation to the environment that may interfere with digestibility of tissue from the point of view of the rumen in cattle. Were planted ten cultivars in a completely randomized blocks with three repetitions. Was collected vegetative material, which histological slides were prepared from middle third of the sections of roots and leaves. Were observed differences (p>0.05) in the roots: higher volume of epidermal cells (28.62 µm) and overall diameter (1926.41 µm) of Llanero; thicker vascular cylinder (975.09 µm) and more protoxylem (42.25) in Estrela-roxa and occurrence of aerenchyma in cultivars Piatã, Mulato II, Xaraés, Massai, Llanero and Estrela-roxa; Were found higher proportions of bulliform cells in the leaves (121.07 µm) and thicker leaf mesophyll in U. humidicola Llanero (263.63 µm); higher proportion of sclerenchyma fibers in Xaraés and Marandu; lower results for amount of fibers in P. maximum Massai. We conclude that the cultivars Estrela-roxa, Llanero and Massai have greater adaptability to the environment and better nutritional quality.

  15. Spatiotemporal patterns and dynamics of species richness and abundance of woody plant functional groups in a tropical forest landscape of Hainan Island, South China.

    PubMed

    Zhang, Zhi-Dong; Zang, Run-Guo; Qi, Yao-Dong

    2008-05-01

    Tropical forests are among the most species-diverse ecosystems on Earth. Their structures and ecological functions are complex to understand. Functional group is defined as a group of species that play similar roles in an ecosystem. The functional group approach has been regarded as an effective way of linking the compositions of complex ecosystems with their ecological functions. To understand the variation of functional groups in species-rich ecosystems after disturbance, the present study investigated the spatial pattern and temporal dynamics of woody plants in a typically fragmented natural forest landscape of Hainan Island in South China. The study area was classified into eight landscape types based on vegetation type, disturbance manner and the time of recovery. The woody plant species were aggregated into seven functional groups based on the growth form, successional status and plant size. The results gained from the present study showed that all functional groups, except for the emergent and canopy tree species, were present in all eight landscape types. Each landscape type had different numbers of dominant functional groups. There are similar species richness and stem abundance structure among functional groups between mid-successional clear cut lowland rainforest and old growth tropical coniferous forest. This similarity exists in selective logged lowland rainforest and old-growth lowland rainforest, as well as among landscape types of montane rainforest. The functional groups with the same successional status had similar patterns of species richness and stem abundance ratios among different landscape types. The variation patterns of functional groups along the successional stages in terms of species richness and stem abundance among the tropical lowland rainforest landscape types were more similar to each other than those in the tropical montane rainforest landscape types. This study provides further support for the competition-colonization tradeoff and

  16. Comparison of Paenibacillus azotofixans Strains Isolated from Rhizoplane, Rhizosphere, and Non-Root-Associated Soil from Maize Planted in Two Different Brazilian Soils

    PubMed Central

    Seldin, Lucy; Rosado, Alexandre Soares; da Cruz, Davi William; Nobrega, Alberto; van Elsas, Jan Dirk; Paiva, Edilson

    1998-01-01

    Paenibacillus azotofixans is a nitrogen-fixing bacterium often found in soil and in the rhizospheres of different grasses. In this study, two Brazilian clay soils were planted with cross-hybrid maize (BR-201) and four stages of plant growth were analyzed to characterize the P. azotofixans populations present in the rhizoplanes, rhizospheres, and non-root-associated soils (herein called nonrhizospheres). A total of 106 strains were isolated and identified as P. azotofixans with an API 50CH kit, by classical biochemical tests, and via the use of specific primers based on the 16S rRNA gene in PCRs. To compare the isolated strains, phenotypic characteristics were determined and three different probes were used in hybridization experiments: two nif probes and one probe comprising a 0.58-kb fragment cloned from the P. azotofixans C3L4 genome. These results were used to construct a dendrogram, in which two main clusters could be observed. One cluster contained exclusively strains from Várzea soil, and the other contained the majority of strains from Cerrado soil. The 60 strains from Várzea soil and the 46 strains from Cerrado soil were further analyzed with REP and BOX primers, respectively. Based on the patterns obtained, it was possible to identify 21 different groups among strains from Várzea soil and 4 different groups among strains from Cerrado soil. These different patterns were tested by multivariate analysis of variance, and differences in the populations of P. azotofixans during the four stages of plant growth were demonstrated. Moreover, strains isolated from the rhizoplanes, rhizospheres, and nonrhizospheres of maize planted in Cerrado and Várzea soils were shown to be statistically different; the diversity of P. azotofixans strains was affected by the soil type. PMID:9758811

  17. The Role of Edaphic Environment and Climate in Structuring Phylogenetic Pattern in Seasonally Dry Tropical Plant Communities

    PubMed Central

    Moro, Marcelo Freire; Silva, Igor Aurélio; de Araújo, Francisca Soares; Nic Lughadha, Eimear; Meagher, Thomas R.; Martins, Fernando Roberto

    2015-01-01

    Seasonally dry tropical plant formations (SDTF) are likely to exhibit phylogenetic clustering owing to niche conservatism driven by a strong environmental filter (water stress), but heterogeneous edaphic environments and life histories may result in heterogeneity in degree of phylogenetic clustering. We investigated phylogenetic patterns across ecological gradients related to water availability (edaphic environment and climate) in the Caatinga, a SDTF in Brazil. Caatinga is characterized by semiarid climate and three distinct edaphic environments – sedimentary, crystalline, and inselberg –representing a decreasing gradient in soil water availability. We used two measures of phylogenetic diversity: Net Relatedness Index based on the entire phylogeny among species present in a site, reflecting long-term diversification; and Nearest Taxon Index based on the tips of the phylogeny, reflecting more recent diversification. We also evaluated woody species in contrast to herbaceous species. The main climatic variable influencing phylogenetic pattern was precipitation in the driest quarter, particularly for herbaceous species, suggesting that environmental filtering related to minimal periods of precipitation is an important driver of Caatinga biodiversity, as one might expect for a SDTF. Woody species tended to show phylogenetic clustering whereas herbaceous species tended towards phylogenetic overdispersion. We also found phylogenetic clustering in two edaphic environments (sedimentary and crystalline) in contrast to phylogenetic overdispersion in the third (inselberg). We conclude that while niche conservatism is evident in phylogenetic clustering in the Caatinga, this is not a universal pattern likely due to heterogeneity in the degree of realized environmental filtering across edaphic environments. Thus, SDTF, in spite of a strong shared environmental filter, are potentially heterogeneous in phylogenetic structuring. Our results support the need for scientifically

  18. Seasonal variation and processing of vascular plant organic matter in tropical montane catchments as reflected by riverine DOC compositions

    NASA Astrophysics Data System (ADS)

    Hernes, P.; Dyda, R. Y.; McDowell, W. H.

    2015-12-01

    Tropical rivers are responsible for two thirds of global fluxes of terrigenous organic matter to the oceans, yet because of their remote locations relative to most industrialized countries, they are poorly studied compared to temperate and even Arctic rivers. This study measured lignin biomarkers on weekly samples from two Puerto Rican rivers, the Mameyes and the Rio Icacos, over the course of ~9 months in order to investigate watershed controls on organic matter export via rivers. In both rivers, carbon-normalized yields of lignin increased with discharge, indicating higher organic matter contributions from vascular plants and lower contributions from microbial sources. Lignin biomarkers can be used to distinguish between conifer and deciduous trees as well as woody and nonwoody tissues, and the source signatures of the two rivers were essentially the same, indicating similar vegetation and sources of organic materials to both rivers. Thus, differences in diagenetic lignin parameters can be attributed to differences in processing within the two watersheds. For example, the Rio Icacos is a much flashier system with much higher sediment loads during storm events, which can lead to significant exchange of organic matter between the dissolved and particulate phase. Acid to aldehyde ratios for vanillyl and syringyl lignin phenols, (Ad:Al)v and (Ad:Al)s, are commonly used indicators of degradation. Plots of (Ad:Al)s vs. (Ad:Al)v for the two rivers reveal a significantly steeper slope for the Mameyes, which could reflect differences in the mineralogy between the systems, as the Mameyes watershed is underlain by volcaniclastic materials while the Rio Icacos is underlain by granodiorite. It is a commonly held assumption that base materials and soils should exert a strong influence on riverine organic matter compositions, but paired watershed studies are comparatively rare even in temperate climates. Hence, measureable differences between the two systems studied here

  19. The role of edaphic environment and climate in structuring phylogenetic pattern in seasonally dry tropical plant communities.

    PubMed

    Moro, Marcelo Freire; Silva, Igor Aurélio; de Araújo, Francisca Soares; Nic Lughadha, Eimear; Meagher, Thomas R; Martins, Fernando Roberto

    2015-01-01

    Seasonally dry tropical plant formations (SDTF) are likely to exhibit phylogenetic clustering owing to niche conservatism driven by a strong environmental filter (water stress), but heterogeneous edaphic environments and life histories may result in heterogeneity in degree of phylogenetic clustering. We investigated phylogenetic patterns across ecological gradients related to water availability (edaphic environment and climate) in the Caatinga, a SDTF in Brazil. Caatinga is characterized by semiarid climate and three distinct edaphic environments - sedimentary, crystalline, and inselberg -representing a decreasing gradient in soil water availability. We used two measures of phylogenetic diversity: Net Relatedness Index based on the entire phylogeny among species present in a site, reflecting long-term diversification; and Nearest Taxon Index based on the tips of the phylogeny, reflecting more recent diversification. We also evaluated woody species in contrast to herbaceous species. The main climatic variable influencing phylogenetic pattern was precipitation in the driest quarter, particularly for herbaceous species, suggesting that environmental filtering related to minimal periods of precipitation is an important driver of Caatinga biodiversity, as one might expect for a SDTF. Woody species tended to show phylogenetic clustering whereas herbaceous species tended towards phylogenetic overdispersion. We also found phylogenetic clustering in two edaphic environments (sedimentary and crystalline) in contrast to phylogenetic overdispersion in the third (inselberg). We conclude that while niche conservatism is evident in phylogenetic clustering in the Caatinga, this is not a universal pattern likely due to heterogeneity in the degree of realized environmental filtering across edaphic environments. Thus, SDTF, in spite of a strong shared environmental filter, are potentially heterogeneous in phylogenetic structuring. Our results support the need for scientifically

  20. Crosses prior to parthenogenesis explain the current genetic diversity of tropical plant-parasitic Meloidogyne species (Nematoda: Tylenchida).

    PubMed

    Fargette, Mireille; Berthier, Karine; Richaud, Myriam; Lollier, Virginie; Franck, Pierre; Hernandez, Adan; Frutos, Roger

    2010-08-01

    The tropical and subtropical parthenogenetic plant-parasitic nematodes Meloidogyne are polyphagous major agricultural pests. Implementing proper pest management approaches requires a good understanding of mechanisms, population structure, evolutionary patterns and species identification. A comparative analysis of the mitochondrial vs nuclear diversity was conducted on a selected set of Meloidogyne lines from various geographic origins. Mitochondrial co2-16S sequences and AFLP markers of total DNA were applied because of their ability to evidence discrete genetic variation between closely related isolates. Several distinct maternal lineages were present, now associated with different genetic backgrounds. Relative discordances were found when comparing mitochondrial and nuclear diversity patterns. These patterns are most likely related to crosses within one ancestral genetic pool, followed by the establishment of parthenogenesis. In this case, they mirror the genetic backgrounds of the original individuals. Another aspect could be that species emergence was recent or on process from this original genetic pool and that the relatively short time elapsed since then and before parthenogenesis settlement did not allow for lineage sorting. This could also be compatible with the hypothesis of hybrids between closely related species. This genetic pool would correspond to a species as defined by the species interbreeding concept, but also including the grey area of species boundaries. This complex process has implications on the way genotypic and phenotypic diversity should be addressed. The phenotype of parthenogenetic lines is at least for part determined by the ancestral amphimictic genetic background. A direct consequence is, therefore, in terms of risk management, the limited confidence one can have on the direct association of an agronomic threat to a simple typing or species delineation. Risk management strategies and tools must thus consider this complexity when

  1. Complete Chloroplast Genome Sequence of an Orchid Model Plant Candidate: Erycina pusilla Apply in Tropical Oncidium Breeding

    PubMed Central

    Pan, I-Chun; Liao, Der-Chih; Wu, Fu-Huei; Daniell, Henry; Singh, Nameirakpam Dolendro; Chang, Chen; Shih, Ming-Che; Chan, Ming-Tsair; Lin, Choun-Sea

    2012-01-01

    Oncidium is an important ornamental plant but the study of its functional genomics is difficult. Erycina pusilla is a fast-growing Oncidiinae species. Several characteristics including low chromosome number, small genome size, short growth period, and its ability to complete its life cycle in vitro make E. pusilla a good model candidate and parent for hybridization for orchids. Although genetic information remains limited, systematic molecular analysis of its chloroplast genome might provide useful genetic information. By combining bacterial artificial chromosome (BAC) clones and next-generation sequencing (NGS), the chloroplast (cp) genome of E. pusilla was sequenced accurately, efficiently and economically. The cp genome of E. pusilla shares 89 and 84% similarity with Oncidium Gower Ramsey and Phalanopsis aphrodite, respectively. Comparing these 3 cp genomes, 5 regions have been identified as showing diversity. Using PCR analysis of 19 species belonging to the Epidendroideae subfamily, a conserved deletion was found in the rps15-trnN region of the Cymbidieae tribe. Because commercial Oncidium varieties in Taiwan are limited, identification of potential parents using molecular breeding method has become very important. To demonstrate the relationship between taxonomic position and hybrid compatibility of E. pusilla, 4 DNA regions of 36 tropically adapted Oncidiinae varieties have been analyzed. The results indicated that trnF-ndhJ and trnH-psbA were suitable for phylogenetic analysis. E. pusilla proved to be phylogenetically closer to Rodriguezia and Tolumnia than Oncidium, despite its similar floral appearance to Oncidium. These results indicate the hybrid compatibility of E. pusilla, its cp genome providing important information for Oncidium breeding. PMID:22496851

  2. Phenological patterns of Spodoptera Guenée, 1852 (Lepidoptera: Noctuidae) is more affected by ENSO than seasonal factors and host plant availability in a Brazilian Savanna.

    PubMed

    Piovesan, Mônica; Specht, Alexandre; Carneiro, Eduardo; Paula-Moraes, Silvana Vieira; Casagrande, Mirna Martins

    2017-09-29

    The identification of factors responsible for the population dynamics is fundamental for pest management, since losses can reach 18% of annual production. Besides regular seasonal environmental factors and crop managements, additional supra-annual meteorological phenomena can also affect population dynamics, although its relevance has been rarely investigated. Among crop pests, Spodoptera stands out due to its worldwide distribution, high degree of polyphagy, thus causing damages in several crops in the world. Aiming to distinguish the relevance of different factors shaping population dynamics of Spodoptera in an ecosystem constituted of dry and rainy seasons, the current study used circular statistics to identify phenological patterns and test if its population fluctuation is driven by El Niño-Southern Oscillation (ENSO) effect, seasonal meteorological parameters, and/or host plant availability. Samplings were done in an intercropping system, in the Brazilian Savanna, during the new moon cycles between July/2013 and June/2016. Species were recorded all year round, but demonstrated differently non-uniform distribution, being concentrated in different seasons of the year. Population fluctuations were mostly affected by the ENSO intensity, despite the contrasting seasonal meteorological variation or host plant availability in a 400-m radius. Studies involving the observation of supra-annual phenomena, although rare, reach similar conclusions in relation to Neotropical insect fauna. Therefore, it is paramount to have long-term sampling studies to obtain a more precise response of the pest populations towards the agroecosystem conditions.

  3. Regionally-defined niche-breadth of tropical African freshwater plant species predicts their global latitudinal range

    NASA Astrophysics Data System (ADS)

    Kennedy, Michael; Lang, Pauline; Tapia-Grimaldo, Julissa; Varandas-Martins, Sara; Bruce, Allanah; Moore, Isabel; Sichingabula, Henry; Bottino, Flávia; Murphy, Kevin

    2016-04-01

    This study tested the hypothesis that the measured niche-breadth of river plant species (macrophytes) occurring within a closely-defined geographical area in southern tropical Africa (Zambia), may predict the larger-scale biogeographical range of these species. Two measures of niche-breadth were calculated for 44 riverine macrophyte species commonly occurring in Zambia, using an approach based on PCA ordination with bio-physico-chemical ordination input variables: altitude, stream order, stream flow, pH, conductivity, soluble reactive phosphate concentration (SRP), benthic macroinvertebrate Average Score per Taxon (ASPT), and individual abundance of nine benthic macroinvertebrate families showing differing water quality tolerance, as indicated by their Sensitivity Weightings within the Zambian Invertebrate Scoring System (ZISS). Macrophyte large-scale latitudinal range was derived from world geopositional records held by online databases, supplemented by records held by the authors. The two niche-breadth metrics divided the species into narrow-niche and intermediate/broad-niche categories, showing significant variation in altitude, stream flow, conductivity, SRP and ASPT, but not stream order or pH. There was no evidence to suggest that macrophyte alpha-diversity (as a measure of number of individual niches that may co-exist in a given habitat) showed any significant relationship with individual species niche-breadth. However, macrophyte alpha-diversity was significantly positively correlated with altitude, and significantly negatively related to conductivity, pH, ASPT, SRP, stream flow, and stream order. Narrow-niche macrophyte species included a higher proportion of Afrotropical endemics than did species with broader niche size. There were significant predictive relationships between macrophyte niche breadth and latitudinal range of the target species at global and Afrotropical scales, but not for the Neotropical range of species which occurred in both the

  4. In vitro Effects of Four Native Brazilian Medicinal Plants in CYP3A4 mRNA Gene Expression, Glutathione Levels, and P-Glycoprotein Activity

    PubMed Central

    Mazzari, Andre L. D. A.; Milton, Flora; Frangos, Samantha; Carvalho, Ana C. B.; Silveira, Dâmaris; de Assis Rocha Neves, Francisco; Prieto, Jose M.

    2016-01-01

    Erythrina mulungu Benth. (Fabaceae), Cordia verbenacea A. DC. (Boraginaceae), Solanum paniculatum L. (Solanaceae) and Lippia sidoides Cham. (Verbenaceae) are medicinal plant species native to Brazil shortlisted by the Brazilian National Health System for future clinical use. However, nothing is known about their effects in metabolic and transporter proteins, which could potentially lead to herb-drug interactions (HDI). In this work, we assess non-toxic concentrations (100 μg/mL) of the plant infusions for their in vitro ability to modulate CYP3A4 mRNA gene expression and intracellular glutathione levels in HepG2 cells, as well as P-glycoprotein (P-gp) activity in vincristine-resistant Caco-2 cells (Caco-2 VCR). Their mechanisms of action were further studied by measuring the activation of human pregnane X receptor (hPXR) in transiently co-transfected HeLa cells and the inhibition of γ-glutamyl transferase (GGT) in HepG2 cells. Our results show that P-gp activity was not affected in any case and that only Solanum paniculatum was able to significantly change CYP3A4 mRNA gene expression (twofold decrease, p < 0.05), this being correlated with an antagonist effect upon hPXR (EC50 = 0.38 mg/mL). Total intracellular glutathione levels were significantly depleted by exposure to Solanum paniculatum (-44%, p < 0.001), Lippia sidoides (-12%, p < 0.05) and Cordia verbenacea (-47%, p < 0.001). The latter plant extract was able to decrease GGT activity (-48%, p < 0.01). In conclusion, this preclinical study shows that the administration of some of these herbal medicines may be able to cause disturbances to metabolic mechanisms in vitro. Although Erythrina mulungu appears safe in our tests, active pharmacovigilance is recommended for the other three species, especially in the case of Solanum paniculatum. PMID:27594838

  5. Lippia alba (Verbenaceae): A new tropical autopolyploid complex?

    PubMed

    Reis, Aryane C; Sousa, Saulo M; Vale, Aline A; Pierre, Patrícia M O; Franco, Ana L; Campos, José Marcello S; Vieira, Roberto F; Viccini, Lyderson F

    2014-06-01

    • Premise of the study: Tropical regions have high species diversity, and polyploidization is a major mechanism of speciation in plants. However, few cases of natural polyploidy have been reported in tropical regions. Lippia alba, is a tropical, aromatic shrub with a wide distribution, extensive morphological plasticity, and several chemotypes. The species has long been recognized as a diploid with 2n = 30 chromosomes. Recently, two variations in chromosome number (2n = 60; 2n = 12-60) have been reported, suggesting the occurrence of polyploidy within the species.• Methods: Flow cytometry was used to investigate the genome size in 106 accessions from 14 Brazilian States. Conventional and molecular cytogenetic techniques and pollen viability analysis were employed to characterize each chromosome number observed.• Key results: The DNA 1C-value varied from 1.17 to 3.45 pg, showing a large variation in genome size. Five distinct chromosome numbers were observed (2n = 30, 38, 45, 60, 90); three are cytogenetically described here for the first time. The 5S rDNA signals varied proportionally according to each chromosome number, but 45S rDNA sites did not. High rates of meiotic irregularity were observed, mainly in cytotypes with higher chromosome numbers.• Conclusions: The data provide new support for the occurrence of a polyploid series in Lippia alba. We provide a hypothesis for how this complex may have arisen. Other cryptic polyploid complexes may remain undiscovered in tropical regions.

  6. Experiences from the Brazilian Atlantic Forest: ecological findings and conservation initiatives.

    PubMed

    Joly, Carlos A; Metzger, Jean Paul; Tabarelli, Marcelo

    2014-11-01

    The Brazilian Atlantic Forest hosts one of the world's most diverse and threatened tropical forest biota. In many ways, its history of degradation describes the fate experienced by tropical forests around the world. After five centuries of human expansion, most Atlantic Forest landscapes are archipelagos of small forest fragments surrounded by open-habitat matrices. This 'natural laboratory' has contributed to a better understanding of the evolutionary history and ecology of tropical forests and to determining the extent to which this irreplaceable biota is susceptible to major human disturbances. We share some of the major findings with respect to the responses of tropical forests to human disturbances across multiple biological levels and spatial scales and discuss some of the conservation initiatives adopted in the past decade. First, we provide a short description of the Atlantic Forest biota and its historical degradation. Secondly, we offer conceptual models describing major shifts experienced by tree assemblages at local scales and discuss landscape ecological processes that can help to maintain this biota at larger scales. We also examine potential plant responses to climate change. Finally, we propose a research agenda to improve the conservation value of human-modified landscapes and safeguard the biological heritage of tropical forests.

  7. [Historical research of cinchona cultivation in Japan (Part 2). Useful tropical plants introduced from Java and India in the early Meiji era].

    PubMed

    Nagumo, Seiji; Sasaki, Yohei; Takido, Michio

    2010-01-01

    In the early Meiji era, Takeaki Enomoto made a proposal to the government that cinchona and coffee seedlings be introduced to Japan. In response, the Meiji government dispatched Masatsugu Takeda of the Ministry of Internal Affairs to Java and India from March to August 1878 for the purpose of investigating useful plants of tropical origin and introducing them to Japan. This paper clarifies the route to those destinations and the plants obtained locally. Using the seeds obtained from India during his travels, the cultivation of cinchona was attempted in 1882 for the first time in Japan. In Ogasawara, coffee cultivation was conducted, again for the first time in Japan, using coffee seeds brought back from Java. The cultivation of coffee was successful and served as the foundation of the Ogasawara coffee that exists to this day. Takeda also introduced a number of books and materials related to useful tropical plants available as a result of his travels, which contributed to the promotion of new industries and businesses in the Meiji era.

  8. Categorization of the trophic status of a hydroelectric power plant reservoir in the Brazilian Amazon by statistical analyses and fuzzy approaches.

    PubMed

    da Costa Lobato, Tarcísio; Hauser-Davis, Rachel Ann; de Oliveira, Terezinha Ferreira; Maciel, Marinalva Cardoso; Tavares, Maria Regina Madruga; da Silveira, Antônio Morais; Saraiva, Augusto Cesar Fonseca

    2015-02-15

    The Amazon area has been increasingly suffering from anthropogenic impacts, especially due to the construction of hydroelectric power plant reservoirs. The analysis and categorization of the trophic status of these reservoirs are of interest to indicate man-made changes in the environment. In this context, the present study aimed to categorize the trophic status of a hydroelectric power plant reservoir located in the Brazilian Amazon by constructing a novel Water Quality Index (WQI) and Trophic State Index (TSI) for the reservoir using major ion concentrations and physico-chemical water parameters determined in the area and taking into account the sampling locations and the local hydrological regimes. After applying statistical analyses (factor analysis and cluster analysis) and establishing a rule base of a fuzzy system to these indicators, the results obtained by the proposed method were then compared to the generally applied Carlson and a modified Lamparelli trophic state index (TSI), specific for trophic regions. The categorization of the trophic status by the proposed fuzzy method was shown to be more reliable, since it takes into account the specificities of the study area, while the Carlson and Lamparelli TSI do not, and, thus, tend to over or underestimate the trophic status of these ecosystems. The statistical techniques proposed and applied in the present study, are, therefore, relevant in cases of environmental management and policy decision-making processes, aiding in the identification of the ecological status of water bodies. With this, it is possible to identify which factors should be further investigated and/or adjusted in order to attempt the recovery of degraded water bodies. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Systematic screening of plant extracts from the Brazilian Pantanal with antimicrobial activity against bacteria with cariogenic relevance.

    PubMed

    Brighenti, F L; Salvador, M J; Delbem, Alberto Carlos Botazzo; Delbem, Ádina Cleia Bottazzo; Oliveira, M A C; Soares, C P; Freitas, L S F; Koga-Ito, C Y

    2014-01-01

    This study proposes a bioprospection methodology regarding the antimicrobial potential of plant extracts against bacteria with cariogenic relevance. Sixty extracts were obtained from ten plants--(1) Jatropha weddelliana, (2) Attalea phalerata, (3) Buchenavia tomentosa, (4) Croton doctoris, (5) Mouriri elliptica, (6) Mascagnia benthamiana, (7) Senna aculeata, (8) Unonopsis guatterioides, (9) Allagoptera leucocalyx and (10) Bactris glaucescens--using different extraction methods - (A) 70° ethanol 72 h/25°C, (B) water 5 min/100°C, (C) water 1 h/55°C, (D) water 72 h/25°C, (E) hexane 72 h/25°C and (F) 90° ethanol 72 h/25°C. The plants were screened for antibacterial activity at 50 mg/ml using the agar well diffusion test against Actinomyces naeslundii ATCC 19039, Lactobacillus acidophilus ATCC 4356, Streptococcus gordonii ATCC 10558, Streptococcus mutans ATCC 35688, Streptococcus sanguinis ATCC 10556, Streptococcus sobrinus ATCC 33478 and Streptococcus mitis ATCC 9811. The active extracts were tested to determine their minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), cytotoxicity and chemical characterization. Forty-seven extracts (78%) were active against at least one microorganism. Extract 4A demonstrated the lowest MIC and MBC for all microorganisms except S. gordonii and the extract at MIC concentration was non-cytotoxic. The concentrated extracts were slightly cytotoxic. Electrospray ionization with tandem mass spectrometry analyses demonstrated that the extract constituents coincided with the mass of the terpenoids and phenolics. Overall, the best results were obtained for extraction methods A, B and C. The present work proved the antimicrobial activity of several plants. Particularly, extracts from C. doctoris were the most active against bacteria involved in dental caries disease.

  10. Emissions of biogenic volatile organic compounds and subsequent photochemical production of secondary organic aerosol in mesocosm studies of temperate and tropical plant species

    NASA Astrophysics Data System (ADS)

    Wyche, K. P.; Ryan, A. C.; Hewitt, C. N.; Alfarra, M. R.; McFiggans, G.; Carr, T.; Monks, P. S.; Smallbone, K. L.; Capes, G.; Hamilton, J. F.; Pugh, T. A. M.; MacKenzie, A. R.

    2014-06-01

    Silver birch (Betula pendula) and three Southeast Asian tropical plant species (Ficus cyathistipula, Ficus benjamina and Caryota millis) from the pantropical fig and palm genera were grown in a purpose-built and environment-controlled whole-tree chamber. The volatile organic compounds emitted from these trees were characterised and fed into a linked photochemical reaction chamber where they underwent photooxidation under a range of controlled conditions (RH ∼65-89%, VOC/NOx ∼3-9 and NOx ∼2 ppbV). Both the gas phase and the aerosol phase of the reaction chamber were monitored in detail using a comprehensive suite of on-line and off-line, chemical and physical measurement techniques. Silver birch was found to be a high monoterpene and sesquiterpene, but low isoprene emitter, and its emissions were observed to produce measureable amounts of SOA via both nucleation and condensation onto pre-existing seed aerosol (YSOA 26-39%). In contrast, all three tropical species were found to be high isoprene emitters with trace emissions of monoterpenes and sesquiterpenes. In tropical plant experiments without seed aerosol there was no measurable SOA nucleation, but aerosol mass was shown to increase when seed aerosol was present. Although principally isoprene emitting, the aerosol mass produced from tropical fig was mostly consistent (i.e., in 78 out of 120 aerosol mass calculations using plausible parameter sets of various precursor specific yields) with condensation of photooxidation products of the minor VOCs co-emitted; no significant aerosol yield from condensation of isoprene oxidation products was required in the interpretations of the experimental results. This finding is in line with previous reports of organic aerosol loadings consistent with production from minor biogenic VOCs co-emitted with isoprene in principally-isoprene emitting landscapes in Southeast Asia. Moreover, in general the amount of aerosol mass produced from the emissions of the principally

  11. Emissions of biogenic volatile organic compounds and subsequent photochemical production of secondary organic aerosol in mesocosm studies of temperate and tropical plant species

    NASA Astrophysics Data System (ADS)

    Wyche, K. P.; Ryan, A. C.; Hewitt, C. N.; Alfarra, M. R.; McFiggans, G.; Carr, T.; Monks, P. S.; Smallbone, K. L.; Capes, G.; Hamilton, J. F.; Pugh, T. A. M.; MacKenzie, A. R.

    2014-12-01

    Silver birch (Betula pendula) and three Southeast Asian tropical plant species (Ficus cyathistipula, Ficus benjamina and Caryota millis) from the pantropical fig and palm genera were grown in a purpose-built and environment-controlled whole-tree chamber. The volatile organic compounds emitted from these trees were characterised and fed into a linked photochemical reaction chamber where they underwent photo-oxidation under a range of controlled conditions (relative humidity or RH ~65-89%, volatile organic compound-to-NOx or VOC / NOx ~3-9 and NOx ~2 ppbV). Both the gas phase and the aerosol phase of the reaction chamber were monitored in detail using a comprehensive suite of on-line and off-line chemical and physical measurement techniques. Silver birch was found to be a high monoterpene and sesquiterpene but low isoprene emitter, and its emissions were observed to produce measurable amounts of secondary organic aerosol (SOA) via both nucleation and condensation onto pre-existing seed aerosol (YSOA 26-39%). In contrast, all three tropical species were found to be high isoprene emitters with trace emissions of monoterpenes and sesquiterpenes. In tropical plant experiments without seed aerosol there was no measurable SOA nucleation, but aerosol mass was shown to increase when seed aerosol was present. Although principally isoprene emitting, the aerosol mass produced from tropical fig was mostly consistent (i.e. in 78 out of 120 aerosol mass calculations using plausible parameter sets of various precursor specific yields) with condensation of photo-oxidation products of the minor volatile organic compounds (VOCs) co-emitted; no significant aerosol yield from condensation of isoprene oxidation products was required in the interpretations of the experimental results. This finding is in line with previous reports of organic aerosol loadings consistent with production from minor biogenic VOCs co-emitted with isoprene in principally isoprene-emitting landscapes in Southeast

  12. Where Is My Food? Brazilian Flower Fly Steals Prey from Carnivorous Sundews in a Newly Discovered Plant-Animal Interaction

    PubMed Central

    Rivadavia, Fernando; Gonella, Paulo M.; Pérez-Bañón, Celeste; Mengual, Ximo; Rojo, Santos

    2016-01-01

    A new interaction between insects and carnivorous plants is reported from Brazil. Larvae of the predatory flower fly Toxomerus basalis (Diptera: Syrphidae: Syrphinae) have been found scavenging on the sticky leaves of several carnivorous sundew species (Drosera, Droseraceae) in Minas Gerais and São Paulo states, SE Brazil. This syrphid apparently spends its whole larval stage feeding on prey trapped by Drosera leaves. The nature of this plant-animal relationship is discussed, as well as the Drosera species involved, and locations where T. basalis was observed. 180 years after the discovery of this flower fly species, its biology now has been revealed. This is (1) the first record of kleptoparasitism in the Syrphidae, (2) a new larval feeding mode for this family, and (3) the first report of a dipteran that shows a kleptoparasitic relationship with a carnivorous plant with adhesive flypaper traps. The first descriptions of the third instar larva and puparium of T. basalis based on Scanning Electron Microscope analysis are provided. PMID:27144980

  13. Where Is My Food? Brazilian Flower Fly Steals Prey from Carnivorous Sundews in a Newly Discovered Plant-Animal Interaction.

    PubMed

    Fleischmann, Andreas; Rivadavia, Fernando; Gonella, Paulo M; Pérez-Bañón, Celeste; Mengual, Ximo; Rojo, Santos

    2016-01-01

    A new interaction between insects and carnivorous plants is reported from Brazil. Larvae of the predatory flower fly Toxomerus basalis (Diptera: Syrphidae: Syrphinae) have been found scavenging on the sticky leaves of several carnivorous sundew species (Drosera, Droseraceae) in Minas Gerais and São Paulo states, SE Brazil. This syrphid apparently spends its whole larval stage feeding on prey trapped by Drosera leaves. The nature of this plant-animal relationship is discussed, as well as the Drosera species involved, and locations where T. basalis was observed. 180 years after the discovery of this flower fly species, its biology now has been revealed. This is (1) the first record of kleptoparasitism in the Syrphidae, (2) a new larval feeding mode for this family, and (3) the first report of a dipteran that shows a kleptoparasitic relationship with a carnivorous plant with adhesive flypaper traps. The first descriptions of the third instar larva and puparium of T. basalis based on Scanning Electron Microscope analysis are provided.

  14. Modeled effects of climate change and plant invasion on watershed function across a steep tropical rainfall gradient

    Treesearch

    Ayron M. Strauch; Christian P. Giardina; Richard A. MacKenzie; Chris Heider; Tom W. Giambelluca; Ed Salminen; Gregory L. Bruland

    2017-01-01

    Climate change is anticipated to affect freshwater resources, but baseline data on the functioning of tropical watersheds is lacking, limiting efforts that seek to predict how watershed processes, water supply, and streamflow respond to anticipated changes in climate and vegetation change, and to management. To address this data gap, we applied the distributed...

  15. Soil communities and plant litter decomposition as influenced by forest debris: Variation across tropical riparian and upland sites.

    Treesearch

    Honghua Ruana; Yiqing Lib; Xiaoming Zouc

    2005-01-01

    Forest debris on ground surface can interact with soil biota and consequently change ecosystem processes across heterogeneous landscape. We examined the interactions between forest debris and litter decomposition in riparian and upland sites within a tropical wet forest. Our experiment included control and debris-removal treatments. Debris-removal reduced leaf litter...

  16. Afforestation by natural regeneration or by tree planting: examples of opposite hydrological impacts evidenced by long-term field monitoring in the humid tropics

    NASA Astrophysics Data System (ADS)

    Lacombe, G.; Ribolzi, O.; de Rouw, A.; Pierret, A.; Latsachak, K.; Silvera, N.; Pham Dinh, R.; Orange, D.; Janeau, J.-L.; Soulileuth, B.; Robain, H.; Taccoen, A.; Sengphaathith, P.; Mouche, E.; Sengtaheuanghoung, O.; Tran Duc, T.; Valentin, C.

    2015-12-01

    The humid tropics are exposed to an unprecedented modernization of agriculture involving rapid and highly-mixed land-use changes with contrasted environmental impacts. Afforestation is often mentioned as an unambiguous solution for restoring ecosystem services and enhancing biodiversity. One consequence of afforestation is the alteration of streamflow variability controlling habitats, water resources and flood risks. We demonstrate that afforestation by tree planting or by natural forest regeneration can induce opposite hydrological changes. An observatory including long-term field measurements of fine-scale land-use mosaics and of hydro-meteorological variables has been operating in several headwater catchments in tropical Southeast Asia since 2001. The GR2M water balance model repeatedly calibrated over successive 1 year periods, and used in simulation mode with specific rainfall input, allowed the hydrological effect of land-use change to be isolated from that of rainfall variability in two of these catchments in Laos and Vietnam. Visual inspection of hydrographs, correlation analyses and trend detection tests allowed causality between land-use changes and changes in seasonal flows to be ascertained. In Laos, the combination of shifting cultivation system (alternation of rice and fallow) and the gradual increase of teak tree plantations replacing fallow, led to intricate flow patterns: pluri-annual flow cycles induced by the shifting system, on top of a gradual flow increase over years caused by the spread of the plantation. In Vietnam, the abandonment of continuously cropped areas mixed with patches of tree plantations led to the natural re-growth of forest communities followed by a gradual drop in streamflow. Soil infiltrability controlled by surface crusting is the predominant process explaining why two modes of afforestation (natural regeneration or planting) led to opposite changes in flow regime. Given that commercial tree plantations will continue to

  17. Topology of Plant - Flower-Visitor Networks in a Tropical Mountain Forest: Insights on the Role of Altitudinal and Temporal Variation.

    PubMed

    Cuartas-Hernández, Sandra; Medel, Rodrigo

    2015-01-01

    Understanding the factors determining the spatial and temporal variation of ecological networks is fundamental to the knowledge of their dynamics and functioning. In this study, we evaluate the effect of elevation and time on the structure of plant-flower-visitor networks in a Colombian mountain forest. We examine the level of generalization of plant and animal species and the identity of interactions in 44 bipartite matrices obtained from eight altitudinal levels, from 2200 to 2900 m during eight consecutive months. The contribution of altitude and time to the overall variation in the number of plant (P) and pollinator (A) species, network size (M), number of interactions (I), connectance (C), and nestedness was evaluated. In general, networks were small, showed high connectance values and non-nested patterns of organization. Variation in P, M, I and C was better accounted by time than elevation, seemingly related to temporal variation in precipitation. Most plant and insect species were specialists and the identity of links showed a high turnover over months and at every 100 m elevation. The partition of the whole system into smaller network units allowed us to detect small-scale patterns of interaction that contrasted with patterns commonly described in cumulative networks. The specialized but erratic pattern of network organization observed in this tropical mountain suggests that high connectance coupled with opportunistic attachment may confer robustness to plant-flower-visitor networks occurring at small spatial and temporal units.

  18. Topology of Plant - Flower-Visitor Networks in a Tropical Mountain Forest: Insights on the Role of Altitudinal and Temporal Variation

    PubMed Central

    Cuartas-Hernández, Sandra; Medel, Rodrigo

    2015-01-01

    Understanding the factors determining the spatial and temporal variation of ecological networks is fundamental to the knowledge of their dynamics and functioning. In this study, we evaluate the effect of elevation and time on the structure of plant-flower-visitor networks in a Colombian mountain forest. We examine the level of generalization of plant and animal species and the identity of interactions in 44 bipartite matrices obtained from eight altitudinal levels, from 2200 to 2900 m during eight consecutive months. The contribution of altitude and time to the overall variation in the number of plant (P) and pollinator (A) species, network size (M), number of interactions (I), connectance (C), and nestedness was evaluated. In general, networks were small, showed high connectance values and non-nested patterns of organization. Variation in P, M, I and C was better accounted by time than elevation, seemingly related to temporal variation in precipitation. Most plant and insect species were specialists and the identity of links showed a high turnover over months and at every 100 m elevation. The partition of the whole system into smaller network units allowed us to detect small-scale patterns of interaction that contrasted with patterns commonly described in cumulative networks. The specialized but erratic pattern of network organization observed in this tropical mountain suggests that high connectance coupled with opportunistic attachment may confer robustness to plant-flower-visitor networks occurring at small spatial and temporal units. PMID:26513664

  19. A study on transfer factors of 60Co and 65Zn from soil to plants in the tropical environment of Bangladesh.

    PubMed

    Mollah, A S; Begum, A

    2001-04-01

    Soil to plant transfer factor (TF) of 60Co and 65Zn was determined from radioisotope experiments on plants grown in pots under outdoor ambient tropical conditions for three growing seasons (1995-1998). The TFs were obtained for different plants/crops such as, rice, bean, peanuts pineapple, cabbage, tomato, spinach and grass. The average TF values of 60Co are found to be 0.087. 0.15, 0.12, 0.67, 0.28, 0.79, 1.03 and 0.34 respectively for the above mentioned plants/crops. In case of 65Zn, the average TF values are found to be 2.24, 1.17. 0.89, 1.09, 0.78, 1.34, 2.92 and 1.78, respectively, for the above mentioned plants/crops. The data will be useful to assess the radiation exposure to man associated with the releases of radionuclides from nuclear facilities by means of radiological assessment models that require transfer factors as input parameters to predict the contamination of radionuclides in foodchain.

  20. Plant phenological water cycle and implications for using δ2H-alkanes as paleo proxy in a semi-arid tropical climate

    NASA Astrophysics Data System (ADS)

    De Wispelaere, Lien; Bodé, Samuel; Hervé-Fernández, Pedro; Hemp, Andreas; Verschuren, Dirk; Boeckx, Pascal

    2017-04-01

    Lake Challa is a steep-sided crater lake situated in equatorial East Africa, a tropical semi-arid area with bimodal rainfall pattern. The δ2H and δ18O of precipitation, lake water, groundwater, plant xylem water and plant leaf water were measured across different plant species, seasons and plant habitats in the vicinity of Lake Challa, as well as the hydrogen-isotopic composition of leaf wax n-alkanes (δ2Hwax). Long chain n-alkanes of terrestrial plant leaf waxes provide information on plant-water relations and have been widely used as proxy in paleoclimate and paleovegetation reconstructions. In our study, we found that plants rely mostly on water from the 'short rains' falling from October till December (northeast monsoon), as these recharge the soil pores after the long dry season. This plant-available, static, water pool is only slightly replenished by the 'long rains' falling from February to May (southeast monsoon), in agreement with the 'two water world' hypothesis according to which plants rely on a static water pool separated from a more mobile water pool that recharges the groundwater. Spatial variability in water resource use exists in the study region with plants at the lakeshore relying on water of different isotopic composition, i.e isotopically evaporated lake water at the lakeshore vs. non- or slightly evaporated precipitation in the savannah and on the crater rim. This spatial resource partitioning is recorded by elevated δ2H values in the leaf wax lipids of plants at the lakeshore. The distribution of n-alkanes in the fresh leaves shows a unimodal distribution pattern reaching a maximum at n-C29 and n-C31 for both shrubs and trees, while C4 grasses are dominated by n-C31. However, the relative abundance of n-C31 was higher at the lakeshore compared to the savannah and crater rim (when grasses were not included). According to our results, plant species and their associated leaf phenology are the primary factors influencing the enrichment in

  1. Assessment of Plant Functional Types in Tropical Arid and Semi-Arid Ecosystems of India Using Remote Sensing Data and GIS

    NASA Astrophysics Data System (ADS)

    Sudhakar Reddy, C.; Krishna, P. Hari; Murthy, M. S. R.

    2011-09-01

    Tropical ecosystems undergo changes caused by season, climate or multiple anthropogenic impacts. Such changes may cause gradual or rapid shifts from one state to another. There has been a focus on functional classifications of plants to find tools for monitoring and assessing species status in changing environments. It has been recognised that plant biological characteristics can be related to their response to predominant environmental factors and interactions between other organisms. These findings have resulted in a search for plant functional types (PFTs) that are user-defined groups of species with similar response to environmental resources and disturbance associated to common biological traits. Now, identification of plant functional types is priority area in the climate change research. Satellite Earth observation data is an important tool in providing considerable information on extracting PFT information at global and regional levels. From the modelling perspective, some of the current needs are the refinement of processes that govern community assembly, such as natural and anthropogenic disturbances. PFTs used in large-scale models are insufficient to represent the diversity of responses in natural plant communities. The currently available MODIS PFT map was generated by re-labeling the IGBP land cover type classes. However, the error magnitudes of the MODIS PFT product and their spatial and temporal distributions have not been fully characterized. Remotely sensed derived information of the phenology, community composition and vegetation structure are the key inputs to integrate with the variability in precipitation and temperature to map the spatial distribution of Plant functional types. PFTs allows accurate representation of the land surface by separately specifying the composition and structure of PFTs within a grid cell. Very little research efforts are discernible in India that explicitly address the PFTs. In the present study five natural

  2. Community patterns of tropical tree phenology derived from Unmanned Aerial Vehicle images: intra- and interspecific variation, association with species plant traits, and response to interannual climate variation

    NASA Astrophysics Data System (ADS)

    Bohlman, Stephanie; Rifai, Sami; Park, John; Dandois, Jonathan; Muller-Landau, Helene

    2017-04-01

    Phenology is a key life history trait of plant species and critical driver of ecosystem processes. There is strong evidence that phenology is shifting in temperate ecosystems in response to climate change, but tropical forest phenology remains poorly quantified and understood. A key challenge is that tropical forests contain hundreds of plant species with a wide variety of phenological patterns, which makes it difficult to collect sufficient ground-based field data to characterize individual tropical tree species phenologies. Satellite-based observations, an important source of phenology data in northern latitudes, are hindered by frequent cloud cover in the tropics. To quantify phenology over a large number of individuals and species, we collected bi-weekly images from unmanned aerial vehicles (UAVs) in the well-studied 50-ha forest inventory plot on Barro Colorado Island, Panama. The objective of this study is to quantify inter- and intra-specific responses of tropical tree leaf phenology to environmental variation over large spatial scales and identify key environmental variables and physiological mechanisms underpinning phenological variation. Between October 2014 and December 2015 and again in May 2015, we collected a total of 35 sets of UAV images, each with continuous coverage of the 50-ha plot, where every tree ≥ 1 cm DBH is mapped. UAV imagery was corrected for exposure, orthorectified, and then processed to extract spectral, texture, and image information for individual tree crowns, which was then used as inputs for a machine learning algorithm that successfully predicted the percentages of leaf, branch, and flower cover for each tree crown (r2=0.76 between observed and predicted percent branch cover for individual tree crowns). We then quantified cumulative annual deciduousness for each crown by fitting a non-parametric curve of flexible shape to its predicted percent branch time series and calculated the area under the curve. We obtained the species

  3. Popular medicinal uses of Calea uniflora Less. (Asteraceae) and its contribution to the study of Brazilian medicinal plants.

    PubMed

    Ramos, Luan S; Cardoso, Paula S; Freitas, Michele D; Paghan, Renato; Borges, Marília S; Citadini-Zanette, Vanilde; Barlow, James W; Amaral, Patrícia A; Dalbó, Silvia

    2016-01-01

    Calea uniflora Less. is widely used in southern Santa Catarina (Brazil), but there are no scientific studies which support its use. Then, this study was proposed to determine of the percentage use of C. uniflora in a city of southern Brazil and documentation of the knowledge that the population has about this species. The survey was conducted with semi-structured interviews using a questionnaire applied to 372 participants. In analyzing the results, it was observed that of the 94.1% who recognized C. uniflora, 74.3% utilize it as a medicinal plant and 65.4% of such knowledge originates in childhood, mainly through the family (84.6%). 93% reported using inflorescences macerated in alcohol or rum; this extract is generally used topically for wound healing and muscle pain. Furthermore, some reported using small quantities of this extract orally to treat cold and flu. Regarding effectiveness and safety, 97% stated an improvement in symptoms with the use of the plant, while 98.5% stated that it has no toxicity. In light of these results, future phytochemical, pharmacological and toxicological analyses should be designed in order to ensure rational and safe use of this species.

  4. In vitro acaricidal efficacy of plant extracts from Brazilian flora and isolated substances against Rhipicephalus microplus (Acari: Ixodidae).

    PubMed

    Valente, Paula Pimentel; Amorim, Juliana Mendes; Castilho, Rachel Oliveira; Leite, Romário Cerqueira; Ribeiro, Múcio Flávio Barbosa

    2014-01-01

    The tick Rhipicephalus microplus causes significant losses in livestock cattle and has developed increasing resistance to the primary acaricides that are used to treat these infections. The objective of this study was to identify new biomolecules or isolated substances showing acaricidal activity from plants. Larval packet tests were conducted to evaluate the effects of 11 species of plants and three isolated substances (betulinic acid, eugenol, and nerolidol) on R. microplus. An adult female immersion test was performed with the substance that showed the highest larvicidal activity, which was evaluated for inhibition of reproduction. Tests using Licania tomentosa, Hymenaea stigonocarpa, Hymenaea courbaril, Stryphnodendron obovatum, Jacaranda cuspidifolia, Jacaranda ulei, Struthanthus polyrhizus, Chrysobalanus icaco, Vernonia phosphorea, Duguetia furfuracea, and Simarouba versicolor extracts as well as the isolated substance betulinic acid indicated lower acaricidal effects on R. microplus larvae. The extract displaying the best larvicidal activity was the ethanolic extract from L. tomentosa at a concentration of 60%, resulting in a mortality rate of 40.3%. However, nerolidol and eugenol showed larvicidal activity, which was highest for eugenol. Nerolidol caused a 96.5% mortality rate in the R. microplus larvae at a high concentration of 30%, and eugenol caused 100% mortality at a concentration of 0.3%. In the adult immersion test, 5% eugenol was identified as a good biomolecule for controlling R. microplus, as demonstrated by its high acaricidal activity and inhibition of oviposition.

  5. Assessing the impacts of canopy openness and flight parameters on detecting a sub-canopy tropical invasive plant using a small unmanned aerial system

    NASA Astrophysics Data System (ADS)

    Perroy, Ryan L.; Sullivan, Timo; Stephenson, Nathan

    2017-03-01

    Small unmanned aerial systems (sUAS) have great potential to facilitate the early detection and management of invasive plants. Here we show how very high-resolution optical imagery, collected from small consumer-grade multirotor UAS platform at altitudes of 30-120 m above ground level (agl), can be used to detect individual miconia (Miconia calvescens) plants in a highly invaded tropical rainforest environment on the island of Hawai'i. The central aim of this research was to determine how overstory vegetation cover, imagery resolution, and camera look-angle impact the aerial detection of known individual miconia plants. For our finest resolution imagery (1.37 cm ground sampling distance collected at 30 m agl), we obtained a 100% detection rate for sub-canopy plants with above-crown openness values >40% and a 69% detection rate for those with >20% openness. We were unable to detect any plants with <10% above crown openness. Detection rates progressively declined with coarser spatial resolution imagery, ending in a 0% detection rate for the 120 m agl flights (ground sampling distance of 5.31 cm). The addition of forward-looking oblique imagery improved detection rates for plants below overstory vegetation, though this effect decreased with increasing flight altitude. While dense overstory canopy cover, limited flight times, and visual line of sight regulations present formidable obstacles for detecting miconia and other invasive plant species, we show that sUAS platforms carrying optical sensors can be an effective component of an integrated management plan within challenging subcanopy forest environments.

  6. In vitro activities of plant extracts from the Brazilian Cerrado and Pantanal against Rhipicephalus (Boophilus) microplus (Acari: Ixodidae).

    PubMed

    Barbosa, Carolina da Silva; Borges, Ligia Miranda Ferreira; Nicácio, José; Alves, Reginaldo Dias; Miguita, Carlos Henrique; Violante, Ivana Maria Póvoa; Hamerski, Lidilhone; Garcez, Walmir Silva; Garcez, Fernanda Rodrigues

    2013-07-01

    A total of 73 ethanol extracts from different anatomical parts of 44 plant species belonging to 24 families, native to the Mid-Western region of Brazil, were assessed in vitro for their effect on the reproductive cycle of engorged females of the cattle tick Rhipicephalus (Boophilus) microplus, using the adult immersion test. All extracts were evaluated at the concentration of 0.2 % and, among the extracts tested, the one obtained from the fruits of Guarea kunthiana (Meliaceae) proved to be highly efficacious, showing 99.1 % of product effectiveness. Extracts from other three species were shown to be moderately active, namely Nymphaea amazonum trunk (Nymphaeaceae) [51.7 %], Strychnos pseudoquina trunk (Loganiaceae) [48 %] [corrected] and Ocotea lancifolia leaves (Lauraceae) [34.5 %], while the remaining extracts were shown to be weakly active or inactive. This is the first report on the bioactivity of these species on egg production by engorged females of R. microplus.

  7. Molecular characterization of nitrogen-fixing bacteria isolated from brazilian agricultural plants at São Paulo state

    PubMed Central

    Reinhardt, Érica. L.; Ramos, Patrícia L.; Manfio, Gilson P.; Barbosa, Heloiza R.; Pavan, Crodowaldo; Moreira-Filho, Carlos A.

    2008-01-01

    Fourteen strains of nitrogen-fixing bacteria were isolated from different agricultural plant species, including cassava, maize and sugarcane, using nitrogen-deprived selective isolation conditions. Ability to fix nitrogen was verified by the acetylene reduction assay. All potentially nitrogen-fixing strains tested showed positive hybridization signals with a nifH probe derived from Azospirillum brasilense. The strains were characterized by RAPD, ARDRA and 16S rDNA sequence analysis. RAPD analyses revealed 8 unique genotypes, the remaining 6 strains clustered into 3 RAPD groups, suggesting a clonal origin. ARDRA and 16S rDNA sequence analyses allowed the assignment of 13 strains to known groups of nitrogen-fixing bacteria, including organisms from the genera Azospirillum, Herbaspirillum, Pseudomonas and Enterobacteriaceae. Two strains were classified as Stenotrophomonas ssp. Molecular identification results from 16S rDNA analyses were also corroborated by morphological and biochemical data. PMID:24031239

  8. Terrestrial Carbon Fluxes from Deforestation in the Brazilian Amazon and Cerrado Regions Predicted from MODIS Satellite Data and Ecosystem Modeling

    NASA Astrophysics Data System (ADS)

    Klooster, S.; Potter, C.; Genovese, V.

    2008-12-01

    The NASA-CASA (Carnegie Ames Stanford Approach) simulation model based on satellite observations of monthly vegetation cover from the Moderate Resolution Imaging Spectroradiometer (MODIS) was used to estimate tropical forest and savanna (Cerrado) carbon pools for the Brazilian Amazon region over the period 2000-2004. Adjustments for mean age of forest stands were carried out across the region, resulting in a new mapping of aboveground biomass pools based on MODIS satellite data. Yearly maps of newly deforested lands from the Brazilian PRODES (Programa de calculo do desflorestamento da Amazonia ) project were combined with these NASA-CASA biomass predictions to generate seasonal budgets of potential carbon and nitrogen trace gas losses from biomass burning events. Simulations of plant residue and soil carbon decomposition were conducted in the NASA-CASA model during and following deforestation events to track the fate of aboveground biomass pools that were cut and burned each year across the region.

  9. Post-treatment with plant extracts used in Brazilian folk medicine caused a partial reversal of the antiproliferative effect of glyphosate in the Allium cepa test.

    PubMed

    Frescura, Viviane Dal-Souto; Kuhn, Andrielle Wouters; Laughinghouse, Haywood Dail; Paranhos, Juçara Terezinha; Tedesco, Solange Bosio

    2013-08-01

    Species of the genus Psychotria are used for multiple purposes in Brazilian folk medicine, either as water infusions, baths or poultices. This study was aimed to evaluate the genotoxic and antiproliferative effects of infusions of Psychotria brachypoda and P. birotula on the Allium cepa test. Exposure to distilled water was used as a negative control, while exposure to glyphosate was used as a positive control. The interaction of extracts (as a post-treatment) with the effects of glyphosate was also studied. Results showed that glyphosate and the extracts of both P. brachypoda and P. birotula reduced the mitotic index as compared with the negative control (distilled water). Surprisingly, however, both extracts from P. brachypoda and P. birotula caused a partial reversal of the antiproliferative effect of glyphosate when used as a post-treatment. Glyphosate also induced the highest number of cells with chromosomal alterations, which was followed by that of P. birotula extracts. However, the extracts from P. brachypoda did not show any significant genotoxic effect. Post-treatment of glyphosate-treated samples with distilled water allowed a partial recovery of the genotoxic effect of glyphosate, and some of the Psychotria extracts also did so. Notably, post-treatment of glyphosate-treated samples with P. brachypoda extracts induced a statistically significant apoptotic effect. It is concluded that P. brachypoda extracts show antiproliferative effects and are not genotoxic, while extracts of P. birotula show a less potent antiproliferative effect and may induce chromosomal abnormalities. The finding of a partial reversion of the effects of glyphosate by a post-treatment with extracts from both plants should be followed up.

  10. Plant functional types are more efficient than climate in predicting spectrums of trait variation in evergreen angiosperm trees of tropical Australia and China

    NASA Astrophysics Data System (ADS)

    Togashi, H. F.; Prentice, I. C. C.; Atkin, O. K.; Bloomfield, K. J.; Bradford, M.; Weerasinghe, L. K.; Harrison, S. P.; Evans, B. J.; Liddell, M. J.; Wang, H.; Cao, K. F.; Fan, Z.

    2015-12-01

    The representation of Plant Functional Types (PFTs) in current generation of Dynamic Global Vegetation Models (DGVMs) is excessively simplistically. Key ecophysiological properties, such as photosynthesis biochemistry, are most times merely averaged and trade-off with other plant traits is often neglected. Validation of a PFT framework based in photosynthetic process is crucial to improve reliability of DGVMs. We present 431 leaf-biochemical and wood level measurements in evergreen angiosperm trees of tropical forests in Australia and China that were divided in four spectrums of plant trait variation: metabolic, structural, hydraulic and height dimensions. Plant traits divided in each of these dimensions adopt survival strategies reflected more clearly by trade-off within each spectrum, and in some extent across spectrums. Co-ordination theory (that Rubisco- and electron-transport limited rates of photosynthesis are co-limiting) and least-coast theory (that intercellular to ambient CO2 concentration minimizes the combined costs per unit carbon assimilation, regulating maximum height and wood density) expectations matched PFT (which takes in account canopy position and light access, and life spam) variation. Our findings suggest that climate (air moisture, air temperature, light) has lower power representing these dimensions, in comparison to the PFT framework.

  11. Tropical malabsorption

    PubMed Central

    Ramakrishna, B S; Venkataraman, S; Mukhopadhya, A

    2006-01-01

    Malabsorption is an important clinical problem both in visitors to the tropics and in native residents of tropical countries. Infections of the small intestine are the most important cause of tropical malabsorption. Protozoal infections cause malabsorption in immunocompetent hosts, but do so more commonly in the setting of immune deficiency. Helminth infections occasionally cause malabsorption or protein‐losing enteropathy. Intestinal tuberculosis, chronic pancreatitis and small‐bowel bacterial overgrowth are important causes of tropical malabsorption. In recent years, inflammatory bowel disease and coeliac disease have become major causes of malabsorption in the tropics. Sporadic tropical sprue is still an important cause of malabsorption in adults and in children in South Asia. Investigations to exclude specific infective, immunological or inflammatory causes are important before considering tropical sprue as a diagnosis. This article briefly reviews the management of tropical sprue and presents an algorithm for its investigation and management. PMID:17148698

  12. Tropical Rainforests.

    ERIC Educational Resources Information Center

    Nigh, Ronald B.; Nations, James D.

    1980-01-01

    Presented is a summary of scientific knowledge about the rainforest environment, a tropical ecosystem in danger of extermination. Topics include the current state of tropical rainforests, the causes of rainforest destruction, and alternatives of rainforest destruction. (BT)

  13. Tropical Rainforests.

    ERIC Educational Resources Information Center

    Nigh, Ronald B.; Nations, James D.

    1980-01-01

    Presented is a summary of scientific knowledge about the rainforest environment, a tropical ecosystem in danger of extermination. Topics include the current state of tropical rainforests, the causes of rainforest destruction, and alternatives of rainforest destruction. (BT)

  14. Tropical malabsorption.

    PubMed

    Ramakrishna, B S; Venkataraman, S; Mukhopadhya, A

    2006-12-01

    Malabsorption is an important clinical problem both in visitors to the tropics and in native residents of tropical countries. Infections of the small intestine are the most important cause of tropical malabsorption. Protozoal infections cause malabsorption in immunocompetent hosts, but do so more commonly in the setting of immune deficiency. Helminth infections occasionally cause malabsorption or protein-losing enteropathy. Intestinal tuberculosis, chronic pancreatitis and small-bowel bacterial overgrowth are important causes of tropical malabsorption. In recent years, inflammatory bowel disease and coeliac disease have become major causes of malabsorption in the tropics. Sporadic tropical sprue is still an important cause of malabsorption in adults and in children in South Asia. Investigations to exclude specific infective, immunological or inflammatory causes are important before considering tropical sprue as a diagnosis. This article briefly reviews the management of tropical sprue and presents an algorithm for its investigation and management.

  15. Brazilian gemstones

    NASA Astrophysics Data System (ADS)

    Franco, Rui Ribeiro

    1981-04-01

    Brazil counts as a gemmological province because of the variety of gem minerals present in the country. Most Brazilian states and territories produce gemstones, the State of Minas Gerais being the most important producer both in volume and in number of species. Diamonds are chiefly derived by panning from alluvial deposits in Minas Gerais, Mato Grosso and Goiás. Among other gemstones, the most important are aquamarines, beryls, chrysoberyls, topazes, amethysts, tourmalines, emeralds and agates, and their respective varieties. The occurrences of these gemstones, as well as of a great number of others, are described for each state in which they are found.

  16. Effect of planting time and density on yield and quality of peppermint (mentha piperita L.) under su-tropical condition.

    PubMed

    Sharma, P C; Kanjilal, P B

    1999-01-01

    A field trial was conducted at the research farm of RRL, Jorhat during 1995 and 1996 to study the performance of Mentha Piperita under varying dates of planting and row spacings, maximum herbage and oil yield were obtained from January plants crops. Yield deceased when planting was delayed planting at a closer row spacing of 45 cm recorded the maximum herbage yield of 61'92 q/a while the yield was reduced with wider row spacing of 360 cm or 75cm. However, the quality of oil as measured by the menthol content (71'0 - 72'3% was not affected by planting time as well as spacings.

  17. In vitro growth-inhibitory effect of Brazilian plants extracts against Paenibacillus larvae and toxicity in bees.

    PubMed

    Piana, Mariana; de Brum, Thiele F; Boligon, Aline A; Alves, Camilla F S; de Freitas, Robson B; Nunes, Letícia T; Mossmann, Natalia J; Janovik, Vanessa; Jesus, Roberta S; Vaucher, Rodrigo A; Santos, Roberto C V; Athayde, Margareth L

    2015-01-01

    American foulbrood (AFB) is a serious worldwide spreading disease in bees caused by Paenibacillus larvae. Plants extracts are known to decrease or inhibit the growth of these bacteria. The purpose of this study was to evaluate the antimicrobial activity of Calendula. officinalis, Cariniana domestica, and Nasturtium officinale extracts against the P. larvae and to evaluate the toxicity of the extracts in bees. In vitro activity against P. larvae of the extracts was evaluated by micro dilution method and the minimal inhibitory concentrations (MICs) were also determined. The concentrations used in the toxicity test were established based on the MIC values and by the spraying application method. The P. larvae was susceptible to the evaluated crude extract of C. officinalis and N. officinale. To C. domestica, only the ethyl acetate (EtAc) fraction and n-butanol (BuOH) fractions had activity against P. larvae. Toxicity analysis in bees showed no toxicity for N. officinale crude extract and for C. domestica BuOH fraction during 15 days of treatment, however, some deaths of bees occurred during the first three days of treatment with C. officinalis and C. domestica EtAc fraction. The results with these species were firstly described and showed that N. officinale crude extract and C. domestica BuOH fraction both presented not toxic effects in the concentration tested by the spraying application method, and can be a useful alternative for treatment or prevention of AFB.

  18. Positive Effects of Plant Genotypic and Species Diversity on Anti-Herbivore Defenses in a Tropical Tree Species

    PubMed Central

    Moreira, Xoaquín; Abdala-Roberts, Luis; Parra-Tabla, Víctor; Mooney, Kailen A.

    2014-01-01

    Despite increasing evidence that plant intra- and inter-specific diversity increases primary productivity, and that such effect may in turn cascade up to influence herbivores, there is little information about plant diversity effects on plant anti-herbivore defenses, the relative importance of different sources of plant diversity, and the mechanisms for such effects. For example, increased plant growth at high diversity may lead to reduced investment in defenses via growth-defense trade-offs. Alternatively, positive effects of plant diversity on plant growth may lead to increased herbivore abundance which in turn leads to a greater investment in plant defenses. The magnitude of trait variation underlying diversity effects is usually greater among species than among genotypes within a given species, so plant species diversity effects on resource use by producers as well as on higher trophic levels should be stronger than genotypic diversity effects. Here we compared the relative importance of plant genotypic and species diversity on anti-herbivore defenses and whether such effects are mediated indirectly via diversity effects on plant growth and/or herbivore damage. To this end, we performed a large-scale field experiment where we manipulated genotypic diversity of big-leaf mahogany (Swietenia macrophylla) and tree species diversity, and measured effects on mahogany growth, damage by the stem-boring specialist caterpillar Hypsipyla grandella, and defensive traits (polyphenolics and condensed tannins in stem and leaves). We found that both forms of plant diversity had positive effects on stem (but not leaf) defenses. However, neither source of diversity influenced mahogany growth, and diversity effects on defenses were not mediated by either growth-defense trade-offs or changes in stem-borer damage. Although the mechanism(s) of diversity effects on plant defenses are yet to be determined, our study is one of the few to test for and show producer diversity effects on

  19. Positive effects of plant genotypic and species diversity on anti-herbivore defenses in a tropical tree species.

    PubMed

    Moreira, Xoaquín; Abdala-Roberts, Luis; Parra-Tabla, Víctor; Mooney, Kailen A

    2014-01-01

    Despite increasing evidence that plant intra- and inter-specific diversity increases primary productivity, and that such effect may in turn cascade up to influence herbivores, there is little information about plant diversity effects on plant anti-herbivore defenses, the relative importance of different sources of plant diversity, and the mechanisms for such effects. For example, increased plant growth at