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Sample records for cedro cedrela fissilis

  1. Re-induction of desiccation tolerance after germination of Cedrela fissilis Vell. seeds.

    PubMed

    Masetto, Tathiana E; Faria, Jose M; Fraiz, Ana C R

    2014-09-01

    This work aimed to characterize the re-induction of desiccation tolerance (DT) in germinated seeds, using polyethylene glycol (PEG 8000). Cell changes were investigated through cytological assays (cell viability and transmission electronic microscopy) as well as DNA integrity during loss and re-establishment of DT. The loss of DT was characterized by drying germinated seeds with different radicle lengths (1, 2, 3, 4 and 5 mm) in silica gel, decreasing the moisture content to ten percentage points intervals, followed by pre-humidification (100% RH / 24 h) and rehydration. To re-induce DT, germinated seeds were treated for 72 h with PEG (-2.04 MPa) and PEG (-2.04 MPa) + ABA (100 µM) before dehydration. Germinated seeds did not tolerate desiccation to 10% moisture content, irrespectively of the radicle length. However, when incubated in PEG, those with 1 and 2 mm long radicle attained 71% and 29% survival, respectively. The PEG+ABA treatment was efficient to re-establish DT in seeds with 1 mm long radicles (100% survival). The ultrastructural assays of the cells of germinated seeds with 2 and 5 mm length confirmed the obtained physiological results. Germinated seeds of C. fissilis constitute a useful tool for desiccation tolerance investigations. PMID:25140505

  2. Floral Development in the Tribe Cedreleae (Meliaceae, Sub-family Swietenioideae): Cedrela and Toona

    PubMed Central

    Gouvêa, Cantídio Fernando; Dornelas, Marcelo Carnier; Rodriguez, Adriana Pinheiro Martinelli

    2008-01-01

    Background and Aims Floral development of Cedrela and Toona, the genera comprising the basal tribe Cedreleae of the sub-family Swietenioideae of Meliaceae, is described. The focus was on three endangered, ecologically and economically important species: Cedrela fissilis, Cedrela odorata and Toona ciliata. The aims of the study were to characterize the patterns of floral development in the tribe and to establish apomorphic and plesiomorphic floral characters in relation to other taxa within the family based on the current molecular phylogeny of Meliaceae. Methods A detailed floral structural and developmental study was completed using both scanning electron microscopy and visualization of microtome sections with a light microscope. Key Results Twelve floral developmental stages were identified. The initial development of the pentamerous flowers of both Toona and Cedrela is strikingly similar. The morphological differences observed between them are due to differential patterns of organ elongation and adnation/connation occurring late in development. Additionally, the formation of functionally male and female flowers was found to occur at specific positions within the inflorescence. Conclusions Due to the basal position of the tribe Cedreleae in the phylogeny of Meliaceae, functionally either male or female pentamerous flowers and the presence of (at least partially) free stamens may be considered plesiomorphic traits within the family. In contrast, sympetaly and the absence of nectaries in Cedrela species are synapomorphies. PMID:17981877

  3. Limonoids from the stem bark of Cedrela odorata.

    PubMed

    Kipassa, Nsiama Tienabe; Iwagawa, Tetsuo; Okamura, Hiroaki; Doe, Matsumi; Morimoto, Yoshiki; Nakatani, Munehiro

    2008-05-01

    Four nomilin/obacunol derivatives and a swietenolide derivative, together with seven known limonoids, were isolated from stem bark of Cedrela odorata and their structures established by spectroscopic methods. Antifeedant activity of the isolated compounds was also tested. PMID:18417175

  4. The CEDROS ignimbrite, Faial island (Azores, Portugal)

    NASA Astrophysics Data System (ADS)

    Caniaux, Guy

    2010-05-01

    About 25 ignimbrites are known on the various islands of the Azorean archipelago. Most of them can be observed on São Miguel and Terceira islands, where they are considered as associated with caldeira-forming eruptions. In the Azores, ignimbrites form generally low volume deposits, although their volumes are largely unknown due to the particular geometry of the islands and the unknown fraction entering the ocean. Except the Povoação (Duncan et al., 1999) and Fogo ignimbrites (Wallenstein, 1999) on São Miguel island, or the ignimbrites of Terceira island (Self, 1976; Guertisser et al., 2009), most ignimbrites have not been extensively studied. The Cedros ignimbrite on Faial island, is the most recent and accessible ignimbrite of the Azores. Its age (1200 B.P.) is well constrained by several C14 datings (Shotton et al., 1970; Chovelon, 1982; Madeira et al., 1995; Pacheco, 2001). It formed during one of the latest and largest explosive events of the holocene activity of the Vulcão da Caldeira (1043 m), an event certainly at the origin of the present morphology of its large caldeira (Pacheco, 2001; Forjaz et al., 2006). The deposit is easily accessible since it outcrops at the surface except when partly covered by only one, more recent, thin deposit. The ignimbrite was produced at the end of a magmatic and hydromagmatic, sub-plinian eruption, with pumice fall deposits and multiple flow / fall ash deposits located on the north-western flank of the volcano (Pacheco, 2001). A detailed mapping of the ignimbrite is proposed, based on more than 300 documented outcrops. The mapping reveals the existence of 9 different units, radially spread on the northern flank of the volcano where it forms lobes some kilometers in length. Lobes never exceed 20 m in thickness. In the upper part of the volcano, the units were largely channeled either in deep valleys carved on the steep slopes of the main cone, either in the two branches of the well marked Pedro Miguel - Ribeira Funda graben. In the lower part of the volcano, the pyroclastic density currents had rather linear trajectories, weakly influenced by the local topography. Most of the units entered the ocean at the end of their terrestrial pathways, some after jumping high sea cliffs. The volume of the ignimbrite on land is small, nearly 0.06 km3 but the fraction deposited in the ocean is not known. The ignimbrite is light grey, non-welded through its thickness, even in maximum section up to 18 m. Several lithofacies have been identified, some depending on the distance to the vent, some clearly related to the local topography. The conspicuous variations of various lithofacies along the same unit can be associated with different mechanisms of transport and emplacement.

  5. Effect of latitudinal gradient and impact of logging on genetic diversity of Cedrela lilloi along the Argentine Yungas Rainforest.

    PubMed

    Inza, Maria V; Zelener, Noga; Fornes, Luis; Gallo, Leonardo A

    2012-11-01

    Cedrela lilloi C. DC. (cedro coya, Meliaceae), an important south American timber species, has been historically overexploited through selective logging in Argentine Yungas Rainforest. Management and conservation programs of the species require knowledge of its genetic variation patterns; however, no information is available. Molecular genetic variability of the species was characterized to identify high-priority populations for conservation and domestication purposes. Fourteen native populations (160 individuals) along a latitudinal gradient and with different logging's intensities were assessed by 293 polymorphic AFLP (amplified fragment length polymorphism) markers. Genetic diversity was low (Ht = 0.135), according to marginal location of the species in Argentina. Most of the diversity was distributed within populations (87%). Northern populations showed significant higher genetic diversity (R(2)= 0.69) that agreed with latitudinal pattern of distribution of taxonomic diversity in the Yungas. Three clusters were identified by Bayesian analysis in correspondence with northern, central, and southern Yungas. An analysis of molecular variance (AMOVA) revealed significant genetic differences among latitudinal clusters even when logging (Φ(RT) = 0.07) and unlogging populations (Φ(PT) = 0.10) were separately analyzed. Loss of genetic diversity with increasing logging intensity was observed between neighboring populations with different disturbance (Φ(PT) = 0.03-0.10). Bottlenecks in disturbed populations are suggested as the main cause. Our results emphasize both: the necessity of maintaining the genetic diversity in protected areas that appear as possible long-term refuges of the species; and to rescue for the national system of protected areas some high genetic diversity populations that are on private fields. PMID:23170208

  6. Effect of latitudinal gradient and impact of logging on genetic diversity of Cedrela lilloi along the Argentine Yungas Rainforest

    PubMed Central

    Inza, Maria V; Zelener, Noga; Fornes, Luis; Gallo, Leonardo A

    2012-01-01

    Cedrela lilloi C. DC. (cedro coya, Meliaceae), an important south American timber species, has been historically overexploited through selective logging in Argentine Yungas Rainforest. Management and conservation programs of the species require knowledge of its genetic variation patterns; however, no information is available. Molecular genetic variability of the species was characterized to identify high-priority populations for conservation and domestication purposes. Fourteen native populations (160 individuals) along a latitudinal gradient and with different logging's intensities were assessed by 293 polymorphic AFLP (amplified fragment length polymorphism) markers. Genetic diversity was low (Ht = 0.135), according to marginal location of the species in Argentina. Most of the diversity was distributed within populations (87%). Northern populations showed significant higher genetic diversity (R2= 0.69) that agreed with latitudinal pattern of distribution of taxonomic diversity in the Yungas. Three clusters were identified by Bayesian analysis in correspondence with northern, central, and southern Yungas. An analysis of molecular variance (AMOVA) revealed significant genetic differences among latitudinal clusters even when logging (ΦRT = 0.07) and unlogging populations (ΦPT = 0.10) were separately analyzed. Loss of genetic diversity with increasing logging intensity was observed between neighboring populations with different disturbance (ΦPT = 0.03–0.10). Bottlenecks in disturbed populations are suggested as the main cause. Our results emphasize both: the necessity of maintaining the genetic diversity in protected areas that appear as possible long-term refuges of the species; and to rescue for the national system of protected areas some high genetic diversity populations that are on private fields. PMID:23170208

  7. In vitro rhizogenesis: histoanatomy of Cedrela odorata (Meliaceae) microcuttings.

    PubMed

    Millán-Orozco, Liliana; Corredoira, Elena; San José, Maria del Carmen

    2011-03-01

    Cedrela odorata (Meliaceae) is considered as one of the most valuable forest tree in the tropics. Clonal propagation of this species provide an alternative method to propagate superior genotypes, being the production of good quality adventitious roots one of the most important steps in micropropagation techniques. The sequence of anatomical changes that takes place during the formation of adventitious roots in shoots of Cedrela odorata cultured in vitro is described in this study. Eigth-week-old shoots, from multiplication cultures, were rooted in Murashige and Skoog's medium (1962) with half-strength macronutrients and with 0 or 1 mg/l indole-3-butyric acid (IBA). Between 12 and 24h after the start of rooting, some cambium, phloem and interfascicular parenchyma cells became dense cytoplasm, nuclei with prominent nucleoli and the first cell divisions were observed, especially in shoots treated with auxin (dedifferentiation phase). After 3-4 days, the number of dedifferentiated cells and mitotic divisions increased considerably, and the formation of groups of some 30-40 meristematic cells (meristemoids) was observed (induction phase). The first primordial roots developed from the 4th-5th day. The vascular tissues of these primordia connected to those of the explant, and roots began to emerge from the base by day 6. Development of the primordial roots was similar in the control shoots and shoots treated with 1 mg/l IBA, although there were more roots per explant in the latter. PMID:21513204

  8. Petrology and Geochronology of High-Grade Metamorphic Rocks from Cedros Island, Baja California, Mexico

    NASA Astrophysics Data System (ADS)

    Gonzales, D.; Leech, M. L.

    2014-12-01

    High-grade metamorphic rocks exposed on Cedros Island, Baja California, Mexico, record the Mesozoic subduction history of western North America. Blocks of amphibolite, blueschist, and eclogite crop out in a serpentinite-matrix mélange on the southeast and southwestern parts of Cedros Island. Amphibolite blocks contain Amp + Ep + Ab + Chl ± Ms ± Grt ± Ttn ± Qz; blueschist blocks have the assemblage Na-Amp + Ms + Lw + Qz ± Ttn ± Grt ± Jd ± Chl; and eclogite blocks are comprised primarily of Omp + Grt with retrograde Na-Amp + Ms + Lw. Blueschists from Cedros have been dated using 40Ar/39Ar step-heating of white mica and sodic amphiboles that yield ages from 103 ± 4 Ma to 94.9 ± 1.1 Ma, respectively, that represent cooling during exhumation. Apatite fission-track dating gives ages from 32 ± 4 Ma to 22 ± 3 Ma that record exhumation through the upper crust. Related Mesozoic subduction zone rocks of the Franciscan Complex crop out in a serpentinite-matrix mélange along coastal northern California. The Franciscan rocks are older, yielding 40Ar/39Ar step-heating ages of hornblende from amphibolite ranging from 159 to 156 Ma and represent an older part of the subduction history of the oceanic Farallon plate along western North America. I will determine the prograde and peak metamorphic P-T conditions for these high-grade rocks using petrography, mineral chemistries, and isochemical phase diagram modeling with Perple_X to generate complete P-T paths. I will then supplement these data with Sm-Nd and Lu-Hf geochronology for these high-grade Cedros rocks to evaluate their subduction/exhumation history, and develop a tectonic model for these southernmost Franciscan-type rocks. Ultimately, I will compare my results to Franciscan rocks in northern California to better understand the Mesozoic subduction margin of western North America.

  9. New triterpenoids with protein tyrosine phosphatase 1B inhibition from Cedrela odorata.

    PubMed

    Wu, Wen-Bin; Zhang, Hua; Dong, Shi-Hui; Sheng, Li; Wu, Yan; Li, Jia; Yue, Jian-Min

    2014-01-01

    Two new apotirucallane-type triterpenoids, cedrodorols A-B (1 and 2), along with seven known compounds (3-9), were isolated from the twigs and leaves of Cedrela odorata. Their structures were elucidated on the basis of extensive spectroscopic analysis. Compounds 1 and 2 showed significant inhibitory activity against protein tyrosine phosphatase 1B (PTP1B) with the IC50 values of 13.09 and 3.93 μg/ml, respectively. PMID:24841003

  10. Four new tetranortriterpenoids from cedrela odorata associated with leaf rejection by exopthalmus jekelianus

    PubMed

    Veitch; Wright; Stevenson

    1999-09-01

    Four new tetranortriterpenoids, 3-deoxo-3beta,8beta-epoxy-6, 14alpha-dihydroxy-8,14-dihydromexicanolide (cedrodorin, 1); 3-deoxo-3beta,8beta-epoxy-6-acetoxy-14alpha-hydroxy-8, 14-dihydromexicanolide (6-acetoxycedrodorin, 2); 3-deoxo-3beta, 8beta-epoxy-6-deoxy-9alpha,14alpha-dihydroxy-8, 14-dihydromexicanolide (6-deoxy-9alpha-hydroxycedrodorin, 3); and 3-deoxo-3beta,8beta-epoxy-6,9alpha,14alpha-trihydroxy-8, 14-dihydromexicanolide (9alpha-hydroxycedrodorin, 4), have been isolated from the leaves of Cedrela odorata by HPLC. Their molecular structures were determined by 1D and 2D NMR. Three of the compounds are associated with leaf rejection by the polyphagous, folivorous weevil, Exopthalmus jekelianus. The importance of these compounds as insect deterrents in C. odorata, and their potential value in the selection of insect-resistant clones for timber plantations is discussed. PMID:10514309

  11. Tissue culture methods for the clonal propagation and genetic improvement of Spanish red cedar (Cedrela odorata).

    PubMed

    Peña-Ramírez, Yuri; Juárez-Gómez, Juan; González-Rodríguez, José Antonio; Robert, Manuel L

    2012-01-01

    The choice of a method to culture red cedar tissues depends on the final objectives pursued. If homogeneous clonal material is required for experimental purposes, the easiest way is to generate the lines through adventitious shoot induction from seedlings germinated from seeds. If the objective is to generate high yielding material for plantation purposes, the choice will be the same method but starting from mature vegetative tissues from selected elite plants. Most of the process are the same, but the initial steps are less efficient and much more elaborate. If the purpose is to generate lines with new genetic characteristics through somaclonal variation, mutagenesis, or genetic transformation, somatic embryogenesis will be required. No single method in its present form is suitable for all purposes. Eventually, the efficient production of somatic embryos from rejuvenated shoots collected from mature selected plants is the ideal way to culture this species, but for the time being we have to choose one or the other. In this chapter, we present a grafting procedure to rejuvenate and maintain mother plants in the greenhouse and the in vitro culture systems we have developed for the production of Cedrela odorata propagules using explants from both young seedlings and mature tissues from selected old trees. Using a modified TY17 medium and the BioMINT(®) temporary immersion system, we obtained high multiplication and ex vitro transplantation rates for efficient large-scale propagation of this species. PMID:22610624

  12. Threat to cedar, Cedrela odorata, plantations in Vietnam by the weevil, Aclees sp.

    PubMed

    Thu, Pham Quang; Quang, Dao Ngoc; Dell, Bernard

    2010-01-01

    The recent decline and death of young cedar, Cedrela odorata L. (Sapindales: Meliaceae), plantations in Vietnam is caused by Aclees sp. (Coleoptera: Curculionidae), a wood-boring brown weevil. A field study was undertaken in three-year-old plantations in two districts in Thanh Hoa province in August 2008. Trees were heavily impacted by the weevil, Aclees; the infestation level (P) ranged from 80 to 100% and the average damage index (R) ranged from 1.8 to 2.8. Observations over one year enabled the life history to be determined. Eggs were laid (February to March, September to November) inside the bark from the base of the trunk up to 60 cm in height. Larvae formed extensive feeding tunnels in the inner bark and sap wood. Pupation occurred in feeding tunnels or pupal chambers in the sapwood. Adults emerged twice a year, February to March and August to October. It is concluded that Aclees is a threat to C. odorata plantations in tropical regions of the world, and quarantine measures should be implemented to reduce the risk of spread. PMID:21271846

  13. The tree Cedrela odorata (Meliaceae): a morphologically subdivided species in Costa Rica.

    PubMed

    Navarro, Carlos; Ward, Sheila; Hernández, Marvin

    2002-03-01

    In Latin America. Cedrela odorata is a wide ranging species that occurs in several environments, where it shows significant morphological variation. A common garden experiment was established with seedlings from 63 families of ten populations from two habitat types (mesic and dry), distributed throughout Costa Rica, to examine the relationships between quantitative variation and site of population origin. Seedlings from dry areas tended to be distinct from those from mesic areas, with climatic grouping of provenance explaining a mean of 52% of the total variance and 80% of the genetic variance. Cluster analysis for seedling traits showed two natural groupings of families, which corresponded for the most part with the regional population groupings into mesic (Atlantic and South Pacific) and dry (North Pacific) groups. Cluster analysis based on seed weight and size also separated populations into mesic and dry climatic groups. Seeds from populations in dry areas were 43% heavier, and seedlings were 61% taller, 117% greater in diameter, and with leaflets 39% longer and 81% wider. These differences may be related to fast growth in the dry zone for taking advantage of early life cycle moisture availability. These findings may indicate incipient speciation in C. odorata in Costa Rica. Evaluation of reproductive isolating mechanisms between populations from the mesic and dry zones, and of clines at potential zones of hybridization would assist in testing a speciation hypothesis. PMID:12298247

  14. Chloroplast DNA phylogeography reveals colonization history of a Neotropical tree, Cedrela odorata L., in Mesoamerica.

    PubMed

    Cavers, S; Navarro, C; Lowe, A J

    2003-06-01

    Spanish Cedar (Cedrela odorata L.) is a globally important timber species which has been severely exploited in Mesoamerica for over 200 years. Using polymerase chain reaction-restriction fragment length polymorphisms, its chloroplast (cp) DNA phylogeography was studied in Mesoamerica with samples from 29 populations in six countries. Five haplotypes were characterized, phylogenetically grouped into three lineages (Northern, Central and Southern). Spatial analysis of ordered genetic distance confirmed deviation from a pattern of isolation by distance. The geographically proximate Northern and Central cpDNA lineages were genetically the most differentiated, with the Southern lineage appearing between them on a minimum spanning tree. However, populations possessing Southern lineage haplotypes occupy distinct moist habitats, in contrast to populations possessing Northern and Central lineage haplotypes which occupy drier and more seasonal habitats. Given the known colonization of the proto-Mesoamerican peninsula by South American flora and fauna prior to the formation of the Isthmus of Panama, it seems most likely that the observed population structure in C. odorata results from repeated colonization of Mesoamerica from South American source populations. Such a model would imply an ancient, pre-Isthmian colonization of a dry-adapted type (possessing the Northern lineage or a prototype thereof), with a secondary colonization via the land bridge. Following this, a more recent (possibly post-Pleistocene) expansion of moist-adapted types possessing the Southern lineage from the south fits the known vegetation history of the region. PMID:12755874

  15. Threat to Cedar, Cedrela odorata, Plantations in Vietnam by the Weevil, Aclees sp.

    PubMed Central

    Thu, Pham Quang; Quang, Dao Ngoc; Dell, Bernard

    2010-01-01

    The recent decline and death of young cedar, Cedrela odorata L. (Sapindales: Meliaceae), plantations in Vietnam is caused by Aclees sp. (Coleoptera: Curculionidae), a wood-boring brown weevil. A field study was undertaken in three-year-old plantations in two districts in Thanh Hoa province in August 2008. Trees were heavily impacted by the weevil, Aclees; the infestation level (P) ranged from 80 to 100% and the average damage index (R) ranged from 1.8 to 2.8. Observations over one year enabled the life history to be determined. Eggs were laid (February to March, September to November) inside the bark from the base of the trunk up to 60 cm in height. Larvae formed extensive feeding tunnels in the inner bark and sap wood. Pupation occurred in feeding tunnels or pupal chambers in the sapwood. Adults emerged twice a year, February to March and August to October. It is concluded that Aclees is a threat to C. odorata plantations in tropical regions of the world, and quarantine measures should be implemented to reduce the risk of spread. PMID:21271846

  16. Antioxidant and Antiglycating Constituents from Leaves of Ziziphus oxyphylla and Cedrela serrata

    PubMed Central

    Ahmad, Rizwan; Ahmad, Niyaz; Naqvi, Atta Abbas; Exarchou, Vassiliki; Upadhyay, Atul; Tuenter, Emmy; Foubert, Kenn; Apers, Sandra; Hermans, Nina; Pieters, Luc

    2016-01-01

    Ziziphus oxyphylla and Cedrela Serrata plants have a folkloric use in Pakistan for treatments of different ailments, i.e., Jaundice, Hepatitis, Diabetes, and antimicrobial. Until now, none of the research studies have reported any phytochemical work on leaves of these two plants. This study aimed to isolate and perform phytochemical analysis in order to search for the constituent having the active role in treatment of the aforementioned ailments. A bioassay-guided fractionation and isolation procedure was used to isolate the concerned phytochemicals present in leaf extracts of Z. oxyphylla and C. serrata. The process involved the hyphenated techniques, i.e., Flash Chromatography, Semi-Preparative HPLC/DAD, UPLC/MS, and NMR in order to isolate and elucidate the structure of the phytochemicals. Seven compounds (1–7) were isolated and identified as flavonoids, more in particular glycosides of quercetin and kaempferol. They showed DPPH scavenging activity, compound 3 (isoquercitrin) being the most active one with an IC50 of 10.8 µg/mL (positive control quercetin; IC50 3.6 µg/mL). The superoxide-radical scavenging and total antioxidant (ABTS) assays indicated IC50 values ranging from 200 to 910 µg/mL and 170 to 320 µg/mL, respectively (positive control quercetin: 374 and 180 µg/mL, respectively). Furthermore, these compounds had low IC50 values for inhibition of protein glycation (AGEs inhibition), ranging from 530 to 818 µg/mL, comparable to aminoguanidine (510 µg/mL) used as a positive control. This study resulted in the identification of seven flavonoid glycosides for the first time from the leaves of Z. oxyphylla and C. serrata with antioxidative and antiglycating activities. PMID:26999227

  17. Antioxidant and Antiglycating Constituents from Leaves of Ziziphus oxyphylla and Cedrela serrata.

    PubMed

    Ahmad, Rizwan; Ahmad, Niyaz; Naqvi, Atta Abbas; Exarchou, Vassiliki; Upadhyay, Atul; Tuenter, Emmy; Foubert, Kenn; Apers, Sandra; Hermans, Nina; Pieters, Luc

    2016-01-01

    Ziziphus oxyphylla and Cedrela Serrata plants have a folkloric use in Pakistan for treatments of different ailments, i.e., Jaundice, Hepatitis, Diabetes, and antimicrobial. Until now, none of the research studies have reported any phytochemical work on leaves of these two plants. This study aimed to isolate and perform phytochemical analysis in order to search for the constituent having the active role in treatment of the aforementioned ailments. A bioassay-guided fractionation and isolation procedure was used to isolate the concerned phytochemicals present in leaf extracts of Z. oxyphylla and C. serrata. The process involved the hyphenated techniques, i.e., Flash Chromatography, Semi-Preparative HPLC/DAD, UPLC/MS, and NMR in order to isolate and elucidate the structure of the phytochemicals. Seven compounds (1-7) were isolated and identified as flavonoids, more in particular glycosides of quercetin and kaempferol. They showed DPPH scavenging activity, compound 3 (isoquercitrin) being the most active one with an IC50 of 10.8 µg/mL (positive control quercetin; IC50 3.6 µg/mL). The superoxide-radical scavenging and total antioxidant (ABTS) assays indicated IC50 values ranging from 200 to 910 µg/mL and 170 to 320 µg/mL, respectively (positive control quercetin: 374 and 180 µg/mL, respectively). Furthermore, these compounds had low IC50 values for inhibition of protein glycation (AGEs inhibition), ranging from 530 to 818 µg/mL, comparable to aminoguanidine (510 µg/mL) used as a positive control. This study resulted in the identification of seven flavonoid glycosides for the first time from the leaves of Z. oxyphylla and C. serrata with antioxidative and antiglycating activities. PMID:26999227

  18. Long-term trends in cellulose delta13 C and water-use efficiency of tropical Cedrela and Swietenia from Brazil.

    PubMed

    Hietz, Peter; Wanek, Wolfgang; Dünisch, Oliver

    2005-06-01

    Elevated CO(2) concentrations ([CO(2)]) affect plant water relations and photosynthesis, and the increase in atmospheric [CO(2)] over the past 100-200 years has been related to changes in stomatal density and the carbon isotope ratio (delta(13)C) in tree rings and leaves from herbarium specimens. Because many tropical trees do not produce annual growth rings and their wood is therefore difficult to date, no trends in delta(13)C of tropical trees have been reported. Wood from Cedrela odorata L. (tropical cedar) and Swietenia macrophylla King (bigleaf mahogany), which do produce annual rings, was collected from a primary rain forest in Aripuanã, Brazil (10 degrees 09' S, 59 degrees 26' W). We measured wood cellulose delta(13)C in 10-year growth increments from 37 Cedrela trees (between 11 and 151 years old in 2001) and 16 Swietenia trees (48-126 years old). A comparison of delta(13)C in cellulose of trees from different decades and of trees of different cambial ages showed that the amount of delta(13)C was largely related to the decade the wood was produced in, and not, or only to a minor extent, to tree age. Cellulose delta(13)C decreased from -26.0 to -27.3 per thousand in Cedrela and from -25.7 to -27.1 per thousand in Swietenia, with the largest changes occurring during the past 50 years. Based on these data and the trends in atmospheric [CO(2)] and delta(13)CO(2), we calculated that the internal [CO(2)] increased from about 220 to 260 ppm and that intrinsic water-use efficiency increased by 34% in Cedrela and by 52% in Swietenia. This may have implications for the water cycle and may explain the trend toward increased tree growth and turnover observed in some tropical forests. PMID:15805094

  19. Pharmacological and Genotoxic Properties of Polyphenolic Extracts of Cedrela odorata L. and Juglans regia L. Barks in Rodents

    PubMed Central

    Almonte-Flores, Dulce Carolina; Paniagua-Castro, Norma; Escalona-Cardoso, Gerardo; Rosales-Castro, Martha

    2015-01-01

    Evaluation of the phenolic compounds and antioxidant activity of Cedrela odorata L. and Juglans regia L. bark extracts was performed in vitro. Juglans regia showed greater extract concentration and higher antioxidant activity. Hypoglycemic activity in rats was assessed by generating a glucose tolerance curve and determining the area under the curve (AUC). Diabetes was later induced by an injection with streptozotocin (65 mg/kg of b.w.) and confirmed after 24 hours. The extract was administered (200 mg/kg b.w.) over 10 days, and blood glucose was monitored and compared with a control group. The glucose AUC showed a hypoglycemic effect of J. regia and C. odorata in normal rats. Both extracts reduced hepatic lipid peroxidation in diabetic rats. Polyphenolic extracts reduced cholesterol levels in a hypercholesterolemic mouse model and decreased hepatic lipid peroxidation. Polyphenolic extract doses of 100 and 200 mg/kg b.w. were administered alone or with cyclophosphamide (CPA) 50 mg/kg ip, which was used as a positive control. Analyses were performed using leukocytes in a comet assay after 4 and 24 h of treatment. Genotoxic effects were evaluated by the comet assay, which showed that while J. regia extract had no effect, C. odorata extract induced slight damage at 200 mg/kg, with the formation of type 0 and 1 comets. PMID:25945104

  20. Pharmacological and Genotoxic Properties of Polyphenolic Extracts of Cedrela odorata L. and Juglans regia L. Barks in Rodents.

    PubMed

    Almonte-Flores, Dulce Carolina; Paniagua-Castro, Norma; Escalona-Cardoso, Gerardo; Rosales-Castro, Martha

    2015-01-01

    Evaluation of the phenolic compounds and antioxidant activity of Cedrela odorata L. and Juglans regia L. bark extracts was performed in vitro. Juglans regia showed greater extract concentration and higher antioxidant activity. Hypoglycemic activity in rats was assessed by generating a glucose tolerance curve and determining the area under the curve (AUC). Diabetes was later induced by an injection with streptozotocin (65 mg/kg of b.w.) and confirmed after 24 hours. The extract was administered (200 mg/kg b.w.) over 10 days, and blood glucose was monitored and compared with a control group. The glucose AUC showed a hypoglycemic effect of J. regia and C. odorata in normal rats. Both extracts reduced hepatic lipid peroxidation in diabetic rats. Polyphenolic extracts reduced cholesterol levels in a hypercholesterolemic mouse model and decreased hepatic lipid peroxidation. Polyphenolic extract doses of 100 and 200 mg/kg b.w. were administered alone or with cyclophosphamide (CPA) 50 mg/kg ip, which was used as a positive control. Analyses were performed using leukocytes in a comet assay after 4 and 24 h of treatment. Genotoxic effects were evaluated by the comet assay, which showed that while J. regia extract had no effect, C. odorata extract induced slight damage at 200 mg/kg, with the formation of type 0 and 1 comets. PMID:25945104

  1. Molecular phylogenetics of Neotropical Cedreleae (mahogany family, Meliaceae) based on nuclear and plastid DNA sequences reveal multiple origins of "Cedrela odorata".

    PubMed

    Muellner, Alexandra N; Pennington, Terence D; Chase, Mark W

    2009-08-01

    This study focuses on the 17 Neotropical species described in Cedrela (Meliaceae; Cedreleae), in particular C. odorata, which has been shown in past population genetic studies to be more variable than other tree species. We sampled two sets of molecular markers, nuclear ribosomal spacers (nrITS), and several plastid regions (the psbB, psbN, psbT exons and the trnS-trnG spacer). Both sets of markers produced congruent results using parsimony, maximum likelihood and Bayesian methods for a set of taxa that include outgroups (outside Cedreleae) as well as other members of the related genera within Cedreleae. All results confirm current delimitation of Cedreleae and genetic distinctiveness for four new species with divergent morphologies. Our study also provides evidence that there are several genetic entities among the accessions of C. odorata that have distinct ranges or habitat preferences. These entities may constitute new species, are morphologically cryptic and require a great deal more investigation to delimit their ranges. Our results have important implications for conservation of Cedrela odorata, which is heavily harvested throughout its range in the American tropics. PMID:19348956

  2. Interaction of nutrient limitation and elevated CO2 concentration on carbon assimilation of a tropical tree seedling (Cedrela odorata).

    PubMed

    Carswell, F E; Grace, J; Lucas, M E; Jarvis, P G

    2000-08-01

    Carbon assimilation by Cedrela odorata L. (Meliaceae) seedlings was investigated in ambient and elevated CO2 concentrations ([CO2]) for 119 days, using small fumigation chambers. A solution containing macro- and micronutrients was supplied at two rates. The 5% rate (high rate) was designed to avoid nutrient limitation and allow a maximum rate of growth. The 1% rate (low rate) allowed examination of the effect of the nutrient limitation-elevated CO2 interaction on carbon assimilation. Root growth was stimulated by 23% in elevated [CO2] at a high rate of nutrient supply, but this did not lead to a change in the root:shoot ratio. Total biomass did not change at either rate of nutrient supply, despite an increase in relative growth rate at the low nutrient supply rate. Net assimilation rates and relative growth rates were stimulated by the high rate of nutrient addition, irrespective of [CO2]. We used a biochemical model of photosynthesis to investigate assimilation at the leaf level. Maximum rate of electron transport (Jmax) and maximum velocity of carboxylation (Vcmax) did not differ significantly with CO2 treatment, but showed a substantial reduction at the low rate of nutrient supply. Across both CO2 treatments, mean Jmax for seedlings grown at a high rate of nutrient supply was 75 micromol m(-2) s(-1) and mean Vcmax was 27 micromol m(-2) s(-1). The corresponding mean values for seedlings grown at a low rate of nutrient supply were 36 micromol m(-2) s(-1) and 15 micromol m(-2) s(-1), respectively. Concentrations of leaf nitrogen, on a mass basis, were significantly decreased by the low nutrient supply rate, in proportion to the observed decrease in photosynthetic parameters. Chlorophyll and carbohydrate concentrations of leaves were unaffected by growth [CO2]. Because there was no net increase in growth in response to elevated [CO2], despite increased assimilation of carbon at the leaf level, we hypothesize that the rate of respiration of non-photosynthetic organs was increased. PMID:11303573

  3. Root endophyte interaction between ectomycorrhizal basidiomycete Tricholoma matsutake and arbuscular mycorrhizal tree Cedrela odorata, allowing in vitro synthesis of rhizospheric "shiro".

    PubMed

    Murata, Hitoshi; Yamada, Akiyoshi; Maruyama, Tsuyoshi; Endo, Naoki; Yamamoto, Kohei; Ohira, Tatsuro; Shimokawa, Tomoko

    2013-04-01

    The ectomycorrhizal basidiomycete Tricholoma matsutake associates with members of the Pinaceae such as Pinus densiflora (red pine), forming a rhizospheric colony or "shiro," which produces the prized "matsutake" mushroom. We investigated whether the host specificity of T. matsutake to conifers is innately determined using somatic plants of Cedrela odorata, a tropical broad-leaved tree (Meliaceae) that naturally harbors arbuscular mycorrhizal fungi. We found that T. matsutake could form in vitro shiro with C. odorata 140 days after inoculation, as with P. densiflora. The shiro was typically aromatic like that of P. densiflora. However, this was a root endophytic interaction unlike the mycorrhizal association with P. densiflora. Infected plants had epidermal tissues and thick exodermal tissues outside the inner cortex. The mycelial sheath surrounded the outside of the epidermis, and the hyphae penetrated into intra- and intercellular spaces, often forming hyphal bundles or a pseudoparenchymatous organization. However, the hyphae grew only in the direction of vascular bundles and did not form Hartig nets. Tricholoma fulvocastaneum or "false matsutake" naturally associates with Fagaceae and was also able to associate with C. odorata as a root endophyte. With T. matsutake, C. odorata generated a number of roots and showed greatly enhanced vigor, while with T. fulvocastaneum, it generated a smaller number of roots and showed somewhat lesser vigor. We argue that the host-plant specificity of ectomycorrhizal matsutake is not innately determined, and that somatic arbuscular mycorrhizal plants have a great potential to form mutualistic relationships with ectomycorrhizal fungi. PMID:23064771

  4. Short communication. Characterization of chloroplast region rrn16-rrn23S from the tropical timber tree Cedrela odorata L. and de novo construction of a transplastomic expression vector suitable for Meliaceae trees and other economically important crops.

    PubMed

    López-Ochoa, L A; Apolinar-Hernández, M M; Peña-Ramírez, Y J

    2015-01-01

    The forest tree Spanish cedar (Cedrela odorata L.) is well-known for its high-value timber; however, this species is attacked by the shoot borer (Hypsipyla grandella) during its early years of development, resulting in branched stems and making the plants useless for high-quality wood production. The generation of resistant varieties expressing entomotoxic proteins may be an alternative to pesticide treatments. The use of plastid transformation rather than nuclear transformation should be used because it reduces the risk of transgene dissemination by pollen. Chloroplast transformation vectors require an expression cassette flanked by homologous plastid sequences to drive plastome recombination. Thus, C. odorata plastome sequences are a prerequisite. The rrn16-rrn23 plastome region was selected, cloned, and characterized. When the sequence identity among the rrn16-rrn23 regions from C. odorata and Nicotiana tabacum was compared, 3 inDels of 240, 104, and 39 bp were found that might severely affect transformation efficiency. Using this region, a new transformation vector was developed using pUC19 as a backbone by inserting the rrn16-trnI and trnA-rrn23 sequences from C. odorata and adding 2 independent expression cassettes into the trnI-trnA intergenic region, conferring spectinomycin resistance, the ability to express the gfp reporter gene, and a site that can be used to express any other gene of interest. PMID:25730086

  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

    2016-08-01

    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. PMID:26852633

  6. Biological Control of Saltcedar (Cedro salado) (Tamarix spp.) in the United States, with Implications for Mexico

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The ever increasing invasion by exotic organisms from other continents poses one of the greatest threats to the well-being of North American native ecosystems. Among the worst of these is saltcedar (Tamarix spp.). These are shrubs to small trees introduced from Asia and the Mediterranean area into...

  7. [Cedrela odorata (Meliaceae) potential for dendrochronological studies in the Selva Central of Perú].

    PubMed

    Pereyra Espinoza, Manuel Jesús; Inga Guillen, Gaby Janet; Santos Morales, Mariano; Arisméndiz Rodríguez, Rodolfo

    2014-06-01

    Despite the progress made during the past 20 years, searching dendrochronological potential in tropical and subtropical tree species, tropical dendrochronology, is still in a development stage. The aim of this research was to determine the potential of C. odorata for dendrochronological studies in the Selva Central of Perú. The tree-ring anatomical characteristics were carefully examined and we were able to develop a 215 year (1795-2 009) tree-ring chronology and correlate it with precipitation records. The tree-ring chronology was developed based on 47 series of 27 trees. Tree rings are clearly delimited by large pore diameters in earlywood and small ones in latewood associated with marginal and paratracheal parenchyma. The tree-ring chronology was related to precipitation records from Satipo and significant correlations were found with the previous rainy season and late dry season of the current growth period. Moreover, we found close relationship between tree growth and total precipitations of the hydrological period (December to September) for the interval 1990-2009. These results demonstrate the influence of rainfall at different stages of C. odorata radial growth. The good discrimination of annual rings, strong relationship with precipitation, the wide range and longevity of trees (200 years) make C. odorata a very promising species for dendrochronological studies in tropical and subtropical forest of America. PMID:25102658

  8. Identification of endangered or threatened Costa Rican tree species by wood anatomy and fluorescence activity.

    PubMed

    Moya, Róger; Wiemann, Michael C; Olivares, Carlos

    2013-09-01

    A total of 45 native Costa Rican tree species are threatened or in danger of extinction, but the Convention on International Trade Endangered Species (CITES) includes only eight of these in its Appendices. However, the identification of other species based on their wood anatomy is limited. The present study objective was to describe and to compare wood anatomy and fluorescence activity in some endangered or threatened species of Costa Rica. A total of 45 (22 endangered and 23 threatened with extinction) wood samples of these species, from the xylaria of the Instituto Tecnológico de Costa Rica and the Forest Products Laboratory in Madison, Wisconsin, were examined. Surface fluorescence was positive in eight species, water extract fluorescence was positive in six species and ethanol extract fluorescence was positive in 24 species. Almost all species were diffuse porous except for occasional (Cedrela odorata, C. fissilis, Cordia gerascanthus) or regular (C. salvadorensis and C. tonduzii) semi-ring porosity. A dendritic vessel arrangement was found in Sideroxylon capari, and pores were solitary in Guaiacum sanctum and Vantanea barbourii. Vessel element length was shortest in Guaiacum sanctum and longest in Humiriastrum guianensis, Minquartia guianensis and Vantanea barbourii. Finally, anatomical information and fluorescence activity were utilized to construct an identification key of species, in which fluorescence is a feature used in identification. PMID:24027913

  9. 75 FR 47301 - Cedro Hill Wind LLC; Butler Ridge Wind Energy Center, LLC; High Majestic Wind Energy Center, LLC...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-05

    ...; Notice of Effectiveness of Exempt Wholesale Generator Status July 29, 2010. Take notice that during the month of June 2010, the status of the above-captioned entities as Exempt Wholesale Generators...

  10. Endosymbiotic copepods may feed on zooxanthellae from their coral host, Pocillopora damicornis

    NASA Astrophysics Data System (ADS)

    Cheng, Y.-R.; Dai, C.-F.

    2010-03-01

    The Xarifiidae is one of the most common families of endosymbiotic copepods that live in close association with scleractinian corals. Previous studies on xarifiids primarily focused on their taxonomy and morphology, while their influence on corals is still unknown. In this study, we collected a total of 1,579 individuals belonging to 6 species of xarifiids from 360 colonies of Pocillopora damicornis at Nanwan Bay, southern Taiwan from July 2007 to May 2008. Furthermore, using optical and electron microscopic observations, we examined the gut contents of Xarifia fissilis, the most abundant species of the Xarifiidae that we collected. We found that the gut of X. fissilis was characterized by a reddish-brown color due to the presence of numerous unicellular algae with diameters of 5-10 μm. TEM observations indicated that the unicellular algae possessed typical characteristics of Symbiodinium including a peripheral chloroplast, stalked pyrenoids, starch sheaths, mesokaryotic nuclei, amphiesmas, an accumulation body, and mitochondria. After starving the isolated X. fissilis in the light and dark (light intensity: 140 μmol photon m-2 s-1; photoperiod: 12 h light/12 h dark) for 2 weeks, fluorescence was clearly visible in its gut and fecal pellets under fluorescent microscopic observations. The cultivation experiment supports the hypothesis that the unicellular algae were beneficial to the survival of X. fissilis under light conditions, possibly through transferring photosynthates to the hosts. These results suggest that X. fissilis may consume and retain unicellular algae for further photosynthesis.

  11. A new species of Jahnulales from Las Ilusiones Lagoon, Tabasco, Mexico

    Technology Transfer Automated Retrieval System (TEKTRAN)

    During a study on biodiversity of freshwater ascomycetes from an urban tropical lagoon, an ascomycete with similar morphology to species of Jahnulales was obtained. Smooth surface test blocks of Pinus sp., Bucida sp., Cedrela sp. and Tabebuia sp. were submerged in pairs close to a private house whar...

  12. Predicting the direction of ornament evolution in Trinidadian guppies (Poecilia reticulata)

    PubMed Central

    Kemp, Darrell J.; Reznick, David N.; Grether, Gregory F.; Endler, John A.

    2009-01-01

    Sexual selection is thought to be opposed by natural selection such that ornamental traits express a balance between these two antagonistic influences. Phenotypic variation among populations may indicate local shifts in this balance, or that different stable ‘solutions’ are possible, but testing these alternatives presents a major challenge. In the guppy (Poecilia reticulata), a small freshwater fish with male-limited ornamental coloration, these issues can be addressed by transplanting fish among sites of varying predation pressure, thus effectively manipulating the strength and nature of natural selection. Here, we contrast the evolutionary outcome of two such introductions conducted in the Trinidadian El Cedro and Aripo Rivers. We use sophisticated colour appraisal methods that account for full spectrum colour variation and which incorporate the very latest visual sensitivity data for guppies and their predators. Our data indicate that ornamentation evolved along different trajectories: whereas Aripo males evolved more numerous and/or larger orange, black and iridescent markings, El Cedro males only evolved more extensive and brighter iridescence. Examination of the El Cedro experiment also revealed little or no ornamental evolution at the control site over 29 years, which contrasts markedly with the rapid (approx. 2–3 years) changes reported for introduction populations. Finally, whole colour-pattern analysis suggested that the greatest visual difference between El Cedro introduction and control fish would be perceived by the two most salient viewers: guppies and the putatively dangerous predator Crenicichla alta. We discuss whether and how these evolutionary trajectories may result from founder effects, population-specific mate preferences and/or sensory drive. PMID:19776075

  13. Long-term trends in nitrogen isotope composition and nitrogen concentration in brazilian rainforest trees suggest changes in nitrogen cycle.

    PubMed

    Hietz, Peter; Dünisch, Oliver; Wanek, Wolfgang

    2010-02-15

    Direct or indirect anthropogenic effects on ecosystem nitrogen cycles are important components of global change. Recent research has shown that N isotopes in tree rings reflect changes in ecosystem nitrogen sources or cycles and can be used to study past changes. We analyzed trends in two tree species from a remote and pristine tropical rainforest in Brazil, using trees of different ages to distinguish between the effect of tree age and long-term trends. Because sapwood differed from heartwood in delta(15)N and N concentration and N can be translocated between living sapwood cells, long-term trends are best seen in dead heartwood. Heartwood delta(15)N in Spanish cedar (Cedrela odorata) and big-leaf mahogany (Swietenia macrophylla) increased with tree age, and N concentrations increased with age in Cedrela. Controlling for tree age, delta(15)N increased significantly during the past century even when analyzing only heartwood and after removing labile N compounds. In contrast to northern temperate and boreal forests where wood delta(15)N often decreased, the delta(15)N increase in a remote rainforest is unlikely to be a direct signal of changed N deposition. More plausibly, the change in N isotopic composition indicates a more open N cycle, i.e., higher N losses relative to internal N cycling in the forest, which could be the result of changed forest dynamics. PMID:20092248

  14. Long-term trends in nitrogen isotope composition and nitrogen concentration in Brazilian rainforest trees suggest changes in nitrogen cycle

    PubMed Central

    Hietz, Peter; Dünisch, Oliver; Wanek, Wolfgang

    2010-01-01

    Direct or indirect anthropogenic effects on ecosystem nitrogen cycles are important components of global change. Recent research has shown that N isotopes in tree rings reflect changes in ecosystem nitrogen sources or cycles and can be used to study past changes. We analysed trends in two tree species from a remote and pristine tropical rainforest in Brazil, using trees of different ages to distinguish between the effect of tree age and long-term trends. Because sapwood differed from heartwood in δ15N and N concentration and N can be translocated between living sapwood cells, long-term trends are best seen in dead heartwood. Heartwood δ15N in Spanish cedar (Cedrela odorata) and big-leaf mahogany (Swietenia macrophylla) increased with tree age, and N concentrations increased with age in Cedrela. Controlling for tree age, δ15N increased significantly during the past century even when analysing only heartwood and after removing labile N compounds. In contrast to northern temperate and boreal forests where wood δ15N often decreased, the δ15N increase in a remote rainforest is unlikely to be a direct signal of changed N deposition. More plausibly, the change in N isotopic composition indicates a more open N cycle, i.e. higher N losses relative to internal N cycling in the forest, which could be the result of changed forest dynamics. PMID:20092248

  15. Extreme Drought Events Revealed in Amazon Tree Ring Records

    NASA Astrophysics Data System (ADS)

    Jenkins, H. S.; Baker, P. A.; Guilderson, T. P.

    2010-12-01

    The Amazon basin is a center of deep atmospheric convection and thus acts as a major engine for global hydrologic circulation. Yet despite its significance, a full understanding of Amazon rainfall variability remains elusive due to a poor historical record of climate. Temperate tree rings have been used extensively to reconstruct climate over the last thousand years, however less attention has been given to the application of dendrochronology in tropical regions, in large part due to a lower frequency of tree species known to produce annual rings. Here we present a tree ring record of drought extremes from the Madre de Dios region of southeastern Peru over the last 190 years. We confirm that tree ring growth in species Cedrela odorata is annual and show it to be well correlated with wet season precipitation. This correlation is used to identify extreme dry (and wet) events that have occurred in the past. We focus on drought events identified in the record as drought frequency is expected to increase over the Amazon in a warming climate. The Cedrela chronology records historic Amazon droughts of the 20th century previously identified in the literature and extends the record of drought for this region to the year 1816. Our analysis shows that there has been an increase in the frequency of extreme drought (mean recurrence interval = 5-6 years) since the turn of the 20th century and both Atlantic and Pacific sea surface temperature (SST) forcing mechanisms are implicated.

  16. RELEASE AND MUCOADHESION PROPERTIES OF DICLOFENAC MATRIX TABLETS FROM NATURAL AND SYNTHETIC POLYMER BLENDS.

    PubMed

    Odeniyi, Michael A; Khan, Nasir H; Peh, Kok K

    2015-01-01

    The delayed release and mucoadhesive properties of Cedrela gum and hydroxypropylmethylcellulose blend in diclofenac sodium tablet formulations were evaluated. Tablets were prepared by direct compression and the crushing strength and detachment force were found to increase from 74.49 ± 1.22 to 147.25 ± 2.57 N and 0.302 ± 0.36 to 1.141 ± 0.05 N from low to high level of polymers, respectively. The release kinetics followed Korsmeyer-Peppas release and the n varied between 0.834 and 1.273, indicating that the release mechanism shifts from Fickian to super case I (anomalous release). The drug release profile fits a pulsatile-release pattern characterized by a lag time followed by a more or less rapid and complete drug release. The Cedrela gum-hydroxypropylmethylcelluse blend tablets delayed diclofenac release for 2 h and sustained the release for 12 h. The polymer blend delayed drug release in the 0.1 M HCl simulating gastric environment and subsequent release pH 6.8 phosphate buffer. PMID:26642664

  17. Antifungal activity of 10 Guadeloupean plants.

    PubMed

    Biabiany, Murielle; Roumy, Vincent; Hennebelle, Thierry; François, Nadine; Sendid, Boualem; Pottier, Muriel; Aliouat, El Moukhtar; Rouaud, Isabelle; Lohézic-Le Dévéhat, Françoise; Joseph, Henry; Bourgeois, Paul; Sahpaz, Sevser; Bailleul, François

    2013-11-01

    Screening of the antifungal activities of ten Guadeloupean plants was undertaken to find new extracts and formulations against superficial mycoses such as onychomycosis, athlete's foot, Pityriasis versicolor, as well as the deep fungal infection Pneumocystis pneumonia. For the first time, the CMI of these plant extracts [cyclohexane, ethanol and ethanol/water (1:1, v/v)] was determined against five dermatophytes, five Candida species, Scytalidium dimidiatum, a Malassezia sp. strain and Pneumocystis carinii. Cytotoxicity tests of the most active extracts were also performed on an HaCat keratinocyte cell line. Results suggest that the extracts of Bursera simaruba, Cedrela odorata, Enterolobium cyclocarpum and Pluchea carolinensis have interesting activities and could be good candidates for developing antifungal formulations. PMID:23280633

  18. Antimalarial activity of tropical Meliaceae extracts and gedunin derivatives.

    PubMed

    MacKinnon, S; Durst, T; Arnason, J T; Angerhofer, C; Pezzuto, J; Sanchez-Vindas, P E; Poveda, L J; Gbeassor, M

    1997-04-01

    Extracts of 22 species of Meliaceae were examined for antimalarial activity using in vitro tests with two clones of Plasmodium falciparum, one sensitive to chloroquine (W2) and one chloroquine-resistant (D6). Twelve extracts were found to have activity, including extracts of Cedrela odorata wood and Azadirachta indica leaves, which contained the limonoid gedunin. These extracts were more effective against the W2 clone than the D6 clone, suggesting there is no cross-resistance to chloroquine. Gedunin was extracted in quantity, and nine derivatives prepared for a structure-activity study, which revealed essential functionalities for activity. The study also included four other limonoids derived from related Meliaceae. Only gedunin had better activity than chloroquine against the W2 clone. This active principle could be used to standardize a popular crude drug based on traditional use of A. indica in West Africa. PMID:9134742

  19. Traditionally-used antimalarials from the Meliaceae.

    PubMed

    Omar, S; Zhang, J; MacKinnon, S; Leaman, D; Durst, T; Philogene, B J R; Arnason, J T; Sanchez-Vindas, P E; Poveda, L; Tamez, P A; Pezzuto, J M

    2003-01-01

    A quantitative ethnobotanical approach to antimalarial drug discovery led to the identification of Lansium domesticum Corr. Ser. (Meliaceae) as an important antimalarial used by Kenyah Dyak healers in Indonesian Borneo. Triterpenoid lansiolides with antimalarial activity were isolated from the bark and shown to have activity in both in vitro bioassays with Plasmodium falciparum, and in mice infected with P. berghei. A survey of African and tropical American Meliaceae led to further development of the limonoid gedunin from the traditionally used medicinal plants, tropical cedar, Cedrela odorata L., and neem, Azadirachta indica A. Juss. Gedunin has significant in vitro activity but initially showed poor in vivo activity. In vivo activity was improved by (1) incorporation into an easy to absorb suspension, (2) preparation of a more stable compound, 7-methoxygedunin; and (3) synergism with dillapiol, a cytochrome P450 3A4 inhibitor. The results show the potential for both antimalarial drug and phytomedicine development from traditionally used plants. PMID:12570769

  20. Evaluation of the extent of genetic variation in mahoganies (Meliaceae) using RAPD markers.

    PubMed

    Chalmers, K J; Newton, A C; Waugh, R; Wilson, J; Powell, W

    1994-10-01

    Despite the economic importance of mahoganies (Meliaceae) little is known of the pattern of genetic variation within this family of tropical trees. We describe the application of a polymerase chain reaction (PCR)-based polymorphic DNA assay procedure random amplified polymorphic DNAs (RAPDs) to assess the extent of genetic variation between eight mahogany species from four genera. Pronounced genetic differentiation was found between the species and genera. There was a clear separation of Cedrela odorata from the other species, with 95% of the variable amplification products differing, whereas Lovoa trichilioides, Khaya spp. and Swietenia spp. were more closely grouped. These results are consistent with the current taxonomic viewpoint. A number of markers were found to be diagnostic for particular species, which could be of value in determining the status of putative hybrids. The application of RAPDs to the study of genetic variation in mahoganies is discussed in the context of developing genetic conservation and improvement strategies for these species. PMID:24177901

  1. [Phagodeterrence by a crude extract of common rue (Ruta chalepensis, Rutaceae) and its partitions on Hypsipyla grandella (Lepidoptera: Pyralidae) larvae].

    PubMed

    Barboza, Javier; Hilje, Luko; Durón, Julio; Cartín, Víctor; Calvo, Marco

    2010-03-01

    Hypsipyla grandella (Zeller) larva is maybe the main forest pest in Latin America and the Caribbean, as it bores into the main shoot of trees providing precious woods, such as mahoganies (Swietenia spp.) and cedars (Cedrela spp.). In the search for a preventative method for managing it, the crude leaf extract of common rue (Ruta chalepensis L.), as well as four partitions thereof (water, hexane, dichlorometane, and ethyl acetate), were tested for phagodeterrence. Laboratory bioassays involved increasing concentrations of the crude extract (0.1, 0.32, 1.0, 3.20 and 10.0%w/v) as well as each one of the partitions (in accordance to the yield obtained from the partitioning process), plus rutin, a flavone glycosid. A randomized complete block design, with four replicates, was used. H. grandella instar III larvae were exposed for 24 h to cedar (Cedrela odorata) leaf discs dipped into the respective treatment, after which disc consumption was measured. Strong phagodeterrence was detected at concentrations as low as 0.32 and 0.074%w/v for the crude extract and the hexane partitions, respectively; the ethyl acetate (0.24%w/v) and the water partition (for all of its concentrations), as well as the rutin (starting at 0.064%w/v), caused phagodeterrence, too. Moreover, the crude extract was submitted to a phytochemical screening by means of a number of qualitative tests, to determine possible metabolites causing phagodeterrence, the most important being alkaloids, triterpenes, coumarins and rutin. A particular phytochemical screening was carried out for the hexane partition, which was the most active. PMID:20411703

  2. Photosynthetic nutrient-use efficiency in three fast-growing tropical trees with differing leaf longevities.

    PubMed

    Hiremath, A J

    2000-08-01

    Differences in nutrient-use efficiency have been attributed to differences in leaf habit. It has been suggested that evergreens, with their longer-lived leaves, and therefore longer nutrient retention, are more efficient than deciduous species in their use of nutrients. In tropical trees, however, leaf life span is not always a function of whole-tree deciduousness, leading to the proposal that nutrient-use efficiency is better related to leaf life span than to leaf habit. It was predicted that potential photosynthetic nutrient-use efficiency (maximum potential photosynthesis/leaf nutrient content) would decrease with increasing leaf life span, whereas cumulative photosynthetic nutrient-use efficiency (carbon assimilated over a leaf's life span/total nutrients invested in a leaf) would increase with increasing leaf life span. Potential and cumulative photosynthetic nutrient-use efficiencies (with respect to nitrogen and phosphorus) were measured for three fast-growing tropical trees: Cedrela odorata L. (Meliaceae), Cordia alliodora (R. & P.) Cham. (Boraginaceae), and Hyeronima alchorneoides Allemão (Euphorbiaceae). Mean leaf life spans of the three species varied about threefold and ranged from 50 to 176 days. The predictions were partially supported: Cedrela odorata had the shortest-lived leaves and the highest potential nitrogen-use efficiency, whereas Hyeronima alchorneoides had the longest-lived leaves and the highest cumulative nitrogen- and phosphorus-use efficiencies. Potential phosphorus-use efficiency, however, was invariant among species. It is suggested that there are potential tradeoffs between leaf characteristics that lead to high potential and cumulative nutrient-use efficiencies. High potential nutrient-use efficiency may be beneficial in high-nutrient environments, whereas high cumulative nutrient-use efficiency may be of greater benefit to species in low-nutrient environments. PMID:11303568

  3. [Phagodeterrent and systemic activity of a fomulation derived from an extract of common rue (Ruta chalepensis, Rutaceae) on Hypsipyla grandella (Lepidoptera: Pyralidae) larvae].

    PubMed

    Barboza, Javier; Hilje, Luko; Durón, Julio; Cartín, Víctor; Calvo, Marco A

    2010-03-01

    A key neotropical pest of mahoganies (Swietenia spp.) and cedars (Cedrela spp.), the larva of Hypsipyla grandella (Zeller) commonly bores into the main shoot of these valuable timber species, causing forking of the stems. Therefore, it would be desirable to count upon a phagodeterrent and systemic product which could readily protect young tissues. Since crude extracts of common rue foliage (Ruta chalepensis L.) have phagodeterrent activity on H. grandella larva, a product was formulated by combining such an extract with a number of coadjuvants, and was assessed on 75-100 cm tall Spanish cedar (Cedrela odorata L.) trees, inside a greenhouse. A completely randomized design was used, with 10 trees per each one of the following treatments: the formulated product, an absolute control (distilled water), a relative control (carbofuran, 1%m/v in water), and the relative control without the crude extract. Number of attacks to the main shoot, fallen leaves and frass piles were recorded, as well as tunnel length. Regarding these variables, the formulated product provided excellent protection to treated trees, with only 0.1 attacks to the main shoot, on the average, at the end of the evaluation period. Likewise, when the systemic activity of the crude extract was assessed, substances present in it were able to translocate and get assimilated by the trees, thereafter causing phagodeterrence to larvae. Finally, an espectrophotometry analysis (performed at a wavelength of 355 nm) allowed us to determine the concentration (403+/-1 mg/l) and percentage (0.40%) of the flavonoid rutin in the crude extract, which eventually may be used as an analytical marker compound, should an industrial formulation be developed. PMID:20411704

  4. Detection of conduit-controlled ground-water flow in northwestern Puerto Rico using aerial photograph interpretation and geophysical methods

    USGS Publications Warehouse

    Rodríguez-Martínez, Jesús; Richards, Ronald T.

    2000-01-01

    The development potential of ground-water resources in the karst limestone of northwestern Puerto Rico, in an area extending from the Río Camuy to Aguadilla, is uncertain as a result of limited knowledge of the location of areas where a high density of cavities (interconnected fractures, conduits, and other dissolution features) might suggest the occurrence of high water yields. The presence in northwestern Puerto Rico of numerous coastal submarine springs, cavernous porosity in some of the wells, and rivers with entrenched and underground paths, indicate that it is probable that water-bearing, subterranean interconnected cavities occur in the area between the Río Camuy and Aguadilla. The number of exploratory wells needed to determine the location of these conduits or zones of enhanced secondary porosity could be substantially reduced if more information were available about the location of these subterranean features, greatly reducing the drilling costs associated with a trial-and-error exploratory process. A 3-year study was conducted by the U.S. Geological Survey, in cooperation with the Puerto Rico Aqueduct and Sewer Authority, to detect the presence of cavities that might suggest the occurrence of conduit-controlled groundwater flow. Aerial photographs, geologic and topographic maps, and field reconnaissance were used to identify such linear terrain features as ridges, entrenched canyons, and fracture traces. Natural potential and gravity geophysical methods were also used. The following sites were selected for the aerial photograph interpretation and geophysical testing: Caimital Bajo uplands and former Ramey Air Force Base in Aguadilla; Quebrada de los Cedros between Aguadilla and Isabela; the University of Puerto Rico Agricultural Experiment Station, Otilio dairy farm, and Pozo Brujo in Isabela; the Monte Encantado area in Moca and Isabela; and the Rio Camuy cave system in Hatillo and Camuy. In general, the degree of success varied with site and the geophysical method used. At some sites such as Pozo Brujo, the University of Puerto Rico Agricultural Experiment Station, and Monte Encantado area, natural potential anomalies strongly suggest the existence of conduits with flowing water. At most sites, however, the results obtained did not clearly reveal the presence of subsurface cavities that might be associated with the occurrence of conduit-controlled ground-water flow. Sites such as the University of Puerto Rico Agricultural Experiment Station, Pozo Brujo, and Quebrada de los Cedros warrant a more detailed analysis, including a test well drilling phase to confirm the presence of suspected high-yield water-bearing zones.

  5. [Lipid and fatty acid profile of Perna viridis, green mussel (Mollusca: Bivalvia) in different areas of the Eastern Venezuela and the West Coast of Trinidad].

    PubMed

    Koftayan, Tamar; Milano, Jahiro; D'Armas, Haydelba; Salazar, Gabriel

    2011-03-01

    The species Perna viridis is a highly consumed species, which fast growth makes it an interesting aquaculture alternative for Venezuelan and Trinidad coasts. With the aim to contribute with its nutritional value information, this study analyzed lipid and fatty acid contents from samples taken in five locations from Eastern Venezuela and three from Trinidad West Coast. Total lipids were extracted and quantified, from a pooled sample of 100 organisms per location, by standard gravimetric methods, and their identification and quantification was done by TLC/FID (Iatroscan system). Furthermore, the esterified fatty acids of total lipid, phospholipids and triacylglycerols were identified and quantified by gas chromatography. Eastern Venezuela samples from Los Cedros, La Brea and Chaguaramas showed the highest total lipid values of 7.92, 7.74 and 7.53, respectively, and the minimum values were obtained for La Restinga (6.08%). Among lipid composition, Chacopata samples showed the lowest phospholipid concentration (48.86%) and the maximum values for cholesterol (38.87%) and triacylglycerols (12.26%); besides, La Esmeralda and Rio Caribe samples exhibited maximum phospholipids (88.71 and 84.93 respectively) and minimum cholesterol (6.50 and 4.42%) concentrations. Saturated fatty acids represented between 15.04% and 65.55% within total lipid extracts, with maximum and minimum values for La Esmeralda and Chacopata, respectively. Polyunsaturated results resulted between 7.80 and 37.18%, with higher values in La Brea and lower values in La Esmeralda. For phospholipids, saturated fatty acids concentrations varied between 38.81 and 48.68% for Chaguaramas and Chacopata samples, respectively. In the case of polyunsaturated fatty acids, these varied between non detected and 34.51%, with high concentrations in Los Cedros (27.97%) and Chaguaramas (34.51%) samples. For the triacylglycerols, the saturated fatty acids composition oscillated between 14.27 and 53.80% with low concentrations for Chacopata and high concentration for La Restinga; the polyunsaturated fatty acids were between 4.66 and 35.55% with lower values for Chacopata and higher values for Chaguaramas samples. P. viridis is recommended for human being consumption, according to the high content of unsaturated fatty acids found for this species. PMID:21516644

  6. Reinterpretation of Mesozoic ophiolite arc, and blueschist terranes in southwestern Baja California

    SciTech Connect

    Sedlock, R.L. . Geology Dept.)

    1993-04-01

    The nature and significance of disrupted Mesozoic oceanic rocks on Isla Santa Margarita and Isla Magdalena, western Baja California Sur, have been reinterpreted on the basis of detailed mapping and petrologic studies. Three structural units are recognized. (1) The upper plate consists of ophiolitic, arc, and forearc basin rocks. Ophiolitic rocks, including metamorphosed ultramafic rocks, gabbro, dikes, volcanic rocks, and chert, underwent strong contractional deformation and penetrative greenschist-facies metamorphism. Arc rocks, including gabbro, a dike and sill complex, compositionally diverse volcanic rocks, lahars, and volcaniclastic strata, lack a penetrative fabric and are weakly metamorphosed. Forearc basin rocks consist of unmetamorphosed conglomerated and rhythmically bedded siliciclastic turbidites. (2) The lower plate is a subduction complex consisting of weakly to moderately foliated and metamorphosed pillow and massive lavas, breccia, and tuff( ), interbedded red and green siliceous argillite, and rare radiolarian ribbon chert and limestone. Blueschist-facies metamorphism is indicated by lawsonite, aragonite, sodic amphibole, and sodic clino-pyroxene. (3) Serpentine-matrix melange crops out in shallowly dipping fault zones between the upper and lower plates. The structural and petrologic characteristics of the Mesozoic units, the geometry of contacts between them, and the age of extension are similar to those in the Isla Cedros-Vizcalno Peninsula region, 400 km to the northwest. The author infers that syn-subduction extension was a regional event that affected much of the western Baja forearc during the Late Cretaceous and Paleogene.

  7. The P-T-t history of blocks in serpentinite-matrix melange, west-central Baja California

    SciTech Connect

    Baldwin, S.L.; Harrison, T.M.

    1992-01-01

    Thermochronologic, petrologic, and geochemical analyses of epidote-amphibolite-, amphilbolite-, eclogite-, and blueschist-facies blocks in serpentinite-matrix melanges from East San Benito Island and Cedros Island, west-central Baja California, provide constraints on the P-T-t history of this disrupted terrane. Results of {sup 40}Ar/{sup 39}Ar step heating experiments on minerals separated from these blocks vary according to metamorphic grade and indicate different P-T-t histories. Mid-Jurassic (160-170 Ma) epidote-amphibolite- and amphibolite-facies blocks were probably derived from oceanic crust and associated sediments that were metamorphosed during limitation of subduction. Coarse-grained blueschist blocks were likely metamorphosed during continued subduction in late Early Cretaceous time (that is, 115-100 Ma). Some epidote-amphibolite blocks are partially overprinted by blueschist-facies mineral assemblages and apparently record both metamorphic events. Fission-track analyses of apatites indicate that the blocks underwent significantly different post-metamorphic cooling histories. Epidote-amphilbolite and amphibolite blocks cooled below {approximately}100 {degrees}C form mid-Jurassic to Paleocene time; blueschist blocks cooled below {approximately}100 {degrees}C in Oligocene-Miocene time. In general, mafic blocks have trace-element concentrations and REE patterns characteristic of ocean-flood basalts. This study demonstrates that samples with very different P-T-t histories can evidently occur over relatively small length scales (<<1 km) in serpentinite-matrix melanges. 67 refs., 16 figs., 4 tabs.

  8. Lithofacies of deep marine basalts emplaced on a Jurassic backarc apron, Baja California (Mexico)

    SciTech Connect

    Busby-Spera, C.J.

    1987-09-01

    Basalts of the mid-Jurassic Gran Canon Formation, Cedros Island, Mexico, were emplaced on a volcaniclastic apron in a deep marine backarc basin. Elongate pillows and lava tubes, as well as paleocurrent data from the volcaniclastic apron, indicate a southward regional paleoslope away from the island arc source. Basalts emplaced on relatively proximal parts of the apron are nearly entirely pillowed and have thick flow units with mega-pillows. Basalts on distal parts of the apron (about 15 to 20 km down paleo-current) are dominated by pillow fragment breccias (flow foot rubble), and individual lava flows are generally thin, with small pillows, suggesting that the distal ends of lava flows, erupted upslope, are represented. These distal flow fronts, however, are interstratified with features that typically form close to a vent, including thick massive to mega-pillowed lavas and lava tubes up to 8 m in diameter. It is inferred that a fissure (or system of fissures) extended from the arc into the backarc basin, erupting basalt lavas onto both proximal and distal parts of the volcaniclastic apron. Such intraplate volcanism may be common on the hot frontal arc side of backarc basins. 26 references.

  9. Modeling Long-term Creep Performance for Welded Nickel-base Superalloy Structures for Power Generation Systems

    SciTech Connect

    Shen, Chen

    2015-01-01

    We report here a constitutive model for predicting long-term creep strain evolution in ’ strengthened Ni-base superalloys. Dislocation climb-bypassing ’, typical in intermediate ’ volume fraction (~20%) alloys, is considered as the primary deformation mechanism. Dislocation shearing ’ to anti-phase boundary (APB) faults and diffusional creep are also considered for high-stress and high-temperature low-stress conditions, respectively. Additional damage mechanism is taken into account for rapid increase in tertiary creep strain. The model has been applied to Alloy 282, and calibrated in a temperature range of 1375-1450˚F, and stress range of 15-45ksi. The model parameters and a MATLAB code are provided. This report is prepared by Monica Soare and Chen Shen at GE Global Research. Technical discussions with Dr. Vito Cedro are greatly appreciated. This work was supported by DOE program DE-FE0005859

  10. Use of grafting to prevent Hypsipyla grandella (Zeller) (Lepidoptera: Pyralidae) damage to new world Meliaceae species.

    PubMed

    Perez, Julian; Eigenbrode, Sanford D; Hilje, Luko; Tripepi, Robert R; Aguilar, Maria E; Mesen, Francisco

    2010-01-01

    The susceptible species Cedrela odorata and Swietenia macrophylla to attack by Hypsipyla grandella (Zeller) larvae were grafted onto the resistant species Khaya senegalensis and Toona ciliata. Six-month-old grafted plants were then compared to their reciprocal grafts and to both intact (non-grafted) and autografted plants for damage due to H. grandella larvae and for their effects on larval performance. Two experiments were conducted: one in which the apical bud of the main plant shoot was inoculated with H. grandella eggs, and the other in which the bud was inoculated with third instars. Damage in each experiment was assessed by the number of frass piles, number and length of tunnels, number of damaged leaves, and damage to the apical bud. Larval performance was evaluated in terms of time to reach pupation and pupal weight and length. In both experiments, plant damage differed significantly among treatments (P < 0.03). Resistant rootstocks conferred resistance to susceptible scions. In both experiments, grafting by itself, regardless of the rootstock and scion combination, also reduced damage caused by H. grandella larvae. Scions of autografted susceptible species had similar resistance to susceptible scions grafted on resistant rootstocks. Few larvae reached pupation, and their pupal weight and length were similar. PMID:20878001

  11. Root endophyte symbiosis in vitro between the ectomycorrhizal basidiomycete Tricholoma matsutake and the arbuscular mycorrhizal plant Prunus speciosa.

    PubMed

    Murata, Hitoshi; Yamada, Akiyoshi; Yokota, Satoru; Maruyama, Tsuyoshi; Endo, Naoki; Yamamoto, Kohei; Ohira, Tatsuro; Neda, Hitoshi

    2014-05-01

    We previously reported that Tricholoma matsutake and Tricholoma fulvocastaneum, ectomycorrhizal basidiomycetes that associate with Pinaceae and Fagaceae, respectively, in the Northern Hemisphere, could interact in vitro as a root endophyte of somatic plants of Cedrela odorata (Meliaceae), which naturally harbors arbuscular mycorrhizal fungi in South America, to form a characteristic rhizospheric colony or "shiro". We questioned whether this phenomenon could have occurred because of plant-microbe interactions between geographically separated species that never encounter one another in nature. In the present study, we document that these fungi formed root endophyte interactions and shiro within 140 days of inoculation with somatic plants of Prunus speciosa (=Cerasus speciosa, Rosaceae), a wild cherry tree that naturally harbors arbuscular mycorrhizal fungi in Japan. Compared with C. odorata, infected P. speciosa plants had less mycelial sheath surrounding the exodermis, and the older the roots, especially main roots, the more hyphae penetrated. In addition, a large number of juvenile roots were not associated with hyphae. We concluded that such root endophyte interactions were not events isolated to the interactions between exotic plants and microbes but could occur generally in vitro. Our pure culture system with a somatic plant allowed these fungi to express symbiosis-related phenotypes that varied with the plant host; these traits are innately programmed but suppressed in nature and could be useful in genetic analyses of plant-fungal symbiosis. PMID:24158697

  12. Electrophysiological responses of female and male Hypsipyla grandella (Zeller) to Swietenia macrophylla essential oils.

    PubMed

    Soares, Marisi G; Batista-Pereira, Luciane G; Fernandes, João B; Corrêa, Arlene G; da Silva, M Fátima G F; Vieira, Paulo C; Rodrigues Filho, Edson; Ohashi, Orlando S

    2003-09-01

    The mahogany shoot borer, Hypsipyla grandella, is one of the most economically important Neotropical forest pest insects because it attacks valuable timber of the Meliaceae. Despite detailed information on the life cycle of H. grandella, factors influencing attack by the shoot borer are not well known. Electroantennogram studies of borer antennae indicate that both female and male moths elicited significant antennal responses to essential oil of the terminal shoots, mature and senescent leaves, in three concentrations. Gamma-himachalene, germacrene D, germacrene A, cadina-1,4-diene, hexadecanoic acid, and ethyl hexadecanoate appeared in all essential oils from Swietenia macrophylla. Germacrene-D and gamma-himachalene were also present in the active essential oil of Cedrela odorata and Toona ciliata. These findings suggest that these compounds play a role in attracting H. grandella to oviposit on the leaves of these plants. The GC-EAD of essential oil from S. macrophylla mature leaves to female H. grandella antennae led to the identification of beta-caryophyllene as the main constituent responsible for the antennae response. PMID:14584681

  13. Phagodeterrence by Quassia amara (Simaroubaceae) wood extract fractions on Hypsipyla grandella (Lepidoptera: Pyralidae) larvae.

    PubMed

    Soto, Francisco; Hilje, Luko; Mora, Gerardo A; Carballo, Manuel

    2011-03-01

    In Latin America and the Caribbean, precious wood species like mahoganies (Swietenia spp.) and cedars (Cedrela spp.) are seriously injured by the mahogany shootborer, Hypsipyla grandella (Zeller) (Lepidoptera: Pyralidae) larva, which bores into the main shoot of trees. In previous experiments focused on searching for a preventive method for managing this pest, a wood extract of bitterwood, Quassia amara L. ex Blom (Simaroubaceae) had been shown to cause phagodeterrence to larvae. Therefore, three fractions (water, methanol and diethyl ether) of a wood extract were tested for their phagodeterrence to larvae, by means of laboratory and greenhouse trials. Phagodeterrence was assessed by determining their effect on foliage consumption, mortality and signs of damage (number of orifices, sawdust piles, fallen shoots, number of tunnels and tunnel length) caused by larvae on Spanish cedar (C. odorata). Both the methanol and diethyl ether fractions caused phagodeterrence, by strongly reducing foliage consumption and signs of damage, while not causing larval mortality. The lowest concentration at which phagodeterrence was detected for the methanol fraction corresponded to 0.0625%, which is equivalent to a 1.0% of the bitterwood crude extract. However, results with the diethyl ether fraction were unsatisfactory, as none of the treatments differed from the solvent, possibly because of an adverse effect of the solvent on foliar tissues. Phagodeterrent principles from Q. amara derivatives may play an important role in dealing with H. grandella if they are complemented with other integrated pest management preventative tactics. PMID:21513206

  14. Biological activity of Ruta chalepensis (Rutaceae) and Sechium pittieri (Cucurbitaceae) extracts on Hypsipyla grandella (Lepidoptera: Pyralidae) larvae.

    PubMed

    Mancebo, F; Hilje, L; Mora, G A; Castro, V H; Salazar, R

    2001-06-01

    Biological activity of a plant extract (common rue, Ruta chalepensis) and a semi purified fraction (from "tacaco cimarrón", Sechium pittieri) on mahogany shootborer larvae (Hypsipyla grandella) was studied. A randomized complete block design, with four replications, was used. H. grandella third instar larvae were exposed for 24 h to Cedrela odorata leaf discs dipped in several treatment dissolutions of each extract (0.1, 0.32, 1.0, 3.20, and 10%); afterwards, each larva was transferred to a flask containing an artificial diet and was allowed to complete its development. Variables measured included food consumption (foliar area eaten in 24 h), mortality, and developmental effects (developmental time for each larval instar and the pupa, and pupal weight). The common rue extract showed a clear antifeedant activity at a concentration as low as 0.32%, whereas the "tacaco cimarrón" fraction caused toxicity, especially at the two highest concentrations (3.20 and 10%). PMID:11935899

  15. Do persistently fast-growing juveniles contribute disproportionately to population growth? A new analysis tool for matrix models and its application to rainforest trees.

    PubMed

    Zuidema, Pieter A; Brienen, Roel J W; During, Heinjo J; Güneralp, Burak

    2009-11-01

    Plants and animals often exhibit strong and persistent growth variation among individuals within a species. Persistently fast-growing individuals have a higher chance of reaching reproductive size, do so at a younger age, and therefore contribute disproportionately to population growth (lambda). Here we introduce a new approach to quantify this "fast-growth effect." We propose using age-size-structured matrix models in which persistently fast and slow growers are distinguished as they occur in relatively young and old age classes for a given size category. Life-cycle pathways involving fast growth can then be identified, and their contribution to lambda is quantified through loop analysis. We applied this approach to an example species, the tropical rainforest tree Cedrela odorata, that shows persistent growth variation among individuals. Loop analysis showed that juvenile trees reaching the 10-cm diameter class at below-median age contributed twice as much to lambda as slow juvenile growers. Fast growth to larger-diameter categories also contributed disproportionately to lambda. The results were robust to changes in parameter values and life-history trade-offs. These results show that the fast-growth effect can be strong in long-lived species. Persistent growth differences among individuals should therefore be accommodated for in demographic models and life-history studies. PMID:19778168

  16. Phylogenetically diverse AM fungi from Ecuador strongly improve seedling growth of native potential crop trees.

    PubMed

    Schüßler, Arthur; Krüger, Claudia; Urgiles, Narcisa

    2016-04-01

    In many deforested regions of the tropics, afforestation with native tree species could valorize a growing reservoir of degraded, previously overused and abandoned land. The inoculation of tropical tree seedlings with arbuscular mycorrhizal fungi (AM fungi) can improve tree growth and viability, but efficiency may depend on plant and AM fungal genotype. To study such effects, seven phylogenetically diverse AM fungi, native to Ecuador, from seven genera and a non-native AM fungus (Rhizophagus irregularis DAOM197198) were used to inoculate the tropical potential crop tree (PCT) species Handroanthus chrysanthus (synonym Tabebuia chrysantha), Cedrela montana, and Heliocarpus americanus. Twenty-four plant-fungus combinations were studied in five different fertilization and AMF inoculation treatments. Numerous plant growth parameters and mycorrhizal root colonization were assessed. The inoculation with any of the tested AM fungi improved seedling growth significantly and in most cases reduced plant mortality. Plants produced up to threefold higher biomass, when compared to the standard nursery practice. AM fungal inoculation alone or in combination with low fertilization both outperformed full fertilization in terms of plant growth promotion. Interestingly, root colonization levels for individual fungi strongly depended on the host tree species, but surprisingly the colonization strength did not correlate with plant growth promotion. The combination of AM fungal inoculation with a low dosage of slow release fertilizer improved PCT seedling performance strongest, but also AM fungal treatments without any fertilization were highly efficient. The AM fungi tested are promising candidates to improve management practices in tropical tree seedling production. PMID:26260945

  17. Evolution of subsidence styles in forearc basin: example from Cretaceous of southern Vizcaino Peninsula, Baja California, Mexico

    SciTech Connect

    Busby-Spera, C.J.; Boles, J.R.

    1986-04-01

    Late Jurassic to Early Cretaceous arc magmatism is represented by volcaniclastic rocks of the Eugenia Formation in the northern Vizcaino Peninsula and by the metamorphosed Cedros-San Andres volcanoplutonic complex, with a dismembered ophiolitic basement, in the southern peninsula. The Vizcaino Peninsula became the site of forearc sedimentation by the Aptian-Albian (late Early Cretaceous), when arc magmatism moved abruptly eastward to the present-day Peninsular Range. On the southern Vizcaino Peninsula, a conformable stratigraphic section, complicated by later faulting, records a gradual transition from a ridged forearc, broken by basement uplifts and grabens (the Aptian-Albian Asunction Formation), to a broadly subsiding, deep marine forearc basin (the Cenomanian Valle Formation). The basal contact of the Asunction formation has irregular relief caused by brecciated basement rocks and talus accumulated along fault zones. An upward-fining sequence several hundred meters thick records abrupt uplift and gradual denudation of adjacent metamorphic basement. Contemporaneous andesite arc volcanism to the east supplied ash and fresh volcanic detritus to the grabens. Angular sand to boulder-size detritus of the Asunction Formation was derived locally, and includes basic to intermediate meta-igneous rock fragments, with epidote, actinolite, and chlorite, as well as serpentine. Abundant calcareous fossils are commonly unbroken, suggesting local sources for these as well. Angular to subrounded, sand to cobble-sized, intermediate to mafic volcanic rock fragments were derived from a more distant island arc to the east, which occasionally provided intermediate to felsic tuffs to the basin. This source is probably represented by the Aptian-Albian Alisitos Group, which forms much of the western wall of the Late Cretaceous Peninsular Range batholith.

  18. The 27 May 1937 catastrophic flow failure of gold tailings at Tlalpujahua, Michoacán, México

    NASA Astrophysics Data System (ADS)

    Macías, J. L.; Corona-Chávez, P.; Sanchéz-Núñez, J. M.; Martínez-Medina, M.; Garduño-Monroy, V. H.; García-Tenorio, F.; Cisneros-Máximo, G.

    2014-08-01

    On 27 May 1937, after one week of sustained heavy rainfall, a voluminous flood caused the death of at least 300 people and the destruction of the historic El Carmen church and several neighborhoods in the mining region of Tlalpujahua, Michoacán, central Mexico. This destructive flood was triggered by the breaching of the impoundment of the Los Cedros tailings and the sudden release of 16 Mt of water-saturated waste materials. The muddy silty flood, moving at estimated speeds of 20-25 m s-1, was channelized along the Dos Estrellas and Tlalpujahua drainages and devastated everything along its flow path. After advancing 2.5 km downstream, the flood slammed into El Carmen church and surrounding houses at estimated speeds of ~7 m s-1, destroying many of construction walls and covering the church floor with ~2 m of mud and debris. Eyewitness accounts and newspaper articles, together with analysis of archived photographic materials, indicated that the flood consisted of three muddy pulses. This interpretation is confirmed and extended by the results of our geological investigations during 2013 and 2014. Stratigraphic relations and granulometric data for selected proximal and distal samples show that the flood behaved as a hyperconcentrated flow along most of its trajectory. Even though premonitory signs of possible impoundment failure were reported days before the flood, and people living downstream were alerted, authorities ordered no evacuations or other mitigative actions. The catastrophic flood at Tlalpujahua provides a well-documented, though tragic, example of impoundment breaching of a tailings dam caused by the combined effects of intense rainfall, dam weakness, and inadequate emergency-management protocols - unfortunately an all too common case-scenario for most of the world's mining regions.

  19. The ˜1000-years BP explosive eruption of Caldeira Volcano (Faial, Azores): the first stage of incremental caldera formation

    NASA Astrophysics Data System (ADS)

    Pimentel, Adriano; Pacheco, José; Self, Stephen

    2015-05-01

    The ˜1000-years BP eruption of Caldeira Volcano (Faial Island) was one of the last major explosive events recorded in the Azores. It produced a complex succession of pyroclastic deposits, known as the C11, divided into three members. At the base is the Brejo Member, a sequence of fine- to coarse-grained parallel-bedded ash layers found in the NW sector of the island. The middle part corresponds to the Inverno Member, a coarse-grained massive pumice fall deposit, restricted to the north flank of Caldeira Volcano. The top is dominated by the Cedros Member which includes massive to diffuse-stratified lapilli-ash and lithic breccias, exposed along the north and east flanks of the volcano. A minimum bulk volume of at least 0.22 km3 (>0.1 km3 dense rock equivalent (DRE)) is estimated for the C11 eruption, although a large portion may have been deposited offshore. The juvenile products are trachytic (59 wt% SiO2) with a homogenous whole-rock composition and mineral assemblage throughout the pyroclastic succession. However, petrographic and groundmass glass analyses indicate magma mingling/mixing processes between two trachytic batches. The C11 eruption history is divided into three phases (following the member division) with distinct eruptive styles: (1) an initial phreatomagmatic phase caused by rising magma (˜950 °C) encountering a crater pond or aquifer, (2) a fall-dominated phase which established a sub-Plinian column up to 14 km high (mass eruption rate (MER) of 1.2 × 107 kg/s) and (3) prolonged pyroclastic fountaining and sustained quasi-steady pyroclastic density current generation followed by summit collapse. The C11 eruption is interpreted as the first stage in the formation of an incremental caldera. This study provides valuable insights for a better understanding of small but complex explosive eruptions and their impact on ocean islands.

  20. The status of conservation of urban forests in eastern Amazonia.

    PubMed

    Amaral, D D; Vieira, I C G; Salomão, R P; Almeida, S S; Jardim, M A G

    2012-05-01

    This study aims to identify the remnant tree flora in six forest fragments in the metropolitan area of Belém and to analyze these fragments in terms of biological conservation, species richness and diversity in the local urban landscape. The fragments and their respective sampling areas were as follows: Amafrutas reserve (15 ha), Trambioca Is. reserve (2 ha), Bosque Rodrigues Alves city park (15 ha), Combu Is. reserve (10 ha), Gunma Park reserve (10 ha) and Mocambo reserve (5 ha). Inventories were built from lineal plots of 250 m² and included trees with DBH equal to or greater than 10 cm at a height of 1.3 m above ground. Sixty-nine families and 759 species, of which eight were officially listed as endangered (Brazilian National Flora: Ministry of Environment, Normative Instruction of September, 2008; Pará State Flora: Decree Nº. 802 of February 2008) were recorded. These endangered species are: Aspidosperma desmanthum Benth. ex Müll. Arg. (Apocynaceae), Cedrela odorata L. (Meliaceae), Eschweilera piresii S.A Mori (Lecythidaceae), Euxylophora paraensis Huber (Rutaceae), Hymenolobium excelsum Ducke (Leguminosae), Manilkara huberi (Ducke) Chevalier (Sapotaceae), Tabebuia impetiginosa (Mart. ex DC.) Standl. (Bignoniaceae), Mezilaurus itauba (Meisn.) Taub. ex Mez (Lauraceae) and Qualea coerulea Aubl. (Vochysiaceae). Emergency actions such as implementing management plans for already existing Conservation Units, the creation of new such units in areas of primary forest fragments (as in the case of the Amafrutas reserve), as well as the intensification of actions of surveillance and monitoring, should be undertaken by Federal, State, and Municipal environmental agencies so as to ensure the conservation of these last primary forest remnants in the metropolitan area of Belém. PMID:22735132

  1. Tree-ring based reconstruction of Río Bermejo streamflow in subtropical South America

    NASA Astrophysics Data System (ADS)

    Ferrero, María Eugenia; Villalba, Ricardo; De Membiela, Mónica; Ferri Hidalgo, Lidia; Luckman, Brian Henry

    2015-06-01

    Precipitation on the subtropical Andes in northwestern Argentina is the main source of freshwater to rivers, which provide water for consumption, hydroelectric generation and irrigation of agricultural fields. Regional streamflow records for the past 60 years indicate a period of enhanced inter-annual and inter-decadal variability during recent decades. Here we present a long-term perspective of streamflow variations for Río Bermejo, a major river in the subtropics of Argentina-Bolivia. This streamflow reconstruction covers the period 1680-2001 and was performed using principal component regression models based on precipitation sensitive tree-ring width series. Composite tree-ring chronologies from Juglans australis, Cedrela lilloi and Schinopsis lorentzii were used as predictors to reconstruct the May-October (dry season) streamflow variations. Monthly instrumental streamflow records were used to assess the temporal relationship between climatic data and tree-ring records. The regression model explains 52% of the variance of May-October Bermejo discharge (R2adj = 0.499) over the period 1941-1992. Analyses of the frequency, intensity and duration of pluvials and droughts indicates a sustained increase in streamflow since the 1960s, which is exceptional since 1680. Pearson's correlation coefficients between Río Bermejo records against gridded interpolated precipitation and outgoing longwave radiation indicate that the South American monsoon is the main source of regional precipitation and the consequent discharge of subtropical rivers in northern Argentina. Long-term streamflow reconstructions in subtropical South America contribute to our understanding of past and present climate variations and the related large-scale atmospheric features that drive these variations.

  2. Antileishmanial, antitrypanosomal, and cytotoxic screening of ethnopharmacologically selected Peruvian plants.

    PubMed

    González-Coloma, Azucena; Reina, Matías; Sáenz, Claudia; Lacret, Rodney; Ruiz-Mesia, Lastenia; Arán, Vicente J; Sanz, Jesús; Martínez-Díaz, Rafael A

    2012-04-01

    Extracts (34) from eight plant species of the Peruvian Amazonia currently used in traditional Peruvian medicine, mostly as antileishmanial remedies and also as painkiller, antiseptic, antipyretic, anti-inflamatory, antiflu, astringent, diuretic, antipoison, anticancerous, antiparasitic, insecticidal, or healing agents, have been tested for their antileishmanial, antitrypanosomal, and cytotoxic activity. Plant species were selected based on interviews conducted with residents of rural areas. The different plant parts were dried, powdered, and extracted by maceration with different solvents (hexane, chloroform, and 70% ethanol-water). These extracts were tested on promastigote forms of Leishmania infantum strain PB75, epimastigote forms of Trypanosoma cruzi strain Y, and the mammalian CHO cell line. Parasite viability and nonspecific cytotoxicity were analyzed by a modified MTT colorimetric assay method. The isolation and identification of pure compounds from selected extracts were performed by column chromatography, gas chromatography mass spectrometry (GC-MS; mixtures), spectroscopic techniques [MS, infrared (IR), ultraviolet (UV)], and mono and two-dimensional (1)H and (13)C nuclear magnetic resonance (NMR; COSY, HSQC, NOESY) experiments. Chondodendron tomentosum bark and Cedrela odorata were the most active extracts against Leishmania, while C. odorata and Aristoloquia pilosa were the most active against Trypanosoma, followed by Tabebuia serratifolia, Tradescantia zebrina, and Zamia ulei. Six compounds and two mixtures were isolated from Z. ulei [cycasin (1)], T. serratifolia {mixtures 1-2, and naphthoquinones 2-acetyl-4H,9H-naphtho[2,3-b]furan-4,9-dione (2) and 2-(1-hydroxyethyl)-4H,9H-naphtho[2,3-b]furan-4,9-dione (3)}, and C. tomentosum [chondrocurine (4); (S,S')-12-O-methyl(+)-curine (5); and cycleanine (6)]. Four compounds and the two mixtures exhibited significant activity. PMID:21922239

  3. An efficient immunodetection method for histone modifications in plants

    PubMed Central

    2013-01-01

    Background Epigenetic mechanisms can be highly dynamic, but the cross-talk among them and with the genome is still poorly understood. Many of these mechanisms work at different places in the cell and at different times of organism development. Covalent histone modifications are one of the most complex and studied epigenetic mechanisms involved in cellular reprogramming and development in plants. Therefore, the knowledge of the spatial distribution of histone methylation in different tissues is important to understand their behavior on specific cells. Results Based on the importance of epigenetic marks for biology, we present a simplified, inexpensive and efficient protocol for in situ immunolocalization on different tissues such as flowers, buds, callus, somatic embryo and meristematic tissue from several plants of agronomical and biological importance. Here, we fully describe all the steps to perform the localization of histone modifications. Using this method, we were able to visualize the distribution of H3K4me3 and H3K9me2 without loss of histological integrity of tissues from several plants, including Agave tequilana, Capsicum chinense, Coffea canephora and Cedrela odorata, as well as Arabidopsis thaliana. Conclusions There are many protocols to study chromatin modifications; however, most of them are expensive, difficult and require sophisticated equipment. Here, we provide an efficient protocol for in situ localization of histone methylation that dispenses with the use of expensive and sensitive enzymes. The present method can be used to investigate the cellular distribution and localization of a wide array of proteins, which could help to clarify the biological role that they play at specific times and places in different tissues of various plant species. PMID:24341414

  4. Attaining the canopy in dry and moist tropical forests: strong differences in tree growth trajectories reflect variation in growing conditions.

    PubMed

    Brienen, Roel J W; Zuidema, Pieter A; Martínez-Ramos, Miguel

    2010-06-01

    Availability of light and water differs between tropical moist and dry forests, with typically higher understorey light levels and lower water availability in the latter. Therefore, growth trajectories of juvenile trees--those that have not attained the canopy--are likely governed by temporal fluctuations in light availability in moist forests (suppressions and releases), and by spatial heterogeneity in water availability in dry forests. In this study, we compared juvenile growth trajectories of Cedrela odorata in a dry (Mexico) and a moist forest (Bolivia) using tree rings. We tested the following specific hypotheses: (1) moist forest juveniles show more and longer suppressions, and more and stronger releases; (2) moist forest juveniles exhibit wider variation in canopy accession pattern, i.e. the typical growth trajectory to the canopy; (3) growth variation among dry forest juveniles persists over longer time due to spatial heterogeneity in water availability. As expected, the proportion of suppressed juveniles was higher in moist than in dry forest (72 vs. 17%). Moist forest suppressions also lasted longer (9 vs. 5 years). The proportion of juveniles that experienced releases in moist forest (76%) was higher than in dry forest (41%), and releases in moist forests were much stronger. Trees in the moist forest also had a wider variation in canopy accession patterns compared to the dry forest. Our results also showed that growth variation among juvenile trees persisted over substantially longer periods of time in dry forest (>64 years) compared to moist forest (12 years), most probably because of larger persistent spatial variation in water availability. Our results suggest that periodic increases in light availability are more important for attaining the canopy in moist forests, and that spatial heterogeneity in water availability governs long-term tree growth in dry forests. PMID:20033820

  5. Oxygen isotopes in tree rings are a good proxy for Amazon precipitation and El Niño-Southern Oscillation variability

    PubMed Central

    Brienen, Roel J. W.; Helle, Gerd; Pons, Thijs L.; Guyot, Jean-Loup; Gloor, Manuel

    2012-01-01

    We present a unique proxy for the reconstruction of variation in precipitation over the Amazon: oxygen isotope ratios in annual rings in tropical cedar (Cedrela odorata). A century-long record from northern Bolivia shows that tree rings preserve the signal of oxygen isotopes in precipitation during the wet season, with weaker influences of temperature and vapor pressure. Tree ring δ18O correlates strongly with δ18O in precipitation from distant stations in the center and west of the basin, and with Andean ice core δ18O showing that the signal is coherent over large areas. The signal correlates most strongly with basin-wide precipitation and Amazon river discharge. We attribute the strength of this (negative) correlation mainly to the cumulative rainout processes of oxygen isotopes (Rayleigh distillation) in air parcels during westward transport across the basin. We further find a clear signature of the El Niño-Southern Oscillation (ENSO) in the record, with strong ENSO influences over recent decades, but weaker influence from 1925 to 1975 indicating decadal scale variation in the controls on the hydrological cycle. The record exhibits a significant increase in δ18O over the 20th century consistent with increases in Andean δ18O ice core and lake records, which we tentatively attribute to increased water vapor transport into the basin. Taking these data together, our record reveals a fresh path to diagnose and improve our understanding of variation and trends of the hydrological cycle of the world’s largest river catchment. PMID:23027960

  6. Oxygen isotopes in tree rings are a good proxy for Amazon precipitation and El Nino-Southern Oscillation variability.

    PubMed

    Brienen, Roel J W; Helle, Gerd; Pons, Thijs L; Guyot, Jean-Loup; Gloor, Manuel

    2012-10-16

    We present a unique proxy for the reconstruction of variation in precipitation over the Amazon: oxygen isotope ratios in annual rings in tropical cedar (Cedrela odorata). A century-long record from northern Bolivia shows that tree rings preserve the signal of oxygen isotopes in precipitation during the wet season, with weaker influences of temperature and vapor pressure. Tree ring δ(18)O correlates strongly with δ(18)O in precipitation from distant stations in the center and west of the basin, and with Andean ice core δ(18)O showing that the signal is coherent over large areas. The signal correlates most strongly with basin-wide precipitation and Amazon river discharge. We attribute the strength of this (negative) correlation mainly to the cumulative rainout processes of oxygen isotopes (Rayleigh distillation) in air parcels during westward transport across the basin. We further find a clear signature of the El Niño-Southern Oscillation (ENSO) in the record, with strong ENSO influences over recent decades, but weaker influence from 1925 to 1975 indicating decadal scale variation in the controls on the hydrological cycle. The record exhibits a significant increase in δ(18)O over the 20th century consistent with increases in Andean δ(18)O ice core and lake records, which we tentatively attribute to increased water vapor transport into the basin. Taking these data together, our record reveals a fresh path to diagnose and improve our understanding of variation and trends of the hydrological cycle of the world's largest river catchment. PMID:23027960

  7. Precipitation variability inferred from the annual growth and isotopic composition of tropical trees

    NASA Astrophysics Data System (ADS)

    Ballantyne, A. P.; Baker, P. A.; Chambers, J. Q.; Villalba, R.

    2005-12-01

    Here we demonstrate that annual growth and isotopic ratios in tropical trees are responsive to seasonal and annual precipitation variability. We identify several regions of tropical South America characterized by significant relationships between oxygen isotopic ratios (δ 18O) in precipitation and precipitation amount (r = -0.82). Many of these regions are also sensitive to inter-annual variability in the South American Monsoon modulated by the El Niño Southern Oscillation (ENSO). The effectiveness of δ 18O and annual growth of tropical trees as a precipitation proxy is validated by high-resolution sampling of a Tachigali vermelho tree growing near Manaus, Brazil (3.1° S, 60.0° S). Growth in Tachigali spp. was highly correlated with both precipitation and cellulose δ 18O (r = 0.60) and precipitation amount was significantly correlated with δ 18O at a lag of approximately one month (r = 0.56). We also report a multi-proxy record spanning 180 years from Cedrela odorata growing in the Peruvian Amazon near Puerto Maldonado (12.6° S, 69.2° W) revealing a significant relationship between cellulose and monsoon precipitation over the region (r = -0.33). A 150-year record obtained from Polylepis tarapacana growing at Volcan Granada in Northern Argentina (22.0° S, 66.0° W) is also reported with a significant relationship between local monsoon precipitation and a regionally derived ring width index (r = 0.38). Although no significant relationship was revealed between cellulose δ 18O and precipitation in this taxa at this location, separate radii within the same tree revealed a significantly coherent δ 18O signal (r = 0.38). We compared our proxy chronologies with monsoon precipitation reanalysis data for tropical South America, which revealed key features of the South American Monsoon and their sensitivity to ENSO variability.

  8. Low Herbivory among Targeted Reforestation Sites in the Andean Highlands of Southern Ecuador

    PubMed Central

    Adams, Marc-Oliver; Fiedler, Konrad

    2016-01-01

    Insect herbivory constitutes an important constraint in the viability and management of targeted reforestation sites. Focusing on young experimental stands at about 2000 m elevation in southern Ecuador, we examined foliar damage over one season as a function of tree species and habitat. Native tree species (Successional hardwood: Cedrela montana and Tabebuia chrysantha; fast-growing pioneer: Heliocarpus americanus) have been planted among prevailing local landcover types (abandoned pasture, secondary shrub vegetation, and a Pinus patula plantation) in 2003/4. Plantation trees were compared to conspecifics in the spontaneous undergrowth of adjacent undisturbed rainforest matched for height and foliar volume. Specifically, we tested the hypotheses that H. americanus as a pioneer species suffers more herbivory compared to the two successional tree species, and that damage is inversely related to habitat complexity. Overall leaf damage caused by folivorous insects (excluding leafcutter ants) was low. Average leaf loss was highest among T. chrysantha (7.50% ± 0.19 SE of leaf area), followed by H. americanus (4.67% ± 0.18 SE) and C. montana (3.18% ± 0.15 SE). Contrary to expectations, leaf area loss was highest among trees in closed-canopy natural rainforest, followed by pine plantation, pasture, and secondary shrub sites. Harvesting activity of leafcutter ants (Acromyrmex sp.) was strongly biased towards T. chrysantha growing in open habitat (mean pasture: 2.5%; shrub: 10.5%) where it could result in considerable damage (> 90.0%). Insect folivory is unlikely to pose a barrier for reforestation in the tropical Andean mountain forest zone at present, but leafcutter ants may become problematic if local temperatures increase in the wake of global warming. PMID:26963395

  9. Attaining the canopy in dry and moist tropical forests: strong differences in tree growth trajectories reflect variation in growing conditions

    PubMed Central

    Zuidema, Pieter A.; Martínez-Ramos, Miguel

    2009-01-01

    Availability of light and water differs between tropical moist and dry forests, with typically higher understorey light levels and lower water availability in the latter. Therefore, growth trajectories of juvenile trees—those that have not attained the canopy—are likely governed by temporal fluctuations in light availability in moist forests (suppressions and releases), and by spatial heterogeneity in water availability in dry forests. In this study, we compared juvenile growth trajectories of Cedrela odorata in a dry (Mexico) and a moist forest (Bolivia) using tree rings. We tested the following specific hypotheses: (1) moist forest juveniles show more and longer suppressions, and more and stronger releases; (2) moist forest juveniles exhibit wider variation in canopy accession pattern, i.e. the typical growth trajectory to the canopy; (3) growth variation among dry forest juveniles persists over longer time due to spatial heterogeneity in water availability. As expected, the proportion of suppressed juveniles was higher in moist than in dry forest (72 vs. 17%). Moist forest suppressions also lasted longer (9 vs. 5 years). The proportion of juveniles that experienced releases in moist forest (76%) was higher than in dry forest (41%), and releases in moist forests were much stronger. Trees in the moist forest also had a wider variation in canopy accession patterns compared to the dry forest. Our results also showed that growth variation among juvenile trees persisted over substantially longer periods of time in dry forest (>64 years) compared to moist forest (12 years), most probably because of larger persistent spatial variation in water availability. Our results suggest that periodic increases in light availability are more important for attaining the canopy in moist forests, and that spatial heterogeneity in water availability governs long-term tree growth in dry forests. Electronic supplementary material The online version of this article (doi:10.1007/s00442-009-1540-5) contains supplementary material, which is available to authorized users. PMID:20033820

  10. Assessing the extent of "conflict of use" in multipurpose tropical forest trees: a regional view.

    PubMed

    Herrero-Jáuregui, Cristina; Guariguata, Manuel R; Cárdenas, Dairon; Vilanova, Emilio; Robles, Marco; Licona, Juan Carlos; Nalvarte, Walter

    2013-11-30

    In the context of multiple forest management, multipurpose tree species which provide both timber and non-timber forest products (NTFP), present particular challenges as the potential of conflicting use for either product may be high. One key aspect is that the magnitude of conflict of use can be location specific, thus adding complexity to policy development. This paper focuses on the extent to which the potential for conflict of use in multipurpose tree species varies across the Amazonian lowland forests shared by Peru, Bolivia, Colombia, Ecuador and Venezuela, emphasizing the economic dimension of conflict. Based on a review of the current normative and regulatory aspects of timber and NTFP extraction in the five countries, the paper also briefly discusses the opportunities and constraints for harmonization of timber and NTFP management of multipurpose species across the region. It was found that about half of the 336 timber species reviewed across the five countries also have non-timber uses. Eleven timber species are multipurpose in all five countries: Calophyllum brasiliense, Cedrela odorata, Ceiba pentandra, Clarisia racemosa, Ficus insipida, Jacaranda copaia, Schefflera morototoni, Simarouba amara and Terminalia amazonia. Seven other multipurpose species occurred only in either Venezuela (Tabebuia impetiginosa, Spondias mombin, Pentaclethra macroloba, Copaifera officinalis, Chlorophora tinctoria, Carapa guianensis) or Ecuador (Tabebuia chrysantha). Four multipurpose tree species presented the highest potential of conflict of use across the region: Dipteryx odorata, Tabebuia serratifolia, Hymenaea courbaril and Myroxylon balsamum yet these were not evenly distributed across all five countries. None of the five studied countries have specific legislation to promote sustainable use of any of the multipurpose species reported here and thus mitigate potential conflict of use; nor documented management options for integration or else segregation of both their timber and NTFP values. PMID:24061084

  11. Interpopulation differences in exudate feeding of pygmy marmosets in Ecuadorian Amazonia.

    PubMed

    Yépez, Pablo; de la Torre, Stella; Snowdon, Charles T

    2005-06-01

    Local variations in fruit- and leaf-eating have been reported for some primate species; however, similar variations in exudate-feeding of pygmy marmosets, one of the most specialized neotropical primate species, have not been studied. In our 3-year study of four populations of pygmy marmosets in northeastern Ecuador, we characterized their exudate-feeding behavior by describing the use of exudate sources. We tested whether the use of exudate species was related to ecological factors such as the availability of exudate species in an area. We estimated the daily activity budgets of the groups with 1-hr scan samples and found significant interpopulation differences in the time spent on exudate feeding. We recorded a total of 18 exudate species used in the four populations; however, the populations differed in the total number of species used and in the preferred species. The most commonly used plant species were Sterculia apetala at San Pablo, Cedrela odorata at Sacha, Inga marginata at Amazoonico, and Parkia balslevii at Zancudo. We recorded the presence and abundance of the 18 exudate species in 90-m transects in the home range of each group and in one additional control area that contained no marmosets, for each population. Differences in the most-used exudate species among populations did not appear to be related to the availability of these species in each population, i.e., the marmosets did not use at random the exudate species available within their range, nor did they use more often the exudate species that were more abundant in their home ranges. One implication of our results for conservation is that protecting exudate resources based on data from only one area will not be sufficient to preserve pygmy marmosets in all populations. PMID:15940711

  12. Induction of laccases in Trametes versicolor by aqueous wood extracts.

    PubMed

    Bertrand, Brandt; Martínez-Morales, Fernando; Tinoco, Raunel; Rojas-Trejo, Sonia; Serrano-Carreón, Leobardo; Trejo-Hernández, María R

    2014-01-01

    The induction of laccase isoforms in Trametes versicolor HEMIM-9 by aqueous extracts (AE) from softwood and hardwood was studied. Samples of sawdust of Pinus sp., Cedrela sp., and Quercus sp. were boiled in water to obtain AE. Different volumes of each AE were added to fungal cultures to determine the amount of AE needed for the induction experiments. Laccase activity was assayed every 24 h for 15 days. The addition of each AE (50 to 150 μl) to the fungal cultures increased laccase production compared to the control (0.42 ± 0.01 U ml(-1)). The highest laccase activities detected were 1.92 ± 0.15 U ml(-1) (pine), 1.87 ± 0.26 U ml(-1) (cedar), and 1.56 ± 0.34 U ml(-1) (oak); laccase productivities were also significantly increased. Larger volumes of any AE inhibited mycelial growth. Electrophoretic analysis revealed two laccase bands (lcc1 and lcc2) for all the treatments. However, when lcc2 was analyzed by isoelectric focusing, inducer-dependent isoform patterns composed of three (pine AE), four (oak AE), and six laccase bands (cedar AE) were observed. Thus, AE from softwood and hardwood had induction effects in T. versicolor HEMIM-9, as indicated by the increase in laccase activity and different isoform patterns. All of the enzymatic extracts were able to decolorize the dye Orange II. Dye decolorization was mainly influenced by pH. The optimum pH for decolorization was pH 5 (85%), followed by pH 7 (50%) and pH 3 (15%). No significant differences in the dye decolorizing capacity were detected between the control and the differentially induced laccase extracts (oak, pine and cedar). This could be due to the catalytic activities of isoforms with pI 5.4 and 5.8, which were detected under all induction conditions. PMID:23861040

  13. Low Herbivory among Targeted Reforestation Sites in the Andean Highlands of Southern Ecuador.

    PubMed

    Adams, Marc-Oliver; Fiedler, Konrad

    2016-01-01

    Insect herbivory constitutes an important constraint in the viability and management of targeted reforestation sites. Focusing on young experimental stands at about 2000 m elevation in southern Ecuador, we examined foliar damage over one season as a function of tree species and habitat. Native tree species (Successional hardwood: Cedrela montana and Tabebuia chrysantha; fast-growing pioneer: Heliocarpus americanus) have been planted among prevailing local landcover types (abandoned pasture, secondary shrub vegetation, and a Pinus patula plantation) in 2003/4. Plantation trees were compared to conspecifics in the spontaneous undergrowth of adjacent undisturbed rainforest matched for height and foliar volume. Specifically, we tested the hypotheses that H. americanus as a pioneer species suffers more herbivory compared to the two successional tree species, and that damage is inversely related to habitat complexity. Overall leaf damage caused by folivorous insects (excluding leafcutter ants) was low. Average leaf loss was highest among T. chrysantha (7.50% ± 0.19 SE of leaf area), followed by H. americanus (4.67% ± 0.18 SE) and C. montana (3.18% ± 0.15 SE). Contrary to expectations, leaf area loss was highest among trees in closed-canopy natural rainforest, followed by pine plantation, pasture, and secondary shrub sites. Harvesting activity of leafcutter ants (Acromyrmex sp.) was strongly biased towards T. chrysantha growing in open habitat (mean pasture: 2.5%; shrub: 10.5%) where it could result in considerable damage (> 90.0%). Insect folivory is unlikely to pose a barrier for reforestation in the tropical Andean mountain forest zone at present, but leafcutter ants may become problematic if local temperatures increase in the wake of global warming. PMID:26963395

  14. Population size and trends for nesting ospreys in northwestern Mexico: Region-wide surveys, 1977, 1992/1993 and 2006

    USGS Publications Warehouse

    Henny, Charles J.; Anderson, Daniel W.; Vera, Aradit Castellanos; Carton, Jean-Luc E.

    2007-01-01

    We used a double-sampling technique (air plus ground survey) in 2006, with partial double coverage, to estimate the present size of the osprey (Pandion haliaetus) nesting population in northwestern Mexico. With the exception of Natividad, Cedros, and San Benito Islands along the Pacific Coast of Baja California, all three excluded from our coverage in 2006 due to fog, this survey was a repeat of previous surveys conducted by us with the same protocol in 1977 and 1992/1993 (Baja California surveyed in 1992, Sonora and Sinaloa 1993), allowing for estimates of regional population trends. Population estimates at the 'time of aerial survey' include those nesting, but missed from the air. The population estimate for our coverage area in 2006 was 1,343 nesting pairs, or an 81% increase since 1977, but only a 3% increase since 1992/1993. The population on the Gulf side of Baja California generally remained stable during the three surveys (255, 236 and 252 pairs, respectively). The overall Midriff Islands population remained similar from 1992/1993 (308 pairs) to 2006 (289 pairs), but with notable population changes on the largest two islands (Isla Angel de la Guarda: 45 to 105 pairs [+ 60 pairs]; Isla Tiburon: 164 to 109 pairs [- 55 pairs, or -34%]). The estimated osprey population on the Sonora mainland decreased in a manner similar to adjacent Isla Tiburon, i.e., by 26%, from 214 pairs in 1993 to 158 pairs in 2006. In contrast, the population in Sinaloa, which had increased by 150% between 1977 and 1993, grew again by 58% between 1993 and 2006, from 180 to 285 pairs. Our survey confirmed previously described patterns of rapid population changes at a local level, coupled with apparent shifts in spatial distribution. The large ground nesting population that until recently nested on two islands in San Ignacio Lagoon was no longer present on the islands in 2006, but an equivalent number of pairs were found to the north and south of the lagoon, nesting in small towns and along adjoining power-lines, with no overall change in population size for that general area (198 pairs in 1992; 199 in 2006). Use of artificial nesting structures was 4.3% in 1977 and 6.2% in 1992/1993, but jumped to 26.4% in 2006. Use of power poles poses a risk of electrocution to ospreys as well as causes power outages and fires; modification of power poles to safely accommodate osprey nests has been successful in many countries.

  15. Region-wide trends of nesting ospreys in northwestern Mexico: a three-decade perspective

    USGS Publications Warehouse

    Henny, Charles J.; Anderson, Daniel W.; Vera, Aradit Castellanos; Cartron, Jean-Luc E.

    2008-01-01

    We used a double-sampling technique (air plus ground survey) in 2006, with partial double coverage, to estimate the present size of the Osprey (Pandion haliaetus) nesting population in northwestern Mexico (coastal Baja California, islands in the Gulf of California, and coastal Sonora and Sinaloa). With the exception of Natividad, Cedros, and San Benitos islands along the Pacific coast of Baja California (all three excluded from our coverage in 2006 due to fog), this survey was a repeat of previous surveys conducted by us with the same protocol in 1977 and 1992/1993, allowing for estimates of regional population trends. The minimum population estimate for the area we surveyed in 2006 was 1343 nesting pairs, an 81% increase since 1977, but only a 3% increase since 1992/1993. The population on the Gulf side of Baja California generally remained stable during the three surveys (255, 236, and 252 pairs, respectively). The population of the Midriff Islands (Gulf of California in the vicinity of 29°N latitude) remained similar from 1992/1993 (308 pairs) to 2006 (289 pairs), but with notable population changes on the largest two islands (Guardian Angel: 45 to 105 pairs [133% increase]; Tiburón: 164 to 109 pairs [34% decrease]). The minimum estimated Osprey population on the Sonora mainland decreased in a manner similar to adjacent Isla Tiburón, i.e., by 26%, from 214 pairs in 1993 to 158 pairs in 2006. In contrast, the population in coastal Sinaloa, which had increased by 150% between 1977 and 1993, grew again by 58% between 1993 and 2006, from 180 to 285 pairs. Our survey confirmed previously described patterns of rapid population changes at a local level, coupled with apparent shifts in spatial distribution. The large ground-nesting population that until recently nested on two islands in San Ignacio Lagoon ( Pacific Ocean side, Baja California) was no longer present on the islands in 2006, but an equivalent number of pairs were found to the north and south of the lagoon, nesting in small towns and along adjoining overhead electric lines, with no overall change in population size for that general area (198 pairs in 1992; 199 in 2006). Use of artificial nesting structures was 4.3% in 1977 and 6.2% in 1992/1993, but jumped to 26.4% in 2006. Use of poles that support overhead electric lines poses a risk of electrocution to Ospreys and also causes power outages and fires. We recommend modification of these poles to safely accommodate Osprey nests, as has been successfully accomplished in many countries.

  16. Pb, Sr, and Nd isotopic and chemical evidence for a primitive island arc emplacement of the El Arco porphyry copper deposit (Baja California, Mexico)

    NASA Astrophysics Data System (ADS)

    Weber, Bodo; Martínez, Margarita López

    2006-01-01

    The El Arco porphyry copper deposit is located in central Baja California and is a resource containing >600 Mt of ore with ˜0.6% copper. It was emplaced within a relatively primitive Jurassic island arc and it was subsequently metamorphosed and intruded by the Cretaceous Peninsular Ranges batholith. The porphyritic stock intrusion and ore formation at El Arco has recently been dated at ˜165 Ma [Valencia et al. GEOS 24:189 (2004)]. This age is much older than Aptian-Albian K-Ar ages previously reported from El Arco [Barthelmy, Geology of El Arco-Calmallí area, Baja California, México. MSc Thesis, San Diego State University, CA (1975); Baja California Geology. San Diego State University, CA, pp 127-138 (1979)]. The copper mineralization at El Arco is concentrated in a core of potassic alteration in a dioritic porphyritic stock surrounded by propylitic alteration in andesitic lavas. Mafic dikes that intruded the deposit are not mineralized, but they are affected by post-ore low-grade metamorphism. The dikes are compositionally the most primitive rocks, while host rock andesites and the porphyry stock display typical volcanic arc characteristics. The Pb isotope data from sulfides, feldspars, quartz, and whole-rock samples indicate that: (1) the copper-bearing porphyry stock and the surrounding andesites evolved from a similar source with an average μ-value of 9.43; (2) no external Pb was added during mineralization; (3) some Pb isotope compositions were slightly disturbed by a later metamorphic event. Strontium and Nd isotopes show that the magmas evolved from a depleted mantle reservoir with no involvement of older continental crust. Our data favor a model for the formation of the El Arco deposit linked to a Triassic to Jurassic intra-oceanic arc system, cropping out at the western margin of central Baja California in the Cedros-Vizcaíno region. The intra-oceanic arc together with the El Arco deposit was accreted to the active continental margin of North America and metamorphosed during the Early Cretaceous. This model is in disagreement to earlier models that favor the El Arco deposit formation being linked to the Cretaceous continental margin.

  17. 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 the study site was low, and (c) the plant mixes obtain water from more than a single soil layer simultaneously. Temporal factors were important in determining the competition and complementary relations observed among the trees and the perennial monocots. Under the prevailing environmental conditions, water use in these plant associations was determined largely by species-specific attributes such as biomass allocation to fine roots, phenology, and canopy architecture, and to a lesser extent by water limitations. PMID:19419093

  18. Oxygen isotopes in tree rings show good coherence between species and sites in Bolivia

    NASA Astrophysics Data System (ADS)

    Baker, Jessica C. A.; Hunt, Sarah F. P.; Clerici, Santiago J.; Newton, Robert J.; Bottrell, Simon H.; Leng, Melanie J.; Heaton, Timothy H. E.; Helle, Gerhard; Argollo, Jaime; Gloor, Manuel; Brienen, Roel J. W.

    2015-10-01

    A tree ring oxygen isotope (δ18OTR) chronology developed from one species (Cedrela odorata) growing in a single site has been shown to be a sensitive proxy for rainfall over the Amazon Basin, thus allowing reconstructions of precipitation in a region where meteorological records are short and scarce. Although these results suggest that there should be large-scale (> 100 km) spatial coherence of δ18OTR records in the Amazon, this has not been tested. Furthermore, it is of interest to investigate whether other, possibly longer-lived, species similarly record interannual variation of Amazon precipitation, and can be used to develop climate sensitive isotope chronologies. In this study, we measured δ18O in tree rings from seven lowland and one highland tree species from Bolivia. We found that cross-dating with δ18OTR gave more accurate tree ring dates than using ring width. Our "isotope cross-dating approach" is confirmed with radiocarbon "bomb-peak" dates, and has the potential to greatly facilitate development of δ18OTR records in the tropics, identify dating errors, and check annual ring formation in tropical trees. Six of the seven lowland species correlated significantly with C. odorata, showing that variation in δ18OTR has a coherent imprint across very different species, most likely arising from a dominant influence of source water δ18O on δ18OTR. In addition we show that δ18OTR series cohere over large distances, within and between species. Comparison of two C. odorata δ18OTR chronologies from sites several hundreds of kilometres apart showed a very strong correlation (r = 0.80, p < 0.001, 1901-2001), and a significant (but weaker) relationship was found between lowland C. odorata trees and a Polylepis tarapacana tree growing in the distant Altiplano (r = 0.39, p < 0.01, 1931-2001). This large-scale coherence of δ18OTR records is probably triggered by a strong spatial coherence in precipitation δ18O due to large-scale controls. These results highlight the strength of δ18OTR as a precipitation proxy, and open the way for temporal and spatial expansion of precipitation reconstructions in South America.

  19. 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 and replanting or by the phenological traits of the species selected or combined, subject N supplies to leaching loss. PMID:16711039

  20. Complementary soil water use is indicated in mixed native tree plantations, Panama

    NASA Astrophysics Data System (ADS)

    Schwendenmann, L.; Sánchez Bragado, R.; Kunert, N.; Hölscher, D.

    2010-12-01

    Recent approaches to reforestation in the tropics emphasize the establishment of mixed species plantations to provide production but also ecological benefits. However, little is known about the effects of mixed-species stands on soil water utilization und tree water use rates. The objectives of this study were i) to asses seasonal plant water uptake patterns for different species and ii) to examine the effects of species diversity on water uptake and water use rates. The study was conducted in a 7-yr-old plantation in Panama. Five native tree species were planted in mono-, three- and five-species plots. Natural abundance stable isotopic ratios of hydrogen (δ2H) and oxygen (δ18O) in xylem and soil water samples were used to determine water uptake patterns. The contribution of water from each soil layer to xylem water was calculated using the isotope mixing model SISUS (Stable Isotope Sourcing Using Sampling). Sap flux was measured using thermal dissipation probes. Isotope ratios in soil and xylem water fell below the local meteoric water line (LMWL) suggesting some evaporation. Soil water isotope ratio increased with depth from an average of -18 ‰ and -1 ‰ in the surface soil layer (0-10 cm) to -40 ‰ and -8 ‰ at 50-70 cm depth for δ2H and δ18O, respectively. During the dry season δ2H and δ18O of xylem water were negatively correlated with tree water use rates suggesting that trees taking up water from deeper soil horizons were able to maintain higher water use rates. Species tended to differ in their water uptake pattern, especially during the dry season. Cedrela odorata and Hura crepitans were primarily obtaining water (60 to 80%) from the upper 30 cm. In contrast, Tabebuia rosea took up most of its water (75-90%) from soil depths > 30 cm. Xylem water δ2H and δ18O in Anacardium excelsum and Luehea seemannii suggest that water was taken up to equal proportions from all soil horizons. In mixed stands, overall transpirational water use was higher than in mono-specific stands, which can partly be explained by complementary soil water use among the coexisting tree species.

  1. Hydrogeology study of Faial Island, the Azores

    NASA Astrophysics Data System (ADS)

    Coutinho, R. M.; Cruz, J. V.

    2011-12-01

    Azores Archipelago is a Portuguese territory formed by nine islands divided into three groups (eastern, central and western) located in the North Atlantic Ocean. The islands stretch along a NW-SE direction near the so called Azores triple junction, where the North American Plate, the African Plate and the Eurasian Plate meet. Faial Island is the westernmost island of the central group, located between 38°30'56'' to 38°38'40'' N latitude and 28°35'55'' to 28°50'06'' W longitude. Faial is affected by important tectonic features with a WNW-ESE general trend. These features combined with faults with NNW-SSE to NW-SE and NE-SW directions may have conditioned the emplacement of the central volcano with caldera on the central part of the island. In what concerns the geomorphology, besides the central volcano with caldera, one should refer to the graben on the eastern sector, to the scoria cones alignment on the W and to the flattened sector SE of the central volcano. The drainage network is markedly controlled by tectonics and the drainage density is higher on the northern and southern flanks of the central volcano. The origin of the island started more than 800000 years ago with the emplacement of a composite volcano on the NE of the island (Ribeirinha Complex) consisting of a series of lava flows of basaltic to benmoreitic composition and undifferentiated pyroclasts. The complex (Cedros Complex) which followed is about 580000 years old and corresponds to the central volcano formed by suites of basaltic to trachitic lava flows, pyroclasts and domes. Approximately 50000 ago an important fissural activity took place on the eastern part of the island and originated Almoxarife Formation consisting of basaltic to benmoreitic lava flows, scoria cones and tuff cones. The Caldeira Formation (~16000 years) comprises benmoreitic to trachytic materials emitted from the central volcano, whose explosive phases generated ten members formed mainly by pumice fall deposits and pyroclastic flows. Capelo Complex, which is partially contemporary to the previous formation, comprises the western fissural volcanism and the historical eruptions of Cabeço do Fogo and Capelinhos. Groundwater occurs in two main aquifer systems: (1) the basal aquifer that corresponds to the freshwater lens floating over underlying salt water and (2) perched water bodies. 15 drilled wells and 10 hand dug wells extract water from the basal aquifer and about 80 springs drain the volcanic edifices at different altitudes. In what concerns hydrodynamic characterisation, an estimate of the recession constant of the springs yielded values from 2x10-3 to 14.2x10-3. Calculated transmissivity values for the basal aquifer and a perched aquifer are within the range of 9.5x10-3 to 3x10-2 m2/s. Hydraulic diffusivity estimated from tidal effect measurements has a value of 2634 m2/d. Physical and chemical water analysis shows that they are cold, except for two of them. Four water samples show high CO2 contents. Water from springs and from wells not contaminated by salt water intrusion are bicarbonated and sodium rich in composition while water from contaminated wells has higher chloride and magnesium contents. Geochemical modelling indicates that the major mineralizing processes are silicate dissolution and salt water intrusion.

  2. Graben calderas of the Sierra Madre Occidental: The case of Guanajuato, central Mexico

    NASA Astrophysics Data System (ADS)

    Aguirre-Diaz, G. J.; Tristán-González, M.; Labarthe-Hernández, G.; Marti, J.

    2013-12-01

    The Sierra Madre Occidental (SMO) volcanic province is characterized by voluminous silicic ignimbrites that reach an accumulated thickness of 500 to 1500 m. A single ignimbrite can reach up to 350 m thick in its outflow facies. This ignimbrite sequence formed mostly within 38-23 Ma, building up a total estimated volume of ca. 580,000 km3 making the SMO the largest ignimbrite province of the world. We have showed that several and probably most of the SMO ignimbrites were erupted from fissures associated to Basin and Range fault systems or grabens (Geology, 2003), thus naming these volcano-tectonic structures as graben calderas (Caldera Volcanism book, Elsevier, 2008). Generally, the sequence observed in graben calderas include, from oldest to youngest, alluvial fan deposits combined with lacustrine deposits, pyroclastic surge deposits and minor volume ignimbrites, a large-volume ignimbrite that could be massive or made of successive layers, and sometimes silicic lava domes and/or mafic fissural lavas both with vents aligned with the graben trend. Fallout deposits, plinian or non-plinian, are not observed in the sequence. Thus, onset of caldera collapse represented by the major ignimbrite must occur just after deposition of continental sediments within the graben domain. A similar volcano-tectonic development is observed in pull-apart grabens. Therefore, extensional or transtensional tectonics, before and during caldera collapse, and the emplacement of a subgraben shallow silicic magma chamber are the necessary conditions for the development of graben calderas. We describe here the case of the Guanajuato graben caldera, located in the central part of Mexico and in the southeastern portion of the SMO volcanic province. The caldera is part of the economically important mining district of Guanajuato, with 28 silver mines, some active since the 16th century. The caldera structure, a rectangle of 10 x 16 km, was controlled by NW and NE regional fault systems. Most ore deposits occur along this orthogonal faulting network, but mainly along the NW fault of Veta Madre that crosses through the center of the caldera. The mid-Tertiary stratigraphy in Guanajuato follows the general sequence observed in graben calderas; i.e., from oldest to youngest includes 1) at least 1,500 m of alluvial fan deposits within a tectonic basin (Guanajuato Red Conglomerate), 2) pyroclastic flow deposits, consisting of surge deposits (Loseros Formation) that are concordant with a massive, large volume, rhyolitic ignimbrite (Bufa Rhyolite), which is covered by a layered series of pyroclastic flow deposits (Calderones Formation), and 3) effusive volcanism in the form of rhyolitic lava domes (Chichíndaro Rhyolite) and basaltic-andesite dikes and lavas (Cedros Andesite). The Guanajuato graben caldera formed at about 33 Ma, based on our new U-Pb zr age of the main ignimbrite, Bufa Rhyolite.