10,365 research outputs found

    Coral skeleton P/Ca proxy for seawater phosphate: Multi-colony calibration with a contemporaneous seawater phosphate record

    No full text
    A geochemical proxy for surface ocean nutrient concentrations recorded in coral skeleton could provide new insight into the connections between sub-seasonal to centennial scale nutrient dynamics, ocean physics, and primary production in the past. Previous work showed that coralline P/Ca, a novel seawater phosphate proxy, varies synchronously with annual upwelling-driven cycles in surface water phosphate concentration. However, paired contemporaneous seawater phosphate time-series data, needed for rigorous calibration of the new proxy, were lacking. Here we present further development of the P/Ca proxy in Porites lutea and Montastrea sp. corals, showing that skeletal P/Ca in colonies from geographically distinct oceanic nutrient regimes is a linear function of seawater phosphate (PO4 SW) concentration. Further, high-resolution P/Ca records in multiple colonies of Pavona gigantea and Porites lobata corals grown at the same upwelling location in the Gulf of Panama were strongly correlated to a contemporaneous time-series record of surface water PO4 SW at this site (r2 = 0.7–0.9). This study supports application of the following multi-colony calibration equations to down-core records from comparable upwelling sites, resulting in ±0.2 and ±0.1 lmol/kg uncertainties in PO4 SW reconstructions from P. lobata and P. gigantea, respectively.P/Ca Porites lobata (lmol/mol) = (21.1 ? 2.4)PO4 SW (lmol/kg) + (14.3 ? 3.8)P/Ca Pavona gigantea (lmol/mol) = (29.2 ? 1.4)PO4 SW (lmol/kg) + (33.4 ? 2.7)Inter-colony agreement in P/Ca response to PO4 SW was good (±5–12% about mean calibration slope), suggesting that species-specific calibration slopes can be applied to new coral P/Ca records to reconstruct past changes in surface ocean phosphate. However, offsets in the y-intercepts of calibration regressions among co-located individuals and taxa suggest that biologically-regulated “vital effects” and/or skeletal extension rate may also affect skeletal P incorporation. Quantification of the effect of skeletal extension rate on P/Ca could lead to corrected calibration equations and improved inter-colony P/Ca agreement. Nevertheless, the efficacy of the P/Ca proxy is thus supported by both broad scale correlation to mean surface water phosphate and regional calibration against documented local seawater phosphate variations

    Discovery and Percent Colonization of Vesicular-Arbuscular Mycorrhizae in Pueraria lobata

    Get PDF
    Pueraria lobata, more commonly known as Kudzu, was brought from Japan to the United States in 1876. Although originally planted for erosion control, P. lobata\u27s vigorous growth facilitated its escape and caused it to spread over vast areas of land. Today P. lobata is found predominately in the Southeastern United States where it thrives during the summer months, growing up to a foot a day. This growth leads to a vine-like canopy several layers thick with deep set roots which makes removal of the plant extremely difficult. Research on P. lobata is limited and has focused mainly on its role in erosion control. No literature has been found to provide insights into P. lobata \u27s prolific growth. Mycorrhizae may, however, hold the answer. This fungus, present in the roots of many plants, enhances the uptake of essential nutrients and could provide P. lobata with the vigor it needs for such an incredible growth rate. To determine if mycorrhizal association was present, P. lobata roots were collected, stained, and viewed for fungal structures. The presence ofvesicular-arbuscular mycorrhizal fungi (V AM) was established. To further understand P. lobata\u27s dependence on this symbiotic relationship, two factors are important. First, the extent of association between the plant and fungus can be determined by percent colonization of V AM using the magnified intersections method (McGonigle eta/., 1990). Second, experimental growth rate differences between P. lobata planted in sterile soil versus mycorrhizae rich soil would provide direct evidence of its dependence on VAM

    Fish Habitat Utilization Patterns and Evaluation of the Efficacy of Marine Protected Areas in Hawaii: Integration of NOAA Digital Benthic Habitat Mapping and Coral Reef Ecological Studies

    Get PDF
    Over the past four decades, the state of Hawaii has developed a system of eleven Marine Life Conservation Districts (MLCDs) to conserve and replenish marine resources around the state. Initially established to provide opportunities for public interaction with the marine environment, these MLCDs vary in size, habitat quality, and management regimes, providing an excellent opportunity to test hypotheses concerning marine protected area (MPA) design and function using multiple discreet sampling units. NOAA/NOS/NCCOS/Center for Coastal Monitoring and Assessment’s Biogeography Team developed digital benthic habitat maps for all MLCD and adjacent habitats. These maps were used to evaluate the efficacy of existing MLCDs for biodiversity conservation and fisheries replenishment, using a spatially explicit stratified random sampling design. Coupling the distribution of habitats and species habitat affinities using GIS technology elucidates species habitat utilization patterns at scales that are commensurate with ecosystem processes and is useful in defining essential fish habitat and biologically relevant boundaries for MPAs. Analysis of benthic cover validated the a priori classification of habitat types and provided justification for using these habitat strata to conduct stratified random sampling and analyses of fish habitat utilization patterns. Results showed that the abundance and distribution of species and assemblages exhibited strong correlations with habitat types. Fish assemblages in the colonized and uncolonized hardbottom habitats were found to be most similar among all of the habitat types. Much of the macroalgae habitat sampled was macroalgae growing on hard substrate, and as a result showed similarities with the other hardbottom assemblages. The fish assemblages in the sand habitats were highly variable but distinct from the other habitat types. Management regime also played an important role in the abundance and distribution of fish assemblages. MLCDs had higher values for most fish assemblage characteristics (e.g. biomass, size, diversity) compared with adjacent fished areas and Fisheries Management Areas (FMAs) across all habitat types. In addition, apex predators and other targeted resources species were more abundant and larger in the MLCDs, illustrating the effectiveness of these closures in conserving fish populations. Habitat complexity, quality, size and level of protection from fishing were important determinates of MLCD effectiveness with respect to their associated fish assemblages. (PDF contains 217 pages

    Taxonomy of the Crematogaster degeeri-species-assemblage in the Malagasy region (Hymenoptera: Formicidae)

    Get PDF
    We revise the species-level taxonomy of the Crematogaster (Crematogaster) degeerispecies-assemblage, a group of related ants occuring in Madagascar and the wider Malagasy region, and further provide an identification key to all species-groups of the genus Crematogaster in this region. Within the C. degeeri-assemblage, we recognize twelve species based upon morphological data from worker, queen and male ants, as well as genetic data from the barcode region of cytochrome oxidase I. Seven new species are described: Crematogaster alafara Blaimer sp. nov., C. bara Blaimer sp. nov., C. mafybe Blaimer sp. nov., C.maina Blaimer sp. nov., C. malahelo Blaimer sp. nov., C. masokely Blaimer sp. nov., C. ramamy Blaimer sp. nov. Crematogaster tricolor Gerstäcker, 1859 (stat. rev.) and C. dentata Dalla Torre, 1893 (stat. nov.) are raised to species level, and the following new synonymies are proposed: Crematogaster degeeri lunaris Santschi, 1928 as a synonym of C. degeeri Forel, 1886; Crematogaster sewelli improba Forel, 1907 and C. sewelli mauritiana Forel, 1907 as synonyms of C. dentata Dalla Torre, 1893, and C. pacifi ca Santschi, 1919 as a synonym of C. lobata Emery, 1895. Species descriptions, images, and distribution maps and identification keys based on worker ants, as well as on queen ants where available, are presented for all twelve species. In addition, we present a molecular gene tree for cytochrome oxidase I and summarize levels of sequence divergence within and between species of the C. degeeri-species-assemblage. Our findings are discussed in the light of previous work on Malagasy Crematogaster ants

    Occurrence of the Old World bug Megacopta cribraria (Fabricius) (Heteroptera: Plataspidae) in Georgia: a serious home invader and potential legume pest

    Get PDF
    Specimens of Megacopta cribraria (Fabricius) were collected in northern Georgia in late October 2009, where they were invading homes in large numbers. This is the first known occurrence of this species and the family Plataspidae in the New World. Megacopta cribraria was previously known from Asia and Australia. A key is provided to separate Plataspidae from other families of Pentatomoidea in America North of Mexico. A diagnosis and figures are provided to facilitate recognition of M. cribraria. Reported host plants and other aspects of the biology of this species are reviewed. Megacopta cribraria is considered a pest of numerous legumes in Asia, has the potential to provide biological control of kudzu, Pueraria montana var. lobata (Willd.) Ohwi, (Fabaceae) and likely will continue to be a household pest in the vicinity of kudzu fields as well as become a pest of North American legume crops

    Preliminary Phytochemical Analyses of Two Varieties of Adenia Lobata (Jacq) and the Antioxidant Activity of Their Various Solvent Fractions

    Get PDF
    Adenia lobata is a medicinal plant that is traditionally used for the treatment of various diseases such as cancer in some places in eastern Nigeria. Comparative phytochemical analyses were carried out on two varieties of Adenia lobata; Adenia lobata with cordate leaves (ALC) and Adenia lobata with palmate leaves (ALP). ALC was found to possess more phytochemical constituents than ALP. The antioxidant activity of the solvent fractions viz. hexane, dichloromethane (DCM), ethylacetate, butanol and aqueous fractions of each variety of the Adenia lobata was also determined. The highest antioxidant activity (63.87%) was found in the ethylacetate fraction of ALC. These results suggest that the therapeutic use of this plant in the treatment of cancer could be due to its antioxidant activity

    State Records and Confirmations of Arkansas Flat Bugs (Heteroptera: Aradidae)

    Get PDF
    Eight aradid species are reported for the first time from Arkansas including Aneurus pygmaeus, Aradus cincticornis, Aradus crenatus, Quilnus niger, Mezira granulata, Mezira lobata, Mezira sayi, and Neuroctenus simplex. The presence of Aradus acufus, Aradus falleni, and Aradus robustus in Arkansas is confirmed

    Astraea lobata (L) Klotzsch (Euphorbiaceae): An ethnopharmacological review

    Get PDF
    This is a review on the medicinal uses, phytochemistry and biological activities of A. lobata with a view to present a better understanding of the medicinal potentials of the species. Published literature on A. lobata were sourced from databases such as Google Scholar, Web of Science, SciFinder, Scopus, Science Direct, PubMed, Scielo, Springerlink, Google Patents, Espacenet, BioMed Central (BMC) and Medline. Astraea lobata is native to north, central and south America, and now naturalized in Benin, Ghana, Ivory Coast, Nigeria, Senegal and Togo where it is used to treat numerous diseases including dysentery, malaria, menstrual problems, scorpion bite, rheumatism pain, skin cancer, sterility in women and as purgative. Multiple classes of phytochemicals such as alkaloids, anthraquinones, esters, diterpene alcohols, flavonoids, hydroxy ketones, peptides, phenolics, saponins, steroids, tannins, triterpenes and triglycerides have been isolated from fruits, leaves, roots and stems of A. lobata. Scientific studies on A. lobata indicate that it has a wide range of pharmacological activities which include antibacterial, antidiabetic, antiplasmodial, antioxidant, antitrypanosomal and leishmanicidal activities. The wide usage of A. lobata as a herbal medicine calls for detailed pharmacological and phytochemical studies aimed at correlating the documented medicinal uses of the species with its biological activities and phytochemistry.Keywords: Astraea lobata, Euphorbiaceae, herbal medicine, pharmacology, phytochemistr

    East-West Genetic Differentiation in Musk Ducks (Biziura lobata) of Australia Suggests Late Pleistocene Divergence at the Nullarbor Plain

    Get PDF
    Musk Ducks (Biziura lobata) are endemic to Australia and occur as two geographically isolated populations separated by the Nullarbor Plain, a vast arid region in southern Australia. We studied genetic variation in Musk Duck populations at coarse (eastern versus western Australia) and fine scales (four sites within eastern Australia). We found significant genetic structure between eastern and western Australia in the mtDNA control region (UST = 0.747), one nuclear intron (UST = 0.193) and eight microsatellite loci (FST = 0.035). In contrast, there was little genetic structure between Kangaroo Island and adjacent mainland regions within eastern Australia. One small population of Musk Ducks in Victoria (Lake Wendouree) differed from both Kangaroo Island and the remainder of mainland eastern Australia, possibly due to genetic drift exacerbated by inbreeding and small population size. The observed low pairwise distance between the eastern and western mtDNA lineages (0.36%) suggests that they diverged near the end of the Pleistocene, a period characterised by frequent shifts between wet and arid conditions in central Australia. Our genetic results corroborate the display call divergence and Mathews’ (Austral Avian Record 2:83–107, 1914) subspecies classification, and confirm that eastern and western populations of Musk Duck are currently isolated from each other
    corecore