Search results for "DON"
showing 10 items of 8430 documents
Database of diazotrophs in global ocean: abundance, biomass and nitrogen fixation rates
2012
Marine N<sub>2</sub> fixing microorganisms, termed diazotrophs, are a key functional group in marine pelagic ecosystems. The biological fixation of dinitrogen (N<sub>2</sub>) to bioavailable nitrogen provides an important new source of nitrogen for pelagic marine ecosystems and influences primary productivity and organic matter export to the deep ocean. As one of a series of efforts to collect biomass and rates specific to different phytoplankton functional groups, we have constructed a database on diazotrophic organisms in the global pelagic upper ocean by compiling about 12 000 direct field measurements of cyanobacterial diazotroph abundances (based on microscopic …
sPlotOpen – An environmentally balanced, open‐access, global dataset of vegetation plots
2021
Datos disponibles en https://github.com/fmsabatini/sPlotOpen_Code
Redescription of the forgotten New Caledonian weevil genus Callistomorphus Perroud, 1865 (Coleoptera, Curculionidae, Eugnomini) with descriptions of …
2019
Callistomorphusis one of the “forgotten” genera of the tribe Eugnomini inhabiting rain forest in New Caledonia. In this paper, the genusCallistomorphusand the type speciesC.farinosusare redescribed. Eight new species,Callistomorphusfundatussp. n.,C.gibbussp. n.,C.malleussp. n.,C.minimussp. n.,C.rutaisp. n.,C.szoltysisp. n.,C.torosussp. n.andC.turbidussp. n., are described, originating from the main island of New Caledonia. Illustrations and SEM photographs of the external morphology and the male and female terminalia are provided, as well as dorsal habitus colour photographs of the adults, a key to the species, a distribution map, and a discussion of the systematic position ofCallistomorphu…
Defoliation of two-wire vertical trellis: effect on grape quality
2017
ABSTRACTBasal leaves were removed from Cabernet Sauvignon vines trained to a two-wire vertical trellis at fruit set and at veraison. Leaf removal did not modify total soluble solids and titratable acidity at harvest. Defoliation at fruit set of lower cordon recovered the grape anthocyanin composition gap between upper and lower cordons and that produced a positive effect on anthocyanin synthesis. Hence, control of the upper cordon and defoliation of fruit set of the lower cordon treatments showed comparable values of anthocyanins. Defoliation at veraison did not produce any appreciable effect. This study shows that skin anthocyanin composition in a two-wire vertical trellis can be modified …
Revision of the Afrotropical genus Leiodontocercus (Orthoptera, Tettigoniidae, Phaneropterinae) with a description of four new species
2020
Specimens belonging to the genus Leiodontocercus are rare or even absent in natural history museum collections; this is likely due to at least two reasons, notably, their relatively small size, and, the sheer difficulty in finding them in dense Afrotropical forests. Until recently, three species from less than fifteen specimens were known from this genus, whose identification relied on a singular diagnostic character, that is, the shape of the male cerci. The present contribution is based on the examination of thirty specimens collected from various countries, ranging from central to west Africa; apart from the male cerci, a second diagnostic character – the stridulatory file – is used to d…
Taxonomy 2.0: computer-aided identification tools to assist Antarctic biologists in the field and in the laboratory
2020
Species inventories are essential to the implementation of conservation policies to mitigate biodiversity loss and maintain ecosystem services and their value to the society. This is particularly topical with respect to climate change and direct anthropogenic effects on Antarctic biodiversity, with the identification of the most at-risk taxa and geographical areas becoming a priority. Identification tools are often neglected and considered helpful only for taxonomists. However, the development of new online information technologies and computer-aided identification tools provides an opportunity to promote them to a wider audience, especially considering the emerging generation of scientists…
Plankton community composition in relation to availability and uptake of oxidized and reduced nitrogen
2003
Centre de Recherche en Ecologie Marine et Aquaculture de L'Houmeau (CNRS-IFREMER), BP 5, 17137 L'Houmeau, France ABSTRACT: Trends in nitrogen utilization, determined with 15 N-labeled substrates, were related to blooms of distinct phytoplankton groups in the Gulf of Riga, Baltic Sea, during May, June and July 1999. The dominant phytoplankton groups included diatoms, cryptophytes, dinoflagellates, and fila- mentous cyanobacteria. As the water column became progressively more stratified over the growing season, diatoms comprised a smaller proportion of the total phytoplankton assemblage and almost disappeared by late summer. Their disappearance correlated with undetectable surface-water nitra…
Root hair anatomy and morphology in Posidonia oceanica (L.) Delile and substratum typology: First observations of a spiral form
2018
Abstract The morpho-anatomical root hair features of P. oceanica ramets collected in meadows settled on different substrata (sand, matte and rock) were analysed. On each substratum, nine plagiothropic rhizomes each one composed by 3–6 interconnected short shoots were collected between April and May 2016 at 10 m of depth. On sand and on rock, the adventitious roots showed two distinct tubular and spiral-shaped hairs, clustered in yellowish-gray gelatinous pads. Tubular root hair tips were dactiliform and generally attached to grains of rock fragments. Moreover, a sub-circular swelling zone occurred. On matte , root hairs did not form gelatinous pads, were very short and had a simple distal p…
A new genus and nine new species of Eugnomini (Coleoptera, Curculionidae) from New Caledonia
2016
Abstract The genus Rasilinus gen. n. is described (type species Rasilinus tchambicus sp. n.). Nine new species: Rasilinus bicolor sp. n., Rasilinus bifurcatus sp. n., Rasilinus bimaculatus sp. n., Rasilinus grandidens sp. n., Rasilinus longulus sp. n., Rasilinus subgemellus sp. n., Rasilinus subnodulus sp. n., Rasilinus tchambicus sp. n., Rasilinus virgatus sp. n. are described from New Caledonia. Illustrations of the external morphology, male and female terminalia, dorsal habitus colour photographs of the adults, key to species and distribution map of the new genus Rasilinus are provided.
Functional and energetic consequences of climate change on a predatory whelk
2017
Abstract The increasing rise in sea surface temperature caused by human activities currently represents the major threat to biodiversity and natural food webs. In this study we used the Lessepsian mussel Brachidontes pharaonis, one of the most recent invaders of the Mediterranean Sea, as a model to investigate the effect of a novel prey and a chronic increase in temperatures on functional parameters of local consumers, compared to the native mytilid species Mytilaster minimus. In particular we focused on the whelk Stramonita haemastoma, a widespread Mediterranean intertidal predator that actively preys on bivalves, barnacles and limpets, by studying the direct effects of such multiple stres…