12 research outputs found
Iconic relationships in some halophytic Iranian Chenopodiaceae and their rhizospheres
Matinzadeh Z, Breckle S-W, Mirmassoumi M, Akhani H. Iconic relationships in some halophytic Iranian Chenopodiaceae and their rhizospheres. Plant And Soil. 2013;372(1-2):523-539.Previous studies on the identification of ion relations in halophytes have revealed that many members of Chenopodiaceae accumulate high amounts of sodium and chloride even in soils with low salinity, indicating a typical pattern which is genetically fixed. In this study, we followed up with the question of ion relations in different halophyte species with different photosynthetic pathways and different salt tolerance strategies over a complete growing season. Soil and plant samples from five species Climacoptera turcomanica (Litv.) Botsch. (leaf succulent-C-4), Salicornia persica Akhani subsp. rudshurensis Akhani (stem succulent-C-3), Halimocnemis pilifera Moq. (leaf succulent-C-4), Petrosimonia glauca (Pall.) Bunge (leaf succulent-C-4) and Atriplex verrucifera M. Bieb. (recreto-halophyte-C-3) were collected over a complete growing season from a salt flat 60 km W of Tehran. The contents of main cations (Na+, K+, Ca2+, and Mg2+) and chloride were determined in plant and soil samples. Na+ and Cl- concentration in the shoots of two hygro-halophytes Climacoptera turcomanica and Salicornia persica subsp. rudshurensis were constant over the period of the growing season. In contrast, sodium and chloride in the shoots of Halimocnemis pilifera and Petrosimonia glauca showed respectively an increasing and, in the shoots of Atriplex verrucifera, a decreasing, trend. We did not notice any decreasing trend of K+ together with increasing trend of Na+ in the shoots of the studied species; however K+ in the shoots of all examined species was considerably lower than Na+ and Cl-. It was observed that Climacoptera and Salicornia could absorb and retain calcium even in high salinity conditions, while Halimocnemis and Petrosimonia could not. Na+, K+, Cl-, Ca2+, and Mg2+ contents in the shoots of different types of halophytes (stem-succulent, leaf-succulent and excreting halophyte) or different type of photosynthesis (C-3, C-4) are independent of those in their rhizosphere. We concluded that it is controlled by the genetic characteristic of the specific taxon rather than by the environment
Sexual reproduction of the solitary sunset cup coral Leptopsammia pruvoti (Scleractinia, Dendrophylliidae) in the Mediterranean. 2. Quantitative aspects of the annual reproductive cycle
Altered juvenile fish communities associated with invasive Halophila stipulacea seagrass habitats in the U.S. Virgin Islands
Benthic pattern formation in shallow tropical reefscapes: does grazing explain grazing halos?
Little giants: a rapidly invading seagrass alters ecosystem functioning relative to native foundation species
The Coral Trait Database, a curated database of trait information for coral species from the global oceans.
Trait-based approaches advance ecological and evolutionary research because traits provide a strong link to an organism's function and fitness. Trait-based research might lead to a deeper understanding of the functions of, and services provided by, ecosystems, thereby improving management, which is vital in the current era of rapid environmental change. Coral reef scientists have long collected trait data for corals; however, these are difficult to access and often under-utilized in addressing large-scale questions. We present the Coral Trait Database initiative that aims to bring together physiological, morphological, ecological, phylogenetic and biogeographic trait information into a single repository. The database houses species- and individual-level data from published field and experimental studies alongside contextual data that provide important framing for analyses. In this data descriptor, we release data for 56 traits for 1547 species, and present a collaborative platform on which other trait data are being actively federated. Our overall goal is for the Coral Trait Database to become an open-source, community-led data clearinghouse that accelerates coral reef research
Precision Electroweak Measurements on the Z resonance.
We report on the final electroweak measurements performed with data taken at the Z resonance by the experiments operating at the electronâpositron colliders SLC and LEP. The data consist of 17 million Z decays accumulated by the ALEPH, DELPHI, L3 and OPAL experiments at LEP, and 600 thousand Z decays by the SLD experiment using a polarised beam at SLC. The measurements include cross-sections, forwardâbackward asymmetries and polarised asymmetries. The mass and width of the Z boson, mZ and ÎZ, and its couplings to fermions, for example the Ï parameter and the effective electroweak mixing angle for leptons, are precisely measured: The number of light neutrino species is determined to be 2.9840±0.0082, in agreement with the three observed generations of fundamental fermions. The results are compared to the predictions of the Standard Model (SM). At the Z-pole, electroweak radiative corrections beyond the running of the QED and QCD coupling constants are observed with a significance of five standard deviations, and in agreement with the Standard Model. Of the many Z-pole measurements, the forwardâbackward asymmetry in b-quark production shows the largest difference with respect to its SM expectation, at the level of 2.8 standard deviations. Through radiative corrections evaluated in the framework of the Standard Model, the Z-pole data are also used to predict the mass of the top quark, , and the mass of the W boson, . These indirect constraints are compared to the direct measurements, providing a stringent test of the SM. Using in addition the direct measurements of mt and mW, the mass of the as yet unobserved SM Higgs boson is predicted with a relative uncertainty of about 50% and found to be less than at 95% confidence level