Search results for "LAND"

New national and regional bryophyte records, 36

2013

In the moss flora of Uruguay there are recorder ten species of genus Fissidens (Matteri, 2004). Three of them (F. macrobryoides, F. prionocheilos and F. vitreo-limbatus) are species incertae because the type material for the names not was located (Purssel, 2007). As part of project "Studies on Bryophytes in the Cone Sur (Systematic and Phylogeny)" some specimens recently collected in Uruguay were determinate as Fissidens asplenioides a no previously species recorded in this country. The presence of F. asplenioides in Uruguay complete the distribution range of the species in the cone Sur (is present in Argentina, Bolivia, Brazil, Chile and Paraguay). However, within the Neotropical region th…

2018

Allometric relationships linking species characteristics to body size or mass (scaling) are important in biology. However, studies on the scaling of life history traits in the reptiles (the nonavian Reptilia) are rather scarce, especially for the clades Crocodilia, Testudines, and Rhynchocephalia (single extant species, the tuatara). Previous studies on the scaling of reptilian life history traits indicated that they differ from those seen in the other amniotes (mammals and birds), but so far most comparative studies used small species samples and also not phylogenetically informed analyses. Here, we analyzed the scaling of nine life history traits with adult body mass for crocodiles (n = 2…

Descriptors of Posidonia oceanica meadows: Use and application

2005

This work benefited partly from the financial support of the European program ΓNTERREG IIIA Corsica, Sardinia. Tuscany

A global occurrence database of the Atlantic blue crab Callinectes sapidus

2021

The Atlantic blue crab Callinectes sapidus is a portunid native to the western Atlantic, from New England to Uruguay. The species was introduced in Europe in 1901 where it has become invasive; additionally, a significant northward expansion has been emphasized in its native range. Here we present a harmonized global compilation of C. sapidus occurrences from native and non-native distribution ranges derived from online databases (GBIF, BISON, OBIS, and iNaturalist) as well as from unpublished and published sources. The dataset consists of 40,388 geo-referenced occurrences, 39,824 from native and 564 from non-native ranges, recorded in 53 countries. The implementation of quality controls imp…

Hierarchical log Gaussian Cox process for regeneration in uneven-aged forests

2021

We propose a hierarchical log Gaussian Cox process (LGCP) for point patterns, where a set of points x affects another set of points y but not vice versa. We use the model to investigate the effect of large trees to the locations of seedlings. In the model, every point in x has a parametric influence kernel or signal, which together form an influence field. Conditionally on the parameters, the influence field acts as a spatial covariate in the intensity of the model, and the intensity itself is a non-linear function of the parameters. Points outside the observation window may affect the influence field inside the window. We propose an edge correction to account for this missing data. The par…

Seed Bank in Annuals: Competition Between Banker and Non-banker Morphs

2002

Seed bank is a plant life history strategy against the unpredictability of the biotic and the abiotic environment. We simulated competition between a seed banking and a non-banking morph of an annual plant. A constant fraction of the banker morph seeds was allocated to the seed bank, where they had a constant mortality and germination rate. All surviving seeds of the non-banker morph germinated in the next generation. The seedlings of both morphs experienced similar density-dependent mortality. Whether one of the morphs wins or the morphs coexist was evaluated from parameter space plots and statistically with logistic regression analysis. All parameters of the model had a significant, nonli…

Low contribution of Caribbean-based researchers to academic publications on biodiversity conservation in the insular Caribbean.

2021

11 pages; International audience; The insular Caribbean is among the most threatened global biodiversity hotspots, warranting urgent and effective action in conservation. However, the capacity of Caribbean-based researchers to address challenges in biodiversity conservation appears limited. To assess the latter, we used the contribution of Caribbean-based authors to the production of peer-reviewed journal papers on biodiversity conservation in the insular Caribbean as a proxy for research capacity. Moreover, because the insular Caribbean is a complex geopolitical system including sovereign states and overseas territories, we examined the contributions of these two groups to the number of pa…

Vegetation of feather grass steppes in the western Pamir Alai Mountains (Tajikistan, Middle Asia)

2016

Aims: To propose the first syntaxonomical scheme for the graminoid steppe vegetation of the montane and alpine zones in the Pamir-Alai Mts. in Tajikistan with some remarks on its environmental gradients. Location: Tajikistan. Methods: A total of 155 relevés were sampled in 2015 using the seven-degree cover-abundance scale of Braun-Blanquet and subsequently 148 of these relevés were selected and classified by the modified TWINSPAN method using the four step interval scale with cutoff levels of 0%, 5%, 10% and 25% and total inertia as a measure of cluster heterogeneity. Diagnostic species were identified using the phi coefficient as a fidelity measure. The detrended correspondance analysis wa…

NMR structure determination of (11E)-trinervita-1(14),2,11-triene, a new diterpene from sexual glands of termites

2005

Graphical Abstract Full-size image; International audience; Female alates of Nasutitermes ephratae termites from Guadeloupe and Nasutitermes sp. from Brazil produce a diterpene hydrocarbon of the molecular formula C20H30 as the main component of their tergal gland secretion. Analysis of NMR, IR, and mass spectra of the diterpene led to a structure of (11E)-trinervita-1(14),2,11-triene. Based on a comparison with the published oxygenated trinervitane skeleton from termites we prefer the enantiomer with absolute configurations (4R,7S,8R,15S,16S). The suggested structure is supported by ab initio quantum chemical calculation of 1H and 13C chemical shifts for the optimized geometry of the molec…

The defensive secretion of Eurycotis floridana (Dictyoptera, Blattidae, Polyzosteriinae): chemical identification and evidence of an alarm function

1997

0965-1748 doi: DOI: 10.1016/S0965-1748(97)00033-7; The defensive secretion of the cockroach Eurycotis floridana was believed to contain only (E)-2-hexenal. However, we have shown it consists of 40 components, of which 30 were tentatively identified. (E)-2-Hexenal, (E)-2-hexenol and (E)-2-hexenoic acid represented approximately 98% of the organic phase. The other 2% included 10 aldehydes, 10 alcohols, four acids, two lactones and one ether. Four compounds are novel insect exudates: 3-ethoxyhexanal, 3-hydroxyhexanal, [(E)-1-pentenyl]-4-propyl-1,3-dioxane and 3-[(E)-2-hexenoxyl-hexanal. In addition to its well-known allomonal function, we have demonstrated that the defensive secretion also act…