Search results for "sampling"
showing 10 items of 788 documents
Diet Quality Limits Summer Growth of Field Vole Populations
2014
Marked variation occurs in both seasonal and multiannual population density peaks of northern European small mammal species, including voles. The availability of dietary proteins is a key factor limiting the population growth of herbivore species. The objective of this study is to investigate the degree to which protein availability influences the growth of increasing vole populations. We hypothesise that the summer growth of folivorous vole populations is positively associated with dietary protein availability. A field experiment was conducted over a summer reproductive period in 18 vegetated enclosures. Populations of field voles (Microtus agrestis) were randomised amongst three treatment…
Drosophila cuticular hydrocarbons revisited : Mating status alters cuticular profiles
2010
Editor: Frederic Marion-Poll, INRA - Paris 6 - AgroParisTech, France.; International audience; Most living organisms use pheromones for inter-individual communication. In Drosophila melanogaster flies, several pheromones perceived either by contact/at a short distance (cuticular hydrocarbons, CHs), or at a longer distance (cis-vaccenyl acetate, cVA), affect courtship and mating behaviours. However, it has not previously been possible to precisely identify all potential pheromonal compounds and simultaneously monitor their variation on a time scale. To overcome this limitation, we combined Solid Phase Micro-Extraction with gas-chromatography coupled with mass-spectrometry. This allowed us (i…
Forest snail faunas from Transylvania (Romania) and their relationship to the faunas of Central and Northern Europe
2011
Forty-three forest sites in seven sampling areas in mountainous parts of Transylvania were sampled to obtain inventories of their snail faunas, and to make comparisons between these and the faunas of similar sites further north along the Carpathian chain. Sampling areas ran from close to the Ukrainian border in the north to Retezat in the south-west. Altogether, 83 species were found, as well as between 19 and 40 species at individual sites. Sites within the same sampling area had more species in common than in among-area comparisons, although differences between areas did not relate to the distance between them. Such differences appear to be related more to ecological factors than to geogr…
Sampling effort and information quality provided by rare and common species in estimating assemblage structure
2020
Made available in DSpace on 2020-12-12T01:06:11Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-03-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Academy of Finland Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Reliable biological assessments are essential to answer ecological and management questions but require well-designed studies and representative sample sizes. However, large sampling effort is rarely possible, because it demands large financial resources and time, restricting the number of sites sampled, the duration of the study and the sampling effort at each site. In…
Can Deliberately Incomplete Gene Sample Augmentation Improve a Phylogeny Estimate for the Advanced Moths and Butterflies (Hexapoda: Lepidoptera)?
2011
Abstract This paper addresses the question of whether one can economically improve the robustness of a molecular phylogeny estimate by increasing gene sampling in only a subset of taxa, without having the analysis invalidated by artifacts arising from large blocks of missing data. Our case study stems from an ongoing effort to resolve poorly understood deeper relationships in the large clade Ditrysia ( > 150,000 species) of the insect order Lepidoptera (butterflies and moths). Seeking to remedy the overall weak support for deeper divergences in an initial study based on five nuclear genes (6.6 kb) in 123 exemplars, we nearly tripled the total gene sample (to 26 genes, 18.4 kb) but only in a…
Antarctic and Sub-Antarctic Asteroidea database
2018
The present dataset is a compilation of georeferenced occurrences of asteroids (Echinodermata: Asteroidea) in the Southern Ocean. Occurrence data south of 45°S latitude were mined from various sources together with information regarding the taxonomy, the sampling source and sampling sites when available. Records from 1872 to 2016 were thoroughly checked to ensure the quality of a dataset that reaches a total of 13,840 occurrences from 4,580 unique sampling events. Information regarding the reproductive strategy (brooders vs. broadcasters) of 63 species is also made available. This dataset represents the most exhaustive occurrence database on Antarctic and Sub-Antarctic asteroids.
Climate and socio-economic factors explain differences between observed and expected naturalization patterns of European plants around the world
2021
Pouteau, R., et al.
Quantifying and addressing the prevalence and bias of study designs in the environmental and social sciences
2020
Building trust in science and evidence-based decision-making depends heavily on the credibility of studies and their findings. Researchers employ many different study designs that vary in their risk of bias to evaluate the true effect of interventions or impacts. Here, we empirically quantify, on a large scale, the prevalence of different study designs and the magnitude of bias in their estimates. Randomised designs and controlled observational designs with pre-intervention sampling were used by just 23% of intervention studies in biodiversity conservation, and 36% of intervention studies in social science. We demonstrate, through pairwise within-study comparisons across 49 environmental da…
Can we generate robust species distribution models at the scale of the Southern Ocean?
2018
17 pages; International audience; AimSpecies distribution modelling (SDM) represents a valuable alternative to predict species distribution over vast and remote areas of the ocean. We tested whether reliable SDMs can be generated for benthic marine organisms at the scale of the Southern Ocean. We aimed at identifying the main large‐scale factors that determine the distribution of the selected species. The robustness of SDMs was tested with regards to sampling effort, species niche width and biogeography.LocationSouthern Ocean.MethodsThe impact of sampling effort was tested using two sets of data: one set with all presence‐only data available until 2005, and a second set using all data avail…
Effectiveness of Posidonia oceanica biotic indices for assessing the ecological status of coastal waters in the Saronikos Gulf (Aegean Sea, Eastern M…
2017
Biotic indices are considered key assessment tools in most national and European policies aimed at improving the quality of coastal waters. At present, several Water Framework Directive (WFD)-compliant biotic indices based on the marine angiosperm Posidonia oceanica have been developed and applied in the Mediterranean Sea. In this study, we investigated the effectiveness of four different P. oceanica indices (POMI, PREI, Valencian CS, and BiPo) in evaluating the ecological status of coastal waters in a case study area of Greece. The evaluation, comparison, and validation of the Ecological Status Class (ESC) assessments obtained by each index were based on a set of eight common sites that en…