Search results for "Population"
showing 10 items of 9945 documents
No apparent effect of invasive alien goldenrod on soil microbial communities or soil fauna feeding activity
2020
Abstract Invasive alien species spreading in abandoned agricultural landscape may negatively affect native organisms, including plants and soil biota. This study assessed the effects of invasion by Solidago sp. (goldenrod) in southern Poland on soil fauna feeding activity and on soil microorganism activity, biomass, and functional and taxonomic diversity, in a comparisons of paired plots: goldenrod-invaded plots and nearby non-invaded plots of semi-natural grassland. Goldenrod-invaded plots had fewer vascular plant species (paired t-test) than non-invaded ones, and showed a distinct plant community composition (ANOSIM). Non-invaded and invaded plots did not differ in a range of measured soi…
Abundance–variance and abundance–occupancy relationships in a marine host–parasite system: The importance of taxonomy and ecology of transmission
2011
Abundance-occupancy and abundance-variance relationships are two of the most general macroecological patterns capturing essential fundamentals of the structuring of species distributions and are widely documented for free-living animal and plant species populations at different spatial scales. However, empirical data for parasites have been gathered using appropriate sampling designs only recently. We performed analyses across species of the variation in infection parameters and patterns of aggregation of the most widespread parasites in the marine sparid fish Boops boops across seven localities of two marine biogeographical regions, the North East Atlantic and the Mediterranean. We used a …
Spatial dynamics of an invasive bird species assessed using robust design occupancy analysis: the case of the Eurasian collared dove ( Streptopelia d…
2007
Aim The study of the spatial dynamics of invasive species is a key issue in invasion ecology. While mathematical models are useful for predicting the extent of population expansions, they are not suitable for measuring and characterizing spatial patterns of invasion unless the probability of detection is homogeneous across the distribution range. Here, we apply recently developed statistical approaches incorporating detection uncertainty to characterize the spatial dynamics of an invasive bird species, the Eurasian collared dove (Streptopelia decaocto). Location France. Methods Data on presence/absence of doves were recorded from 1996 to 2004 over 1045 grid cells (28 × 20 km) covering th…
Habitat fragmentation and anthropogenic factors affect wildcat Felis silvestris silvestris occupancy and detectability on Mt Etna
2019
International audience; Knowledge of patterns of occupancy is crucial for planning sound biological management and for identifying areas which require paramount conservation attention. The European wildcat Felis silvestris is an elusive carnivore and is classified as ‘least concern' on the IUCN red list, but with a decreasing population trend in some areas. Sicily hosts a peculiar wildcat population, which deserves conservation and management actions, due to its isolation from the mainland. Patterns of occupancy for wildcats are unknown in Italy, and especially in Sicily. We aimed to identify which ecological drivers determined wildcat occurrence on Mt Etna and to provide conservation actio…
Temperature-associated habitat selection in a cold-water marine fish.
2015
1. Habitat selection is a complex process, which involves behavioural decisions guided by the multiple needs and constraints faced by individuals. Climate-induced changes in environmental conditions may alter those trade-offs and resulting habitat use patterns. 2. In this study, we investigated the effect of sea temperature on habitat selection and habitat use of acoustically tagged Atlantic cod (Gadus morhua) at the Norwegian Skagerrak coast. 3. Significant relationships between ocean temperature and habitat selection and use were found. Under favourable sea temperature thresholds (<16 °C), cod selected vegetated habitats, such as eelgrass and macroalgae beds, available in shallow areas. S…
Antifungal and antimycotoxigenic activity of allyl isothiocyanate on barley under different storage conditions
2019
Abstract The present study evaluated the efficacy of allyl isothiocyanate (AITC) in avoiding the growth of Penicillium verrucosum and consequent ochratoxin A (OTA) production in barley during storage for 90 d. Environmental humidity was controlled using saturated salt solutions and moisture content (MC) of the grain was analyzed. Moreover, the residual concentration of AITC on stored barley was also examined. Samples with 20.6% of MC presented the highest absorption of AITC with levels ranging from 75 to 4 mg/kg at day 1 and 90, respectively. The population of P. verrucosum was significantly reduced after 24 h of AITC exposure. After 90 d, the non-treated control group reached a fungal popu…
Cyclic hantavirus epidemics in humans--predicted by rodent host dynamics.
2009
Wildlife-originated zoonotic diseases are a major contributor to emerging infectious diseases. Hantaviruses cause thousands of human disease cases annually worldwide, and understanding and predicting human hantavirus epidemics still poses unsolved challenges. Here we studied the three-level relationships between the human disease nephropathia epidemica (NE), its etiological agent Puumala hantavirus (PUUV) and the rodent host of the virus, the bank vole (Myodes glareolus). A large and long-term data set (14 years, 2583 human NE cases and 4751 trapped bank voles) indicates that the number of human infections shows both seasonal and multi-annual fluctuations, is influenced by the phase of vole…
Spatiotemporal Structure of Host‐Pathogen Interactions in a Metapopulation
2009
International audience; The ecological and evolutionary dynamics of species are influenced by spatiotemporal variation in population size. Unfortunately, we are usually limited in our ability to investigate the numerical dynamics of natural populations across large spatial scales and over long periods of time. Here we combine mechanistic and statistical approaches to reconstruct continuous-time infection dynamics of an obligate fungal pathogen on the basis of discrete-time occurrence data. The pathogen, Podosphaera plantaginis, infects its host plant, Plantago lanceolata, in a metapopulation setting where the presence of the pathogen has been recorded annually for 6 years in similar to 4,00…
Evaluation of Nonpathogenic Fusarium oxysporum and Pseudomonas fluorescens for Panama Disease Control
2011
Publication Inra prise en compte dans l'analyse bibliométrique des publications scientifiques mondiales sur les Fruits, les Légumes et la Pomme de terre. Période 2000-2012. http://prodinra.inra.fr/record/256699; Nonpathogenic Fusarium oxysporum endophytes from healthy banana roots were evaluated for their ability to reduce Fusarium wilt of banana (Panama disease). Isolates were identified morphologically and by using species-specific primers. Pathogenicity was confirmed by inoculating banana plantlets in the greenhouse. Nonpathogenic F. oxysporum isolates were grouped into 14 haplotype groups by polymerase chain reaction restriction fragment length polymorphism analysis of the intergenic sp…
A large-scale, higher-level, molecular phylogenetic study of the insect order Lepidoptera (moths and butterflies).
2013
Background Higher-level relationships within the Lepidoptera, and particularly within the species-rich subclade Ditrysia, are generally not well understood, although recent studies have yielded progress. We present the most comprehensive molecular analysis of lepidopteran phylogeny to date, focusing on relationships among superfamilies. Methodology / Principal Findings 483 taxa spanning 115 of 124 families were sampled for 19 protein-coding nuclear genes, from which maximum likelihood tree estimates and bootstrap percentages were obtained using GARLI. Assessment of heuristic search effectiveness showed that better trees and higher bootstrap percentages probably remain to be discovered even …