Les données représentées ici, révèlent que la densité de population varie sensiblement d'une zone à l’autre. On distingue très clairement ou sont les zones les plus peuplées. Dans cette carte, les zones de plus forte densité dépassent 30.000 habitants par Km². Celles à très forte densité dépassent 7.000 habitants par Km². La forte densité est au-delà de 5.200 habitants par Km². Les dernières catégories sont à 3.330 habitants par Km², et 1.500 habitants par Km².

Les données utilisées proviennent du produit FranceIRIS® développé par Esri France, les informations de population utilisées sont de 2011.

Cycling is becoming trendier. Although the progression of bicycle use between 2019 and 2020 in France largely depended on the size of the city, the expansion was positive in all categories. For medium-sized cities, between 20,000 and 50,000 and those with more than one million inhabitants, a very sharp increase in bicycle use ranging from 17 and 31 percent was observed. This trend even increased to 33 and 57 percent, respectively, during non-containment periods.

COVID-19, a springboard for cycling? The COVID-19 epidemic has led to the implementation of social distancing measures in France and the bicycle is a means of transport that responds to these new constraints. Naturally, it is in cities where the population density is higher (such as Paris) that the most spectacular increase in bicycle use in France is taking place. Overall, it is in urban areas where cycling is making the most progress, with a 31 percent increase in 2020 (excluding the confinement period).

Aware of this new craze and of the health issues at stake, the French government has released 50 euros in 2020 for each citizen to help get his or her bicycle back into working order. This state participation is not unique to France. That same year, many European countries such as Finland raised public funds to invest in cycling.

Facilities for cycling in France The development of cycling in France requires new infrastructures to accommodate this new mass of cyclists. Even if this trend is national, investment depends on local authorities and cities. A city's policy and the choice of local elected officials will then have an influence on the implementation of infrastructure adapted to the practice. The conditions for cycling therefore vary from one French city to another. For example, the availability of bicycle paths per inhabitant in 2017 was seven times higher in Strasbourg than in Nice. Opinion polls on bicycle use also vary greatly from one city to another. Among French cities with more than 200,000 inhabitants, Strasbourg, again, was named the most bike-friendly city in France. On the contrary, cycling conditions in Marseille are very poor, according to the inhabitants who find the safety conditions for cycling, as well as the comfort and the possibilities of parking bikes to be insufficient.

Cette carte représente la proportion des moins de 18 ans. C'est à dire le rapport entre la population des moins de 18 ans et la population totale. On distingue très clairement les zones où la proportion des moins de 18 ans est la plus importante (en jaune). Dans la majeure partie des cas, cette proportion augmente plus on s'éloigne des centres villes. Les données utilisées proviennent du produit FranceIRIS® développé par Esri France.

The effective population size (Ne) is a key parameter in conservation and evolutionary biology, reflecting the strength of genetic drift and inbreeding. While demographic estimations of Ne are logistically and time-consuming, genetic methods have become more widely used due to increasing data availability. Nonetheless, accurately estimating Ne remains challenging, with few studies comparing Ne estimates across molecular markers types and estimators such as single-sample methods based on linkage disequilibrium or sibship analyses versus methods based on temporal variance in allele frequencies. This study aims at bridging this gap by analysing single-sample and temporally-spaced populations in the southern damselfly (Coenagrion mercuriale), a bioindicator Odonata species of conservation concern found in southwestern Europe’s freshwater stream networks. 77 local populations were sampled from a semi-urbanised area located in eastern France near Strasbourg city, yielding 2,842 individuals th..., , , # Levels and spatial patterns of effective population sizes in the southern damselfly (Coenagrion mercuriale): on the need to carefully interpret single-point and temporal estimations to set conservation guidelines

https://doi.org/10.5061/dryad.83bk3jb34

Description of the data and file structure

-Microsatellite genotypes (samples locations and genotypes at 10 microsatellite loci)

-2092 SNPs genotypes (samples locations and genotypes at 2092 SNPs loci)

Files and variables

File: Southern_Damselfly_Sample_microsatellite_genotype_and_locations.xlsx

Description: Southern_Damselfly_Sample_microsatellite_genotype_and_locations.xlsx – File containing for each sample: the name of the individual (Sample_Name), the name of the site where it was sampled (ID_Site), the sampling year (Year), population location (Longitude_EPSG4326 [East], Latitude_EPSG4326 [North]), individual multilocus genotypes at 10 microsatellite loci.

All...

Cette carte représente la proportion des plus de 65 ans. C'est à dire le rapport entre la population des plus de 65 ans et la population totale. On distingue très clairement les zones où la proportion des plus de 65 ans est la plus importante (en jaune). Les données utilisées proviennent du produit FranceIRIS® développé par Esri France.

Among selected cities in France, Strasbourg stood out in terms of cyclist and pedestrian safety in 2022. Strasbourg earned a score of 80 percent, highlighting the relatively low number of pedestrian and cyclist deaths in relation to its population size. Meanwhile, Paris secured a score of 65 percent, closely followed by Marseille at 63 percent.

According to a survey conducted in early 2018, half of the surveyed French declared using the bike as a mean of transportation. However, 23 percent of them said to bike less than once a month and only five percent used the bicycle daily or almost daily as their transportation.  The vast majority of French surveyed by the French bicycle touring federation declared taking a bike for leisure activities, while almost a third said using it as a mean of transportation.

Usage of bicycles in city areas in France

Strasbourg, Grenoble and Bordeaux were the cities with the highest percentage of employees who used the bike to go to work in France in 2015 : in these metropoles between 11 and 16 percent of the working population went to work cycling. In Paris only four percent of employees did so. This ratio appears to be more important when people commute within city-centers or big cities, which would be linked to the presence of better cycling infrastructures.

Overall bicycle mobility goals in France

On the observation that daily bike use represents only three percent of all daily travels, the French government stressed in September 2018 a “Plan Vélo” (Bicycle Plan). This to increase the bicycle mobility until 2024, along with the goal of ensuring security and to better cycling infrastructures. most of French bike users seemed to still feel unsecure when cycling in cities in a survey conducted in 2017.

Ce graphique présente le classement des villes ayant le plus d'habitants en France en 2021. Paris était la ville plus peuplée de France, la capitale comptait plus de deux millions de personnes, soit plus du double que Marseille, deuxième ville de France. Saint-Denis (La Réunion) était la ville la plus importante des territoires et départements d'outre-mer. Ces données ne prennent en compte que la population des communes et non les habitants des aires urbaines.