Search results for "Spatial"

Distribution spatiale de la diversité microbienne des sols à l’échelle du territoire national

2012

Le sol représente un exceptionnel réservoir de biodiversité microbienne tant en termes d’abondance et de richesse spécifique, qu’en termes de fonctions et de processus impliqués dans les flux de matière et d’énergie. Ce réservoir assure et supporte de nombreux services écosystémiques à la base de la durabilité des systèmes de production exploités par l’Homme. Cette grande biodiversité lui confère des capacités d’adaptation (résistance, résilience, redondance fonctionnelle,…) face aux activités anthropiques et aux changements globaux, et constitue ainsi une véritable assurance écologique pour l’Homme et ses moyens de production. Néanmoins, de nombreuses connaissances restent encore à acquéri…

Dynamiques spatio-temporelles de la vigne (Vitis vinifera) au cours de l’Holocène en France d’après les enregistrements archéobotaniques (graines et …

2021

International audience; Le vin joue un rôle économique et culturel capital depuis l’âge du Fer en France. Dès cette époque, la viticulture s’implante dans le Midi méditerranéen puis va progressivement se diffuser dans la zone tempérée. L’archéologie a bien montré à quel point le Haut-Empire romain représente une étape clé dans cette diffusion (Poux et al. 2011). Cependant, les différents marqueurs à disposition de l’archéologie culturelle et spatiale (aménagements, structures, mobiliers) sont généralement limités à des fenêtres chrono-géographiques particulières. Changeant en fonction du contexte technique, culturel et environnemental, aucun ne permet véritablement de suivre l’expansion de …

Designing ‘trait-based null model’ approaches to investigate community assembly mechanisms

2014

SPEEAECOLDURGEAPSIéquipe CAPA; During the last decade, many studies have addressed the signature of community assembly processes by assessing the deviation of a functional diversity pattern from that expected in null communities, using a randomization algorithm. The basic principle has been to compare the functional structure of a ‘local community’ with a set of randomly generated communities from a ‘regional species pool’. Specifically, it allows assessing the extent to which species constituting a community are functionally more or less similar than expected under the assumption of a random assembly, thus revealing the influence of assembly processes such as competition or environmental a…

Spatial distribution of ammonia-oxidizing bacteria and archaea across a 44-hectare farm related to ecosystem functioning

2011

Characterization of spatial patterns of functional microbial communities could facilitate the understanding of the relationships between the ecology of microbial communities, the biogeochemical processes they perform and the corresponding ecosystem functions. Because of the important role the ammonia-oxidizing bacteria (AOB) and archaea (AOA) have in nitrogen cycling and nitrate leaching, we explored the spatial distribution of their activity, abundance and community composition across a 44-ha large farm divided into an organic and an integrated farming system. The spatial patterns were mapped by geostatistical modeling and correlations to soil properties and ecosystem functioning in terms …

Environmental spillovers and their impacts on housing prices: A spatial hedonic analysis

2015

This paper investigates the spatial dimension of environmental factors on housing prices. We develop spatial hedonic models to estimate the implicit prices of various environmental attributes. The spatial dimension can be interpreted in terms of local or global spillovers. We conduct an empirical study in the Loire estuary (France). We focus on natural areas and more artificialized ones (ocean frontage, wetlands, rivers, and noisy roads). We show that, depending on the spatial model used, the implicit price is more than just the estimated coefficient value and combines both a feedback effect and a propagation effect.

Economies d'agglomération et configurations spatiales dans les espaces ruraux

1997

The question to be addressed here is that of the agglomeration/dispersion forces that are likely to account for the location of people and jobs in rural areas and the way they explain spatial patterns in rural areas depending on urban influence. Economic geography models may provide suitable tools with which to investigate the organization of rural areas. We first review these models, focusing on dispersion forces, which rest basically on land consumption and transport costs. We suggest then a set of hypotheses concerning the main forces at work in rural areas. Intensity of agglomeration economies is hypothesized to be related to the urban size, which in turn induces increasing land rents a…

Toward a socio-cognitive approach of spatial data co-production

2010

The abilities of territorial communities to understand and control their development in a sustainable and equitable way, depend on territorial information sharing. In this context, the paper intends to understand and analyse the issues of spatial data co-production process. It provides understanding and operation elements so that spatial data sharing can progressively evolve into geomatics learning networks, also termed "communities of practice". This communities of practice offer, in our view, one of the most important component of Territorial Intelligence

L'organisation spatiale du plateau Saint-Marcel: Un habitat urbanisé de la fin du premier âge du Fer

2011

La méthode HBDS : Hypergraph-Based Data Structure

2011

Présentation de la méthode pour de la modélisation géographique

Observations of land use transformations during the Neolithic using exploratory spatial data analysis: contributions and limitations

2010

International audience; The settlement pattern analysis in archaeology implies some methodological questions. In this paper, we question some issues about the use of geostatistical methods for the observation of land use transformations during the Neolithic. We have developed two examples in Burgundy (France): the first one on a regional scale and the second one on a micro-regional scale. Using different ESDA approaches (Ripley’K function, Nearest Neighbour Distance, Kernel Density Estimation), we would like to underline what the methodological and archaeological contributions and their limits are. Both experiences point out that the results obtained depend not only on the analytical scale,…