Search results for "conservation."

The Role of Excited Oxygen Molecules in the Formation of the Secondary Ozone Layer at 87 to 97 km

2018

The secondary ozone layer is located at elevations of 87 to 97 km in the upper mesosphere – lower thermosphere. It overlaps with the ionospheric D-layer. Daytime intensive UV radiation is dissociating O2 molecules to O atoms and photoexcitating O2 molecules up to 11.07eV level. Ozone photolysis between the wavelengths of 118.7–121.6 nm produces three oxygen atoms from one ozone molecule. Collision reactions of O2(B3 Σu —) and O2(X3 Σg —, υ≥26) with O2(X3 Σg —, υ=0) produce additional oxygen atoms. The number of oxygen atoms is maintained at such a high level that a small but significant ozone concentration survives. UV radiation weakens radically during the night. The number of O atoms show…

Developing and comparing methods for mapping habitat types and conservation values using remote sensing data and GIS methods

2014

Investigations into the development and role of a Mediterranean intertidal bioconstruction for coastal conservation: the Vermetid Reef

2017

Vermetid reefs are intertidal biogenic habitats created by a dense aggregation of mollusks, frequently cemented by calcareous algae, and are typical of sub-tropical and warm–temperate rocky shores. These bioconstructions are valuable key-habitats of the coastal zones, increasing their productivity and biological value. In the Mediterranean, the main vermetid reef builders belong to the genus Dendropoma and are associated to encrusting coralline red algae. These organisms are ecosystem engineers protected under international European Legislation, although vermetid reef conservation is limited by a lack of biological and ecological knowledge. The two-way interactions between biota and the phy…

Effets du bruit marin sur le changement des poissons sparidés juvéniles entre les espèces et les stades de développement

2023

International audience; Marine noise is an emerging pollutant inducing a variety of negative impacts on many animal taxa, including fish. Fish population persistence and dynamics rely on the supply of early life stages, which are often very sensitive to disturbance. Impacts of marine noise pollution (MNP) on juvenile fish have rarely been investigated in temperate regions. This is particularly true for the Mediterranean Sea, which is considered as an MNP hotspot due to intensive maritime traffic. In this study, we investigate the relationship between MNP related to boat traffic and (i) assemblage structure and (ii) the density of juvenile fishes (post-settlers at different stages) belonging…

Chimpanzees surviving in a fragmented high‐altitude forest landscape of the Congolese Albertine Rift

2021

This paper documents a community of eastern chimpanzees (Pan troglodytes schweinfurthii Giglioli, 1872) inhabiting three relict forest fragments situated on the Lake Albert escarpment, down the Ituri highlands, of eastern Democratic Republic of the Congo (DRC). The area explored had a combined forested surface of ±18.15 km2 in 2017, shrinking by 1.2% per year between 2010 and 2015. Between 2015 and 2017, we found 160 chimpanzee nests along 37.6 km of pilot walks, some up to 2,000 m altitude. Another 123 nests logged along 6.7 km transects led to an estimate of chimpanzee density of 4.62 weaned individuals per square kilometer of forest habitat. Camera‐trap images and direct observations rev…

Vegetation series as a marker of interactions between rural settlements and landscape: new insights from the archaeological record in Western Sicily

2020

[EN] Plant communities are complex and dynamic elements of the landscape, intertwined with both natural factors and human activities. Vegetation series reflect the environmental characteristics of the landscape, but also the anthropic impact, one of the exogenous forces that most profoundly affects the landscape formation process. This paper aims to investigate the interactions between long-term human settlement catchment areas and vegetation series. The case study area of the Sicani Mountains (Central-Western Sicily) proved to be an ideal place to perform GIS-based spatial analysis in order to compare a data set of rural archaeological sites and land units created through the mapping of ve…

Warning signalling in European vipers and their mimics : implications for conservation of the smooth snake

2014

Town, industry and city

1995

Une première partie regroupera quelques réflexions conceptuelles et méthodologiques sur les économies d'agglomération et le phénomène d'agglomération. On y trouvera des précisions sur les sources, la nature et le classement des économies d'agglomération et des forces qui peuvent les contrarier, ainsi que sur la dynamique propre du phénomène d'agglomération. Dans une deuxième partie, nous examinerons plus précisément l'intérêt et les limites de l'assimilation entre l'agglomération de la production et la ville, en analysant comment la dimension productive est liée aux autres dimensions de la ville, notamment la dimension sociale. Nous chercherons en particulier quelles représentations de la v…

Définir la ville

1996

The city can hardly be grasped by a simple definition. Most of the available definitions are statistical or descriptive and they fail to represent the complex, multidimensional and changing nature of the urban phenomenon. The definition proposed in this paper is related to economic theory of city formation and is based on the agglomeration process and the diversity of agents and activities.

Effective Practices in Mitigating Soil Erosion from Fields

2017

Soil erosion by water is a natural process that cannot be avoided. Soil erosion depends on many factors, and a distinction should be made between humanly unchangeable (e.g., rainfall) and modifiable (e.g., length of the field) soil erosion factors. Soil erosion has both on-site and off-site effects. Soil conservation tries to combine modifiable factors so as to maintain erosion in an area of interest to an acceptable level. Strategies to control soil erosion have to be adapted to the desired land use. Knowledge of soil loss tolerance, T, i.e., the maximum admissible erosion from a given field, allows technicians or farmers to establish whether soil conservation practices need to be applied …