Search results for " fIsh"
showing 10 items of 1414 documents
13C composition of dissolved organic carbon in upland forested catchments of the Morvan Mountains (France): Influence of coniferous and deciduous veg…
2007
10 pages; International audience; One of the main environmental changes caused by human activities is that of land use. These changes influence the quantity and quality of the dissolved organic matter (DOM) fluxes through the vegetation–soil–stream system. The aim of this work is to evaluate the influence of the substitution of native deciduous forests by well managed coniferous forests on dissolved organic carbon (DOC) fluxes and their associated carbon isotopic composition (d13CDOC). DOC fluxes and d13CDOC were monitored for 2 years in the streams of four similar upland forested catchments in the Morvan Mountains (France). Mean annual DOC concentrations and fluxes were 2–4 times lower in …
Simulation of nitrous oxide emissions from wheat-cropped soils using CERES
2005
Estimation of nitrous oxide (N2O) emissions from arable soils, in relation to crop fertilization, is essential to devise strategies to mitigate the impact of agriculture on global warming. This paper presents the development and test of a N2O model resulting from the linkage of a dynamic soil-crop simulation model (CERES) with two sub-models of N2O production and reduction in soils. These sub-models (NOE and NGAS) account for both the nitrification and denitrification pathways. The resulting models (CERES–NOE and CERES–NGAS) were tested against experimental data collected on three contrasting wheat-cropped soils representative of the Beauce agricultural region in France. Although the input …
Soil erosion in sloping vineyards assessed by using botanical indicators and sediment collectors in the Ruwer-Mosel valley
2016
Steep slopes, erodible soils, rill and ephemeral gullies, compaction due to wheel. traffic and human trampling are common features in vineyards around the world and result in high soil erosion rates. However, little is known about seasonal and spatial variations of soil erosion rates due to factors such as the impact of the vine plantation, harvest, and tillage on the soil redistribution over the long-term temporal scale. The goal of this study is to assess long-term soil erosion rates and the impact of management on sediment and runoff yield by means of Gerlach troughs and a topographical approach based on botanic benchmarks in two paired vineyards with different ages (3 and 35 years) loca…
Methane production and oxidation potentials in relation to water table fluctuations in two boreal mires
1999
We studied the response of methane production and oxidation potentials in a minerotrophic and an ombrotrophic mire to water table fluctuations. In profiles where water table had not varied, the water-saturated layers showed significant potentials while the unsaturated layers did not. The production potentials in the saturated layers below water level ranged from 0.1 to 2.4 m gC H4 h ˇ1 (g d.w.) ˇ 1 and oxidation potentials (first order reaction rate constants) betweenˇ0.010 andˇ0.120 h ˇ1 (g d.w.) ˇ 1 . In profiles with constant water level, the maximal production potential occurred 20 cm and maximal oxidation potential 10 cm below water level. When water table varied only a little, product…
Land set-up systems in Italy: A long tradition of soil and water conservation sewed up to a variety of pedo-climatic environments
2020
Land set-up systems in Italy were and, in a few cases, still are integral parts of agricultural landscapes. The soils of Italy mirror a wide variety of climates and morphologies and derive from a great diversity of parent materials influenced by different soil temperature and moisture regimes. Furthermore, their development was influenced by several anthropogenic activities over time including land settings. Land set-up systems have been widely used throughout the Italian soilscape to regulate surface and underground water and to improve the physical soil features in a way that ensures mixed herbaceous and tree-crops cultivation. In recent times, new technologies have been introduced in agr…
Economic performance and risk of farming systems specialized in perennial crops: An analysis of Italian hazelnut production
2019
Abstract Assessing farm profitability and economic risk is important to support farmers' decisions. Several factors affect yields and product prices, in turn influencing farmers' income level and economic risk. However, the literature has often neglected to explicitly account for the role of product quality. This is particularly important for crops such as hazelnut because farmers' prices vary according to the quality of the harvested product. Furthermore, it seems fundamental to disentangle the role of parameters influencing farm results, noticeably yield, product price and quality. This is because farmers select their risk management tools to satisfy their needs, but these are often suita…
First shark record from the Upper Cretaceous of the Kuril Islands, Far East Russia
2020
Abstract The first find of a Late Cretaceous shark tooth, or of any cartilaginous fish for that matter, from the Kuril Islands in the Russian Far East is recorded as Carcharias sp. (Lamniformes, Carchariidae). The specimen originates from Maastrichtian strata on the island of Shikotan that are assigned to the Malokurilsk Formation. It constitutes an extremely rare find from rocks of this age in the northwest Pacific region. External and internal dental structures have been reconstructed by the use of computed tomography. The vasculature of this lamniform tooth is first modelled by CT scanning and shown under different angles, which allows an assessment of the spatial arrangement of hierarch…
Current Wildland Fire Patterns and Challenges in Europe: A Synthesis of National Perspectives
2021
Changes in climate, land use, and land management impact the occurrence and severity of wildland fires in many parts of the world. This is particularly evident in Europe, where ongoing changes in land use have strongly modified fire patterns over the last decades. Although satellite data by the European Forest Fire Information System provide large-scale wildland fire statistics across European countries, there is still a crucial need to collect and summarize in-depth local analysis and understanding of the wildland fire condition and associated challenges across Europe. This article aims to provide a general overview of the current wildland fire patterns and challenges as perceived by natio…
Soil physicochemical and microbial drivers of temperature sensitivity of soil organic matter decomposition under boreal forests
2020
Abstract Soil organic matter (SOM) in boreal forests is an important carbon sink. The aim of this study was to assess and to detect factors controlling the temperature sensitivity of SOM decomposition. Soils were collected from Scots pine, Norway spruce, silver birch, and mixed forests (O horizon) in northern Finland, and their basal respiration rates at five different temperatures (from 4 to 28 °C) were measured. The Q10 values, showing the respiration rate changes with a 10 °C increase, were calculated using a Gaussian function and were based on temperature-dependent changes. Several soil physicochemical parameters were measured, and the functional diversity of the soil microbial communit…
Current and Future Influence of Environmental Factors on Small Pelagic Fish Distributions in the Northwestern Mediterranean Sea
2020
Managing for the Future: Understanding the Relative Roles of Climate and Fishing on Structure and Dynamics of Marine Ecosystems.-- 20 pages, 15 figures, supplementary material https://www.frontiersin.org/articles/10.3389/fmars.2020.00622/full#supplementary-material