Search results for " forest"
showing 10 items of 1940 documents
Organic carbon dynamics in soil particle-size separates of sandy Spodosols when forest is cleared for maize cropping
2003
Summary In southwest France, much of the forest lands on sandy Spodosols has been converted to continuous maize cropping in the last few decades. To evaluate the impacts of such change on the content and properties of the soil organic matter, we compared the amount of organic carbon and 13C natural abundance in soil and particle-size separates at three locations, selected on the basis of different contents of 0–50 μm particles (clay + silt). After three decades of cultivation, the amount of carbon from the forest pools (Cf) decreased by about 60%, attributable mainly to easily degradable material in sand-sized fractions (−70%). However, a recalcitrant residue remained in soil at a constant …
Efficacy and foliar absorption of flupyrsulfuron-methyl and prosulfocarb applied alone or in mixture on Lolium multiflorum and wheat
2001
Des melanges de flupyrsulfuron-methyle et de prosulfocarbe concus pour ameliorer la lutte contre Lolium multiflorum Lam. dans le ble (Triticum aestivum L.) ont ete etudies grâce a des essais biologiques sur plantes entieres et a des etudes de penetration foliaire. Dans les essais biologiques, le flupyrsulfuron-methyle et le prosulfocarbe etaient appliques a 6-7 doses, seuls ou en melange dans les rapports 1:400, 1:40 et 1:4 (p/p). Les courbes de reponse etaient ajustees au moyen de modeles logistiques et l'action conjuguee etait evaluee par la methode des isoboles. Dans les essais biologiques conduits en serre sur L. multiflorum, l'action conjuguee des melanges montrait une additivite de do…
The relationship between copper accumulated in vineyard calcareous soils and soil organic matter and iron
2002
Summary The intensive use for over 100 years of copper sulphate (Bordeaux mixture) to fight mildew in vineyards has led to a substantial accumulation of copper (Cu) in surface soils. To assess the effects of such large concentrations, the surface soils of 10 Burgundy vineyards were sampled and analysed for total organic matter (carbon and nitrogen) and metal (copper and iron) contents. Physical (i.e. size fractionation) and chemical (sequential extraction) methods were used to determine the distribution of these elements. The most Cu-contaminated plots showed the largest accumulation of organic carbon and Cu in the coarse sand and fine sand fractions. Copper was strongly correlated with org…
Nutrient Additions Affecting Matter Turnover in Forest and Pasture Ecosystems
2013
Nutrient inputs into ecosystems of the tropical mountain rainforest region are projected to further increase in the next decades. To investigate whether important ecosystem services such as nutrient cycling and matter turnover in native forests and pasture ecosystems show different patterns of response, two nutrient addition experiments have been established: NUMEX in the forest and FERPAST at the pasture. Both ecosystems already responded 1.5 years after the start of nutrient application (N, P, NP, Ca). Interestingly, most nutrients remained in the respective systems. While the pasture grass was co-limited by N and P, most tree species responded to P addition. Soil microbial biomass in the…
Accounting More Precisely for Peat and Other Soil Carbon Resources
2012
In the context of “recarbonization”, it is important to know where the soil C stocks are located and how much of these are prone to emission to the atmosphere. While it may appear to be a trivial question considering available global estimates and maps, yet there is a strong need to emphasize that erroneous estimates are made in assessing the global soil C stocks. Without doubt, peatlands hold the single most important soil C stock at the global scale, and these soils are mostly located in the northern latitudes between 50°N and 70°N. However, there are additional wetlands or other ecosystems which also hold potentially relevant amounts of soil C stocks. From the soil science perspective, i…
Enabling Sociability When Using Virtual Reality Applications : A Design Science Research Approach
2019
Immersive virtual reality applications aim at providing an all-encompassing spatial experience where a user can feel like being in another world or dimension. The systems are inherently designed for individual use as the devices disconnect the user from the physical environment. However, the applications are seldom used alone. Specifically, when used for sales and marketing, the user often needs help from other people but also benefits from social interaction as a part of the experience. Design research methodology is applied to three iterative development versions of a virtual-reality application. The focus of the evaluation of the artifacts is in the social use emphasizing three sociabili…
Problem Space Identification for Developing Virtual Reality Learning Environments
2021
Our study argues that the extant literature on virtual reality-based learning environments (VRLEs) currently lacks proper definitions and context descriptions for a problem space, which is fundamental for conducting design science research (DSR). Without properly conducted problem space identification, the most pivotal problems cannot be identified resulting solutions lacking validity and unreliable evaluations. This is a major challenge for the DSR in the educational field, but also for the research on VRLEs. The purpose of this paper is to introduce a novel DSR method to support rigorous problem space identification, which would allow rigorous and profound problem space analysis. The inst…
Soil moisture variations from boreal forests to the tundra
2023
Soil moisture has a profound influence on life on Earth, and this vital water resource varies across space and time. Here, we explored soil moisture variations in boreal forest and tundra environments, where comprehensive soil moisture datasets are scarce. We installed soil moisture sensors up to 14 cm depth at 503 measurement sites within seven study areas across northern Europe. We recorded 6,138,528 measurements to capture soil moisture variations of the snowless season from April to September 2020. We described the spatio-temporal patterns of soil moisture, and test how these patterns are linked to topography and how these links vary in space and time. We found large spatial variation a…
Extent and persistence of soil water repellency induced by pines in different geographic regions
2018
The extent (determined by the repellency indices RI and RIc) and persistence (determined by the water drop penetration time, WDPT) of soil water repellency (SWR) induced by pines were assessed in vastly different geographic regions. The actual SWR characteristics were estimated in situ in clay loam soil at Ciavolo, Italy (CiF), sandy soil at Culbin, United Kingdom (CuF), silty clay soil at Javea, Spain (JaF), and sandy soil at Sekule, Slovakia (SeF). For Culbin soil, the potential SWR characteristics were also determined after oven-drying at 60°C (CuD). For two of the three pine species considered, strong (Pinus pinaster at CiF) and severe (Pinus sylvestris at CuD and SeF) SWR conditions we…
APPLICAZIONE DI CRITERI E INDICATORI DELLA CERTIFICAZIONE PEFC DI GESTIONE FORESTALE SOSTENIBILE: DUE CASI STUDIO A CONFRONTO NEL TERRITORIO SICILIANO
2018
La Sicilia non ha ancora complessi forestali la cui gestione sostenibile sia stata certificata. Questo lavoro è volto a analizzare la possibilità di applicare i criteri e indicatori di certificazione di GFS secondo lo schema PEFC a due casi studio: i boschi del comune di Bivona (AG) e una foresta situata sulle Madonie (PA). Entrambi sono rappresentativi di ambienti ecologici diversi e importanti dell’isola. L’analisi pone in luce le criticità più significative della gestione attualmente adottata e la mancanza di comunicazione con i portatori d’interesse. Application of Criteria and Indicators of Sustainable Forest Management PEFC Certification: two case studies in Sicily Sicily currently ha…