39 research outputs found

    Effectiveness of the GAEC cross compliance standards Rational management of set aside, Grass strips to control soil erosion and Vegetation buffers along watercourses on surface animal diversity and biological quality of soil

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    Landscape simplification and loss of natural and semi-natural habitats are the major causes of biodiversity decrease in agricultural landscapes. In order to mitigate the effects of intensive agricultural management the Ministry of Agricultural, Food and Forestry Policies in Italy has included the agronomic measures Rational management of set aside, Grass strips to control soil erosion and Vegetation buffers along watercourses in the decree on cross compliance. In this paper we review the results of a field research performed in Central Italy. The aim of the study was to evaluate the efficacy of the above mentioned GAEC standards for animal diversity enhancement. Using different animal groups as indicators, superficial Arthropod fauna and Herpetofauna, we found striking differences in the biodiversity levels of areas characterized by the application or by the lack of GAEC standards, with the latter being characterized by a significatively impoverished fauna. In particular, the set aside area and the buffer of riparian vegetation resulted of primary importance to allow higher biodiversity levels. Also the analysis of the biological quality of the soil, as assessed through the QBS-ar index based on edaphic micro-Arthropod fauna, indicated a higher quality of semi-natural habitats with respect to arable lands

    Changes in soil aggregation and glomalin-related soil protein content as affected by the arbuscular mycorrhizal fungal species Glomus mosseae and Glomus intraradices.

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    Arbuscular mycorrhizal (AM) fungi are key organisms of the soil/plant system, influencing soil fertility and plant nutrition, and contributing to soil aggregation and soil structure stability by the combined action of extraradical hyphae and of an insoluble, hydrophobic proteinaceous substance named glomalin-related soil protein (GRSP). Since the GRSP extraction procedures have recently revealed problems related to co-extracting substances, the relationship between GRSP and AM fungi still remains to be verified. In this work the hypothesis that GRSP concentration is positively correlated with the occurrence of AM fungi was tested by using Medicago sativa plants inoculated with different isolates of Glomus mosseae and Glomus intraradices in a microcosm experiment. Our results show that (i) mycorrhizal establishment produced an increase in GRSP concentration – compared to initial values – in contrast with non-mycorrhizal plants, which did not produce any change; (ii) aggregate stability, evaluated as mean weight diameter (MWD) of macroaggregates of 1–2 mm diameter, was significantly higher in mycorrhizal soils compared to non-mycorrhizal soil; (iii) GRSP concentration and soil aggregate stability were positively correlated with mycorrhizal root volume and weakly correlated with total root volume; (iv) MWD values of soil aggregates were positively correlated with values of total hyphal length and hyphal density of the AM fungi utilized. The different ability of AM fungal isolates to affect GRSP concentration and to form extensive and dense mycelial networks, which may directly affect soil aggregates stability by hyphal enmeshment of soil particles, suggests the possibility of selecting the most efficient isolates to be utilized for soil quality improvement and land restoration programs

    Traditional landscape and rural development: comparative study in three terraced areas in northern, central and southern Italy to evaluate the efficacy of GAEC standard 4.4 of cross compliance

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    The recent National Strategic Plan 2007-2013 has introduced landscape as a strategic objective of the rural sector. This represents a minor revolution in the way of visualizing the role of the landscape, together with that of agriculture and the rural territory as a whole, and demonstrates the importance of treating the landscape with a systematic point of view. As part of the Efficond project, three sample areas have been identified, each of about 800-1000 hectares, in zones with important historical - cultural landscapes that are included in the National Catalogue of Historical Rural Landscapes. For each sample area a methodology has been applied, defined Historical Cultural Evaluation Approach, developed as part of a project for the monitoring of the Tuscan landscape that we have simplified and adapted. This methodology is based on the consideration that the landscape is the result of the centuries-old interaction between man and the environment, and so to define an element of the landscape as characteristic it is necessary to evaluate the land use dynamics and landscape changes that took place in the past, identifying those that have persisted for a long time, are slowly evolving or stabilized. The study of the historical landscape, which in the proposed methodology refers to the 50’s, has been done through the interpretation and analysis of aerial photographs taken on the GAI flight in 1954, and has allowed the characteristic, traditional and historical elements of that landscape to be identified and an insight to be gained into the cultural identity of the area. Through the creation of specific indices of density and intensity of the terracing obtained by photo-interpretation, field surveys and GIS elaborations, it was possible to classify the sample areas for this specific and important landscape element, compare the results in two periods and evaluate their frequency in the territory. Multi-temporal comparative analysis is being used increasingly often, especially for the study of territories of value, and in our case has been accompanied both by mapping of the landscape dynamics, which identifies the areas subject to transformations in the considered period, and by tables and figures that allow the evolution of a unit of land use to be followed, observing how this has evolved over time. The evaluation of these evolutionary dynamics has then been integrated with a set of indices, in part borrowed from landscape ecology, and in part specifically developed for areas historically shaped by man, which demonstrate that the landscape has become less fragmented and that the layout of fields has been adapted to a different agricultural model that has profoundly changed the structure of the traditional landscape. The efficacy of the laws protecting the characteristic elements of the landscape is strictly linked to the maintenance of its diversity and typicality and conservation of the complexity of the landscape mosaic. Its evaluation necessitates a historical analysis of the evolutionary dynamics conducted at a purely local level

    Hierarchical modelling of multiphase flows using fully resolved fixed mesh and PDF approaches

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    Fully–resolved simulations of multiphase flow phenomena and in particular particulate flow simulations are computationally expensive and are only feasible on massively parallel computer clusters. A 3D SIMPLE type pressure correction algorithm is implemented and extensively tested and parallelized to exploit the power of massively parallel computing clusters currently available. Domain decomposition and communication schemes applicable to a general unstructured or structured multi–block CFD codes are discussed and algorithms are proposed, implemented and tested. Several high–performance linear solvers and a multi–grid strategy for the current framework are implemented and the best types of solvers are identified. A 2D CFD code is developed by the author to test several possible fixed–mesh strategies. Variations of immersed boundary (IB) and fictitious domain (FD) methods are implemented and compared. FD methods are identified to have better properties especially if other transport phenomena are also considered. Therefore an FD method is adapted by the author for the SIMPLE type flow solvers and is extended to heat transfer problems. The method is extensively tested for the simulation of flow around stationary in addition to freely moving particles and forced motion where both natural and forced convection are considered. The method is used to study the flow and heat transfer around a stationary cylinder and a new high resolution correlation is devised for the estimation of the local Nusselt number curves. Free fall problem for a single circular cylinder is considered and the effects of internal heat generation and also long term behavior of single cold particle subject to natural convection are also studied in detail. A particle collision strategy is also adapted and tested for the particle–particle collision problems. The FD algorithm is extended to the 3D framework and the flow around single stationary sphere and also free fall of a single sphere are used to validate the FD algorithm in 3D. A unique polydispersed fluid-particle turbulent modelling process is reviewed and the closure problem for this framework is studied in detail. Two methods for the closure of the non–integer moments which results from the polydispersity of the particles are proposed namely PDF reconstruction using Laguerre polynomials and a unique direct method named Direct Fractional Method of Moments (DFMM). The latter is derived using the results of the fractional calculus by writing an equation for the fractional derivatives of the moment generating function. The proposed methods are tested on a number of problems consisting of analytical, experimental and DNS simulations to asses their validity and viability which shows that both methods provide accurate results with DFMM having more desirable properties.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

    Physico-chemical and mineralogical properties influencing water-stability of aggregates of some italian surface soils

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    Consiglio Nazionale delle Ricerche (CNR). Biblioteca Centrale / CNR - Consiglio Nazionale delle RichercheSIGLEITItal

    INTERNATIONAL CONFERENCE "Soil and Hillslope Management using scenario analysis and runoff-erosion models: a critical evaluation of current techniques" Firenze dal 7 al 9 maggio 2007

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    tema: la valutazione critica delle tecniche attuali e dei modelli di deflusso/erosione per la gestione e la conservazione del suolo in ambiente collinare in particolare mediante lo sviluppo di analisi di scenario Il convegno di terr\ue0 sotto il patrocinio dell Commissione europea (nell'ambito del programma COST634). del CNR- Istituto di Ricerca per la protezione Idrogeologica, delle universit\ue0 di Bologna e Firenze, delle regioni Emilia Romagna e Toscana, delle autorit\ue0 di Bacino del fiume Arno e del Fiume Reno, dell'istituto per lo studio e la Difesa del suolo di Firenze. La web page ufficiale del convegno \ue8 la seguente: http://www.fi.cnr.it/irpi/cost634/index.html OBJECTIVES & CONFERENCE FOCUS TOPIC Soils and hillslopes need to be properly managed, understanding process interactions in a way that can be transferred between areas. Feedbacks due to policy and external changes should be estimated in advance through scenario analysis. Usually there is a gap between scientific knowledge, technical tools and the realities to which scenario analysis needs to be applied. The workshop will address these issues in the context of models at all scales. PROPOSED THEMES AND SESSIONS session 1 - Models and scenario analysis at farm and catchment scales: Selecting models appropriate for particular areas and problems; session 2 - Evaluation of model performance: field calibration and validation; session 3 - Transfer of models to un-instrumented areas: a) are relevant processes described in adequate details?, b) end user confidence in model output; session 4 - Land use modification and model response: changes in flux connectivity and response times ; session 5 - Tolerable soil loss: a) Modernising the concept , b) What parameters determine limits? session 6 - Models to support environmental policy objectives:Scenario analysi
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