1,721,005 research outputs found

    Organic carbon and alkalinity increase in topsoil after rangeland restoration. A case study on Atriplex nummularia L.

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    This research studied the impact of fodder shrub plantations (Atriplex nummularia Lindl.) on topsoil properties, with particular reference to organic carbon, nitrogen, and soluble salts, in the Marrakech region (central Morocco). The studied plantation interventions were carried out to rehabilitate degraded rangeland and to mitigate desertification. The field experiment was conducted by drawing seventeen 50-m-long transects designed according to the ecological patch–interpatch approach defined by the Landscape Function Analysis. The top soil (0–5 cm) was sampled in 134 microsites, covering the main patch and interpatch types in plantation and control plots. The following variables were determined: pH, carbonates, organic carbon, total nitrogen, electrical conductivity, and soluble ions (Na+, K+, Ca2+, Mg2+ Cl, NO3, SO42 and PO43). Statistical analyses were carried out to analyse changes between sites and between patch types. Most of the studied properties were strongly affected by the spatial pattern defined by the plantation, particularly when the sites with higher biomass production were considered. Organic carbon increased by around 63% and 117% when the under canopy patches were compared, respectively, to the between-plants interpatches and to the control plots, a strong positive effect considering the aridity of the study area. On the other hand, a stronger increase was detected under canopy for most soluble salts and sodium adsorption rate. On average, the latter increased by 350% and up to 450% under the best developed plants, a stronger impact than observed in previous research, highlighting the very strong plant effect on the soil surface alkalinity.This research studied the impact of fodder shrub plantations (Atriplex nummularia Lindl.) on topsoil properties, with particular reference to organic carbon, nitrogen, and soluble salts, in the Marrakech region (central Morocco). The studied plantation interventions were carried out to rehabilitate degraded rangeland and to mitigate desertification

    A contribution on Sardinia soils. The new Ecopedological Map and case studies on soil consumption by structures

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    The present work, carried out in the frame of the MEDCOASTLAND project, constitutes a contribution to the knowledge of Mediterranean soil resources and of the opportunities for their conservation and valorisation, as well as the related degradation threats. The study focuses on Sardinia (Italy) and touches two different but linked aspects: the recent developments of the regional soil cartography, based on the new European technical guidelines and the soil consumption due to urbanisation in some areas of the island characterised by different economic development processes. The first aspect constitutes an example of recovery and valorisation of existing pedological information in view of systematising the available knowledge and providing support to soil conservation planning. The second refers to soil loss by urbanization, which is one of the most important causes of irreversible land degradation, especially in coastal areas. The authors considered a total area of about 210,000 ha, where soil consumption was estimated both as total areas and as losses of agricultural land capacity. The results show that the relevant soil loss observed is not caused by a rise in resident population, but is driven by the strong tourism and residential development. Both the Ecopedological Map and the study on soil consumption have been conducted by the NRD

    Il metodo ESAs per la modellizzazione del rischio di desertificazione. Applicazione in un’area della Sardegna nord-occidentale

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    Tecniche di elaborazione GIS e osservazioni di campagna sono state integrate allo scopo di valutare la sensibilità alla desertificazione dei suoli di un’area della Sardegna settentrionale (Comune di Sassari). Ai fini della valutazione della vulnerabilità è stato applicato il modello ESAs (Environmentally Sensitive Areas to desertification - C. Kosmas, 1998) sviluppato nell’ambito del progetto MEDALUS III (EC – DG RES) e attualmente in corso di validazione e revisione nell’ambito del progetto DESERTLINKS (EC – DG RES), del quale gli autori sono partners. Il metodo ESAs utilizza un set di quindici indicatori raggruppati in quattro categorie (qualità del suolo, del clima, della vegetazione e della gestione del territorio). Gli indicatori vengono gestiti in layer indipendenti e successivamente aggregati in 4 indici sintetici, a loro volta poi combinati nell’indice finale di sensibilità. Il calcolo dei singoli indicatori è basato su sistemi di pesi predefiniti, mentre gli indici sono ottenuti attraverso algoritmi basati su medie geometriche. L’ottenimento delle informazioni necessarie ha richiesto l’analisi e l’integrazione di svariati documenti cartografici disponibili, nonché il recupero e la valutazione di numerose osservazioni dirette, in particolare pedologiche (profondità, tessitura, pietrosità superficiale, drenaggio), effettuate nell’area nel corso di vari progetti e campagne di rilevamento. L’implementazione del modello ha evidenziato l’elevata vulnerabilità dell’area considerata. L’esperienza ha inoltre permesso di evidenziare alcuni aspetti di criticità del modello stesso, fornendo elementi utili alla sua validazione
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