Search results for "Land Use change"

Channel forms recovery in an ephemeral river after gravel mining (Palancia River, Eastern Spain)

2017

[EN] During the 1970s, the Palancia River was intensively affected by gravel mining instream. This activity completely destroyed the fluvial forms, devastating the original wandering pattern. At the end of the 1980s, gravel mining ceased and the river started a process of recovery, only altered by several clearing operations. The aim of this work is to describe these processes of change, analyzing the river's morphosedimentary conditions through a GIS analysis of aerial photographs previous to, simultaneous with, and subsequent to the intense gravel mining activity. Results explain the current difficulties of some ephemeral rivers to recover their original forms, because of the sediment and…

An assessment of the global impact of 21st century land use change on soil erosion

2017

Human activity and related land use change are the primary cause of accelerated soil erosion, which has substantial implications for nutrient and carbon cycling, land productivity and in turn, worldwide socio-economic conditions. Here we present an unprecedentedly high resolution (250 × 250 m) global potential soil erosion model, using a combination of remote sensing, GIS modelling and census data. We challenge the previous annual soil erosion reference values as our estimate, of 35.9 Pg yr−1 of soil eroded in 2012, is at least two times lower. Moreover, we estimate the spatial and temporal effects of land use change between 2001 and 2012 and the potential offset of the global application o…

Effect of cactus pear cultivation after Mediterranean maquis on soil carbon stock, δ13C spatial distribution and root turnover

2014

Abstract Mediterranean ecosystems are characterized by nearly complete replacement of natural vegetation by intensive croplands and orchards leading to strong soil degradation. Organic carbon is usually accumulated in soils under maquis leading to partial regeneration of fertility for future agricultural use. The aim of this work was to investigate the effect of land use change from maquis to agriculture on soil organic carbon (SOC) stock and its spatial distribution in a Mediterranean system. Three Mediterranean land use systems (seminatural vegetation, cactus pear crop and olive grove) were selected in Sicily and analysed for soil C stocks and their δ13C. Total SOC and δ13C were measured …

Anthropedogenesis and Land Use Change: influences on soil qualities and functions.

2014

Soil carbon and soil physical properties under land use change in a protected area of Sicily

2010

This work investigated the role of land cover and land use change as a soil’s ability to store carbon and reduce carbon dioxide emission in a Mediterranean area. Using both historic records and land cover crop maps we estimated the effect of land cover change on the carbon stock from 1972 to 2008 in a natural reserve (Grotta di S. Ninfa) in the West of Sicily. Five paired sites in different soil types were selected and five land use classes (arable land, vineyard, olivegrove, gariga, eucalyptus afforestation) were analyzed. We studied the effect of land use on soil organic carbon (SOC) content in bulk soil and 1000-2000 m, 500-1000 m, 250-500 m, 63-250 m, 25-63 m and <25 m size fractions. F…

Factors Influencing Soil Organic Carbon Stock Variations in Italy During the Last Three Decades

2010

Soils contain about three times the amount of carbon globally available in vegetation, and about twice the amount in the atmosphere. However, soil organic carbon (SOC) has been reduced in many areas, while an increase in atmospheric CO2 has been detected. Recent research works have shown that it is likely that past changes in land use history and land management were the main reasons for the loss of carbon rather than higher temperatures and changes of precipitation resulting from climate change. The primary scope of this work was to estimate soil organic carbon stock (CS) variations in Italy during the last three decades and to relate them to land use changes. The study was also aimed at f…

Effect of the conversion of mangroves into shrimp farms on carbon stock in the sediment along the southern Red Sea coast, Saudi Arabia

2019

The conservation of coastal ecosystems and specially mangroves ‘‘blue carbon’’ is receiving more attention as consequence of their recognition as high ecosystem carbon stocks and for the fact that these areas are undergoing land conversion. The aim of the present study is to evaluate the impact of land use changes due to conversion of mangroves to shrimp farms on the bulk density (SBD), organic carbon (SOC) concentration, and SOC stock in the sediments along the southern Saudi Arabian Red Sea coast. Shrimp farms and mangrove locations showed significant (P < 0.001) differences in SBD with high mean values in the sediments of shrimp farms. Shrimp farms and mangrove locations showed significa…

Subsurface flow and large-scale lateral saturated soil hydraulic conductivity in a Mediterranean hillslope with contrasting land uses

2017

Abstract The lateral saturated hydraulic conductivity, Ks,l , is the soil property that mostly governs subsurface flow in hillslopes. Determinations of Ks,l at the hillslope scale are expected to yield valuable information for interpreting and modeling hydrological processes since soil heterogeneities are functionally averaged in this case. However, these data are rare since the experiments are quite difficult and costly. In this investigation, that was carried out in Sardinia (Italy), large-scale determinations of Ks,l were done in two adjacent hillslopes covered by a Mediterranean maquis and grass, respectively, with the following objectives: i) to evaluate the effect of land use change o…

Agricultural land abandonment in Mediterranean environment provides ecosystem services via soil carbon sequestration

2016

Abandonment of agricultural land leads to several consequences for ecosystem functions. Agricultural abandonment may be a significant and low cost strategy for carbon sequestration and mitigation of anthropogenic CO2 emissions due to the vegetation recovery and increase in soil organic matter. The aim of this study was to: (i) estimate the influence of different Soil Regions (areas characterized by a typical climate and parent material association) and Bioclimates (zones with homogeneous climatic regions and thermotype indices) on soil organic carbon (SOC) dynamics after agricultural land abandonment; and (ii) to analyse the efficiency of the agri-environment policy (agri-environment measur…

Spatial variability of channel changes in a mediterranean ephemeral stream in the last six decades (1946-2006)

2014

An analysis of morphological changes during the last six decades is presented for the Rambla de Cervera, a Mediterranean ephemeral stream located in the eastern sector of the Iberian Mountain Range. The studied channel (16.5 km) has two contrasted sectors: a horst confined sector (5.5 km) and a graben sector (11 km). Channel changes were analysed through the analysis of aerial photographs, with geographical information systems (GIS) and comparison of topographic surveys made with a GPS-RTK. Between 1946 and 2006 the Rambla de Cervera, underwent channel adjustments comparable to those observed in other Mediterranean rivers. The gravel channel markedly narrowed, losing width (68.5%) and chann…