Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 5 de 5
Filter
Add more filters










Database
Language
Publication year range
1.
Sci Total Environ ; 738: 140206, 2020 Oct 10.
Article in English | MEDLINE | ID: mdl-32660774

ABSTRACT

United Nations established 2021-2030 as the decade for ecosystem restoration and "prevent, halt and reverse the degradation of ecosystems worldwide". Ecosystem and land degradation are a global phenomenon. As a consequence of land degradation, in the late 1990s, the "Grain for Green Program" (GFGP) was established in Loess Plateau (China). It converted slope farmlands to forest or grassland over the, resulting in a visible "greening" trend. Other effects of GFGP on soil properties, land production, hydrological conditions, ecosystem services, and policy implications are the topics of this Special Issue. This Special Issue includes 17 contributions that cover recent research carried out in Loess Plateau in the mentioned topics at different spatial and temporal scales. The collection of papers presented in this Special Issue discusses critical issues in vegetation restoration and sustainable land management in the region. This Special Issue will contribute to United Nations strategy for ecosystems restoration.

2.
Environ Res ; 183: 109160, 2020 04.
Article in English | MEDLINE | ID: mdl-32000004

ABSTRACT

Mediterranean mountains are facing great environmental and socioeconomic challenges in the current framework of Global Change. One of these is soil degradation, which is one of the major threats in those territories. Soil degradation is more dramatic where eco-geomorphology and land uses with less vegetation cover promote soil erosion. Soil erosion is influenced by soil erodibility, which can be assessed by different methodologies, e.g. RUSLE K factor and aggregate stability of soils. This study deals with the validation of RUSLE K factor by means of soil aggregate stability analysed in two-contrasted watersheds from one Mediterranean mountainous region in South of Spain, under sub-humid and semiarid climatic conditions. In both of them, landscape dynamic from 1956 to 2016 was analysed in order to characterize the modifications in land uses. A total of 361-soil samples was also taken covering all land uses for analysing aggregate stability of soils as well as those soil properties needed to calculate the RUSLE K factor. The results indicated that: i) landscape dynamic was influenced by changes in land uses contributing mainly to an increment in vegetation cover in the rainiest watershed; ii) the analysed soil properties showed very few significant differences between watersheds and between land uses, especially regarding organic matter content; and iii) the validation of K Factor using aggregate stability was better in the rainiest watershed and, within this one, in the natural land uses and irrigated cultivations, meaning where the biotic factors were more influential. These results implicated more researches are necessary, principally, focussed on the validation of the RUSLE K parameter using different fractions of aggregates as well as considering other eco-geomorphological parameters.


Subject(s)
Environmental Monitoring , Soil , Mediterranean Region , Rain , Spain
4.
Sci Total Environ ; 636: 1480-1489, 2018 Sep 15.
Article in English | MEDLINE | ID: mdl-29913608

ABSTRACT

Prescribed fire is a common management practice in Mediterranean region to reduce the amount of fuel and to decrease the wildfire risk. The objective of this study is to assess the effect of a prescribed fire on some soil properties, hydrological response and vegetation recovery in experimental plots 5 years after. The results showed that: i) with the exception of electrical conductivity, the prescribed fire did not affect the analyzed soil properties, and ii) overland flow and sediment transport were increased during the first two years, returning to levels pre-fire, 5 years post-fire. The rainfall threshold for overland flow generation was lower during the following months after the prescribed fire owing to the depletion of the vegetation cover. Immediately after the fire, the vegetation cover was of 1.9%, being the three main soil surface components that dominated the hydrological response: charcoal and decayed wood; blackish and greyish ash, and bare soil. However, these areas decreased very rapidly during the second year following the fire, principally, owing to the regrowth of herbaceous plants and shrubs. In addition, the vegetation cover in burned plots was 16.1% higher than that measured in the unburned ones. Overall, the prescribed fire only had an impact on runoff and sediment transport in the two years post-fire, as consequence of vegetation removal.

5.
Sci Total Environ ; 578: 469-475, 2017 Feb 01.
Article in English | MEDLINE | ID: mdl-27836340

ABSTRACT

Spring grassland fires are common in boreal areas as a consequence of slash and burn agriculture used to remove dry grass to increase soil nutrient properties and crop production. However, few works have investigated fire impacts on these grassland ecosystems, especially in the immediate period after the fire. The objective of this work was to study the short-term impacts of a spring grassland fire in Lithuania. Four days after the fire we established a 400m2 sampling grid within the burned area and in an adjacent unburned area with the same topographical, hydrological and pedological characteristics. We collected topsoil samples immediately after the fire (0months), 2, 5, 7 and 9months after the fire. We analysed soil pH, electrical conductivity (EC), major nutrients including calcium (Ca), magnesium (Mg), sodium (Na), and potassium (K), and the minor elements aluminium (Al), manganese (Mn), iron (Fe) and zinc (Zn). We also calculated the soil Na and K adsorption ratio (SPAR), Ca:Mg and Ca:Al. The results showed that this low-severity grassland fire significantly decreased soil pH, Al, and Mn but increased EC, Ca, Mg, and K,. There was no effect on Na, Fe, and Zn. There was a decrease of EC, Ca, Mg, and Na from 0months after the fire until 7months after the fire, with an increase during the last sampling period. Fire did not significantly affect SPAR. Ca:Mg decreased significantly immediately after the fire, but not to critical levels. Ca:Al increased after the fire, reducing the potential effects of Al on plants. Overall, fire impacts were mainly limited to the immediate period after the fire.

SELECTION OF CITATIONS
SEARCH DETAIL
...