Search results for "Arid environment"
showing 10 items of 12 documents
Using hydrological connectivity to detect transitions and degradation thresholds: Applications to dryland systems
2020
In arid and semi-arid ecosystems, shortage of water can trigger changes in landscapes’ structures and function leading to degradation and desertification. Hydrological connectivity is a useful framework for understanding water redistribution and scaling issues associated with runoff and sediment production, since human and/or natural disturbances alter surface water availability and pathways increasing/decreasing connectivity. In this paper, we illustrate the use of the connectivity framework for several examples of dryland systems that are analysed at a variety of spatial and temporal scales. In doing so, we draw particular attention to the analysis of coevolution of system structures and …
Evolution of organic carbon pools and microbial diversity in hyperarid anthropogenic soils
2016
Abstract We investigated the organic carbon pools and the microbial diversity and activity in anthropogenic terraced soils in a desert area of Southern Peru to highlight how the introduction of agriculture influences carbon evolution and storage and genetic and functional diversity of soil microbiota over time. Five sites were selected considering soils cultivated since 5, 15, 20, 35 and 65 years, sampled along the profile depth (0–20 and 20–40 cm layer). Soil and microbial parameters comprised by organic carbon pools, microbial respiration, microbial community physiological profile (CLPP) and microbial diversity (PCR-DGGE) were determined. The results showed that the highest C concentratio…
Are remote sensing evapotranspiration models reliable across South American ecoregions?
2021
Many remote sensing-based evapotranspiration (RSBET) algorithms have been proposed in the past decades and evaluated using flux tower data, mainly over North America and Europe. Model evaluation across South America has been done locally or using only a single algorithm at a time. Here, we provide the first evaluation of multiple RSBET models, at a daily scale, across a wide variety of biomes, climate zones, and land uses in South America. We used meteorological data from 25 flux towers to force four RSBET models: Priestley–Taylor Jet Propulsion Laboratory (PT-JPL), Global Land Evaporation Amsterdam Model (GLEAM), Penman–Monteith Mu model (PM-MOD), and Penman–Monteith Nagler model (PME-VI).…
No till soil organic carbon sequestration could be overestimated when slope effect is not considered
2020
Abstract No tillage (NT) soil management has been considered a strategy for the implementation of environmental sustainability and a possible tool of soil organic carbon (SOC) sequestration. Considering the wide range of data on SOC change after NT application in relation to conventional tillage (CT) in different studies, further researches are needed over a diverse range of soil and climate before a proper estimation of the benefits can be provided by the NT. A data set composed of cereal cropping system studies, comparing the SOC content under CT and NT was compiled from the literature using the scientific repositories “Scopus” and “Science direct”. This aims to i) discriminate and quanti…
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…
Pedogenesis and Variability in Soil Properties in a Floodplain of a Semiarid Environment in Southwestern Sicily (Italy).
2010
We performed a pedological study of the variability in soils in a floodplain area of a semiarid region in southwestern Sicily. The objectives of our research were to (i) investigate the role of parent material, erosion, and distribution processes on soil pedogenesis and horizon differentiation; (ii) evaluate the statistical distribution of soil properties; and (iii) interpret these distributions in terms of pedogenic and other processes. Our results showed that not all soil properties examined followed a normal distribution and that even when logtransformed, the degree of normality of the soil salinity data did not improve. Furthermore, principal component analysis was performed to investig…
Grassland fire effect on soil organic carbon reservoirs in a semiarid environment
2013
Abstract. The aim of this work was to investigate the effect of an experimental fire used for grassland management on soil organic carbon (SOC) stocks. The study was carried out on Hyparrhenia hirta (L.) Stapf (Hh) grassland and Ampelodesmos mauritanicus (Desf.) T. Durand & Schinz (Am) grasslands located in the north of Sicily. Soil samples were collected at 0–5 cm before and after the experimental fire, and SOC was measured. During the grassland fire, soil surface temperature was monitored. Biomass of both grasses was analysed in order to determine dry weight and its chemical composition. The results showed that SOC varied significantly with vegetation type, while it is not affecte…
Effect of Afforestation on Soil Carbon and Nitrogen Content on a Mediterranean Island (Lampedusa, Italy)
2015
During the 20th century, large surfaces in the Mediterranean countries were subject to afforestation activities, mostly affecting abandoned agricultural lands. Under semi-arid climate conditions, Pinus spp. were the most frequently used species for these activities. The effect of pine plantations on soil organic carbon (SOC) and nitrogen (N) content in Lampedusa Island (South Italy) was investigated. SOC and soil N content under pine plantations of different ages (14, 24 and 43 years since plantation) were compared with SOC and soil N content in garrigue communities, which were dominated by shrubs, subshrubs and perennial herbs. The results showed that SOC content is affected by plantation …
Genetic and morphologic diversity of European fan palm (Chamaerops humilisL.) populations from different environments from Sicily
2014
Chamaerops humilis is decreasing in abundance in Mediterranean Europe, which has induced the European community to call for its protection in Special Areas of Conservation. However, information about its genetic and morphological variability, which is crucial to the development of any conservation strategies, is insufficient. The present study aimed to investigate the genetic and morphological variability of C. humilis in Sicily, which was selected as a model because of the high number of dense populations. The relationships between morphological traits and climatic variables were studied to highlight patterns of adaptation to the environment, along with the genetic similarity among the pop…
Source of calcium for pedogenic CaCO3 formation in benchmark soils of a Mediterranean semiarid environment
2004
Calcic and petrocalcic horizons (Bk and Bkm, respectively) commonly occur in soils of arid and semiarid regions. Studies carried out to investigate the source of calcium in CaCO3 formation have shown that dust and parent materials represent the main sources. The aim of this study was to investigate if gypsum may be a source of calcium for calcium carbonate formation and, eventually, to quantify it. Five soil pedons, developing on “Serie Gessoso- Solfifera”, were selected in a very representative forest Mediterranean ecosystem in Sicily (I). Pedons were opened, described in field and sampled according to the sequence of genetic horizons. Soil samples were analyzed to investigate 87/86Sr rati…