Cherchell: an Algerian Mediterranean Historical City with a Rich Islamic Heritage Housing

Islamic residential architecture has some common architectural and architectonic elements issued from shared values such as privacy, simplicity and sobriety. Applied to residential architecture, these values led to some characteristic spaces and architectural elements such as patios or arcs. However, the Islamic civilisation is composed by different cultures spread on a great geographical area; this variety induced different interpretations of these elements by using different building shapes or materials. In this paper, we will present an example of this interpretation in the historical coastal city of Cherchell in northern Algeria. The city of Cherchell is a historic coastal city that witnessed the passage of several civilizations before the arrival of the Islamic one since its founding more than 2500 years ago. This specific situation as historical coastal city allowed the exchange with different civilizations around the Mediterranean Sea, giving rise in the Islamic period to a typical earth architecture characterised by a specific arch's typology. The objective of this article is to present an interpretation of Islamic heritage housing architecture in a Mediterranean historical coastal city (through two specific elements: building material and architectonic element). The long term aim of this study is the dissemination of traditional technics and know-how in order restore cultural heritage buildings and construct new projects with a strong Islamic identity

Editorial: Carbon storage in agricultural and forest soils

International audienc

Role of Grasslands and Grassland Management for Biogeochemical Cycles and Biodiversity. Setting up Long-Term Manipulation Experiments in France

Land use for grassland is recognised to have some beneficial effects for biodiversity and the environment: (i) regulation of the water cycle and protection of soils against erosion, (ii) accumulation of organic matter in soil and sequestration of atmospheric C, (iii) regulation of the N cycle and attenuation of the risk for N leaching, (iv) recycling of nutrients and improvement of soil quality, (v) improvement of biodiversity of vegetation, soil microbes and micro- and meso-fauna. All these effects depend upon the management of the grassland: cutting vs. grazing, stocking density, level of N inputs. Management decisions often result from short- term objectives, whereas the soil-vegetation interactions are long-term processes. Therefore, a steady state is usually not reached, which makes it difficult to determine the overall environmental effects of changes in land use and in grassland management

Land-use intensification differentially affects bacterial, fungal and protist communities and decreases microbiome network complexity

Background: Soil microbial communities are major drivers of cycling of soil nutrients that sustain plant growth and productivity. Yet, a holistic understanding of the impact of land-use intensification on the soil microbiome is still poorly understood. Here, we used a field experiment to investigate the long-term consequences of changes in land-use intensity based on cropping frequency (continuous cropping, alternating cropping with a temporary grassland, perennial grassland) on bacterial, protist and fungal communities as well as on their co-occurrence networks. Results: We showed that land use has a major impact on the structure and composition of bacterial, protist and fungal communities. Grassland and arable cropping differed markedly with many taxa differentiating between both land use types. The smallest differences in the microbiome were observed between temporary grassland and continuous cropping, which suggests lasting effects of the cropping system preceding the temporary grasslands. Land-use intensity also affected the bacterial co-occurrence networks with increased complexity in the perennial grassland comparing to the other land-use systems. Similarly, co-occurrence networks within microbial groups showed a higher connectivity in the perennial grasslands. Protists, particularly Rhizaria, dominated in soil microbial associations, as they showed a higher number of connections than bacteria and fungi in all land uses. Conclusions: Our findings provide evidence of legacy effects of prior land use on the composition of the soil microbiome. Whatever the land use, network analyses highlighted the importance of protists as a key element of the soil microbiome that should be considered in future work. Altogether, this work provides a holistic perspective of the differential responses of various microbial groups and of their associations to agricultural intensification

Land-use intensification differentially affects bacterial, fungal and protist communities and decreases microbiome network complexity

Background Soil microbial communities are major drivers of cycling of soil nutrients that sustain plant growth and productivity. Yet, a holistic understanding of the impact of land-use intensification on the soil microbiome is still poorly understood. Here, we used a field experiment to investigate the long-term consequences of changes in land-use intensity based on cropping frequency (continuous cropping, alternating cropping with a temporary grassland, perennial grassland) on bacterial, protist and fungal communities as well as on their co-occurrence networks. Results We showed that land use has a major impact on the structure and composition of bacterial, protist and fungal communities. Grassland and arable cropping differed markedly with many taxa differentiating between both land use types. The smallest differences in the microbiome were observed between temporary grassland and continuous cropping, which suggests lasting effects of the cropping system preceding the temporary grasslands. Land-use intensity also affected the bacterial co-occurrence networks with increased complexity in the perennial grassland comparing to the other land-use systems. Similarly, co-occurrence networks within microbial groups showed a higher connectivity in the perennial grasslands. Protists, particularly Rhizaria, dominated in soil microbial associations, as they showed a higher number of connections than bacteria and fungi in all land uses. Conclusions Our findings provide evidence of legacy effects of prior land use on the composition of the soil microbiome. Whatever the land use, network analyses highlighted the importance of protists as a key element of the soil microbiome that should be considered in future work. Altogether, this work provides a holistic perspective of the differential responses of various microbial groups and of their associations to agricultural intensification

The contribution of farm-scale experiments to the understanding of soil processes and implications for ecosystem services [Guest Editors' Introduction]

[No abstract available

Soybean yield does not rely on mineral fertilizer in rotation with flooded rice under a no-till integrated crop-livestock system

In subtropical lowlands, the introduction of soybean and livestock in rotation are an alternative to rice monoculture. Due to the nutrient cycling process improved by animal grazing in winter fertilized pastures, soybean may not respond to mineral fertilization under a no-till integrated crop–livestock system (ICLS). Thus, the objectives of this study were to evaluate (i) the soybean yield response to different fertilization levels of phosphorus (P) and potassium (K) and (ii) the relationship between soybean yield and soil chemical properties sampled in different soil layers, in a no-till ICLS in subtropical lowlands. Two field studies were conducted in a system that included a soybean-flooded rice rotation integrated with cattle grazing during the winter season. During the 2015/2016 cropping season, five levels of P and K fertilization were applied to the soil. During the 2017/2018 cropping season, the relationships between soybean yield and soil chemical properties were evaluated under no fertilization treatment. Soybean yield under an ICLS did not respond to P and K fertilization, even when the soil P level was below the critical threshold. The associations between soybean yield and soil chemical properties were greatest in the 10–20 cm soil layer as compared with the 0–10 cm soil layer, especially for available P, followed by pH and soil organic matter (SOM). The crop rotation and ICLS adoption under no-till reduced the soybean reliance for mineral fertilization prior to cropping. Results of this study inform producers of possible fertilization adjustments, in which supplementing mineral fertilizer for soybean may not be necessary

Modeling Carbon and Water Fluxes of Managed Grasslands: Comparing Flux Variability and Net Carbon Budgets between Grazed and Mowed Systems

The CenW ecosystem model simulates carbon, water, and nitrogen cycles following ecophysiological processes and management practices on a daily basis. We tested and evaluated the model using five years eddy covariance measurements from two adjacent but differently managed grasslands in France. The data were used to independently parameterize CenW for the two grassland sites. Very good agreements, i.e., high model efficiencies and correlations, between observed and modeled fluxes were achieved. We showed that the CenW model captured day-to-day, seasonal, and interannual variability observed in measured CO2 and water fluxes. We also showed that following typical management practices (i.e., mowing and grazing), carbon gain was severely curtailed through a sharp and severe reduction in photosynthesizing biomass. We also identified large model/data discrepancies for carbon fluxes during grazing events caused by the noncapture by the eddy covariance system of large respiratory losses of C from dairy cows when they were present in the paddocks. The missing component of grazing animal respiration in the net carbon budget of the grazed grassland can be quantitatively important and can turn sites from being C sinks to being neutral or C sources. It means that extra care is needed in the processing of eddy covariance data from grazed pastures to correctly calculate their annual CO2 balances and carbon budgets

How do microbial communities in top- and subsoil respond to root litter addition under field conditions?

© 2016 Elsevier LtdContrasting microbial community composition and activity at different soil depths may affect root litter decomposition. These effects have up to now been investigated mainly in laboratory studies, which may not be able to take into account complex in situ conditions. Our study aimed to analyze the composition and activity of microbial communities after addition of 13C labeled wheat root litter to a loamy soil under grassland at 30, 60 and 90 cm depths, during a three-year field experiment. We investigated the dynamics of bacterial and fungal abundances and community structures by DNA genotyping and pyrosequencing of 16S and 18S rDNAs. The genetic structures of bacterial and fungal communities were evaluated by automated ribosomal intergenetic spacer analysis. The functions of these communities were analysed by determination of extracellular enzyme activities and viable microbial communities involved in 13C labeled organic matter decomposition studied by 13C PLFAs. The abundance of fungal and bacterial communities (16S and 18S rDNAs and PLFA) and the potential activities of enzymes involved in the C- and N-cycles were significantly higher at the top 30 cm compared with deeper soil throughout the experiment. Both were stimulated by fresh litter input. A trend to decreasing bacterial and fungal richness was noted after root litter addition at 30 cm, while richness of bacteria at 90 cm and those of fungi at 60 and 90 cm increased. Moreover, root litter addition caused a reduction of the Shannon Weaver Diversity index and a shift in microbial community structure at all three depths, which was more pronounced for bacteria at 30 and 60 cm and for fungi at 90 cm. The changes during litter degradation resulted in similar dynamics of most enzyme activities at all depths. Chitinase activity was enhanced after 29 months compared to initial conditions indicating the availability of high amounts of microbial detritus. The degrading microbial community as assessed by 13C PLFA showed similar temporal dynamics at all three depths. Fungal contribution to this community decreased during later stages of litter degradation, while the contribution of Gram+ bacteria increased. We conclude that litter addition led to convergence of microbial communities of top- and subsoil through stimulation of copiotrophic populations. Soil microbial community structures are thus connected with the amount of fresh litter input. Enzyme activities and 13C PLFA reflect to some extent the changes occurring during degradation, i.e. exhaustion of fresh plant material and accumulation of detritus

Trans European decomposition index study in arable soils with different crop species diversity using 13C-labelled litter

Póster presentado en la Sessión 8 en el Joint European Stable Isotope Users group Meeting JESIUM 2022 Kuopio, Finland Online 10–14 October 2022.Mixed species systems are currently increasing in area in Europe providing opportunities for sustainable intensification of agriculture. The agroforestry systems cover about 9% of the utilized agricultural area and integrated crop livestock systems occupy a major place in the European agricultural area including perennial forage grasses and grasslands sown with varying degrees of duration. Intercropping and other mixed cash crop systems are currently less developed in the EU. The EU EJP-SOIL funded MIXROOT-C project (2021-2024) is gaining a management-oriented understanding of the effect of mixed-species root systems on carbon flow and organic matter accumulation in European agricultural soils.N