Drought differently destabilizes soil structure in a chronosequence of abandoned agricultural lands

Climate change is causing an increase in the frequency and severity of drought, and this has a significant influence on the global C cycle as soils are the main sink for C in terrestrial ecosystems. Drought can have serious consequences for the structural stability of the soil, which influences the protection of the organic matter stored in the soils and hence its mineralization. In this work we study the effects of an extreme drought event on the structural stability of the soil in Mediterranean annual grasslands developed after the abandonment of agricultural activity. This was done by building a chronosequence of abandoned vineyards and determining the changes in the stability of the soil aggregates and organic matter by monitoring these parameters for three consecutive years in permanent plots with different ages of abandonment. This period of time included an extreme drought event in the second year with a strong positive thermal anomaly, which caused a serious structural destabilization of the soil and had a major impact on the soil C and N cycles. The breakdown of the soil aggregates left unprotected a large amount of organic substrates that were rapidly mineralized when the environmental conditions were favourable for soil biological activity. This had significant repercussions on the functioning of these abandoned ecosystems, which became sources of atmospheric CO2, when under normal conditions they act as C sinks. Furthermore, the effects of this extreme event were more severe in the plots with longer periods of abandonment, which have the highest amount of C accumulated in the soil

Mediterranean grassland succession as an indicator of changes in ecosystem biodiversity and functionality

The abandonment of agricultural lands triggers a secondary succession of plant species which implies important changes in soil quality. Annual Mediterranean grasslands are known to be persistent on abandoned agriculture lands in the western Mediterranean. We used plant taxonomic and functional approaches to determine the role of Mediterranean grasslands as an indicator of changes in ecosystem biodiversity and functionality. We tested the hypothesis that Mediterranean grasslands are a suitable model for monitoring biodiversity and soil fertility in a secondary succession. Soil and vegetation features on 21 permanent plots were monitored in 2016 and 2020. Numerical classifications based on floristic composition showed two different plant communities independently of the sampling year: early-stage grasslands in the first post-abandonment decade and late-stage grasslands after the first post-abandonment decade. Generalized linear model and redundancy analysis also revealed differences in growth forms, functional traits and soil functionality between communities. Late-stage grasslands was characterized by enriched bryophyte coverage and an impoverishment in hemicryptophytes and plant latex segregators growing on soils with a higher hydrolase enzyme activity and TOC content compared to early-stage grassland. Our results suggest that annual Mediterranean grasslands growing on siliceous soils denoting a mature-stage succession, and floristically characterized by the symbiont plant with Ascomycota, Tuberaria guttata, and a high bryophyte cover, are worthy of recognition for conservation

Estudio de los suelos de los alrededores del Balneario de Villavieja de Nules (Castellón de la Plana)

Soil is the first natural barrier that has to be crossed by the compounds deposited on the Earth's surface to reach aquifers. Knowing about the physicochemical properties involved in the infiltration processes, as well as the soil type, are essential parameters which allows us to analyze the risk of contamination affecting the composition of groundwater. In this work, the environmental factors of the area around the Balneario de Villavieja Nules (Castellón de la Plana) are described, and some of the chemical, physical, and mineralogical characteristics of four soils are analyzed. Most particularly C, N, pH, CE, CIC y CO3 2‐, as well as texture, bulk density, particle density, porosity, hydraulic parameters and clay fraction mineralogy were determined. The results showed that the environmental characteristics of the area, together with the types of soil analyzed slow down the water flow processes.El  suelo  es  la  primera  barrera  natural  que  han  de  atravesar  los  compuestos  depositados  en  la  superficie  terrestre  para  llegar  a  los  acuíferos.  Conocer  las  propiedades  fisicoquímicas  que  intervienen  en  los  procesos  de  infiltración,  así  como  saber  el  tipo  de  suelo,  son  parámetros  esenciales  que  nos  permite  analizar  el  riesgo  de  contaminación  que  afecta  la  composición  del  agua  subterránea.  En  este  trabajo  se  describen  los factores ambientales de la zona, y se analizan  algunas  de  las  propiedades  químicas,  físicas  y  mineralógicas  de  cuatro  suelos  característicos  de los alrededores del Balneario de Villavieja de  Nules  (Castellón  de  la  Plana).  Para  ello  se  ha  obtenido el contenido en: C, N, pH, CE, CIC y CO3  2‐,  así  como  se  ha  determinado:  textura,  densidad  aparente,  densidad  real,  porosidad,  parámetros  hidráulicos  y  la  mineralogía  de  la  fracción  arcilla.  De  los  resultados  se  desprende  que  las  características  ambientales  de  la  zona,  junto  a  los  tipos  de  suelos  analizados  ralentizan  los procesos de flujos descendentes

Suelos del entorno del balneario

Soil characteristics are decisive in groundwater quality. The impact of human activities, especially in areas subject to agricultural pressure, involves potential risks which may be critical to the viability of the water resource. This work gathers together the study of three representative soils located in the thermal environment of “Villa Olmedo”, Valladolid. All of them have developed from arkoses and found around 750 m elevation in a zone of flat topography. Morphological, physical, chemical and mineralogical properties of these soils were analyzed. They are poorly developed, coarse textured, with pH close to neutrality and antric features in the surface horizons. El conocimiento del suelo es imprescindible para comprender el riesgo de la posible afectación de las aguas subterráneas, especialmente en áreas sometidas a una fuerte presión de actividad agrícola. Se presenta el estudio de tres suelos localizados en los alrededores del Balneario “Villa de Olmedo”, provincia de Valladolid. Se han desarrollado a partir de arcosas, situados en topografía llana, con una altitud entorno a los 750 m y bajo clima Mediterráneo templado. Se analizaron las propiedades morfológicas, físicas, químicas y mineralógicas de los suelos. En general, son suelos poco evolucionados, con textura gruesa, pH próximos a la neutralidad y horizontes superficiales con características ántricas.

Comparison of soil quality indexes calculated by network and principal component analysis for carbonated soils under different uses

There is an urgent need to conserve and improve the quality of agricultural soils in the coming decades. Decision tools capable of providing reliable information about soil quality are needed, and soil quality index (SQI) is one of the most used. Principal component analysis (PCA) is the common methodology to calculate it, however in some cases fails to differentiate soil quality properly. Therefore, the aim of this work is to assess a SQI through a different methodology as network analysis (NTA) and compare it with PCA, assuming that soil uses affect soil qualities differently. From soils with different uses (rainfed, olive grove and forest) network analysis and principal component analysis have been used to select a minimum dataset (MDS) to generate SQI from 36 physical, chemical and biological soil variables. Using NTA, geometric mean of the enzyme activities (GMEAN), bulk density (BD) and phosphatase activity (phos) where selected as indicators, while PCA selected total organic carbon (TOC), free Fe oxides (FeF), crystalline Mn oxides (MnX), pH, electrical conductivity (EC) and percentage of coarse sand (CS). Four SQI were calculated from each MDS through linear and non-linear scoring equations and by additive integration and weights. The SQI generated by NTA were more useful than those generated by PCA, as in addition to having fewer indicators they were able to better differentiate the uses in the study. This greater resolution capacity of the NTA would be the consequence of a better selection of indicators using this method than using PCA

Estudio de los suelos del entorno del Balneario de San Nicolás (Almería)

Las propiedades físico-químicas de los suelos que se encuentran en la parte superficial de las capas freáticas, juegan un papel muy importante en las características hidroquímicas de las aguas subyacentes, pues fenómenos como disolución, hidrolisis y procesos de óxido-reducción de fracciones minerales y orgánicas de los suelos influyen de forma significativa en la composición de las mismas. Además, textura, estructura y materia orgánica del suelo son factores claves en la regulación del régimen hidrodinámico. En este trabajo analizamos las características edáficas de cuatro suelos muy significativos de los alrededores del Balneario de San Nicolás, ubicado en Alhama de Almería, Alpujarra Almeriense, situada a 450 msnm en la ladera norte de la Sierra de Gádor. Son suelos con escaso desarrollo, tipo AC, formados a partir de materiales sedimentarios constituidos por margas arenosas, calcarenitas, dolomías y yeso, los situados en las proximidades del Valle del Andarax, y por materiales de derrubios de ladera y pie de monte, con predominio de cuarcita, dolomías, calizas y calizas margosas, los situados en la Sierra de Gádor. Los suelos son carbonatados y están saturados, siendo el calcio el catión mayoritario. Presentan pHs básicos, bajo contenido en materia orgánica y texturas gruesas. Cuarzo, calcita, dolomita y yeso son los minerales más abundantes entre los no laminares, y son las micas los filosilicatos presentes en mayor proporción. El predominio de texturas gruesas y la perdida de estructura en los horizontes profundos son determinantes en el grado de infiltración. Se han incluido en las unidades Regosoles y Calcisoles

Estudio de los suelos de los alrededores del balneario de Paracuellos de Jiloca (Zaragoza)

El aprovechamiento de las aguas mineromedicinales como medio para sanar de forma natural se conoce desde épocas ancestrales. Sus acciones terapéuticas están condicionadas con los gases y las fases sólidas que contengan, y estos dependen del equilibrio y la composición de la atmosfera, los suelos y las rocas.Estos equilibrios están relacionados con la temperatura y la presión del sistema, y cualquier cambio puede producir una variación que afecte a los procesos de disolución y precipitación de los minerales, y por tanto, a la concentración de elementos químicos en las aguas.La composición del suelo juega un papel determinante ya que en su interior se producen reacciones de sorción-desorción, complejación-disociación, disolución-precipitación, que determinan la movilidad de los constituyentes orgánicos e inorgánicos que forman el suelo. En función del resultado de estas reacciones los elementos y compuestos pude quedarse, o alcanzar las aguas subyacentes. En este trabajo analizamos las características edáficas de cuatro suelos muy representativos de los alrededores de la localidad de Paracuellos de Jiloca, localidad donde se encuentra la casa balneario. Pertenece la zona al Sistema Ibérico, en el Valle del Jiloca, situado a una altitud de 586 msnm y se encuentra a 4,6 km de Calatayud. Son suelos con escaso desarrollo, tipo AC, formados a partir de materiales sedimentarios constituidos por conglomerados, calizas margosas y yesos. Presentan pHs básicos, poca materia orgánica, texturas gruesas, son carbonatados y están saturados, siendo el calcio el catión mayoritario. La alta pedregosidad, el predominio de las texturas gruesas,y estructuras débiles, condiciona una porosidad elevada lo que hace que estos suelos tengan un alto grado de infiltración

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Soil and vegetation dynamics in a chronosequence of abandoned vineyards

Euro-Mediterranean countries have undergone radical changes in their traditional landscapes due to the abandonment of rural areas. Natural vegetation rapidly colonizes abandoned lands and cause changes in ecosystem functioning. Our main objective was to study how time since abandonment of vineyards influences the physical, chemical and biological properties of the soil and the vegetation composition and cover. In 2016, we selected a chronosequence of six abandoned vineyards (1, 3, 7, 11, 25 and 40 years), an active vineyard, and a plot of land that has not been used as a vineyard for at least the last 60 years. Soil physical-chemical variables, including the organic matter fractions and available nutrients, were analysed. To observe the variation in the biochemical properties of the soils, the activities of 11 enzymes were determined, relating to the main macronutrient cycles: carbon (C), nitrogen (N), phosphorous (P) and sulphur (S) cycling. Three sites (1 m2 ) were randomly established on each plot within the area occupied by annual grasslands, and species cover was estimated in order to obtain the species density and cover of plant functional traits. Our results showed that the abandonment caused major changes in the functioning of the ecosystems. Secondary succession in abandoned vineyards was characterized by a significant increase in plant species density and by changes in the composition of the annual grasslands, from an early brassicaceous community to a late cistaceous community. This was accompanied by an increase in soil TOC (0.38–1.78%) and TN (0.14 to 0.26 %) content, and the activity of most enzymes. These changes occurred more rapidly during the first two decades after abadonment

Interannual climate variability determines the efficiency of functional recovery in dry Mediterranean abandoned vineyards

European abandoned lands have been increasing in recent decades, and this is occurring in a climate change scenario in which the consequences of their interactions are still little known. We tested the hypothesis that the functionality of abandoned lands responds differently to year‐to‐year climate variations depending on the time since the cessation of agricultural activity. We constructed a chronosequence in Mediterranean abandoned vineyards at six different years of abandonment in 2016 (1, 3, 7, 11, 25, 40), in a current vineyard and in land not dedicated to vineyards. Soil total organic carbon (TOC), total nitrogen (TN) and available nutrients, enzyme activities relating to the main macronutrient cycles and plant‐community attributes were studied at 24 sites over three consecutive years. A total of 144 samplings were performed. TOC, TN, most enzyme activities and plant species density increased throughout the chronosequence, although interannual climate variability also had a significant influence. The extreme drought event increased the activity of enzymes related to the carbon (C) and nitrogen (N) cycle, as well as the stock of TOC after a subsequent decrease in TOC when environmental conditions became favourable. In contrast, plant species density and the cover of certain plant functional traits such as mycorrhizal symbiotic plants (Cistaceae) and N‐fixers (Fabaceae) decreased significantly. Our results also demonstrated that extreme drought events had a higher negative impact on lands that had been abandoned for longer. We therefore conclude that extreme drought events damage the functionality of Mediterranean abandoned agrosystems, thus affecting all its compartments and jeopardising its functionality