A novel method is proposed for designing an energy storage system (ESS) which is dedicated to the reduction of the uncertainty of short-term wind power forecasts up to 48 h. The investigation focuses ...on the statistical behavior of the forecast error and the state of charge (SOC) of the ESS. This approach gives an insight into the influence of the forecast conditions (horizon, quality) on the distribution of SOC. With this knowledge, an optimized sizing of the ESS can be done with a well-defined uncertainty limit. For this study, one-year time series of power output measurements and forecasts were available for two wind farms. As a reference, different forecast quality degrees are simulated based on a persistence approach. With the forecast data, empirical probability density functions (pdfs) are generated which are the basis of the proposed method. This approach can lead to a considerable reduction of the ESS and provides important information about the unserved energy. This unserved energy represents the remaining forecast uncertainty. As a consequence, the proposed probabilistic method permits the sizing of energy storage systems as a function of the desired remaining forecast uncertainty, reducing simultaneously power and energy capacity.
1. Metal mining in drylands generates waste tailings with high toxicity, physical instability, as well as water and thermal stresses that hamper their biological colonization. This limits the ...restoration of ecosystem functions that are essential to re-integrate these artificial micro-deserts within the landscape matrix. 2. We assessed the functional role of local nurse plant species and their traits to restore ecosystem functions related to soil fertility, soil microbial productivity and the reduction of abiotic stress. We sampled 30 metalliferous tailings in a mining district from semi-arid Spain to detect nurse plant species and quantify their ability to promote essential functions from their establishment on the barren substrate up to the adult stage. 3. We found 11 plant species acting as nurses out of 102 species able to colonize barren soils. Ten nurses further triggered a cascade of effects increasing soil fertility and microbial productivity and/or lowering soil abiotic stress. 4. Plant species with larger life-forms and longer periods of establishment since tailing abandonment contributed the most to the promotion of ecosystem functions. C4 plant species developing root systems with lower intensivity and depth:laterality ratios, as well as leaves with lower carbon:nitrogen ratios (C:N) induced a faster recovery of ecosystem functions. 5. Synthesis and applications. We propose a protocol for selecting key species to be used in restoration programmes based on their ability to restore ecosystem functions under extremely stressful conditions. We encourage combination of multiple target species with complementary traits in order to reinforce the rehabilitation of ecosystem functions.
Plant facilitation, an ecological interaction that benefits at least one species without harming the other, is increasingly used as a restoration tool. To restore degraded habitats under a ...facilitation framework, practitioners must correctly select both the benefactor (nurse) and the beneficiary (facilitated) species.
Based on community assembly and species coexistence theory, we propose selecting plant species that largely differ in a suite of functional traits so that competition is minimized and facilitation maximized due to functional complementarity. To apply this guideline in a pilot restoration experiment performed in metalliferous mine tailings in South‐Eastern Spain, we first built the plant–plant facilitative interaction network naturally occurring in a set of 12 tailings. After characterizing each species with 20 morphological and physiological traits, we verified that facilitative interactions were predominantly established between functionally distant species.
Then, we designed a sowing experiment combining 50 nurse‐facilitated species pairs separated by a wide range of functional distances. The success of seedling establishment significantly increased with the functional distance between the nurse and the facilitated plant species.
Synthesis and applications. We encourage the use of ecological facilitation together with trait‐based species selection to design restoration programmes based on the principle of increasing functional distance between target species. This method may not only promote the restoration of the plant cover but also impact paramount ecosystem functions, thus being an efficient low‐cost restoration practice in abiotically stressful ecosystems.
We encourage the use of ecological facilitation together with trait‐based species selection to design restoration programmes based on the principle of increasing functional distance between target species. This method may not only promote the restoration of the plant cover but also impact paramount ecosystem functions, thus being an efficient low‐cost restoration practice in abiotically stressful ecosystems.
Fire alters the structure and composition of above‐ and belowground communities with concurrent shifts in phylogenetic diversity. The inspection of postfire trends in the diversity of ecological ...communities incorporating phylogenetic information allows to better understand the mechanisms driving fire resilience. While fire reduces plant phylogenetic diversity based on the recruitment of evolutionarily related species with postfire seed persistence, it increases that of soil microbes by limiting soil resources and changing the dominance of competing microbes. Thus, during postfire community reassembly, plant and soil microbes might experience opposing temporal trends in their phylogenetic diversity that are linked through changes in the soil conditions. We tested this hypothesis by investigating the postfire evolution of plant and soil microbial (fungi, bacteria and archaea) communities across three 20‐year chronosequences. Plant phylogenetic diversity increased with time since fire as pioneer seeders facilitate the establishment of distantly related late‐successional shrubs. The postfire increase in plant phylogenetic diversity fostered plant productivity, eventually recovering soil organic matter. These shifts over time in the soil conditions explained the postfire restoration of fungal and bacterial phylogenetic diversity, which decreased to prefire levels, suggesting that evolutionarily related taxa with high relative fitness recover their competitive superiority during community reassembly. The resilience to fire of phylogenetic diversity across biological domains helps preserve the evolutionary history stored in our ecosystems.
Nurse plants drive the assembly of facilitated communities and commonly promote plant–soil feedbacks, and are thus recognized as key engineers in abiotically stressful ecosystems. The literature ...neglects; however, the role of the communities which benefit from the presence of the nurse as contributors to soil ecosystem functions. We hypothesized that the nurse and its beneficiaries synergistically enhance essential ecosystem functions mediated by soil microbiota.
To track how plant–plant facilitation impacts plant–soil feedbacks, we selected three nurse species in semi‐arid mine tailings and defined three microsites (open space, nurse canopy and nurse + facilitated canopy). In each microsite, we quantified 18 abiotic and biotic variables associated with four functions: reduction in climatic stress, reduction in edaphic stress, soil fertility and soil microbial productivity (decomposition and nutrient cycling).
Litter biomass increased from open spaces to the microsite beneath the nurses, and further beneath the nurses and their beneficiaries. Litter biomass was a good predictor of both the reduction in climatic stress and increase in edaphic stress (likely owing to metal bioaccumulation). We attributed increments in soil organics and heterotrophic respiration beneath the nurses and their beneficiaries, compared to nurses alone, to biomass effects through increased litter deposition. Variation in fertility and microbial productivity among microsites shaped by the nurses and their facilitated communities was attributed to both diversity and biomass effects. In particular, fertility was promoted beneath phenotypically diverse facilitated communities, as inferred from ten above‐ and below‐ground traits. However, microbial productivity increased at low levels of root biomass likely due to reduced plant–microbe competition for nutrients.
Synthesis. Our results show that facilitated plant communities sheltered by nurse species relieve local abiotic stress and promote plant–microbe interactions, both through biomass and biodiversity effects. These observations shift the conception of facilitated species from simple beneficiaries of the nurse's effects to co‐drivers of essential ecosystem functions.
Resumen
Las plantas nodriza actúan como especies clave ensamblando la comunidad vegetal y promoviendo las interacciones planta‐suelo en ecosistemas de alto estrés gobernados por facilitación. Sin embargo, habitualmente se ignora el papel adicional que la comunidad de especies facilitadas puede ejercer sobre las funciones ecosistémicas del suelo. En este trabajo hipotetizamos que la comunidad de plantas facilitadas contribuye sinérgicamente con la nodriza a la mejora de funciones ecosistémicas mediadas por la microbiota edáfica.
Para evaluar cómo la facilitación entre plantas promueve las interacciones planta‐suelo seleccionamos tres nodrizas en depósitos mineros con vegetación parcheada en ambientes semiáridos y definimos tres micrositios (claro, copa bajo nodriza y copa bajo nodriza con comunidad de facilitadas). Posteriormente, cuantificamos en dichos micrositios 18 variables abióticas y bióticas relacionadas con cuatro funciones principales: reducción del estrés climático, reducción del estrés edáfico, fertilidad edáfica y productividad microbiana (descomposición y ciclado de nutrientes).
La biomasa de hojarasca aumentó en el sentido claro < nodriza <nodriza con facilitadas, y fue un buen predictor de la reducción del estrés climático, aunque incrementó la concentración edáfica de algunos metales pesados. Observamos un incremento de la fertilidad y de la respiración heterotrófica en el micrositio nodriza con facilitadas con respecto a la nodriza, que atribuimos a un efecto del aumento en biomasa (biomass effect) promovido por una mayor deposición de hojarasca. La variabilidad en la fertilidad y productividad microbiana bajo la nodriza con facilitadas la atribuimos tanto a un efecto de la variación en biomasa como en diversidad (diversity effect). En particular, la fertilidad se incrementó en comunidades de facilitadas más diversas fenotípicamente (fenotipo medido a partir de 10 rasgos aéreos y subterráneos). Por el contrario, la productividad microbiana aumentó en micrositios nodriza + facilitada con una menor biomasa de raíces, probablemente debido a una menor competencia planta‐microorganismo por los nutrientes.
Síntesis. Nuestros resultados cambian la concepción de las especies facilitadas como meras beneficiarias de la presencia de una nodriza, para atribuirles un papel como promotoras de funciones ecosistémicas esenciales, mediadas por los efectos de la diversidad y biomasa sobre el estrés abiótico y las interacciones con la microbiota edáfica.
Our results show that facilitated plant communities sheltered by nurse species relieve local abiotic stress and promote plant–microbe interactions, both through biomass and biodiversity effects. These observations shift the conception of facilitated species from simple beneficiaries of the nurse’s effects to co‐drivers of essential ecosystem functions.
The most important single event of the last years in wind energy technology is the reduction in the cost of producing wind electricity offshore, a reduction that can reach 75%, depending on the ...system boundary considered, for installations commissioned by 2024. Surprisingly, there is very little scientific literature showing how this reduction is being achieved.
The objective of this paper is to analyse the evidence behind cost reduction in one of the most significant cost elements of offshore wind farms, the installation of foundations and turbines. This cost is directly dependent on the daily rates of the installation vessels and on the days it takes to install those wind farm elements. Therefore, we collected installation data from 87 wind farms installed from 2000 to 2017, to establish the exact time for installation in each.
The results show that advances have reached 70% reduction in installation times throughout the period for the whole set, turbine plus foundation. Most of these improvements (and the corresponding impact in reducing costs) relate to the larger size of turbines installed nowadays. There is, therefore, not any leap forward in the installation process, but only incremental improvements applied to turbines that are now four times as large as in 2000.
•This study analyses the details of 87 wind farms installed between 2000 and 2017.•Offshore wind installation of turbines and foundations take now 29% of the time per MW compared to the early 2000s.•The main reason is the larger size of turbines, then 2 MW and now 7–9 MW.•Larger turbines means less foundations are needed, thus also saving in foundations installation.
Biogeochemical processes and ecosystemic functions are mostly driven by soil microbial communities. However, most methods focus on evaluating the total microbial community and fail to discriminate ...its active fraction which is linked to soil functionality. Precisely, the activity of the microbial community is strongly limited by the availability of organic carbon (C) in soils under arid and semi‐arid climate. Here, we provide a complementary genomic and metaproteomic approach to investigate the relationships between the diversity of the total community, the active diversity and ecosystem functionality across a dissolved organic carbon (DOC) gradient in southeast Spain. DOC correlated with the ecosystem multifunctionality index composed by soil respiration, enzyme activities (urease, alkaline phosphatase and β‐glucosidase) and microbial biomass (phospholipid fatty acids, PLFA). This study highlights that the active diversity (determined by metaprotoemics) but not the diversity of the whole microbial community (evaluated by amplicon gene sequencing) is related to the availability of organic C and it is also connected to the ecosystem multifunctionality index. We reveal that DOC shapes the activities of bacterial and fungal populations in Mediterranean semi‐arid soils and determines the compartmentalization of functional niches. For instance, Rhizobales thrived at high‐DOC sites probably fuelled by metabolism of one‐C compounds. Moreover, the analysis of proteins involved in the transport and metabolism of carbohydrates revealed that Ascomycota and Basidiomycota occupied different nutritional niches. The functional mechanisms for niche specialization were not constant across the DOC gradient.
Due to the increasing importance of mangroves in climate change mitigation projects, more accurate and cost-effective aboveground biomass (AGB) monitoring methods are required. However, field ...measurements of AGB may be a challenge because of their remote location and the difficulty to walk in these areas. This study is based on the Livelihoods Fund Oceanium project that monitors 10,000 ha of mangrove plantations. In a first step, the possibility of replacing traditional field measurements of sample plots in a young mangrove plantation by a semiautomatic processing of UAV-based photogrammetric point clouds was assessed. In a second step, Sentinel-1 radar and Sentinel-2 optical imagery were used as auxiliary information to estimate AGB and its variance for the entire study area under a model-assisted framework. AGB was measured using UAV imagery in a total of 95 sample plots. UAV plot data was used in combination with non-parametric support vector regression (SVR) models for the estimation of the study area AGB using model-assisted estimators. Purely UAV-based AGB estimates and their associated standard error (SE) were compared with model-assisted estimates using (1) Sentinel-1, (2) Sentinel-2, and (3) a combination of Sentinel-1 and Sentinel-2 data as auxiliary information. The validation of the UAV-based individual tree height and crown diameter measurements showed a root mean square error (RMSE) of 0.21 m and 0.32 m, respectively. Relative efficiency of the three model-assisted scenarios ranged between 1.61 and 2.15. Although all SVR models improved the efficiency of the monitoring over UAV-based estimates, the best results were achieved when a combination of Sentinel-1 and Sentinel-2 data was used. Results indicated that the methodology used in this research can provide accurate and cost-effective estimates of AGB in young mangrove plantations.
Plant taxa and traits do not necessarily show synchronous responses to ecological disturbance. Based on the observation that taxonomically over‐diversified communities might be phenotypically ...redundant, we speculated that taxonomic and phenotypic community reassembly might be decoupled after fire in Mediterranean ecosystems.
We applied a multi‐trait approach to describe plant community re‐assembly after fire across three 20‐year chronosequences based on 117 species and 23 traits, including whole‐plant, above‐ground and below‐ground traits. We quantified the post‐fire trajectories of different plant traits by analysing their community‐weighted means individually. We estimated the short‐ and long‐term phenotypic diversity of burned plots based on sets of traits. We also tested if trait and species turnover are decoupled across post‐fire trajectories. Finally, we calculated phenotypic redundancy, and assessed if above‐ and below‐ground traits have contrasted responses during post‐fire community reassembly.
Individually, 16 out of 23 traits were affected by fire in the short term. Plant phenotypic diversity (stdMPD) decreased immediately after fire, driven by changes in whole‐ and above‐ground traits. Both whole‐ and above‐ground stdMPD in burned plots described positive trajectories across the chronosequences tending to converge with long‐unburned plots, whereas below‐ground stdMPD remained unaltered through time.
Taxonomic and phenotypic beta diversity showed decoupled trajectories due to a larger species than trait replacement across time since fire. Finally, overall phenotypic redundancy of the studied plant communities described a regressive trajectory, similarly to above‐ground traits, whereas root traits kept a steady phenotypic redundancy through time.
Synthesis. We provide evidence that above‐ and below‐ground traits describe different recovery trajectories after fire, with significant effects on the phenotypic redundancy of plant communities. Our results encourage the use of multi‐trait approaches to understand how the plant reassembly operates after disturbance, in order to refine ecological theory. This strategy might improve the efficacy of restoration programs through a functional approach to species selection.
Resumen
Las especies de plantas y sus rasgos no necesariamente muestran una sincronía en la respuesta ante una perturbación ecológica. A partir de la observación de que comunidades con alta diversidad taxonómica pueden ser fenotípicamente redundantes, especulamos que el reensamblaje taxonómico y el fenotípico de la comunidad tras un incendio podrían estar desacoplados en los ecosistemas mediterráneos.
Siguiendo una aproximación multi‐rasgo, describimos el reensamblaje de comunidades vegetales tras el fuego en tres cronosecuencias de 20 años, que incluyen 117 especies y 23 rasgos generales, aéreos y de raíces. Cuantificamos las trayectorias postincendio de cada rasgo mediante el análisis de las medias ponderadas de la comunidad. Estimamos la diversidad fenotípica a corto y a largo plazo en parcelas quemadas y las comparamos con las medias de parcelas no quemadas. También evaluamos si el remplazo de especies y rasgos están desacoplados a lo largo de las trayectorias de recuperación postincendio. Finalmente, calculamos la redundancia fenotípica y evaluamos si ésta evoluciona de manera diferente en rasgos aéreos y subterráneos durante el reensamblaje de la comunidad tras el fuego.
Individualmente, 16 de los 23 rasgos se vieron afectados por el fuego a corto plazo. La diversidad fenotípica vegetal (stdMPD) se redujo inmediatamente después del fuego, debido a cambios en rasgos generales y en rasgos aéreos de la comunidad. Ambos tipos de rasgos mostraron una trayectoria positiva a lo largo de las cronosecuencias, tendiendo a converger con los rasgos de las parcelas no quemadas. Por el contrario, el stdMPD de los rasgos subterráneos se mantuvo inalterado a lo largo del tiempo.
La beta‐diversidad taxonómica y fenotípica mostraron trayectorias desacopladas debido a un mayor remplazamiento de especies que de rasgos a lo largo de las cronosecuencias. Finalmente, la redundancia fenotípica de los rasgos generales y de los aéreos describieron una trayectoria regresiva, mientras que los rasgos asociados a las raíces presentaron una redundancia fenotípica estable a lo largo del tiempo.
Síntesis. mostramos evidencias de que los rasgos aéreos y subterráneos describen distintas trayectorias de recuperación después del fuego, con efectos significativos sobre la redundancia fenotípica de las comunidades. Nuestros resultados sugieren el uso de aproximaciones basadas en múltiples rasgos para un mejor estudio mecanicista del proceso de reensamblaje de las comunidades tras una perturbación. Mediante esta estrategia se puede mejorar tanto la teoría ecológica como la eficacia de los programas de restauración, mediante la aplicación de enfoques funcionales en la selección de especies.
The authors provide evidence that above‐ and below‐ground traits describe different recovery trajectories after fire, with significant effects on the phenotypic redundancy of plant communities. These results encourage the use of multi‐trait approaches to understand how the plant reassembly operates after disturbance, in order to refine ecological theory. This strategy might improve the efficacy of restoration programs through a functional approach to species selection.
Catheter associated urinary tract infections are common during hospitalization due to the formation of bacterial biofilms on the indwelling device. In this study, we report an innovative ...biotechnology-based approach for the covalent functionalization of silicone catheters with antifouling zwitterionic moieties to prevent biofilm formation. Our approach combines the potential bioactivity of a natural phenolics layer biocatalytically conjugated to sulfobetaine-acrylic residues in an enzymatically initiated surface radical polymerization with laccase. To ensure sufficient coating stability in urine, the silicone catheter is plasma-activated. In contrast to industrial chemical methods, the methacrylate-containing zwitterionic monomers are polymerized at pH 5 and 50 °C using as an initiator the phenoxy radicals solely generated by laccase on the phenolics-coated catheter surface. The coated catheters are characterized by X-ray photoelectron spectroscopy (XPS), Fourier transformed infrared (FTIR) analysis, atomic force microscopy (AFM), and colorimetrically. Contact angle and protein adsorption measurements, coupled with in vitro tests with the Gram-negative Pseudomonas aeruginosa and Gram-positive Staphylococcus aureus in static and dynamic conditions, mimicking the operational conditions to be faced by the catheters, demonstrate reduced biofilm formation by about 80% when compared to that of unmodified urinary catheters. The zwitterionic coating did not affect the viability of the human fibroblasts (BJ-5ta) over seven days, corresponding to the extended useful life of urinary catheters.
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