Are leaf, stem and hydraulic traits good predictors of individual tree growth?

Acord transformatiu CRUE-CSICA major foundation of trait-based ecology is that traits have an impact on individual performance. However, trait-growth relationships have not been extensively assessed in trees, especially outside tropical ecosystems. In addition, measuring traits directly related to physiological processes remains difficult and the differences between inter- and intraspecific relationships are seldom explored. Here, we use individual-level data on a set of hydraulic, leaf and stem traits to assess their ability to predict basal area increment (BAI) and growth efficiency (BAI per unit of tree leaf area, GE) among and within species for six dominant tree species along a water availability gradient under Mediterranean climate (Catalonia, NE Spain). Measured traits include: leaf mass per area (LMA), leaf nitrogen concentration (N), leaf C isotopic composition (δC), the leaf water potential at turgor loss (P), stem wood density (WD) and branch-level estimates of the Huber value (Hv), sapwood- and leaf-specific hydraulic conductivity (K and K) and resistance to xylem embolism (P). Trait-growth associations were generally weak, particularly for BAI and within species. High values of both growth metrics were associated with 'conservative' leaf and hydraulic traits. In particular, BAI was negatively associated with K (and wood density), while GE increased with LMA, allocation to sapwood relative to leaves (Hv) and resistance to xylem embolism (P). Climate effects on BAI and GE were indirectly mediated by changes in traits, stand structure and tree basal area. Overall, these results suggest that maintaining functionality over extended periods of time may be more important than maximum gas exchange or hydraulic capacity to achieve high radial growth under Mediterranean climates. Our study reveals that widely used 'functional traits' may be poor predictors of tree growth variability along environmental gradients. Moreover, trait effects (when present) do not necessarily conform to simple hypotheses based on our understanding of organ-level processes. An improved understanding of trait coordination along common axes of variation together with a revaluation of the variables that better reflect whole-tree performance can greatly improve our understanding of trait-growth relationships. A free Plain Language Summary can be found within the Supporting Information of this article

Avaluació de l'aplicació de la biomassa produïda a la Vall d'Alinyà per la producció d'energia calorífica

L'estudi analitza detalladament les energies que s'utilitzen actualment a la població d'Alinyà (Lleida, Catalunya, Espanya). Les energies més utilitzades amb fins calorífics provenen d'energies fòssils (95,3%). Aquest tipus d'energia, des de un punt de vista econòmic, és inviable donat l'augment continuat dels preus d'aquest tipus de combustibles. A més a més el petroli ha arribat al peak oil. Tenint en compte la delicada situació que viuen actualment els combustibles fòssils, en particular el petroli, fa pensar que el futur està encaminat a produir energia a partir d'altres fonts. Una bona opció és començar a utilitzar biomassa com a font energètica. La zona d'estudi presenta un stock de biomassa 8,4 vegades superior a la que es necessitaria a Alinyà per produir calor i ACS a totes les llars. Per això, en aquest estudi, s'estimen possibles escenaris on es podria aplicar la biomassa que es produeix a la Vall d'Alinyà. S'estima que les calderes individuals serien l'escenari més viable, ja que tècnicament són eficients i s'adeqüen a les característiques de les llars d'aquesta població. Posteriorment, es realitza un estudi de les emissions de CO2 i s'observa que, si s'utilitzés biomassa com a font energètica a Alinyà ,es reduirien 11,3 vegades (91,11%) les emissions de CO2.Éste estudio analiza con detalle las energías que se utilizan actualmente en la población de Alinyà (Lleida, Cataluña, España). Las energías más usadas con fines caloríficos provienen de energías fósiles (95,3%). Estos tipos de energía, desde un punto de vista económico, son inviables dado el aumento continuado de precios de éste tipo de combustibles. Además, el petróleo ha llegado al peak oil. Teniendo en cuenta la delicada situación que viven actualmente los combustibles fósiles, en particular el petróleo, hace pensar que el futuro está encaminado a producir energía a partir de otras fuentes. Una buena opción es empezar a usar biomasa como fuente energética. La zona de estudio presenta un stock de biomasa 7,4 veces superior a la que se necesita en Alinyà para producir calor i ACS a todas les casas. Por eso, en éste estudio, se estiman posibles escenarios donde se podría aplicar la biomasa que se produce en la Vall de Alinyà. Se estima que las calderas individuales serían el escenario más viable, ya que técnicamente son eficientes i se adaptan a las características de las casas de la población. Posteriormente, se realiza un estudio de las emisiones de CO2 i se observa que, si se utilizase biomasa como fuente energética en Alinyà, se reducirían 11,3 veces (91,11%) les emisiones de CO2.The present study (or document) analyzes in detail which energies are used nowadays in Alinyà town. Most used energies with heating purposes come from fossil forms of energy (95,3%). Those kinds of energies are economically unviable due to continual cost increases. Moreover, petroleum has reached the peak oil. Considering the sensitive situation fossil fuels are, particularly petroleum, suggest that future energy production will use other sources. A good option is begin with biomass as energy source. The area of study has a stock 8,4 times larger than needed to supply heat and sanitary hot water to Alinyà's homes. Therefore several scenarios to implement biomass produced in the Vall d'Alinyà, are evaluated in this study. Is foreseen that individual boilers would be the most feasible scenario due to their technical efficiency and adaptability to houses characteristics. Afterwards, a CO2 emission study it's made. Results evidence that if only biomass is used as energy source in Alinyà, CO2 emissions would be reduced 11,3 times (91,11%)

Non-structural carbohydrate dynamics associated with drought-induced die-off in woody species of a shrubland community

The relationship between plant carbon economy and drought responses of co-occurring woody species can be assessed by comparing carbohydrate (C) dynamics following drought and rain periods, relating these dynamics to species' functional traits. We studied nine woody species coexisting in a continental Mediterranean shrubland that experienced severe drought effects followed by rain. During drought, NSC concentrations were overall lower in stems and roots of plants experiencing leaf loss, while SS decreases were smaller. Roots had higher NSC concentrations than stems. After the rain, NSC concentrations continued to decrease, while SS increased. Green foliage recovered after rain, particularly in plants previously experiencing higher leaf loss, independently of NSC concentrations during drought. Species with lower WD tended to have more SS during drought and lower SS increases after rain. In low-WD species, plants with severe leaf loss had lower NSC relative to undefoliated ones. No significant relationship was found between H or SLA and C content or dynamics. Our community-level study reveals that, while responses were species-specific, C stocks overall diminished in plants affected by prolonged drought and did not increase after a pulse of seasonal rain. Dynamics were faster for SS than NSC. We found limited depletion of SS, consistent with their role in basal metabolic, transport and signalling functions. In a scenario of increased drought under climate change, NSC stocks in woody plants are expected to decrease differentially in coexisting species, with potential implications for their adaptive abilities and community dynamics

Failure analysis of MIM and MIS structures using point-to-event distance and angular probability distributions

Multiple breakdown (BD) spots are generated in large (>10 -4 cm 2 ) circular and square area metal-insulator-metal and metal-insulator-semiconductor devices using ramped and constant-voltage electrical stresses. Due to the important local thermal effects that take place at the very moment of the formation of the conductive paths spanning the insulating layer, the failure events become visible on the top metal electrode of the structures as a point pattern. The resulting point-to-event distance and angular histograms are compared with the theoretical distributions corresponding to a complete spatial randomness (CSR) process. The location of the voltage probe tip over the top electrode is considered here as the singular point from which the positions of the BD spots are referred to. In this way, we are able to assess the influence of the probe point on the final BD spot distribution. In most of the cases, this distribution is consistent with CSR, but after prolonged electrical stress, a deviation is detected. This departure from CSR is ascribed to the concentration of the current lines in the top electrode toward the center of the structure. The methods reported here are general and can be used for analyzing the generation of similar point patterns occurring in other structures or material systems

Are leaf, stem and hydraulic traits good predictors of individual tree growth? (FUN2FUN project)

A major foundation of trait-based ecology is that traits have an impact on individual performance. However, trait-growth relationships have not been extensively tested in trees, especially outside tropical ecosystems. In addition, measuring traits directly related to physiological processes (‘hard traits’) remains difficult and the differences between inter- and intraspecific relationships are seldom explored. Here, we use individual-level data on a set of hydraulic, leaf and stem traits to explore which traits are the best predictors of basal area increment (BAI) and growth efficiency (BAI per unit of tree leaf area, GE) among and within species for six dominant tree species along a water availability gradient under Mediterranean climate (Catalonia, NE Spain). Measured traits include: leaf mass per area (LMA), leaf nitrogen concentration (N), leaf C isotopic composition (d13C), stem wood density (WD), branch-level estimates of the Huber value (Hv), the sapwood-specific hydraulic conductivity (KS), the leaf-specific hydraulic conductivity (KL) and resistance to xylem embolism (P50), and the leaf water potential at turgor loss (Ptlp). Traits were better predictors of GE than BAI and significant relationships were largely driven by differences among species means. Contrary to our initial hypotheses, high values of both growth metrics were associated with ‘conservative’ leaf and hydraulic traits. In particular, BAI was negatively associated with wood density and hydraulic efficiency per unit leaf area (KL), while GE increased with LMA, allocation to sapwood relative to leaves (Hv) and resistance to xylem embolism (P50). Climate effects on BAI and GE were indirectly mediated by changes in traits, stand structure and tree size. Overall, these results suggest that maintaining functionality over extended periods of time may be more important that maximum gas exchange or hydraulic capacity to achieve high radial growth under Mediterranean climates. Our study reveals that the relationships between ‘functional’ traits and tree performance along environmental gradients are complex and do not necessarily conform to simple hypotheses based on our understanding of organ-level processes. Trait integration along common axes of variation together with a revaluation of the variables that better reflect whole-tree performance can greatly improve our understanding of trait-growth relationships

Avaluació de l'aplicació de la biomassa produïda a la Vall d'Alinyà per la producció d'energia calorífica

L'estudi analitza detalladament les energies que s'utilitzen actualment a la població d'Alinyà (Lleida, Catalunya, Espanya). Les energies més utilitzades amb fins calorífics provenen d'energies fòssils (95,3%). Aquest tipus d'energia, des de un punt de vista econòmic, és inviable donat l'augment continuat dels preus d'aquest tipus de combustibles. A més a més el petroli ha arribat al peak oil. Tenint en compte la delicada situació que viuen actualment els combustibles fòssils, en particular el petroli, fa pensar que el futur està encaminat a produir energia a partir d'altres fonts. Una bona opció és començar a utilitzar biomassa com a font energètica. La zona d'estudi presenta un stock de biomassa 8,4 vegades superior a la que es necessitaria a Alinyà per produir calor i ACS a totes les llars. Per això, en aquest estudi, s'estimen possibles escenaris on es podria aplicar la biomassa que es produeix a la Vall d'Alinyà. S'estima que les calderes individuals serien l'escenari més viable, ja que tècnicament són eficients i s'adeqüen a les característiques de les llars d'aquesta població. Posteriorment, es realitza un estudi de les emissions de CO2 i s'observa que, si s'utilitzés biomassa com a font energètica a Alinyà ,es reduirien 11,3 vegades (91,11%) les emissions de CO2.Éste estudio analiza con detalle las energías que se utilizan actualmente en la población de Alinyà (Lleida, Cataluña, España). Las energías más usadas con fines caloríficos provienen de energías fósiles (95,3%). Estos tipos de energía, desde un punto de vista económico, son inviables dado el aumento continuado de precios de éste tipo de combustibles. Además, el petróleo ha llegado al peak oil. Teniendo en cuenta la delicada situación que viven actualmente los combustibles fósiles, en particular el petróleo, hace pensar que el futuro está encaminado a producir energía a partir de otras fuentes. Una buena opción es empezar a usar biomasa como fuente energética. La zona de estudio presenta un stock de biomasa 7,4 veces superior a la que se necesita en Alinyà para producir calor i ACS a todas les casas. Por eso, en éste estudio, se estiman posibles escenarios donde se podría aplicar la biomasa que se produce en la Vall de Alinyà. Se estima que las calderas individuales serían el escenario más viable, ya que técnicamente son eficientes i se adaptan a las características de las casas de la población. Posteriormente, se realiza un estudio de las emisiones de CO2 i se observa que, si se utilizase biomasa como fuente energética en Alinyà, se reducirían 11,3 veces (91,11%) les emisiones de CO2.The present study (or document) analyzes in detail which energies are used nowadays in Alinyà town. Most used energies with heating purposes come from fossil forms of energy (95,3%). Those kinds of energies are economically unviable due to continual cost increases. Moreover, petroleum has reached the peak oil. Considering the sensitive situation fossil fuels are, particularly petroleum, suggest that future energy production will use other sources. A good option is begin with biomass as energy source. The area of study has a stock 8,4 times larger than needed to supply heat and sanitary hot water to Alinyà's homes. Therefore several scenarios to implement biomass produced in the Vall d'Alinyà, are evaluated in this study. Is foreseen that individual boilers would be the most feasible scenario due to their technical efficiency and adaptability to houses characteristics. Afterwards, a CO2 emission study it's made. Results evidence that if only biomass is used as energy source in Alinyà, CO2 emissions would be reduced 11,3 times (91,11%)

Contemporary use of cefazolin for MSSA infective endocarditis: analysis of a national prospective cohort

Objectives: This study aimed to assess the real use of cefazolin for methicillin-susceptible Staphylococcus aureus (MSSA) infective endocarditis (IE) in the Spanish National Endocarditis Database (GAMES) and to compare it with antistaphylococcal penicillin (ASP). Methods: Prospective cohort study with retrospective analysis of a cohort of MSSA IE treated with cloxacillin and/or cefazolin. Outcomes assessed were relapse; intra-hospital, overall, and endocarditis-related mortality; and adverse events. Risk of renal toxicity with each treatment was evaluated separately. Results: We included 631 IE episodes caused by MSSA treated with cloxacillin and/or cefazolin. Antibiotic treatment was cloxacillin, cefazolin, or both in 537 (85%), 57 (9%), and 37 (6%) episodes, respectively. Patients treated with cefazolin had significantly higher rates of comorbidities (median Charlson Index 7, P <0.01) and previous renal failure (57.9%, P <0.01). Patients treated with cloxacillin presented higher rates of septic shock (25%, P = 0.033) and new-onset or worsening renal failure (47.3%, P = 0.024) with significantly higher rates of in-hospital mortality (38.5%, P = 0.017). One-year IE-related mortality and rate of relapses were similar between treatment groups. None of the treatments were identified as risk or protective factors. Conclusion: Our results suggest that cefazolin is a valuable option for the treatment of MSSA IE, without differences in 1-year mortality or relapses compared with cloxacillin, and might be considered equally effective

Effects of pre-operative isolation on postoperative pulmonary complications after elective surgery: an international prospective cohort study an international prospective cohort study

We aimed to determine the impact of pre-operative isolation on postoperative pulmonary complications after elective surgery during the global SARS-CoV-2 pandemic. We performed an international prospective cohort study including patients undergoing elective surgery in October 2020. Isolation was defined as the period before surgery during which patients did not leave their house or receive visitors from outside their household. The primary outcome was postoperative pulmonary complications, adjusted in multivariable models for measured confounders. Pre-defined sub-group analyses were performed for the primary outcome. A total of 96,454 patients from 114 countries were included and overall, 26,948 (27.9%) patients isolated before surgery. Postoperative pulmonary complications were recorded in 1947 (2.0%) patients of which 227 (11.7%) were associated with SARS-CoV-2 infection. Patients who isolated pre-operatively were older, had more respiratory comorbidities and were more commonly from areas of high SARS-CoV-2 incidence and high-income countries. Although the overall rates of postoperative pulmonary complications were similar in those that isolated and those that did not (2.1% vs 2.0%, respectively), isolation was associated with higher rates of postoperative pulmonary complications after adjustment (adjusted OR 1.20, 95%CI 1.05–1.36, p = 0.005). Sensitivity analyses revealed no further differences when patients were categorised by: pre-operative testing; use of COVID-19-free pathways; or community SARS-CoV-2 prevalence. The rate of postoperative pulmonary complications increased with periods of isolation longer than 3 days, with an OR (95%CI) at 4–7 days or ≥ 8 days of 1.25 (1.04–1.48), p = 0.015 and 1.31 (1.11–1.55), p = 0.001, respectively. Isolation before elective surgery might be associated with a small but clinically important increased risk of postoperative pulmonary complications. Longer periods of isolation showed no reduction in the risk of postoperative pulmonary complications. These findings have significant implications for global provision of elective surgical care. We aimed to determine the impact of pre-operative isolation on postoperative pulmonary complications after elective surgery during the global SARS-CoV-2 pandemic. We performed an international prospective cohort study including patients undergoing elective surgery in October 2020. Isolation was defined as the period before surgery during which patients did not leave their house or receive visitors from outside their household. The primary outcome was postoperative pulmonary complications, adjusted in multivariable models for measured confounders. Pre-defined sub-group analyses were performed for the primary outcome. A total of 96,454 patients from 114 countries were included and overall, 26,948 (27.9%) patients isolated before surgery. Postoperative pulmonary complications were recorded in 1947 (2.0%) patients of which 227 (11.7%) were associated with SARS-CoV-2 infection. Patients who isolated pre-operatively were older, had more respiratory comorbidities and were more commonly from areas of high SARS-CoV-2 incidence and high-income countries. Although the overall rates of postoperative pulmonary complications were similar in those that isolated and those that did not (2.1% vs 2.0%, respectively), isolation was associated with higher rates of postoperative pulmonary complications after adjustment (adjusted OR 1.20, 95%CI 1.05–1.36, p = 0.005). Sensitivity analyses revealed no further differences when patients were categorised by: pre-operative testing; use of COVID-19-free pathways; or community SARS-CoV-2 prevalence. The rate of postoperative pulmonary complications increased with periods of isolation longer than 3 days, with an OR (95%CI) at 4–7 days or ≥ 8 days of 1.25 (1.04–1.48), p = 0.015 and 1.31 (1.11–1.55), p = 0.001, respectively. Isolation before elective surgery might be associated with a small but clinically important increased risk of postoperative pulmonary complications. Longer periods of isolation showed no reduction in the risk of postoperative pulmonary complications. These findings have significant implications for global provision of elective surgical care