Although the analysis of flux data has increased our understanding of the interannual variability of carbon inputs into forest ecosystems, we still know little about the determinants of wood growth. ...Here, we aimed to identify which drivers control the interannual variability of wood growth in a mesic temperate deciduous forest. We analysed a 9‐yr time series of carbon fluxes and aboveground wood growth (AWG), reconstructed at a weekly time‐scale through the combination of dendrometer and wood density data. Carbon inputs and AWG anomalies appeared to be uncorrelated from the seasonal to interannual scales. More than 90% of the interannual variability of AWG was explained by a combination of the growth intensity during a first ‘critical period’ of the wood growing season, occurring close to the seasonal maximum, and the timing of the first summer growth halt. Both atmospheric and soil water stress exerted a strong control on the interannual variability of AWG at the study site, despite its mesic conditions, whilst not affecting carbon inputs. Carbon sink activity, not carbon inputs, determined the interannual variations in wood growth at the study site. Our results provide a functional understanding of the dependence of radial growth on precipitation observed in dendrological studies.
Several clinical scales have been developed to assess the severity of bronchiolitis as well as the probability of needing in-hospital care. A recent systematic review of 32 validated clinical scores ...for bronchiolitis concluded that 6 of them (Wood-Downes, M-WCAS, Respiratory Severity Score, Respiratory Clinical Score, Respiratory Score and Bronchiolitis risk of admission score) were the best ones regarding reliability, sensitivity, validity, and usability. However, to the best of our knowledge, no study has compared all of them in a clinical scenario. Also, after this review, three more scales were published: BROSJOD, Tal modified, and one score developed by PERN. Our main aim was to compare the ability of different clinical scales for bronchiolitis to predict any relevant outcome. A prospective observational study was conducted that included patients of up to 12 months old attended to, due to bronchiolitis, in the paediatric Emergency Department of a secondary university hospital from October 2019 to January 2022. For each patient, the attending clinician filled in a form with the items of the scales, decomposed, in order to prevent the clinician from knowing the score of each scale. Then, the patient was managed according to the protocol of our Emergency Department. A phone call was made to each patient in order to check whether the patient ended up being admitted in the next 48 h. In the case of those that were impossible to contact by phone, the clinical history was reviewed. For the purpose of the study, any of the following were considered to be a relevant outcome: admission to ward and need for supplementary oxygen, non-invasive ventilation (NIV) or intravenous fluids, and admission to the paediatric intensive care unit (PICU) within the next 48 h or death. For the aim of the study, the area under the curve (AUC) and the odds ratio (OR) for a relevant outcome were calculated in each scale. Also, the best cut-off point was estimated according to the Youden index, and its sensitivity (Sn) and specificity (Sp) for a relevant outcome were calculated. We included 265 patients (52.1% male) with a median age of 5.3 months (P
25
-P
75
2.6–7.4). Among them, 46 (17.4%) had some kind of relevant outcome. AUC for prediction of a relevant outcome ranged from 0.705 (Respiratory Score) to 0.786 (BRAS), although no scale performed significantly better than others. A score ≤ 2 in the PERN scale showed a sensitivity of 91.3% (CI95% 79.7–96.6) for a relevant outcome, with only 4 misdiagnosed patients (only 2 of them needed NIV).
Conclusions
: There were no differences in the performance of the nine scales to predict relevant outcomes in patients with bronchiolitis. However, the PERN scale might be more useful to select patients at low risk of a severe outcome.
What is Known:
• Several clinical scales are used to assess the severity of bronchiolitis. Nevertheless, none of them seems to be better than others.
What is New:
• This is the first study comparing different bronchiolitis scales in a real clinical scenario. None of the nine scales compared performed better than the other. However, the PERN scale might be more useful to select patients at low risk of relevant outcomes.
Drought-triggered declines in forest productivity and associated die-off events have increased considerably due to climate warming in the last decades. There is an increasing interest in quantifying ...the resilience capacity of forests against climate warming and drought to uncover how different stands and tree species will resist and recover after more frequent and intense droughts. Trees form annual growth rings that represent an accurate record of how forest growth responded to past droughts. Here we use dendrochronology to quantify the radial growth of different forests subjected to contrasting climatic conditions in Spain during the last half century. Particularly, we considered four climatically contrasting areas where dominant forests showed clear signs of drought-induced dieback. Studied forests included wet sites dominated by silver fir (Abies alba) in the Pyrenees and beech (Fagus sylvatica) stands in northern Spain, and drought-prone sites dominated by Scots pine (Pinus sylvestris) in eastern Spain and black pine (Pinus nigra) in the semi-arid south-eastern Spain. We quantified the growth reduction caused by different droughts and assessed the short-and long-term resilience capacity of declining vs. non-declining trees in each forest. In all cases, drought induced a marked growth reduction regardless tree vigor. However, the capacity to recover after drought (resilience) at short- and long-term scales varied greatly between declining and non-declining individuals. In the case of beech and silver fir, non-declining individuals presented greater growth rates and capacity to recover after drought than declining individuals. For Scots pine, the resilience to drought was found to be lower in recent years regardless the tree vigor, but the growth reduction caused by successive droughts was more pronounced in declining than in non-declining individuals. In the black pine forest an extreme drought induced a marked growth reduction in declining individuals when accounting for age effects on growth rates. We demonstrate the potential of tree-ring data to record short- and long-term impacts of drought on forest growth and to quantify the resilience capacity of trees.
Abstract
Key message
In European mountain forests, the growth of silver fir (
Abies alba
Mill.), sycamore maple (
Acer pseudoplatanus
L.), European beech (
Fagus sylvatica
L.) and Norway spruce (
...Picea abies
(L.) H. Karst.) seedlings is more strongly affected by ungulate browsing than by elevation. But, the constraint exerted by ungulates, in particular the probability for seedlings to be browsed, increases with elevation for most species.
Context
While concerns about mountain forest regeneration rise due to their high vulnerability to climate change, the increase in wild ungulate populations and the expansion of their range in the last decades exert an additional constraint on the survival and growth of young trees. Understanding how this constraint can vary with elevation is thus a key to assess the consequences of this population increase for the regeneration of mountain forests.
Aims
In this study, we investigate the effect of elevation on (i) the occurrence of browsing for seedlings and on (ii) the reduction in seedling growth induced by ungulate browsing.
Methods
We monitored height growth and browsing occurrence on silver fir, sycamore maple, European beech and Norway spruce seedlings across seven elevation gradients (from 400 to 2013 m) located from France to northern Sweden.
Results
Seedlings of the two most palatable species—fir and maple—were more likely to be browsed at high elevation while the opposite effect was observed for spruce. Browsing strongly reduced seedling growth for all species but Norway spruce, while elevation had no direct effect on seedling growth. This browsing-induced growth reduction was stronger at high elevation for fir seedlings.
Conclusions
Browsing is overall a stronger constraint on seedling growth than elevation for four dominant species of European mountain forests. Elevation can, however, affect both browsing probability and the effect of browsing on seedling growth. Our results highlight the importance of taking into account ungulate pressure and its interactive effect with elevation when forecasting the regeneration of mountain forests under a changing climate.
Vapour pressure deficit is a major driver of seasonal changes in transpiration, but photoperiod also modulates leaf responses. Climate warming might enhance transpiration by increasing atmospheric ...water demand and the length of the growing season, but photoperiod‐sensitive species could show dampened responses. Here, we document that day length is a significant driver of the seasonal variation in stomatal conductance. We performed weekly gas exchange measurements across a common garden experiment with 12 oak species from contrasting geographical origins, and we observed that the influence of day length was of similar strength to that of vapour pressure deficit in driving the seasonal pattern. We then examined the generality of our findings by incorporating day‐length regulation into well‐known stomatal models. For both angiosperm and gymnosperm species, the models improved significantly when adding day‐length dependences. Photoperiod control over stomatal conductance could play a large yet underexplored role on the plant and ecosystem water balances.
We demonstrate that photoperiod exerts a major control on the seasonal pattern of stomatal conductance, being as important as the effects of varying VPD. Inclusion of photoperiod regulation in stomatal models led to significant improvements in model fit across angiosperm and gymnosperm species.
Stomatal closure is one of the earliest responses to water stress but residual water losses may continue through the cuticle and incomplete stomatal closure. Residual conductance (
) plays a large ...role in determining time to mortality but we currently do not understand how do drought and shade interact to alter
because the underlying drivers are largely unknown. Furthermore,
may play an important role in models of water use, but the exact form in which
should be incorporated into modeling schemes is currently being discussed. Here we report the results of a study where two different oak species were experimentally subjected to highly contrasting levels of drought (resulting in 0, 50 and 80% losses of hydraulic conductivity) and radiation (photosynthetic photon flux density at 1,500 μmol m
s
or 35-45 μmol m
s
). We observed that the effects of radiation and drought were interactive and species-specific and
correlated positively with concentrations of leaf non-structural carbohydrates and negatively with leaf nitrogen. We observed that different forms of measuring
, based on either nocturnal conductance under high atmospheric water demand or on the water mass loss of detached leaves, exerted only a small influence on a model of stomatal conductance and also on a coupled leaf gas exchange model. Our results indicate that, while understanding the drivers of
and the effects of different stressors may be important to better understand mortality, small differences in
across treatments and measurements exert only a minor impact on stomatal models in two closely related species.
Global change triggers shifts in forest composition, with warming and aridification being particularly threatening for the populations located at the rear edge of the species distributions. This is ...the case of Scots pine (Pinus sylvestris) in the Mediterranean Basin where uncertainties in relation to its dynamics under these changing scenarios are still high. We analysed the relative effect of climate on the recruitment patterns of Scots pine and its interactions with local biotic and abiotic variables at different spatial scales. Number of seedlings and saplings was surveyed, and their annual shoot growth measured in 96 plots located across altitudinal gradients in three different regions in the Iberian Peninsula. We found a significant influence of climate on demography and performance of recruits, with a non-linear effect of temperature on the presence of juveniles, and a positive effect of precipitation on their survival. Abundance of juveniles of P. sylvestris that underwent their first summer drought was skewed towards higher altitudes than the altitudinal mean range of the conspecific adults and the optimum elevation for seedlings' emergence. At local level, light availability did not influence juveniles' density, but it enhanced their growth. Biotic interactions were found between juveniles and the herb cover (competition) and between the number of newly emerged seedlings and shrubs (facilitation). Results also highlighted the indirect effect that climate exerts over the local factors, modulating the interactions with the pre-existing vegetation that were more evident at more stressful sites. This multiscale approach improves our understanding of the dynamics of these marginal populations and some management criteria can be inferred to boost their conservation under the current global warming.
Pulmonary arterial hypertension is a very infrequent disease, with a variable etiology and clinical expressivity, making sometimes the clinical diagnosis a challenge. Current classification based on ...clinical features does not reflect the underlying molecular profiling of these groups. The advance in massive parallel sequencing in PAH has allowed for the describing of several new causative and susceptibility genes related to PAH, improving overall patient diagnosis. In order to address the molecular diagnosis of patients with PAH we designed, validated, and routinely applied a custom panel including 21 genes. Three hundred patients from the National Spanish PAH Registry (REHAP) were included in the analysis. A custom script was developed to annotate and filter the variants. Variant classification was performed according to the ACMG guidelines. Pathogenic and likely pathogenic variants have been found in 15% of the patients with 12% of variants of unknown significance (VUS). We have found variants in patients with connective tissue disease (CTD) and congenital heart disease (CHD). In addition, in a small proportion of patients (1.75%), we observed a possible digenic mode of inheritance. These results stand out the importance of the genetic testing of patients with associated forms of PAH (i.e., CHD and CTD) additionally to the classical IPAH and HPAH forms. Molecular confirmation of the clinical presumptive diagnosis is required in cases with a high clinical overlapping to carry out proper management and follow up of the individuals with the disease.
Tree taxa are often planted beyond their native range to increase the provision of some ecosystem services. Yet, they can disrupt ecosystem processes in their new ranges, causing changes in the ...provision of other services. Here we review the effects of five widespread tree taxa (Acacia, Ailanthus, Eucalyptus, Pinus and Robinia) on six regulating ecosystem services in areas where they are non-native. We conducted a literature search for pair-wise comparisons between sites dominated by any of the selected taxa and sites with native vegetation. An array of variables were used as indicators for each ecosystem service. Data were analysed using multi-level meta-analyses to compare effects of taxa on each ecosystem service, and effects of the same taxa across contexts. We compiled 857 case studies from 107 source papers. Several taxa tended to increase climate regulation, mostly Eucalyptus. Acacia decreased fire risk prevention. Robinia, Acacia and Ailanthus increased soil fertility, while Eucalyptus and Pinus, tended to decrease it. Soil formation was enhanced by Robinia and Ailanthus. Acacia promoted the increase of water in land pools, while Eucalyptus tended to decrease them. All effects show a large heterogeneity across case studies. Part of this heterogeneity could be attributed to gross climatic differences (i.e. biome), to species differences within each genus, to the structure of the recipient ecosystem, and/or to human management. Managers and policy-makers should consider the context-dependency and the potential effects of non-native trees on a wide range of services to ground their decisions. Our analyses also revealed important gaps of knowledge (e.g. on fire risk prevention, erosion control or water cycle regulation) and some potential publication bias. The methodology used here easily allows for future updates as new information will become available.
Display omitted
•Widespread non-native trees may alter the provision of ecosystem services.•Most non-native trees tend to increase climate regulation.•Tree taxa have contrasted effects on fire risk, soil processes, and the water cycle.•Effects varied across species, biomes and ecosystem types.•Multi-level meta-analysis helps identifying patterns in heterogeneous datasets.
Among 439 infants presenting with symptoms of upper respiratory tract infection and temperature ≥39°C, 19 (4.3% 95% confidence interval, 2.8–6.7) received a diagnosis of urinary tract infection ...(abnormal urine dipstick from a sterile urine sample and positive urine culture). Regardless of respiratory presentation, all infants presenting with a temperature of 39°C should be screened for urinary tract infection.
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