Benefits for nurse and facilitated plants emerge when interactions are considered along the entire life-span

The structure of plant communities is often influenced by facilitative interactions where ‘facilitated’ plants benefit from growing associated with ‘nurse’ plants. Facilitation has been mostly studied from the facilitated plant's perspective, and bidirectional effects between nurse and facilitated plants have received less attention. We hypothesized that reciprocal benefits in plant-plant interactions may emerge when interactions are considered along the life-span of the plants involved. Over one spring, we selected five species with similar life-form and growth strategy, and using a full factorial design, we compared different fitness components along the plants’ life-span (seedling establishment, juvenile growth and reproductive investment in adult plants). We compared: a) plants growing in solitary stands and associated with other plants in vegetation patches; and b) plants that originally functioned as nurse plant (the largest plant of the vegetation patch) and as facilitated (not the largest plant of the vegetation patch). At an early developmental stage, facilitated plants growing in vegetation patches displayed higher seedling establishment and juvenile growth compared to solitary conspecific plants. At a later developmental stage, nurse plants in vegetation patches experienced higher reproductive investment (measured as flower production relative to plant size) compared to solitary plants, while the originally facilitated plants showed similar reproductive investment compared to their solitary pair of similar size. Facilitation is likely a complex interaction in which reciprocal benefits for both facilitated and nurse plants can be detected when interactions are considered along the plants’ life-span. Our results suggest that mutual benefits in plant-plant interactions could be important to sustain diversity in plant communities, but they appeared overlooked and deserve further attention.AMN was supported by a postdoctoral contract from the Spanish Ministry of Economy and Competitiveness (FPDI-2013-16266; IJCI‐2015‐23498). Financial support was also provided by the regional government Generalitat Valenciana (GV/2016/187) and the Spanish Ministry of Economy and Competitiveness (RTI2018-099672-J-I00). RPB was supported by a Percy Sladen Memorial Grant from The Linnean Society

Phylogenetic analysis of secondary metabolites in a plant community provides evidence for trade-offs between biotic and abiotic stress tolerance

Plants' responses to conflicting stresses may result in physiological trade-offs due to the inter-dependent and costly nature of physiological investments. Physiological tradeoffs have been proved within species, but to what extent these trade-offs are the result of phylogenetic constraints remains poorly known. Environmental stresses can vary widely in different biomes, and therefore assessing physiological tradeoffs across species must account for this variation. One way of doing so is to assess it within a community, where the co-occurring species have faced a shared combination of filters to establish. Considering a representative sample of species in a single community, we use a macroevolutionary approach to test the hypothesis that plant physiological trade-offs are evolutionarily conserved within this community (i.e., closely-related species tend to solve the trade-offs similarly). We analyze the content of five metabolites in thirty co-occurring plant species, capturing their range of contrasting exposures to abiotic and biotic stresses (growing solitary and in vegetation patches). Our results support that species investment in response to abiotic stress (i.e., proline and abscisic acid content) is traded off against their investment to face biotic stress (i.e., jasmonic acid and salicylic acid), shown by the contrasting loadings of these two groups of metabolites in the first axes of a principal component analysis (PCA). In addition, the metabolic strategies observed in this community are evolutionarily conserved, as closely related species tend to have similar scores in this PCA, and thus resemble each other in their balance. This is shown by a significant phylogenetic signal in the species’ scores along the first axes of the PCA. Incorporating the evolutionary history of plant species into physiological studies can help to understand the response of plants to multiple stresses currently acting in ecological communities

Functional trait effects on ecosystem stability: assembling the jigsaw puzzle

Under global change, how biological diversity and ecosystem services are maintained in time is a fundamental question. Ecologists have long argued about multiple mechanisms by which local biodiversity might control the temporal stability of ecosystem properties. Accumulating theories and empirical evidence suggest that, together with different population and community parameters, these mechanisms largely operate through differences in functional traits among organisms. We review potential trait-stability mechanisms together with underlying tests and associated metrics. We identify various trait-based components, each accounting for different stability mechanisms, that contribute to buffering, or propagating, the effect of environmental fluctuations on ecosystem functioning. This comprehensive picture, obtained by combining different puzzle pieces of trait-stability effects, will guide future empirical and modeling investigations.This study is the result of an international workshop financed by the Valencian government in Spain (Generalitat Valenciana, reference AORG/2018/) and was supported by Spanish Plan Nacional de I+D+i (project PGC2018-099027-B-I00). E.V. was supported by the 2017 program for attracting and retaining talent of Comunidad de Madrid (no. 2017-T2/ AMB-5406)

Treatment with tocilizumab or corticosteroids for COVID-19 patients with hyperinflammatory state: a multicentre cohort study (SAM-COVID-19)

Objectives: The objective of this study was to estimate the association between tocilizumab or corticosteroids and the risk of intubation or death in patients with coronavirus disease 19 (COVID-19) with a hyperinflammatory state according to clinical and laboratory parameters. Methods: A cohort study was performed in 60 Spanish hospitals including 778 patients with COVID-19 and clinical and laboratory data indicative of a hyperinflammatory state. Treatment was mainly with tocilizumab, an intermediate-high dose of corticosteroids (IHDC), a pulse dose of corticosteroids (PDC), combination therapy, or no treatment. Primary outcome was intubation or death; follow-up was 21 days. Propensity score-adjusted estimations using Cox regression (logistic regression if needed) were calculated. Propensity scores were used as confounders, matching variables and for the inverse probability of treatment weights (IPTWs). Results: In all, 88, 117, 78 and 151 patients treated with tocilizumab, IHDC, PDC, and combination therapy, respectively, were compared with 344 untreated patients. The primary endpoint occurred in 10 (11.4%), 27 (23.1%), 12 (15.4%), 40 (25.6%) and 69 (21.1%), respectively. The IPTW-based hazard ratios (odds ratio for combination therapy) for the primary endpoint were 0.32 (95%CI 0.22-0.47; p < 0.001) for tocilizumab, 0.82 (0.71-1.30; p 0.82) for IHDC, 0.61 (0.43-0.86; p 0.006) for PDC, and 1.17 (0.86-1.58; p 0.30) for combination therapy. Other applications of the propensity score provided similar results, but were not significant for PDC. Tocilizumab was also associated with lower hazard of death alone in IPTW analysis (0.07; 0.02-0.17; p < 0.001). Conclusions: Tocilizumab might be useful in COVID-19 patients with a hyperinflammatory state and should be prioritized for randomized trials in this situatio

Sin / Sense

Sexto desafío por la erradicación de la violencia contra las mujeres del Institut Universitari d’Estudis Feministes i de Gènere «Purificación Escribano» de la Universitat Jaume

Nitrogen transfer between plant species with different temporal N-demand

Phenological segregation among species in a community is assumed to promote coexistence, as using resources at different times reduces competition. However, other unexplored nonalternative mechanisms can also result in a similar outcome. This study first tests whether plants can redistribute nitrogen (N) among them based on their nutritional temporal demand (i.e. phenology). Field 15N labelling experiments showed that 15N is transferred between neighbour plants, mainly from low N-demand (late flowering species, not reproducing yet) to high N-demand plants (early flowering species, currently flowering-fruiting). This can reduce species' dependence on pulses of water availability, and avoid soil N loss through leaching, having relevant implications in the structuring of plant communities and ecosystem functioning. Considering that species phenological segregation is a pervasive pattern in plant communities, this can be a so far unnoticed, but widely spread, ecological process that can predict N fluxes among species in natural communities, and therefore impact our current understanding of community ecology and ecosystem functioning.This research was funded by the Spanish Ministry of Economy and Competitiveness (RTI2018-099672-J-I00, TED2021-129926B-I00) and the Program Ramón y Cajal 2020 (RYC2020-029226-I).Peer reviewe

cannonical_corrs_by_population

cannonical_corrs_by_populatio

The diet of the night heron and a purple heron in the Guadalquivir marshes

The diet of the night heron and purple heron in the Guadalquivir Marshes. Aims: To compare the diet of chicks of night heron Nycticorax nycticorax and purple heron Ardea Pur- purea in the Guadalquivir Marshes. To study the diet of night heron adults during breeding and non-breed- ing seasons. To establish whether the diet of purple heron in Doñana has changed over the past 30 years in response to changes in land use and habitat quality. Location: Heronries in the Guadalquivir Marshes, including the natural marshes of Doñana National Park and transformed marshes dominated by ricefields outside the National Park. Methods: Collection of regurgitates from purple heron chicks (n = 52) and night heron chicks (n = 12) during ringing operations in 2001-2002. Collection of pellets (n = 80) under daytime roosts of night herons in 2001-2002. Results: Purple heron regurgitates were dominated by carp Cyprinus carpio, recorded in 84.6 % of samples and representing 73.3 % of all prey items. Odonata nymphs were present in 13.5 % of samples and aquatic Coleoptera in 9.6 %. Regurgitates from night heron chicks were also dominated by carp, record- ed in 83.3 % of the samples and representing 76.3 % of prey items. Coleoptera larvae were present in 25 % of samples. There was no difference in the size of carp consumed by the two species, but carp taken by purple heron were larger in 2002. Night heron pellets collected outside the breeding colonies lacked fish and were dominated by red swamp crayfish Procambarus clarkii, present in 86.2 % of pellets and repre- senting 44.4 % of prey items. Terrestrial insects were also abundant in pellets. Conclusions: In spite of the great increase in abundance of P. clarkii in natural marshes since earlier studies in 1977-1983, and other major changes in the ecosystem, there has been no detectable change in purple heron diet over this period. Night heron and purple heron chicks in Doñana fed prodominantly on an invasive fish. Outside the breeding colonies, night herons fed predominantly on an invasive crayfish. Key words: Doñana, ecological change, food items, night heron, purple heronLa dieta del martinete y la garza imperial en las marismas del Guadalquivir. Objetivos: Comparar la dieta de los pollos de martinete Nycticorax nycticorax y garza imperial Ardea purpurea en las marismas del Guadalquivir. Estudiar la dieta de los adultos de martinete durante el pe- riodo reproductor y no reproductor. Determinar si la dieta de la garza imperial en Doñana ha cambiado a lo largo de los últimos 30 años, debido a cambios en los usos del suelo y la calidad del hábitat.Peer reviewe

The diet of the night heron and purple heron in the Guadalquivir Marshes

The diet of the night heron and purple heron in the Guadalquivir Marshes. Aims: To compare the diet of chicks of night heron Nycticorax nycticorax and purple heron Ardea Purpurea in the Guadalquivir Marshes. To study the diet of night heron adults during breeding and non-breeding seasons. To establish whether the diet of purple heron in Donana has changed over the past 30 years in response to changes in land use and habitat quality. Location: Heronries in the Guadalquivir Marshes, including the natural marshes of Doñana National Park and transformed marshes dominated by ricefields outside the National Park. Methods: Collection of regurgitates from purple heron chicks (n = 52) and night heron chicks (n = 12) during ringing operations in 2001 -2002. Collection of pellets (n = 80) under daytime roosts of night herons in 2001-2002. Results: Purple heron regurgitates were dominated by carp Cyprinus carpio, recorded in 84.6 % of samples and representing 73.3 % of all prey items. Odonata nymphs were present in 13.5 % of samples and aquatic Coleoptera in 9.6 %. Regurgitates from night heron chicks were also dominated by carp, recorded in 83.3 % of the samples and representing 76.3 % of prey items. Coleoptera larvae were present in 25 % of samples. There was no difference in the size of carp consumed by the two species, but carp taken by purple heron were larger in 2002. Night heron pellets collected outside the breeding colonies lacked fish and were dominated by red swamp crayfish Procambarus clarkii, present in 86.2 % of pellets and representing 44.4 % of prey items. Terrestrial insects were also abundant in pellets. Conclusions: In spite of the great increase in abundance of P. clarkii in natural marshes since earlier studies in 1977-1983, and other major changes in the ecosystem, there has been no detectable change in purple heron diet over this period. Night heron and purple heron chicks in Donana fed prodominantly on an invasive fish. Outside the breeding colonies, night herons fed predominantly on an invasive crayfish.Peer Reviewe