Global patterns and environmental drivers of forest functional composition

Aim To determine the relationships between the functional trait composition of forest communities and environmental gradients across scales and biomes and the role of species relative abundances in these relationships. Location Global. Time period Recent. Major taxa studied Trees. Methods We integrated species abundance records from worldwide forest inventories and associated functional traits (wood density, specific leaf area and seed mass) to obtain a data set of 99,953 to 149,285 plots (depending on the trait) spanning all forested continents. We computed community-weighted and unweighted means of trait values for each plot and related them to three broad environmental gradients and their interactions (energy availability, precipitation and soil properties) at two scales (global and biomes). Results Our models explained up to 60% of the variance in trait distribution. At global scale, the energy gradient had the strongest influence on traits. However, within-biome models revealed different relationships among biomes. Notably, the functional composition of tropical forests was more influenced by precipitation and soil properties than energy availability, whereas temperate forests showed the opposite pattern. Depending on the trait studied, response to gradients was more variable and proportionally weaker in boreal forests. Community unweighted means were better predicted than weighted means for almost all models. Main conclusions Worldwide, trees require a large amount of energy (following latitude) to produce dense wood and seeds, while leaves with large surface to weight ratios are concentrated in temperate forests. However, patterns of functional composition within-biome differ from global patterns due to biome specificities such as the presence of conifers or unique combinations of climatic and soil properties. We recommend assessing the sensitivity of tree functional traits to environmental changes in their geographic context. Furthermore, at a given site, the distribution of tree functional traits appears to be driven more by species presence than species abundance

Integrated global assessment of the natural forest carbon potential

Forests are a substantial terrestrial carbon sink, but anthropogenic changes in land use and climate have considerably reduced the scale of this system1. Remote-sensing estimates to quantify carbon losses from global forests2,3,4,5 are characterized by considerable uncertainty and we lack a comprehensive ground-sourced evaluation to benchmark these estimates. Here we combine several ground-sourced6 and satellite-derived approaches2,7,8 to evaluate the scale of the global forest carbon potential outside agricultural and urban lands. Despite regional variation, the predictions demonstrated remarkable consistency at a global scale, with only a 12% difference between the ground-sourced and satellite-derived estimates. At present, global forest carbon storage is markedly under the natural potential, with a total deficit of 226 Gt (model range = 151–363 Gt) in areas with low human footprint. Most (61%, 139 Gt C) of this potential is in areas with existing forests, in which ecosystem protection can allow forests to recover to maturity. The remaining 39% (87 Gt C) of potential lies in regions in which forests have been removed or fragmented. Although forests cannot be a substitute for emissions reductions, our results support the idea2,3,9 that the conservation, restoration and sustainable management of diverse forests offer valuable contributions to meeting global climate and biodiversity targets

Population immunity and structure of measles cases in the Russian Federation

Relevance. In recent years, in Russia, against the background of a stable high (no less than 95%) coverage of live measles vaccine (GI) inoculations of decreed groups of the population for almost twenty years, increases in morbidity have been registered, reaching the indicators of 3.3(2014) and 3.1 (2019) per 100 ths population and local outbreaks involving the child population. This situation has raised doubts among a number of researchers about the reliability of high vaccination coverage in children and adults. In this regard, some researchers assumed the loss of post-vaccination immunity and suggested revaccination against measles every 10 years for people up to 50 years old. Others suggested serological examination of certain cohorts of the adult population without taking into account the vaccination history for timely detection and vaccination of individuals with primary post-vaccination failures and who have lost post-vaccination immunity. The purpose of the work: to assess the state of population immunity for some manifestations of the epidemic process of measles infection and the feasibility of changing the tactics of vaccination against measles. Materials and methods. The work uses epidemiological operational and retrospective analysis. The research is based on the analysis of official statistics № 2, № 5, № 6, reports of regional centers, «maps of the surveillance of a case of suspected measles…», information and analytical bulletins of the National scientific and methodological center for the supervision of measles and rubella (NNMC). A total of 18,750 documents were analyzed. The average values, the average standard error, the correlation coefficient of the series, the reliability of the correlation coefficient, and the regression coefficient were calculated. Results and discussion. One of the indirect indicators of the state of population immunity is the ratio of vaccinated and not vaccinated against measles in the structure of patients. The analysis showed a steady trend towards the prevalence of cases not vaccinated against measles in the structure: since 2011, more than 70%, and since 2017 – more than 80%. The percentage of vaccinated people is decreasing from 12.8% to 5.4% (2017) and has stabilized in the last 2.5 years at the level of 5.4–7.2%. Over the past 2 years, there has also been some stabilization of the proportion of people twice vaccinated – 9.4–9.8%. Intensive indicators of morbidity confirmed the General trend of extensive indicators. In addition, over the past 3 years, the intensive incidence rate of those vaccinated is 14 times lower than that of those not vaccinated against measles. All this testifies to the lack of accumulation of susceptible individuals due to the loss of post-vaccination immunity and confirms the adequacy of the strategy and tactics of vaccination against measles in our country. The calculation of the regression coefficient showed that with an increase in vaccination coverage of the entire population by one percent, the incidence of measles among unvaccinated people will increase by 1.34 per one hundred thousand unvaccinated people against measles. The prevalence of foci without infection spread (more than 80%) during the analyzed period, and the restriction of secondary measles spread by the second generation of infection reproduction in foci with two or more cases of measles, multiple circulation of genotypes and subtypes of the measles virus also characterizes a fairly high population immunity. Conclusion. The steady predominance of lesions 1 case, limiting secondary spread of infection in outbreaks, the maintenance of the epidemic process of measles through an unvaccinated population indicate adequate tactics and strategy for measles immunization in our country. At the same time, the achieved 74.1% vaccination coverage of the entire population is clearly not enough to prevent sustained endemic transmission of the measles virus, since the reproductive index R<1 can be maintained with vaccination coverage of at least 95%. To increase population immunity, it is necessary to search for new forms of work of pediatricians and therapists with the population to form a commitment to immunization, as well as to legislate responsibility for the consequences of refusing vaccinations, as is done in a number of States. © Tsvirkun OV et al

Suscetibilidade a desinfetantes e perfil de resistência a antimicrobianos em isolados de Escherichia coli

A colibacilose, causada por Escherichia coli, é a enfermidade entérica de maior impacto na produção de suínos, podendo levar à morte do animal. Esta bactéria possui grande capacidade de desenvolver resistência a múltiplos antimicrobianos e a desinfetantes. Desta forma, estudos que abordem mecanismos de resistência e perfil de amostras de campo tornam-se necessários. E. coli é amplamente utilizada como modelo de estudos que exploram a resistência intrínseca e extrínseca a multidrogas. Neste trabalho, buscou-se verificar o perfil de sensibilidade de 62 isolados de E. coli de suínos frente a três desinfetantes e a 13 antimicrobianos. Ainda, em 31 destes isolados foi pesquisada a presença de mecanismo de efluxo. Dos três desinfetantes avaliados, o cloreto de alquil dimetil benzil amônio+poliexietilenonilfenileter foi o que se mostrou mais eficaz (100%), seguido do glutaraldeído+cloreto de alquil dimetil benzil amônio (95,2%) e do cloreto de alquil dimetil benzil amônio (88,8%). Dentre os antimicrobianos testados, observou-se maior resistência para a tetraciclina (62,2%) e maior sensibilidade para o florfenicol (88,6%). A alta sensibilidade dos isolados frente aos desinfetantes pode estar relacionada à ausência de mecanismo de efluxo. O índice de resistência múltipla médio aos antimicrobianos foi de 0,52, o que demonstra um perfil multirresistente dos isolados, conduzindo para a necessidade do uso racional destas drogas em suinocultura