175 research outputs found
Mothers' and fathers' emotional wellbeing and the exercise of the parental role: an empirical investigation
The present investigation had 3 main objectives: 1) to evaluate emotional wellbeing, inferred as levels of time stress (TS) and depression symptoms (DS), in a group of mothers and fathers; 2) to investigate some dimensions of the exercise of the parental role, understood as key components of parenting schemes (for example, self-perception, establishment of positive interactions with the children); and 3) to investigate associations between indicators of parental emotional wellbeing and components of parenting schemes. A total of 51 couples, living in Rio de Janeiro, with different education levels, over 18 years of age, with at least one natural child aged less than 5 years, participated in the study. The mothers and fathers answered questionnaires that evaluated TS, DS, components of parenting schemes, social desirability, and sociodemographic data. The results, compatible with previous studies, indicated that an important proportion of parents in the study presented high levels of time stress and depression symptoms. Several significant associations (pA presente pesquisa teve três objetivos principais: 1) avaliar o bem-estar emocional, inferido como níveis de estresse de sobrecarga de tempo (ST) e sintomas de depressão (SD), em um grupo de mães e pais; 2) investigar algumas dimensões do exercício do papel parental entendidas como importantes componentes dos esquemas parentais (Ex. auto-percepção, estabelecimento de interações positivas com filhos), e 3) investigar associações entre os indicadores de bem-estar emocional parental e os diferentes componentes dos esquemas parentais. Participaram 51 casais, residentes no Rio de Janeiro, com diferentes níveis de escolaridade, maiores de 18 anos, com pelo menos um filho natural com idade inferior a 5 anos. As mães e pais responderam questionários que avaliaram ST, SD, componentes dos esquemas parentais, desejabilidade social, e dados sócio-demográficos. Os resultados, compatíveis com estudos anteriores, indicaram que uma parcela importante dos pais entrevistados apresentou níveis elevados de estresse de sobrecarga de tempo e queixas de depressão. Foram identificadas diversas associações significativas (p < 0,05) entre medidas do bem-estar e dimensões dos esquemas parentais. Foram identificadas, por exemplo, correlações entre ST e SD (r=0,24), ST e auto-percepção do papel parental (r=-0,48); SD e auto-percepção do papel parental (r = -0,45); ST e interação positiva dos pais com os filhos (r = 0,22). Entre outros aspectos, os resultados obtidos podem contribuir para um melhor entendimento das associações entre bem-estar emocional e esquemas parentais e poderão fundamentar futuros projetos de intervenção com pais e mães
Tropical forest lianas have greater non-structural carbohydrate concentrations in the stem xylem than trees
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Rarity of monodominance in hyperdiverse Amazonian forests.
Tropical forests are known for their high diversity. Yet, forest patches do occur in the tropics where a single tree species is dominant. Such "monodominant" forests are known from all of the main tropical regions. For Amazonia, we sampled the occurrence of monodominance in a massive, basin-wide database of forest-inventory plots from the Amazon Tree Diversity Network (ATDN). Utilizing a simple defining metric of at least half of the trees ≥ 10 cm diameter belonging to one species, we found only a few occurrences of monodominance in Amazonia, and the phenomenon was not significantly linked to previously hypothesized life history traits such wood density, seed mass, ectomycorrhizal associations, or Rhizobium nodulation. In our analysis, coppicing (the formation of sprouts at the base of the tree or on roots) was the only trait significantly linked to monodominance. While at specific locales coppicing or ectomycorrhizal associations may confer a considerable advantage to a tree species and lead to its monodominance, very few species have these traits. Mining of the ATDN dataset suggests that monodominance is quite rare in Amazonia, and may be linked primarily to edaphic factors
Effect of working pressure at different spray nozzles on drift quantification in wind tunnel
Evolutionary Heritage Influences Amazon Tree Ecology
Lineages tend to retain ecological characteristics of their ancestors through time. However, for some traits, selection during evolutionary history may have also played a role in determining trait values. To address the relative importance of these processes requires large-scale quantification of traits and evolutionary relationships among species. The Amazonian tree flora comprises a high diversity of angiosperm lineages and species with widely differing life-history characteristics, providing an excellent system to investigate the combined influences of evolutionary heritage and selection in determining trait variation. We used trait data related to the major axes of life-history variation among tropical trees (e.g. growth and mortality rates) from 577 inventory plots in closed-canopy forest, mapped onto a phylogenetic hypothesis spanning more than 300 genera including all major angiosperm clades to test for evolutionary constraints on traits. We found significant phylogenetic signal (PS) for all traits, consistent with evolutionarily related genera having more similar characteristics than expected by chance. Although there is also evidence for repeated evolution of pioneer and shade tolerant life-history strategies within independent lineages, the existence of significant PS allows clearer predictions of the links between evolutionary diversity, ecosystem function and the response of tropical forests to global change
Tropical forest lianas have greater non-structural carbohydrate concentrations in the stem xylem than trees
Lianas (woody vines) are important components of tropical forests and are known to compete with host trees for resources, decrease tree growth and increase tree mortality. Given the observed increases in liana abundance in some forests and their impacts on forest function, an integrated understanding of carbon dynamics of lianas and liana-infested host trees is critical for improved prediction of tropical forest responses to climate change. Non-structural carbohydrates (NSC) are the main substrate for plant metabolism (e.g., growth, respiration), and have been implicated in enabling tree survival under environmental stress, but little is known of how they vary among life-forms or of how liana infestation impacts host tree NSC. We quantified stem total NSC (NSC) concentrations and its fractions (starch and soluble sugars) in trees without liana infestation, trees with more than 50% of the canopy covered by lianas, and the lianas infesting those trees. We hypothesized that i) liana infestation depletes NSC storage in host trees by reducing carbon assimilation due to competition for resources; ii) trees and lianas, which greatly differ in functional traits related to water transport and carbon uptake, would also have large differences in NSC storage, and that As water availability has a significant role in NSC dynamics of Amazonian tree species, we tested these hypotheses within a moist site in western Amazonia and a drier forest site in southern Amazonia. We did not find any difference in NSC, starch or soluble sugar concentrations between infested and non-infested trees, in either site. This result suggests that negative liana impact on trees may be mediated through mechanisms other than depletion of host tree NSC concentrations. We found lianas have higher stem NSC and starch than trees in both sites. The consistent differences in starch concentrations, a long term NSC reserve, between life forms across sites reflect differences in carbon gain and use of lianas and trees. Soluble sugar concentrations were higher in lianas than in trees in the moist site but indistinguishable between life forms in the dry site. The lack of difference in soluble sugars between trees and lianas in the dry site emphasize the importance of this NSC fraction for plant metabolism of plants occurring in water limited environments. Abstract in Portuguese and Spanish are available in the supplementary material. [Abstract copyright: © The Author(s) 2023. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: [email protected].
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