59 research outputs found

    Decision support system for selecting the rootstock, irrigation regime and nitrogen fertilization in winemaking vineyards: WANUGRAPE4.0

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    We aim to develop and transfer to the wine sector a decision support system (DSS) in the frame of WANEGRAPE4.0 project that, integrated into a geographic information system, helps wine growers in i) selecting the most suitable rootstock given some agroecological conditions and oenological objectives; and ii) managing irrigation and nitrogen fertilization in the most suitable way for the selected rootstock and agroecological conditions. The following goals have been achieved. First, the modular structure and information flow of the DSS has been defined. Second, the main algorithms of the water balance module (DSS core part) have been formulated and the module coded in a spreadsheet. Third, this water balance module has been tested with data from field experiments in several regions of Spain. Fourth, the relationships between grapevine water status and production and harvest quality variables have been established, revealing an always-significant effects of the decrease in water stress on vegetative development, yield, and grape composition. Fifth, the nitrogen fertilizer effects on vine performance has been assessed. Sixth, the effects rootstocks have on 5 parameters of vine production and grape quality for winemaking have been established too by doing another meta-analysis of rootstock trials. Seventh, a rootstock selection module has been defined. The WANUGRAPE4.0 project goes on with the integration of all its modules, their coding in a World Wide Web language and their publication on an Internet portal

    Verbal fluency tests: Normative data for Spanish-speaking pediatric population

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    OBJECTIVE: To generate normative data for the phonological and semantic verbal fluency tests (VFT) in Spanish-speaking pediatric populations. METHOD: The sample consisted of 4,373 healthy children from nine countries in Latin America (Chile, Cuba, Ecuador, Guatemala, Honduras, Mexico, Paraguay, Peru, and Puerto Rico) and Spain. Each participant was administered the VFT as part of a larger neuropsychological battery. Scores for letters F, A, S, and animals and fruit categories were normed using multiple linear regressions and standard deviations of residual values. Age, age2, sex, and mean level of parental education (MLPE) were included as predictors in the analyses. RESULTS: The final multiple linear regression models showed main effects for age on all scores, such that scores increased linearly as a function of age. Age2 had a significant effect in Chile (animals), Cuba (A letter, fruits), Ecuador (animals, fruits), Honduras (F letter), Mexico (animals, fruits), Peru (fruits), and Spain (S letters, animals, fruits). Models showed an effect for MLPE in Chile (A letters, animals, fruits), Ecuador (S letter, animals, fruits), Guatelama (F, S letter, animals), Honduras (animals), Mexico (F, A, S letters, animals, fruits), Puerto Rico (A, letters, animals), and Spain (all scores). Sex scores were found significant in Chile (animals), Ecuador (A letter, fruits), Mexico (F letter, fruits), Paraguay (F, A, S letters, fruits), Puerto Rico (F letter, animals, fruits), and Spain (F letter, fruits). CONCLUSIONS: This is the largest multi-national Spanish speaking-pediatric normative study in the world, and as such it will allow neuropsychologists from these countries to have a more accurate way to interpret the phonological and semantic VFT in pediatric populations

    Major axes of variation in tree demography across global forests

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    The future trajectory of global forests is closely intertwined with tree demography, and a major fundamental goal in ecology is to understand the key mechanisms governing spatio-temporal patterns in tree population dynamics. While previous research has made substantial progress in identifying the mechanisms individually, their relative importance among forests remains unclear mainly due to practical limitations. One approach to overcome these limitations is to group mechanisms according to their shared effects on the variability of tree vital rates and quantify patterns therein. We developed a conceptual and statistical framework (variance partitioning of Bayesian multilevel models) that attributes the variability in tree growth, mortality, and recruitment to variation in species, space, and time, and their interactions – categories we refer to as organising principles (OPs). We applied the framework to data from 21 forest plots covering more than 2.9 million trees of approximately 6500 species. We found that differences among species, the species OP, proved a major source of variability in tree vital rates, explaining 28–33% of demographic variance alone, and 14–17% in interaction with space, totalling 40–43%. Our results support the hypothesis that the range of vital rates is similar across global forests. However, the average variability among species declined with species richness, indicating that diverse forests featured smaller interspecific differences in vital rates. Moreover, decomposing the variance in vital rates into the proposed OPs showed the importance of unexplained variability, which includes individual variation, in tree demography. A focus on how demographic variance is organized in forests can facilitate the construction of more targeted models with clearer expectations of which covariates might drive a vital rate. This study therefore highlights the most promising avenues for future research, both in terms of understanding the relative contributions of groups of mechanisms to forest demography and diversity, and for improving projections of forest ecosystems

    Strong floristic distinctiveness across Neotropical successional forests

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    Forests that regrow naturally on abandoned fields are important for restoring biodiversity and ecosystem services, but can they also preserve the distinct regional tree floras? Using the floristic composition of 1215 early successional forests (≤20 years) in 75 human-modified landscapes across the Neotropic realm, we identified 14 distinct floristic groups, with a between-group dissimilarity of 0.97. Floristic groups were associated with location, bioregions, soil pH, temperature seasonality, and water availability. Hence, there is large continental-scale variation in the species composition of early successional forests, which is mainly associated with biogeographic and environmental factors but not with human disturbance indicators. This floristic distinctiveness is partially driven by regionally restricted species belonging to widespread genera. Early secondary forests contribute therefore to restoring and conserving the distinctiveness of bioregions across the Neotropical realm, and forest restoration initiatives should use local species to assure that these distinct floras are maintained

    Strong floristic distinctiveness across Neotropical successional forests.

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    Forests that regrow naturally on abandoned fields are important for restoring biodiversity and ecosystem services, but can they also preserve the distinct regional tree floras? Using the floristic composition of 1215 early successional forests (<20 years) in 75 human-modified landscapes across the Neotropic realm, we identified 14 distinct floristic groups, with a between-group dissimilarity of 0.97. Floristic groups were associated with location, bioregions, soil pH, temperature seasonality, and water availability. Hence, there is large continental-scale variation in the species composition of early successional forests, which is mainly associated with biogeographic and environmental factors but not with human disturbance indicators. This floristic distinctiveness is partially driven by regionally restricted species belonging to widespread genera. Early secondary forests contribute therefore to restoring and conserving the distinctiveness of bioregions across the Neotropical realm, and forest restoration initiatives should use local species to assure that these distinct floras are maintained

    Mycorrhizal feedbacks influence global forest structure and diversity

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    One mechanism proposed to explain high species diversity in tropical systems is strong negative conspecific density dependence (CDD), which reduces recruitment of juveniles in proximity to conspecific adult plants. Although evidence shows that plant-specific soil pathogens can drive negative CDD, trees also form key mutualisms with mycorrhizal fungi, which may counteract these effects. Across 43 large-scale forest plots worldwide, we tested whether ectomycorrhizal tree species exhibit weaker negative CDD than arbuscular mycorrhizal tree species. We further tested for conmycorrhizal density dependence (CMDD) to test for benefit from shared mutualists. We found that the strength of CDD varies systematically with mycorrhizal type, with ectomycorrhizal tree species exhibiting higher sapling densities with increasing adult densities than arbuscular mycorrhizal tree species. Moreover, we found evidence of positive CMDD for tree species of both mycorrhizal types. Collectively, these findings indicate that mycorrhizal interactions likely play a foundational role in global forest diversity patterns and structure
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