7 research outputs found

    Biodiversity recovery of Neotropical secondary forests

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    Old-growth tropical forests harbor an immense diversity of tree species but are rapidly being cleared, while secondary forests that regrow on abandoned agricultural lands increase in extent. We assess how tree species richness and composition recover during secondary succession across gradients in environmental conditions and anthropogenic disturbance in an unprecedented multisite analysis for the Neotropics. Secondary forests recover remarkably fast in species richness but slowly in species composition. Secondary forests take a median time of five decades to recover the species richness of old-growth forest (80% recovery after 20 years) based on rarefaction analysis. Full recovery of species composition takes centuries (only 34% recovery after 20 years). A dual strategy that maintains both old-growth forests and species-rich secondary forests is therefore crucial for biodiversity conservation in human-modified tropical landscapes. Copyright © 2019 The Authors, some rights reserved

    Environmental gradients and the evolution of successional habitat specialization: A test case with 14 Neotropical forest sites

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    Successional gradients are ubiquitous in nature, yet few studies have systematically examined the evolutionary origins of taxa that specialize at different successional stages. Here we quantify successional habitat specialization in Neotropical forest trees and evaluate its evolutionary lability along a precipitation gradient. Theoretically, successional habitat specialization should be more evolutionarily conserved in wet forests than in dry forests due to more extreme microenvironmental differentiation between early and late-successional stages in wet forest. We applied a robust multinomial classification model to samples of primary and secondary forest trees from 14 Neotropical lowland forest sites spanning a precipitation gradient from 788 to 4000 mm annual rainfall, identifying species that are old-growth specialists and secondary forest specialists in each site. We constructed phylogenies for the classified taxa at each site and for the entire set of classified taxa and tested whether successional habitat specialization is phylogenetically conserved. We further investigated differences in the functional traits of species specializing in secondary vs. old-growth forest along the precipitation gradient, expecting different trait associations with secondary forest specialists in wet vs. dry forests since water availability is more limiting in dry forests and light availability more limiting in wet forests. Successional habitat specialization is non-randomly distributed in the angiosperm phylogeny, with a tendency towards phylogenetic conservatism overall and a trend towards stronger conservatism in wet forests than in dry forests. However, the specialists come from all the major branches of the angiosperm phylogeny, and very few functional traits showed any consistent relationships with successional habitat specialization in either wet or dry forests. Synthesis. The niche conservatism evident in the habitat specialization of Neotropical trees suggests a role for radiation into different successional habitats in the evolution of species-rich genera, though the diversity of functional traits that lead to success in different successional habitats complicates analyses at the community scale. Examining the distribution of particular lineages with respect to successional gradients may provide more insight into the role of successional habitat specialization in the evolution of species-rich taxa. © 2015 British Ecological Society

    Environmental gradients and the evolution of successional habitat specialization: a test case with 14 neotropical forest sites

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    Successional gradients are ubiquitous in nature, yet few studies have systematically examined the evolutionary origins of taxa that specialize at different successional stages. Here we quantify successional habitat specialization in Neotropical forest trees and evaluate its evolutionary lability along a precipitation gradient. Theoretically, successional habitat specialization should be more evolutionarily conserved in wet forests than in dry forests due to more extreme microenvironmental differentiation between early and late-successional stages in wet forest. We applied a robust multinomial classification model to samples of primary and secondary forest trees from 14 Neotropical lowland forest sites spanning a precipitation gradient from 788 to 4000mm annual rainfall, identifying species that are old-growth specialists and secondary forest specialists in each site. We constructed phylogenies for the classified taxa at each site and for the entire set of classified taxa and tested whether successional habitat specialization is phylogenetically conserved. We further investigated differences in the functional traits of species specializing in secondary vs. old-growth forest along the precipitation gradient, expecting different trait associations with secondary forest specialists in wet vs. dry forests since water availability is more limiting in dry forests and light availability more limiting in wet forests. Successional habitat specialization is non-randomly distributed in the angiosperm phylogeny, with a tendency towards phylogenetic conservatism overall and a trend towards stronger conservatism in wet forests than in dry forests. However, the specialists come from all the major branches of the angiosperm phylogeny, and very few functional traits showed any consistent relationships with successional habitat specialization in either wet or dry forests.Synthesis. The niche conservatism evident in the habitat specialization of Neotropical trees suggests a role for radiation into different successional habitats in the evolution of species-rich genera, though the diversity of functional traits that lead to success in different successional habitats complicates analyses at the community scale. Examining the distribution of particular lineages with respect to successional gradients may provide more insight into the role of successional habitat specialization in the evolution of species-rich taxa

    Demographic Drivers of Aboveground Biomass Dynamics During Secondary Succession in Neotropical Dry and Wet Forests

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    I do it for myself : A study on motivational differences between contracted and permanent employees in Sweden

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    Over the past decades outsourcing decades outsourcing has become an increasing trend.Firms decide to outsource in order to increase their profits or flexibility and many differentfunctions of the firm may be outsourced, one of them being the Human Resource (HR)function. When it comes to HR outsourcing, recruitment and selection are among the morecommon functions to be outsourced (Ordanini & Silvestri, 2008:373). The motivation foroutsourcing of HR is to reduce cost and increase efficiency (Elmuti, Grunewald and Abebe,2010:177). Outsourcing of HR functions like recruitment can also have negative aspect, forexample lack of loyalty and high turnover (Fisher et al, 2008:202). Previous research hasinvestigated how commitment and loyalty is affected by HR outsourcing (Connelly &Gallagher, 2004:963) and one aspect that has been touched upon but not dealt withexclusively is motivation and therefore this paper will explore it further. Using the following research question: How does motivation vary between individuals working at a company butare hired through a staffing firm versus hired directly by the company? This paper tries to both evaluate the existing literature and provide practicalimplications for managers. In order to explore this question and abductive research approachhas been used where the data and theory are intertwined and played of each other to achievethe purpose (Alvesson & Sköldberg, 2009:4). The data collection consists of eight semistructuredinterviews, four with people hired directly by the company and four that are orhave previously been hired through a staffing company. The study found that the theoretical framework does for the most part explain themotivational behavior of both groups studied, and that the two groups are not alwaysmotivated in the same way. Those hired directly by the company are more interested inreceiving praise, relationships at work, and receiving small tokens of appreciation. The grouphired by staffing companies was more often motivated by an internal drive to satisfythemselves and did not value work relationships to the same extent. The research also showedthat the individual rather than the form of employment plays a big role when it comes to howpeople are motivated. It was also made apparent that education and work situation wereimportant factors influencing the respondent’s motivation

    TRATAMIENTO SINDROMICO DE FLUJO VAGINAL EN GESTANTES ATENDIDAS EN EL CENTRO DE SALUD CHACAPUNCO ENERO A JUNIO 2017

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    TesisObjetivo: Determinar las características del tratamiento sindrómico de flujo vaginal. Metodología: El tipo de investigación es sustantiva, nivel descriptivo y diseño descriptivo simple. Se trabajó con una muestra censal de 30 gestantes que desarrollaron síndrome de flujo vaginal resultados: Las características encontradas en la edad fue edad mínima 17 años y la máxima 40 años, la mayoría presentó 23 años., el 53% son convivientes. Según el grado de instrucción, el 60% de las gestantes tienen primaria, el 47% son amas de casa, el 87% procede del área rural. Dentro de las características clínicas el 67% de las gestantes tienen abundante secreción, las características de las secreciones vaginales son el 67% presentan aspecto leche cortada, el 33% mal olor. Y los síntomas identificados fueron 60% disuria y prurito vulvar. Se encontró que el 60% de las gestantes atendidas tienen como diagnostico presuntivo trichomona y cándida. Las complicaciones encontradas fueron: amenaza de parto prematuro 60%, amenaza de aborto 27%. La respuesta al tratamiento sindrómico de flujo vaginal en gestantes el 73% de las gestantes se suministró el Metronidazol y al 87% con Clotrimazol. Conclusión: El tratamiento sindrómico de flujo vaginal con medicamentos resulto que el 83% de las gestantes fue efectivo y el 17% de las gestantes no fue efectivo. Palabras claves: Síndrome de flujo vaginal, tratamiento y gestantes

    Biomass resilience of Neotropical secondary forests

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