Biodiversity recovery of Neotropical secondary forests

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

Caracterizaci?n ecol?gica y del potencial forestal de bosques secundarios en la Pen?nsula de Nicoya, Costa Rica, y sus relaciones con factores ambientales

Tesis (Mag. Sc. en Manejo y Conservaci?n de Bosques Tropicales y Biodiversidad) -- CATIE. Escuela de Posgrado. Turrialba (Costa Rica), 2015.La recuperaci?n de bosques secundarios en pastizales abandonados se ha convertido en un proceso clave para la conservaci?n y manejo de agro paisajes, ya que est?n estrechamente ligados al mantenimiento de la biodiversidad forestal a trav?s del tiempo. No obstante a pesar de la importancia que tienen estos ecosistemas para establecerse en ?reas perturbadas, son deficientes los conocimientos sobre los factores que interact?an en el establecimiento de las comunidades vegetales de segundo crecimiento. En 53 parcelas temporales de muestreo de 0,12 ha, ubicadas en un rango altitudinal entre 54 a 828 m.s.n.m. se estudiaron todos los ?rboles ? 10 cm dap con el objetivo de contribuir al conocimiento sobre la distribuci?n, composici?n flor?stica, estructura y diversidad de los bosques secundarios, para conocer su potencial forestal y establecer lineamientos de manejo. Se identific? m?s de 150 especies de ?rboles, agrupados en tres tipos de bosques a trav?s de an?lisis multivariados. A partir de esta clasificaci?n, los bosques fueron comparados en relaci?n a su composici?n, estructura, riqueza, diversidad y edad de abandono. El an?lisis de variaci?n de composici?n flor?stica en funci?n de variables de clima, suelo, distancia geogr?fica y altitud, evaluado por medio de partici?n de la varianza indica que el espacio es el principal mecanismo de recambio de especies en el gradiente altitudinal, seguido por el clima. Esto sugiere que la dispersi?n es el principal mecanismo para el recambio de especies y el mantenimiento de la diversidad beta en la explicaci?n de composici?n flor?stica de los bosques secundarios en el gradiente, se?alando adem?s que con respecto al uso anterior del suelo, la carga animal y ocurrencia de incendios tienen influencia sobre la composici?n de la vegetaci?n.The recovery of secondary forests on abandoned pastures has become a key process to conservation and management of agricultural landscapes, as they are closely linked to the maintenance of forest biodiversity through time. However, despite of the importance of these ecosystems to settle down in disturbed areas, the knowledge of factors that interact in the establishment of plant communities of second growth still remains deficient. In 53 temporary sample plots of 0.12 ha, located at an altitude range between 54-828 m a.s.l, we studied all trees ? 10 cm dbh in order to contribute to the knowledge on the distribution, species composition, structure and diversity of secondary forests for their forestry potential and introducing management guidelines. Over 150 species of trees were identified grouped into three types of forests through multivariate analyzes. Based on this classification, the forests were compared in relation to the variables of composition, structure, richness, diversity and age of abandonment. The analysis of variation in species composition in terms of climate, soil variables, altitude and geographic distance, evaluated by variation partitioning indicates that space is the main mechanism of species turnover in the altitudinal gradient, followed by climate. This suggests that dispersion is the main mechanism for species turnover and maintenance of beta diversity in explaining floristic composition of secondary forests in the gradient, further noting that the previous land use, stocking rate and fire occurrence have influence on vegetation composition

Data from: Legume abundance along successional and rainfall gradients in neotropical forests

The nutrient demands of regrowing tropical forests are partly satisfied by nitrogen (N)-fixing legume trees, but our understanding of the abundance of those species is biased towards wet tropical regions. Here we show how the abundance of Leguminosae is affected by both recovery from disturbance and large-scale rainfall gradients through a synthesis of forest-inventory plots from a network of 42 Neotropical forest chronosequences. During the first three decades of natural forest regeneration, legume basal area is twice as high in dry compared to wet secondary forests. The tremendous ecological success of legumes in recently disturbed, water-limited forests is likely related to both their reduced leaflet size and ability to fix N2, which together enhance legume drought tolerance and water-use efficiency. Earth system models should incorporate these large-scale successional and climatic patterns of legume dominance to provide more accurate estimates of the maximum potential for natural N fixation across tropical forests

Functional recovery of secondary tropical forests

One-third of all Neotropical forests are secondary forests that regrow naturally after agricultural use through secondary succession. We need to understand better how and why succession varies across environmental gradients and broad geographic scales. Here, we analyze functional recovery using community data on seven plant characteristics (traits) of 1,016 forest plots from 30 chronosequence sites across the Neotropics. By analyzing communities in terms of their traits, we enhance understanding of the mechanisms of succession, assess ecosystem recovery, and use these insights to propose successful forest restoration strategies. Wet and dry forests diverged markedly for several traits that increase growth rate in wet forests but come at the expense of reduced drought tolerance, delay, or avoidance, which is important in seasonally dry forests. Dry and wet forests showed different successional pathways for several traits. In dry forests, species turnover is driven by drought tolerance traits that are important early in succession and in wet forests by shade tolerance traits that are important later in succession. In both forests, deciduous and compound-leaved trees decreased with forest age, probably because microclimatic conditions became less hot and dry. Our results suggest that climatic water availability drives functional recovery by influencing the start and trajectory of succession, resulting in a convergence of community trait values with forest age when vegetation cover builds up. Within plots, the range in functional trait values increased with age. Based on the observed successional trait changes, we indicate the consequences for carbon and nutrient cycling and propose an ecologically sound strategy to improve forest restoration success

Functional recovery of secondary tropical forests

One-third of all Neotropical forests are secondary forests that regrow naturally after agricultural use through secondary succession. We need to understand better how and why succession varies across environmental gradients and broad geographic scales. Here we present data on functional recovery, using community data on seven plant characteristics (traits) of 1016 forest plots from 30 chronosequence sites across the Neotropics. By analyzing communities in terms of their traits one can enhance understanding of the mechanisms of succession and assess ecosystem recovery

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

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

Data from: Legume Abundance Along Successional And Rainfall Gradients In Neotropical Forests

This database is the product of the 2ndFOR collaborative research network on secondary forests. The database contains total basal area data (in m2 ha-1) of legume trees (Leguminosae) for 1207 secondary forest plots differing in time since abandonment. The plots belong to different chonosequence studies. For a description of the database, see Gei et al. 2018. Legume Abundance Along Successional And Rainfall Gradients In Neotropical Forests. Nature Ecology and Evolution. The file "Legume basal area 2ndFOR data.csv" contains the following variables: Chronosequence: name of the chronosequence site Age: age of the plot (in years), "OG" indicates old-growth forest of unknown age LBA: total basal area of legume trees (Leguminosae) of the plot in m2 ha-1 Reference: a citation for the chronosequence study, if available PI/contact person: name(s) of the principal investigator(s) or contact person(s) for the chronosequence study

Data from: Legume abundance along successional and rainfall gradients in neotropical forests

The nutrient demands of regrowing tropical forests are partly satisfied by nitrogen (N)-fixing legume trees, but our understanding of the abundance of those species is biased towards wet tropical regions. Here we show how the abundance of Leguminosae is affected by both recovery from disturbance and large-scale rainfall gradients through a synthesis of forest-inventory plots from a network of 42 Neotropical forest chronosequences. During the first three decades of natural forest regeneration, legume basal area is twice as high in dry compared to wet secondary forests. The tremendous ecological success of legumes in recently disturbed, water-limited forests is likely related to both their reduced leaflet size and ability to fix N2, which together enhance legume drought tolerance and water-use efficiency. Earth system models should incorporate these large-scale successional and climatic patterns of legume dominance to provide more accurate estimates of the maximum potential for natural N fixation across tropical forests