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Artificial ponds can be important reproductive sites for anurans in human-disturbed habitats. However, this capacity depends on the configuration of the habitat where they are inserted. We evaluated how anuran beta diversity was influenced by the configuration of the surrounding habitat and water parameters in artificial ponds in southern Brazil. Physicochemical parameters of water and the configuration of the surrounding habitat were the elements that best explained the variation in beta diversity. However, the surrounding habitat had a predominant role in the differences between communities. The level of exposed soil was the component that best acted on the turnover component of beta diversity followed by urbanization, which highlights the impact of human presence on anuran diversity. In other words, we observed that anthropogenic changes caused changes in species composition in the evaluated ponds. Among water parameters, only phosphate was relevant for the configuration of communities. Phosphate peaks may result from sewage or fertilizer contamination, not infrequent in the region despite the low human density and the small-scale agriculture economy. Even though they are anthropogenic environments, artificial ponds can help maintain the anuran communities, but their effectiveness will depend on the presence of forest remnants and water quality. [ABSTRACT FROM AUTHOR]

On the sandy coastal plains, environmental filters that limit seedling establishment and survival create a naturally heterogeneous landscape, formed by vegetation patches inserted in a matrix of bare sandy soil. The succession processes in these ecosystems depend on some pioneer species that facilitate the recruitment and survival of other species. Here, we evaluated the spatial pattern and changes of vegetation patches of restinga (i.e., coastal sandy plain vegetation) over one decade (2011–2021). The research was carried out in Alagoas State, Northeast of Brazil. We considered as patches the vegetation islands inserted in a matrix of bare sandy soil and applied methodologies of photointerpretation. Landscape metrics included patch area, edge, shape, and core area. To test the effect of landscape metrics on species occurrence and species richness per patch, we applied generalized linear models (GLM) with binomial and quasi‐Poisson distributions, respectively. We used the "betapart" package to evaluate the importance of turnover and nestedness as drivers of beta diversity among patches. Our data indicate that a key plant (Myrciaria floribunda), which can propagate by root suckers, initiates a succession process, creating regeneration nuclei, which seem to follow a deterministic succession pattern until the patch reaches 10 m2 in area. In the successional sequence, the patches grow and coalesce with neighboring patches. Species richness of patches presented an unimodal response to patch size. Overall, there is a greater contribution of species turnover to among‐patch beta diversity. However, for patches smaller than 10 m2, beta diversity was mostly driven by nestedness, reflecting a process of species addition to the growing patches. The succession pattern found in the study area should be considered for the formulation of nature‐based restoration models, expected to be more efficient and effective for ecosystems with similar environmental filters. [ABSTRACT FROM AUTHOR]

Unplanned urban development has consequences for natural ecosystems, resulting in habitat fragmentation and loss. Arthropod responses to urbanisation are well documented in the Global North, but no clear responses are found for the Global South.We assessed beta diversity, composition, richness and abundance responses of arthropods in Turnera subulata in an urbanisation gradient.Urbanisation affected arthropod communities' composition, and more urbanised areas showed lower insect richness and abundance. Arthropod taxa did not respond homogeneously to urbanisation.Turnover best explained the change in beta diversity along the urbanisation gradient, indicating urbanisation causes species replacement compared to less urbanised areas.We found negative results of urbanisation on the arthropod community on flowers of T. subulata. Our results are a first approximation to the effects of rural–urban gradient of urbanisation on multiple arthropod taxon in Brazil, highlighting the need for maintenance of urban green areas to allow the existence of a richer and more diverse community, especially in the face of the arthropod biodiversity crisis that we are experiencing. [ABSTRACT FROM AUTHOR]

Research on climate has been explored from multiple perspectives over the years. It is generally agreed that global climate (the mean value of the climate ratings of individual members) is positively related to many important individual and organizational outcomes. However, having a positive global climate is not enough. The level of variability in climate dimensions ratings also matters as it could influence how employees appraise their work environment. In this study, we explored the different roles of climate variability, defined as the level of dispersion across climate dimensions, to explain collective turnover. Drawing on signalling theory, we tested the direct and moderating effects of climate variability on collective turnover using a large and heterogeneous database composed of 25,288 individuals from 150 small‐sized to large organizations in different industries. After controlling for global climate, we found that climate variability had a curvilinear association with collective turnover. Although lower levels of climate variability had milder effects on collective turnover, moderate to higher levels of climate variability were associated with higher collective turnover rates. Moreover, climate variability also played a moderating role in the relationship between global climate and collective turnover such that a higher level of climate variability impaired the beneficial effects of a positive global climate on collective turnover. Implications for theory, practice and future research are discussed. [ABSTRACT FROM AUTHOR]

Objective: Biogeographic regionalization represents abstractions of the organisation of life on Earth, and can provide a large‐scaled framework for health management and planning. We aimed at determining a biogeographic regionalization for human infectious diseases in Brazil, and at investigating non‐mutually exclusive hypotheses predicting the observed regions. Methods: Based on the spatial distributions of 12 infectious diseases with mandatory notification (SINAN database, 2007–2020, n = 15,839), we identified regions through a clustering procedure based on beta‐diversity turnover. The analysis was repeated 1000 times by randomly shuffling the rows (0.5° cells) in the original matrix. We evaluated the relative importance of variables using multinomial logistic regression models: contemporary climate (temperature and precipitation), human activity (population density and geographic accessibility), land cover (11 classes), and the full model (all variables). We refined the geographic boundaries of each cluster by polygonising their kernel densities to identify clusters' core zones. Results: The two‐cluster solution showed the best correspondence between disease ranges and clusters geographic limits. The largest cluster occurred with more density in the central and northeastern regions, while the smaller and complementary cluster occurred in the south and southeastern region. The best model for explaining the regionalization was the full model, supporting the 'complex association hypothesis'. The heatmap showed a NE‐S directional display of the cluster's densities, and core zones showed geographic correspondence with tropical + arid (NE) versus temperate (S) climates. Conclusion: Our findings indicate that there is a discernible latitudinal pattern in the turnover of disease in Brazil, and this phenomenon is associated with an intricate interplay between contemporary climate, population activity, and land cover. This generalised biogeographic pattern may offer the earliest insights into the geographic arrangement of diseases in the country. We suggested that the latitudinal pattern could be adopted as a nationwide framework for geographic vaccine allocation. [ABSTRACT FROM AUTHOR]

Aim: To test whether spatial turnover patterns of mountain madicolous insect communities in the Southern Hemisphere support the 'mountain passes are higher in the Tropic' hypothesis (MPHT). To do this, we compared madicolous communities in the Amazon Mountains (equator) and the Atlantic Forest Mountains (23°S). Location: Brazil. Methods: We characterized madicolous insect communities in two elevational gradients between 90 to 3000 m a.s.l. separated by 23° of latitude, totalling 108 sampling sites. Since the MPHT predicts a more intense turnover along elevational gradients at lower latitudes than at higher latitudes, we evaluated beta diversity in the Amazon mountains, at the equator, and in the Atlantic Forest mountains, in the subtropical region. We quantified multiple‐site abundance‐based dissimilarity to assess whether beta diversity was different between both regions. We also performed constrained ordination (db‐RDA) analyses to assess whether community dissimilarity (balanced variation in abundances) was uniquely or jointly explained by environmental, spatial and/or elevational predictors. Additionally, we independently assessed the relationship between community dissimilarity and altitudinal difference in each region and tested for differences in model parameters between regions. Results: Although we found high species turnover in both regions, the community variation explained by environmental factors and altitude was higher in the Amazon than in the Atlantic Forest, as evidenced by db‐RDA and altitudinal difference models. In general, communities were remarkably constrained by spatial predictors, which result from low dispersion capacity of most madicolous insects and low connectivity of madicolous systems. Consequently, the composition of madicolous insects notably diverged between regions, highlighting the complementarity and high conservation value of both systems. Main Conclusions: Our results indicate that the MPHT explains, at the community level, the differences between low‐ and high‐latitude mountain systems in community turnover along elevational gradients, even within a relatively short latitudinal distance in the Southern Hemisphere. [ABSTRACT FROM AUTHOR]

This study evaluated how the edge effect influences the structuration of fruit‐feeding butterfly assemblages in swamp forest fragments of the subtropical Atlantic Forest, Southern Brazil. Sampling was carried out twice in 10 fragments using baited traps placed in sampling units both at the forest edge and 50 m within the forest interior, with the habitats being defined by a set of environmental variables. Richness and abundance were higher for edge habitats with an effect of temperature depending on humidity and luminosity. The subfamily/tribe composition of fruit‐feeding butterflies was segregated between edge and interior and was predicted by wind speed and the interaction between humidity and luminosity. Fifty meters within the forest interior is not sufficient to cause homogenization of butterfly composition between the edge and interior of swamp forest fragments, indicating distinct assemblages in each habitat. The interior harboured forest‐loving butterfly groups while the edge harboured generalist sun‐loving and common butterflies associated with disturbed areas, suggesting resistance to the effects of habitat fragmentation. We highlight the importance of using fruit‐feeding butterfly groups, instead of species, to evaluate edge effects. We also suggest that a heterogeneous matrix with native habitats and distinct semi‐natural land‐use systems be maintained to manage subtropical areas by increasing connectivity within the landscape. Considering the impacts that the Atlantic Forest suffers, increased knowledge of modifications caused at small and regional scales is crucial for the maintenance of ecological processes and represents a tool for conservation planning and environmental agendas. [ABSTRACT FROM AUTHOR]

Anthropogenic stressors on aquatic environments change the relative importance of environmental conditions on spatial species distributions in a regional pool. One way to assess the spatial species distribution is measure the beta diversity. This study analyzed the difference in zooplankton beta diversity between natural lakes and artificial reservoirs, to understand whether reservoirs affect beta diversity, and the relative importance of deterministic processes for the spatial distribution of species. We measured beta diversity using Raup-Crick dissimilarity and analyzed the relative impact of environmental filters on beta diversity in 30 reservoirs and 29 shallow lakes located in Brazil, during two seasons (dry and rainy period). Rotifer beta diversity did not differ between lakes and reservoirs, while copepod beta diversity was higher in reservoirs. Environmental filters were important during the dry period for both lakes and reservoirs, indicating that deterministic processes could drive beta diversity during that season. Environmental productivity, estimated by chlorophyll-a, was associated with zooplankton beta diversity in lakes and reservoirs. The spatial turnover of zooplankton communities depended on the biological characteristics of zooplankton groups, and their responses to environmental filters. [ABSTRACT FROM AUTHOR]

Copyright of Cadernos de Gestão Pública e Cidadania is the property of Fundacao Getulio Vargas, Escola Brasileira de Administracao Publica e de Empresas and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Human activities affect the structure, dynamics and energy flow of aquatic ecosystems. River damming, a common anthropic impact in Brazil, changes solar incidence, water flow and temperature of waterbodies, thereby affecting their fauna. Due to their high sensitivity to environmental changes, the Odonata may be indicators of these impacts. We sampled two ecologically distinct sites, (1) a quasi‐pristine forested area and (2) a nearby human‐impacted reservoir landscape, to evaluate the effects of damming on odonate community structure. The species composition of quasi‐pristine communities was more heterogeneous and differed almost completely (indicating high turnover) from that of the reservoir‐area communities. The capacity of the reservoir to maintain local fauna was almost nil. The communities in the changed landscape had the highest local diversity, which is related to the high occurrence of widespread generalist South American species. We also tested two recently proposed bioindication ratio tools based on the richness or abundance of high‐level taxonomic categories; both effectively reflected the extent of the impacts of damming. The best performing ratios were Coenagrionidae/other Zygoptera richness ratio, Zygoptera/Anisoptera abundance ratio and Libellulidae/other Anisoptera richness ratio. The reservoir landscape promotes biotic homogenization. However, the water supply system entails the preservation of part of the native habitat in its surrounding areas, consequently maintaining forest‐dependent biodiversity in quasi‐pristine environments. Practitioner points: The capacity of the reservoir (the damming process) to maintain quasi‐pristine forested communities was almost nil.The high diversity in the modified landscape (reservoir) is related to the high occurrence of widespread and generalist South American Odonata.Bioindication ratio tools were effective for demonstrating the extent of the impacts of damming. The best performing ratios were Coenagrionidae/other Zygoptera richness ratio, Zygoptera/Anisoptera abundance ratio and Libellulidae/other Anisoptera richness ratio. [ABSTRACT FROM AUTHOR]

Beta diversity helps to understand changes in species composition over space and time, with two key components: nestedness (hierarchical pattern in richer sites) and turnover (species replacement due to niche or dispersal differences). It measures the loss or gain of species (nestedness) and species replacement (turnover) when comparing two or more spatial/temporal/environmental units. As both components require different species conservation strategies, assessing which of them the communities are organized is an important tool for this purpose. Our study aimed to evaluate which two components of beta diversity (nestedness or turnover) are responsible for structuring invertebrate and fish assemblages on the southern coast of Brazil. This region is historically recognized as a shrimp trawling area, a type of fishing with negative impacts on marine biota, such as the removal of species and habitat destruction. Our results suggest that the overall beta diversity values demonstrated a high environmental heterogeneity among the sampled areas. The most significant fraction of the general beta diversity for both assemblages is explained by the spatial turnover component. As depth increased, there was a significant rise in overall beta diversity and species turnover for fish and invertebrate assemblages. In contrast, there were no significant correlations among the nestedness component, the geographical distance and depth. In water mass conditions, fish assemblage decreased with rising chlorophyll and decreasing temperature. Elevated marine phosphate and thick sediments adversely impacted invertebrate composition. Additionally, invertebrate richness showed a positive correlation with fine sand grains. The research conducted along the southern coast of Brazil suggests the utmost importance of these regions in terms of species conservation. Here, the dominant influence of the turnover component shapes the organization of subtropical marine benthic assemblages. Furthermore, these areas receive frequent visits from migratory species, further accentuating their ecological significance. • Trawl fishing can act as a competitive force in the marine benthic ecosystem. • The composition and diversity of fish and invertebrate assemblages are primarily characterized by rare species confined to specific sites. • The impact of turnover on marine assemblages underlines the vital role of the studied areas in the conservation of species. • Beta diversity and turnover component increased significantly with increasing depth for fish and invertebrate assemblages. [ABSTRACT FROM AUTHOR]

Over 70% of the total channel length in all river basins is formed by low order streams, many of which originate on mountaintops. Headwater streams play fundamental roles in processing and transporting terrestrial and aquatic organic matter, often harboring high biodiversity in bottom leaf patches deposited from riparian vegetation. The objective of this study was to assess the variation in taxonomic composition (measured by beta diversity of aquatic macroinvertebrates) among stream sites located in the Espinhaço Meridional Mountain Range, part of a UNESCO Biosphere Reserve in eastern Brazil. We tested two hypotheses. (a) Taxa turnover is the main reason for differences in aquatic insect assemblages within stream sites; we predicted that turnover would be higher than nestedness in all stream sites. (b) Stream site altitude and catchment elevation range are the main explanatory variables for the differences in beta diversity; we predicted that local stream site variables would account for only minor amounts of variation. In both dry and wet seasons, we sampled twice in two habitat types (five leaf patches in pools and five in riffles) in each of nine stream sites distributed in three different river basins. We computed average pairwise beta diversity among sampling stations and seasons in each stream site by using Jaccard and Bray–Curtis indices, and calculated the percentages of diversity resulting from turnover and nestedness. Finally, we tested the degree that local‐ or catchment‐level predictor variables explained beta diversity. We found that turnover was the main component of beta diversity and that both dissolved oxygen and elevation range best explained Bray–Curtis beta diversity. These results reinforce the importance of leaf patches in montane (sky islands) Neotropical savanna streams as biodiversity hotbeds for macroinvertebrates, and that both local and landscape variables explained beta diversity. [ABSTRACT FROM AUTHOR]

Studies on beta diversity across different spatial scales can yield insight into the ecological factors that shape communities and the mechanisms of maintenance and loss of diversity. The coastal rivers in southeast Brazil have different lengths and salinity gradients because of variation in coastal plain width and slope. These differences in environmental characteristics promote natural gradients and patterns of macrophyte assemblage variation within and among rivers. To investigate the drivers of macrophyte beta diversity, we recorded the occurrence of species and life forms and collected limnological variables at 100 sampling sites over 8 unconnected rivers that run directly to the sea. We estimated macrophyte beta diversity, and its nestedness and turnover components, within (local scale) and among (regional scale) coastal rivers using traditional metrics (Jaccard dissimilarity matrix) and a metric that accounts for sampling effect (permutational analysis of multivariate dispersions). At each sampling site, we collected variables from water (nutrients, dissolved oxygen, and pH), sediment (nutrients, salinity, and grain type), and channel (width, littoral declivity, distance from river's mouth, and coastline). For assessment of regional-scale drivers of macrophyte beta diversity, we measured river length and calculated salinity gradient. We evaluated the potential of environmental variables to explain local and regional beta diversity using distance-based redundancy analysis and multiple linear regression. As expected, at the local scale, high species turnover and life-form nestedness were predominantly explained by the rivers' longitudinal gradients (mainly salinity, P, and channel width). At the regional scale, we found that river length explained life-form nestedness among rivers (small rivers are subsets of the largest rivers); however, neither river length nor salinity gradient explained the high species turnover among rivers. We suggest that dispersal limitation among rivers and historical colonization shaped the species pool in each river resulting in almost completely distinct assemblage compositions. This high turnover at the regional scale suggests that conservation strategies for macrophytes must consider multiple rivers and not only the largest ones. Overall, our results suggest that environmental variation strongly influences macrophyte beta diversity within and among coastal tropical rivers. [ABSTRACT FROM AUTHOR]

Species distributions and the mechanisms that produce patterns in the occupation space are recurrent themes in community ecology. Here, we examine beta diversity among assemblages of small mammals in the Cerrado domain of Brazil to partition the effects of turnover and nestedness on species distributions. Our objective was to evaluate whether balanced spatial variation in abundance (β bal) and abundance gradients (β gra) are congruent within and among habitats and localities of the Brazilian Cerrado. In addition, we wanted to understand whether ecological mechanisms, such as dispersal limitation, habitat filtering, and species sorting, drive the distribution patterns of the Cerrado small mammals. We analyzed the occurrence and abundances of small mammals from 16 localities widely distributed across the Cerrado biome, and grouped our data with respect to two distinct spatial scales. Baselga's Bray–Curtis index of dissimilarity and its respective partitions, i.e. balanced variation in abundance (β bal) and abundance gradients (β gra), were estimated between sampling units at the two spatial scales. Thus, we used exponential models to search for distance decay in species similarity between pairs of localities and between similar habitats. Our results show that differences between small mammal assemblages in the Cerrado are driven mainly by species replacement rather than independent gain or loss of species, both at small and large scales. The spatial turnover patterns of small mammals in the Cerrado biome are determined by a combination of large scale (biogeographic, spatial) and local mechanisms (low dispersal and habitat specificity). However, processes occurring at small scales seem to be more important in species sorting than processes occurring at large scales. The spatial configuration of the landscape and the extent and quality of habitats strongly influence the rate of species turnover in Cerrado. Thus, protecting the different types of habitats should be of prime importance to conserving the diversity of Cerrado small mammals. [ABSTRACT FROM AUTHOR]

Software maintenance is the task of modifying a running product previously delivered to the client, in order to correct defects, improve performance or adapt it to the environment. This task is a crucial activity for enterprises. Without it, existing systems would become rapidly out-of-date and inefficient. The purpose of this paper is to present a software maintenance approach used in small and medium-sized business (SMB) organizations in Brazil. Currently, these organizations represent 95.5% of the software companies in the country. The approach presented here indicates how SMB IT companies have improved their software maintenance processes. Multiple case studies were performed to validate this approach. The outcomes showed that strategies associated with managing users' knowledge and development/maintenance teams are relevant to increase the maintenance process effectiveness. This approach involves three aspects: users' knowledge management, maintenance team knowledge and the management and maintenance process. This improvement includes reducing time and also minimizing the number of tickets. The response time for tickets resolution to the end user has been reduced. In addition, IT organizations have minimized the effects associated with both staff and client turnovers. [ABSTRACT FROM AUTHOR]

Analysis of the structure, diversity, and demographic dynamics of tree assemblages in tropical forests is especially important in order to evaluate local and regional successional trajectories.We conducted a long‐term study to investigate how the structure, species richness, and diversity of secondary tropical forests change over time. Trees (DBH ≥ 5 cm) in the Atlantic Forest of southern Brazil were sampled twice during a 10‐year period (2007 and 2017) in six stands (1 ha each) that varied in age from their last disturbance (25, 60, 75, 90, and more than 100 years). We compared forest structure (abundance and basal area), species richness, alpha diversity, demographic rates (mortality, recruitment, and loss or gain in basal area), species composition, spatial beta diversity, and temporal beta diversity (based on turnover and nestedness indices) among stand ages and study years.Demographic rates recorded in a 10‐year interval indicate a rapid and dynamic process of species substitution and structural changes. Structural recovery occurred faster than beta diversity and species composition recovery. The successional gradient showed a pattern of species trade‐off over time, with less spatial dissimilarity and faster demographic rates in younger stands. As stands grow older, they show larger spatial turnover of species than younger stands, making them more stochastic in relation to species composition. Stands appear to split chronologically to some extent, but not across a straightforward linear axis, reflecting stochastic changes, providing evidence for the formation of a nonequilibrium community.Policy implications. These results reiterate the complexity and variability in forest succession and serve as a reference for the evaluation and monitoring of local management and conservation actions and for defining regional strategies that consider the diversity of local successional trajectories to evaluate the effectiveness of restoration measures in secondary forests of the Atlantic Forest biome. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this paper is to discuss two important behaviors related to job mobility in the IT profession, namely, changing jobs to move to another organization (turnover) and changing the profession entirely (turnaway), during a national crisis. Based on the theoretical foundation of the push–pull–mooring perspective, a research model is developed that includes professional self-efficacy (PSE), job insecurity (JI) and job satisfaction (JS) as important antecedents. Design/methodology/approach: Using a positivist approach and a survey method, the authors analyzed data from IT professionals from different economic segments in Brazil. Data collection occurred in two distinctive moments of the largest crisis in modern Brazilian history – a pre-awareness moment (first half of year 2015) and a crisis-conscious moment (first half of year 2016). Findings: The findings reveal that PSE negatively influences JI and positively influences JS, JI positively influences turnaway intention, and JS negatively influences both turnover intention and turnaway intention. The effect of the national crisis was observed in that it further accentuated the intention of IT professionals to leave the profession. Another effect was related to age, as older professionals are less willing to turn over but more willing to turn away. Research limitations/implications: Besides developing a parsimonious model to study both the intention to leave the organization and the intention to leave the profession, the study sheds light on how IT professionals react to economic crises and how the reaction varies by age. Practical implications: The study puts to question the common belief that IT professionals are secure in the job market due to high demand for their skills and investments made by organizations to keep them on the job. Employers must pay attention to JI and turnover/turnaway intentions. Originality/value: This study is among the few to study JI and aspects of the theory of human migration in IT. It is also possibly the first to discuss the effects of a national crisis on the mobility patterns of IT professionals. [ABSTRACT FROM AUTHOR]

Understanding the mechanisms underpinning spatiotemporal diversity patterns of biological communities is a major goal of ecology. We aimed to test two ecological hypotheses: (i) temporal patterns of β-diversity will mostly be driven by nestedness, with a loss of species from summer to winter, and (ii) nestedness values will correlate with climatic variables instead of turnover values, indicating either a loss of species during winter or a gain of species during summer. We sampled dung beetles using standardized sampling protocols along a year in four Atlantic forest sites: two at the northwest and two at the central region of Rio Grande do Sul state, southern Brazil. We partitioned temporal patterns of β-diversity into turnover and nestedness in order to investigate if community changes are driven by species substitution or gain/loss across time. Our results highlighted five main findings: (i) dung beetle composition varied more with sites than site geographic position; (ii) there was almost one and a half 'true' dung beetle assemblages regarding the spatial distribution of species weighed by abundance; (iii) we found a positive influence of mean temperature and a negative influence of relative humidity on both species richness and abundance; (iv) both spatial and temporal dissimilarity among sites were dominated by species replacement, while the relative importance of nestedness was higher in temporal than spatial patterns; (v) there was an effect of precipitation and relative humidity on temporal patterns of β-diversity components, but these effects were site-dependent. Contrary to our expectations, the β-diversity component of turnover dominated both spatial and temporal patterns in dung beetle dissimilarity among sites and months. Distinct climatic variables affected differently the α-diversity and β-diversity components of dung beetle assemblages. Partitioning β-diversity into temporal components is a promising approach to unveil patterns of the community dynamics and to produce insights on mechanisms underlying such patterns. [ABSTRACT FROM AUTHOR]

Background and aims: While the role of deep roots in major ecosystem services has been shown for tropical forests, there have been few direct measurements of fine root dynamics at depths of more than 2 m. The factors influencing root phenology remain poorly understood, creating a gap in the knowledge required for predicting the effects of climate change. We set out to gain an insight into the fine root phenology of fast-growing trees in deep tropical soils. Methods: Fine root growth and mortality of Eucalyptus grandis trees were observed fortnightly using minirhizotrons down to a soil depth of 6 m, from 2 to 4 years after planting. Results: In the topsoil, the highest live root length production was during the rainy summer (20 cm m d) whereas, below 2 m deep, it was at the end of the dry winter (51 cm m d). The maximum root elongation rates increased with soil depth to 3.6 cm d in the 5-6 m soil layer. Conclusions: Our study shows that the effect of the soil depth on the seasonal variations in fine root growth should be taken into account when modelling the carbon, water and nutrient cycles in forests growing on deep tropical soils. [ABSTRACT FROM AUTHOR]

This study investigated the influence of the estuarine plume from the Maranhense Gulf on the phytoplankton community structure and β-diversity. To understand the effects of the regulation mechanisms on shaping phytoplankton community structure and β-diversity along an estuary-ocean continuum in the eastern sector of the Amazon shelf, this study considered spatiotemporal analyses of physical, chemical, and biological variables from May 2019 to June 2020. High temporal environmental heterogeneity was identified in Cumã Bay and significant spatial environmental variability in the estuary-ocean continuum. Based on the thermohaline properties, an estuarine plume was observed alongshore at a distance of approximately 60 km from the coastline. Both phytoplankton community structure and β-diversity varied in time and space. From 189 taxa, thirty-nine indicator species were selected based on their functional traits and indicator value. Skeletonema costatum was considered the best phytoplankton indicator of the estuarine water influence. Turnover was the main component responsible for boosting β-diversity at spatial and temporal scales. The present study was the first performed on an Amazon estuary-ocean continuum which applied diversity metrics (β-diversity) to generate new information about loss of taxon richness and provided important information about spatiotemporal changes in phytoplankton community and environmental heterogeneity. [Display omitted] • Spatiotemporal changes of phytoplankton were studied in an estuary-ocean continuum. • Climate and spatial processes are the main drivers of the phytoplankton community. • Skeletonema costatum was the best indicator of the estuarine water influence. • Turnover was the main component responsible for boosting β-diversity. • Estuarine plume acts as a dispersal filter limiting the phytoplankton distribution. [ABSTRACT FROM AUTHOR]

Descriptions of biodiversity from ecotonal regions are lacking. This knowledge gap results from the difficulty of identifying elements from both biomes/domains and the advancement of human activities that generate small forest fragments. Here it is shown that small forest fragments in an ecotonal region have species richness and abundance in line with other inventories in preserved and non-preserved areas as well as composition and structure differentiated by the presence of species from both domains. The beta diversity among fragments reflects a high turnover supported by the formation of centers of dominance among the most abundant species. Finally, functional diversity favors the group that is tolerant of a wide range of environmental variables and is associated with faunal components. The results indicate that these fragments are important from a conservation standpoint because of the intersection of elements from threatened biomes, which must be managed coherently. However, Brazilian legislation is constantly modified and still allows anthropogenic changes that prevent the persistence of species. [ABSTRACT FROM AUTHOR]

Copyright of Investigación Económica is the property of Universidad Nacional Autonoma de Mexico, Facultad de Economia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Facultad de Ciencias Economicas: Investigacion y Reflexion is the property of Revista Facultad de Ciencias Economicas and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper investigates the relationship between job dissatisfaction and labour turnover in the Brazilian labour market using an objective behavioural measure variable of job satisfaction. Following the methodology adopted by Souza-Poza and Souza-Poza (2007, The Journal of Socio-Economics, 36, 895–913), this paper used various econometric techniques (such as multinomial and ordered probit models) in determining whether job satisfaction is a good predictor of future job quits. In general, the results found show the importance of job satisfaction on future mobility, thereby providing another way to analyse job satisfaction, since the measure used minimizes the subjective effects that are associated with psychological factors. [ABSTRACT FROM AUTHOR]

The tree changes of 1.02 ha of montane forest at the Santa Lúcia Biological Station, southeastern Brazil, were analyzed using two surveys separated by an interval of 11 years with the aim of confirming the patterns of stability of structure and diversity over time. In the original survey all trees with diameter at breast height ≥6.4 cm were sampled. In second survey (this study), dead trees, survivors and recruits in the same forest were reported. The data suggest a dynamic balance of the forest structure because mortality (−1.06% year for number of trees and −0.85% year for basal area) was very close to recruitment (0.89% year) and ingrowth (1.05% year). The high diversity of the original survey ( H′ > 5.2) was maintained by the turnover species. The main tree populations also showed stability of number of trees and basal area. This pattern was shared by most of the 28 local endemic species, ensuring the maintenance of their populations in the plot. [ABSTRACT FROM AUTHOR]

This paper studies the responses of a traditional Brazilian firm to recession and increasing foreign competition as expressed in its subcultural dynamics. A strong association was found between involuntary turnover in the top management team and affiliation with certain clusters of subcultural and even personal values. Although many of the effects found are expressive of themes in the literature on organizational adaptation to adversity, results also suggest unexpected challenges and extensions to current thinking. [ABSTRACT FROM AUTHOR]

Job flows, workers flows and employment flows in Brazil. The labor market is in constant flux. When measuring labor market mobility, it is usual to estimate labor market flow statistics, such as worker reallocation and job reallocation. The goal of this paper is to present previously unknown within plant job reallocation statistics for Brazil. The within plant job reallocation is measured as changes in the occupational mix of the plant. The within plant job reallocation allows a decomposition of worker turnover decomposition into matching, technological change and labor demand factors. Using formal labor market data for Brazil, from 1996 to 2001, our results suggest that technological change accounted for a limited share of worker turnover. More than a quarter of worker turnover can be attributed to labor demand shifts and more than 50% of worker turnover is due to matching. [ABSTRACT FROM AUTHOR]

Extrapolation of local abundance--environment relationships to broader scales provides species distribution models used for conservation planning. We investigated the importance of environmental heterogeneity and geographic distance on pteridophyte species spatial distribution on 38 plots of 250 × 2.5 m distributed over 90 km2 in Central Amazon. Inclusion of canopy openness in our models increased the capacity of predicting community composition even under the narrow range of canopy openness found in our plots. Nevertheless, there was still a large amount of unexplained variance (55--65%). The response of the community to the light gradient was hierarchical and we did not find evidences of light partitioning. Most species were concentrated in low light plots but a few common and abundant occurred along the entire gradient. Soil properties were the major determinants of community composition. Contrary to similar studies, slope was not a good predictor of pteridophyte community composition, indicating that this relationship may be site-specific. There was no correlation between floristic distances and geographic distances. We concluded that mesoscale turnover is low, although locally environmental variation determines high turnover of species. Studies among different Amazonian physiognomies tend to find high levels of beta-diversity. However, coarse comparisons can not reveal subtle patterns that are relevant for biodiversity conservation planning. This study found some important changes on pteridophyte community within the same type of forest, mainly related to environmental heterogeneity, even in narrow ranges of environmental variation. [ABSTRACT FROM AUTHOR]

Changes in the structure and composition of a dry forest fragment were described for a 4-yr period (1994-1998) in the southeastern Brazil (19°12′05″ S and 47°08′02″ W). This is the first dynamic study of a vanishing type of dry forest, which grows on base-rich soils originating from the basalt bedrock of western Minas Gerais State. A survey of trees ≥ 3.2 cm dbh (diameter at breast height, or 1.30 m) was conducted in 26 transects of 50 m × 6 m (0.78 ha). The species were classified into three regeneration guilds – pioneer, light-demanding and shade-tolerant – on the basis of others studies and personal observation. There was a decrease of 10.1% in the number of trees between 1994 and 1998. However, the basal area had an increase of 1.5% in the same period. Size class distributions in 1994 and 1998 were significantly different. The smallest trees (diameter < 10 cm) had the highest mortality rates. Although stand composition showed little change, a few species showed significant imbalance between recruitment and mortality. The studied fragment had mortality (2.3% yr–1) and recruitment (1.6% yr–1) rates similar to other tropical rain forests for trees ≥ 10 cm dbh. The present fragment of forest (turnover time = 39.5 yr, at cut level 10 cm dbh) lies among the most dynamic tropical forests. The main compositional changes were the increase of shade-tolerant trees and decline of pioneer species. The changes in composition and structure over the survey period may reflect the recovery of the forest after 4 yr of conservation. [ABSTRACT FROM AUTHOR]