Assessment of environment, land management, and spatial variables on recent changes in montado land cover in southern Portugal

Montado decline has been reported since the end of the nineteenth century in southern Portugal and increased markedly during the 1980s. Consensual reports in the literature suggest that this decline is due to a number of factors, such as environmental constraints, forest diseases, inappropriate management, and socioeconomic issues. An assessment on the pattern of montado distribution was conducted to reveal how the extent of land management, environmental variables, and spatial factors contributed to montado area loss in southern Portugal from 1990 to 2006. A total of 14 independent variables, presumably related to montado loss, were grouped into three sets: environmental variables, land management variables, and spatial variables. From 1990 to 2006, approximately 90,054 ha disappeared in the montado area, with an estimated annual regression rate of 0.14 % year-1. Variation partitioning showed that the land management model accounted for the highest percentage of explained variance (51.8 %), followed by spatial factors (44.6 %) and environmental factors (35.5 %). These results indicate that most variance in the large-scale distribution of recent montado loss is due to land management, either alone or in combination with environmental and spatial factors. The full GAM model showed that different livestock grazing is one of the most important variables affecting montado loss. This suggests that optimum carrying capacity should decrease to 0.18–0.60 LU ha-1 for livestock grazing in montado under current ecological conditions in southern Portugal.

Estudo dos determinantes do crescimento das empresas familiares portuguesas

No presente estudo procuramos analisar os determinantes do crescimento das empresas familiares portuguesas, através de uma amostra de empresas familiares membros da Associação de Empresas Familiares, durante o período de 2006 a 2014. Com vista ao teste das hipóteses em estudo foram utilizados dados em painel, com modelos de efeitos fixo e aleatório. A variável dependente definida foi o crescimento das vendas. As variáveis independentes definidas foram: dimensão; idade; endividamento; endividamento de curto prazo; endividamento de médio longo prazo; produtividade da mão-de-obra; estrutura do ativo; variável dummy da crise financeira; variável dummy da administração pertencer à família; e variável dummy do género do administrador. Os resultados obtidos confirmam a dimensão, a idade e o endividamento como determinantes do crescimento; ABSTRACT: In the present study we analyzed the determinants of growth of family businesses through a sample of family businesses members of the Family Business Association, during the period between 2006 and 2014. In order to test the hypotheses under study were used panel data, with models of fixed and random effects. The Sales growth was defined as the dependent variable. The independent variables were defined: size; age; debt; short-term debt; medium and long term debt; labor productivity; asset structure; dummy variable of the financial crisis; dummy administration belong to the family; and dummy administrator gender variable. The results confirm the size, age, and debt as determinants of growth.

Obtaining environmental favourability functions from logistic regression

Logistic regression is a statistical tool widely used for predicting species’ potential distributions starting from presence/absence data and a set of independent variables. However, logistic regression equations compute probability values based not only on the values of the predictor variables but also on the relative proportion of presences and absences in the dataset, which does not adequately describe the environmental favourability for or against species presence. A few strategies have been used to circumvent this, but they usually imply an alteration of the original data or the discarding of potentially valuable information. We propose a way to obtain from logistic regression an environmental favourability function whose results are not affected by an uneven proportion of presences and absences. We tested the method on the distribution of virtual species in an imaginary territory. The favourability models yielded similar values regardless of the variation in the presence/absence ratio. We also illustrate with the example of the Pyrenean desman’s (Galemys pyrenaicus) distribution in Spain. The favourability model yielded more realistic potential distribution maps than the logistic regression model. Favourability values can be regarded as the degree of membership of the fuzzy set of sites whose environmental conditions are favourable to the species, which enables applying the rules of fuzzy logic to distribution modelling. They also allow for direct comparisons between models for species with different presence/absence ratios in the study area. This makes themmore useful to estimate the conservation value of areas, to design ecological corridors, or to select appropriate areas for species reintroductions.

Above ground biomass functions with vegetation indices for multiple use systems of two evergreen oaks

Remote sensing is a promising approach for above ground biomass estimation, as forest parameters can be obtained indirectly. The analysis in space and time is quite straight forward due to the flexibility of the method to determine forest crown parameters with remote sensing. It can be used to evaluate and monitoring for example the development of a forest area in time and the impact of disturbances, such as silvicultural practices or deforestation. The vegetation indices, which condense data in a quantitative numeric manner, have been used to estimate several forest parameters, such as the volume, basal area and above ground biomass. The objective of this study was the development of allometric functions to estimate above ground biomass using vegetation indices as independent variables. The vegetation indices used were the Normalized Difference Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), Simple Ratio (SR) and Soil-Adjusted Vegetation Index (SAVI). QuickBird satellite data, with 0.70 m of spatial resolution, was orthorectified, geometrically and atmospheric corrected, and the digital number were converted to top of atmosphere reflectance (ToA). Forest inventory data and published allometric functions at tree level were used to estimate above ground biomass per plot. Linear functions were fitted for the monospecies and multispecies stands of two evergreen oaks (Quercus suber and Quercus rotundifolia) in multiple use systems, montados. The allometric above ground biomass functions were fitted considering the mean and the median of each vegetation index per grid as independent variable. Species composition as a dummy variable was also considered as an independent variable. The linear functions with better performance are those with mean NDVI or mean SR as independent variable. Noteworthy is that the two better functions for monospecies cork oak stands have median NDVI or median SR as independent variable. When species composition dummy variables are included in the function (with stepwise regression) the best model has median NDVI as independent variable. The vegetation indices with the worse model performance were EVI and SAVI.

Motivação e satisfação no trabalho: aplicação numa organização do setor de formação profissional

Os recursos humanos são considerados o ativo mais poderoso e valioso de qualquer organização, mas o seu desempenho é, de uma forma geral, influenciado pela motivação e satisfação no trabalho. Deste modo, a presente investigação pretende analisar a motivação e a satisfação dos colaboradores numa organização do sector da formação profissional. A partir deste pressuposto, pretende-se analisar a motivação e a satisfação dos colaboradores da instituição alvo do estudo, averiguar se se verifica correlação entre as vaiáveis motivacionais (sucesso, afiliação e poder) e as variáveis de satisfação (salário, promoções, colegas de trabalho, superiores hierárquicos e realização da tarefa), analisar o relacionamento entre a variável dependente (satisfação com o salário) e variáveis independentes de natureza sociodemográfica e analisar se a motivação e a satisfação global dos colaboradores são influenciadas pelas variáveis explicativas da análise fatorial de componentes principais. A análise dos dados baseou-se em 72 inquéritos por questionário que foram já validados por autores da motivação (McClelland) e satisfação (Deshpande), aplicados à totalidade dos colaboradores da empresa, ou seja, à população em estudo. Procedeu-se à análise estatística para sustentar toda a parte empírica. Os resultados mostram que os colaboradores da empresa Competir se sentem razoavelmente motivados e satisfeitos, ainda que um pouco mais motivados do que satisfeitos. Concluiu-se que, na generalidade, os colaboradores se sentem motivados essencialmente no que diz respeito ao sucesso e afiliação, e satisfeitos principalmente com os seus colegas de trabalho e com a realização da tarefa. A satisfação com o salário é mais baixa no caso de género feminino, mas tende a aumentar com a antiguidade na empresa; Motivation and Job Satisfaction: An Application in an organization of vocational training sector Abstract: Human resources are considered the most powerful and valuable asset in any organization, but its performance is, in general, influenced by motivation and job satisfaction. The present research intends to analyse the motivation and the satisfaction of the employees in an organization of vocational training sector. Based on this assumption, we intend to analyze the motivation and satisfaction of the employees of the studied institution, to verify if there is a correlation between motivational (success, affiliation and power) and satisfaction variables (salary, promotions, Work, hierarchical superiors and task accomplishment), to analyze the relationship between the dependent variable (satisfaction with the salary) and independent variables of a sociodemographic nature and to analyze if the motivation and the overall satisfaction of the employees are influenced by the explanatory variables of the principal components factorial analysis. Data analysis was based on 72 questionnaire surveys that have already been validated by the authors of motivation (McClelland) and satisfaction (Deshpande), applied to all the company's employees, i.e., the study population. In order to support all the empirical part, were proceeded to the statistical analysis. The results shows that the employees of the company Competir feel reasonably motivated and satisfied, even if a little more motivated than satisfied. It was concluded that, in general, employees feel motivated primarily with regard to success and affiliation, and especially satisfied with their co-workers and with the complete of the task. Satisfaction with salary it’s lower in the case of female gender, but tends to increase with seniority in the company.