Assessing the role of Mediterranean evergreen oaks canopy cover in land surface albedo and temperature using a remote sensing-based approach

Modifications in vegetation cover can have an impact on the climate through changes in biogeochemical and biogeophysical processes. In this paper, the tree canopy cover percentage of a savannah-like ecosystem (montado/dehesa) was estimated at Landsat pixel level for 2011, and the role of different canopy cover percentages on land surface albedo (LSA) and land surface temperature (LST) were analysed. A modelling procedure using a SGB machine-learning algorithm and Landsat 5-TM spectral bands and derived vegetation indices as explanatory variables, showed that the estimation of montado canopy cover was obtained with good agreement (R2 = 78.4%). Overall, montado canopy cover estimations showed that low canopy cover class (MT_1) is the most representative with 50.63% of total montado area. MODIS LSA and LST products were used to investigate the magnitude of differences in mean annual LSA and LST values between contrasting montado canopy cover percentages. As a result, it was found a significant statistical relationship between montado canopy cover percentage and mean annual surface albedo (R2 = 0.866, p < 0.001) and surface temperature (R2 = 0.942, p < 0.001). The comparisons between the four contrasting montado canopy cover classes showed marked differences in LSA (χ2 = 192.17, df = 3, p < 0.001) and LST (χ2 = 318.18, df = 3, p < 0.001). The highest montado canopy cover percentage (MT_4) generally had lower albedo than lowest canopy cover class, presenting a difference of −11.2% in mean annual albedo values. It was also showed that MT_4 and MT_3 are the cooler canopy cover classes, and MT_2 and MT_1 the warmer, where MT_1 class had a difference of 3.42 °C compared with MT_4 class. Overall, this research highlighted the role that potential changes in montado canopy cover may play in local land surface albedo and temperature variations, as an increase in these two biogeophysical parameters may potentially bring about, in the long term, local/regional climatic changes moving towards greater aridity.

A influência do modelo e estrutura de recursos humanos na motivação e comprometimento dos trabalhadores: gestão interna versus Outsourcing

Com esta investigação, pretende-se fazer uma análise comparativa sobre o comprometimento e motivação dos trabalhadores, tendo como fator diferencial a gestão do recrutamento, de modo interno e a gestão por outsourcing. O objetivo principal é verificar se existem diferenças significativas nos dois grupos de trabalhadores, à luz de um quadro teórico muito vasto. Para concretizar esta análise foi elaborado um questionário on-line, com questões de escala manifestadas por afirmações elaboradas, com base no enquadramento teórico que constituiu a revisão da literatura, sobre motivação e comprometimento. Os resultados demonstraram que não existem diferenças significativas nos valores médios dos dois grupos na avaliação dos fatores de motivação, embora em ambos os grupos, se verifique uma grande vontade de darem mais de si à organização, de forma a superarem objetivos. Os valores de motivação revelaram-se muito baixos no geral, nos dois grupos. Em ambos os grupos apurou-se que há mais insatisfação face a fatores recompensatórios (tanto a nível material como imaterial): o salário e o reconhecimento do trabalho. Em relação ao comprometimento, verifica-se menor comprometimento por parte dos trabalhadores outsourcing, não numa análise de comparabilidade de médias gerais, mas numa análise de médias mais específicas de alguns fatores em avaliação: intenções de abandono. As médias das intenções de abandono foram mais visíveis neste grupo. No geral, ambos os trabalhadores dos dois grupos são movidos por um comprometimento instrumental, mais relacionado com as poucas alternativas que o mercado de trabalho dispõe , para uma evolução profissional; Abstract: The influence of human resource management structure in the motivation and commitment of employees: internal management versus outsourcing With this research aims to make a comparative analysis on the commitment and motivation of workers, with the differentiating factor the management of the internal mode recruitment and management by outsourcing. The main objective is to verify whether there are significant differences in the two groups of workers in the light of a very broad theoretical framework. To realize this analysis was prepared an online questionnaire with scale issues raised by elaborate statements, based on the theoretical framework that was the literature review of motivation and commitment. The results showed no significant differences in mean values of the two groups in the evaluation of the motivating factors, although in both groups, that there is a great desire to give more of themselves to the organization in order to overcome objectives. The motivation values proved to be very low in general, in both groups. In both groups it was found that there is more dissatisfaction with the recompensatórios factors (both material and immaterial level): wages and recognition of the work. Regarding the commitment, there is less commitment by the outsourcing workers, not an analysis of comparability of overall averages but a more average specific analysis of some factors reviewed abandonment of intentions. The average dropout intentions were more visible in this group. Overall, both employees of the two groups are driven by an instrumental commitment, more related to the few alternatives that the labor market has for professional development.