Gestão sustentada dos montados de sobro. Soluções de engenharia florestal para a gestão adaptativa

O montado de sobro e os sobreirais são sistemas de produção florestal complexos que resultam da integração de actividades agro pastoris ou pastoris em povoamentos florestais sendo a estrutura e densidade e a dinâmica definida de acordo com a qualidade da estação e objectivos de gestão. No contexto actual é fundamental implementar técnicas de gestão adaptativa associada com modelos de crescimento e sistemas de apoio à decisão, construídos com base em sólidos sistemas de monitorização contínua, para a elaboração de planos de gestão com grande precisão assentes em objectivos de gestão de longo prazo. A implementação dos planos de gestão deve de estar alicerçada em políticas de transferência de conhecimento ligando as universidades e os centros de investigação aos produtores/gestores através da engenharia florestal. O montado de sobro e os sobreirais são particularmente relevantes já que dominam a paisagem a sudoeste da Península Ibérica, ocupando cerca de 0.574 milhões de hectares em Espanha e 0.737 milhões de hectares em Portugal Continental, representando cerca de 61 % da área mundial de sobreiro e 80% da produção mundial de cortiça

Comparison of Pruning Regimes for Stone Pine (Pinus pinea L.) Using a Functional- Structural Plant Model

Functional-Structural Plant Models (FSPM) are becoming important tools for modeling the structure and growth of plants, including complex organisms like trees. These models combine the advantages of empirical, mechanistic, and structural models to simulate the growth of individual plant structures (branches, buds, leaves, etc.). This approach enables realistic evaluation of the plant’s response– including changes in structure and growth to different environmental conditions. We demonstrate the potential use of these models to evaluate individual tree growth under different management regimes (pruning). The data used in this study was obtained from 3-D measurements taken with a FASTRAK Polhemus digitizer, with specific attention given to bud creation and branching. Each branch segment was analyzed to estimate its age, enabling us to document annual structural changes. We use the XL programming language and a GroIMP environment to simulate and compare different pruning scenarios

Optimal Regeneration Regime under Continuous Crown Cover Requirements in Cork Oak Woodlands

In the present work the cork oak tree spatial growth simulator CORKFITS is used to create candidate scenarios for generating a large set of regeneration regimes combining both time and intensity factors with the individual tree spatial information. An optimal regeneration regime under continuous crown cover requirements is sought by applying a dynamic programming algorithm. It is shown that the crown cover constraint influences the total cork production potential in a negative way. The target cover constraint of 50% decreases the cork production by 66% from the potential in 40 years in our mature plot, and approximately 43% in our young plot. Higher crown cover constraint of 70% decreases the potential cork production approximately by 54% in the mature plot and does not have any influence on the younger plot. The observed losses in cork production in relation with the potential with the crown cover constrains need to be compensated economically by the higher availability of growing space for the grazing and livestock part of the montado/dehesa production system

A Floresta no Sul de Portugal: Uma Reserva Estratégica de Recursos que Urge Potenciar

Reflexão sobre a importância da investigação e dos processos de transferência de conhecimento e de tecnologia para a gestão sustentada das áreas de montado em Portugal

Growth modeling in complex forest systems: CORKFITS a tree spatial growth model for cork oak woodlands

Cork oak (Quercus suber L.) woodlands (montado) consist of a multifunctional forest system that covers about 713,000 ha in Portugal. Today, its importance stems from cork production, with Portugal producing half of the cork in the world. As the main economic objectives may change with changes in markets and environment conservation concerns (e.g. biodiversity, water, carbon) there is a need for improved management tools. Spatial tree growth simulators are tools that enable the generation of tree growth scenarios dependent on site and competition status, that allow to simulate large scope management actions. In the present work it is presented a cork oak tree spatial growth simulator, CORKFITS, that was constructed with data generated by the monitoring system installed in 1995. The simulator was built assuming the potential increment modifier principle: z = zpot * modifier + ε, where zpot is the potential growth as function of site; modifier is the reduction factor as function of spatial competition index and the intensity of debark; ε is a random error. CORKFITS is composed by sub growth models (cork, stem, tree height and crown), cork production models and mortality models. Single trees are in cork oak woodlands subjected to natural (genetics and competition) and artificial (debark, crown pruning, root pruning) factors that affects their growth therefore there is a large amount of unexplained variability which creates problems in the modeling phase, the solutions for these problems will be discussed in the present work

International Business Research: Understanding Past Paths to Design Future Research Directions

In this paper we examine the extant research in IB by conducting a bibliometric study of the articles published in three leading international business journals – International Business Review, Journal of International Business Studies and Management International Review, over their entire track record of publication available in the ISI – Institute for Scientific Information. In longitudinal analyses of citation data we ascertain the most relevant works to the international business field. We also identify intellectual interconnectedness in co-citation networks of the research published in each journal. A second-tier analysis delves into publication patterns of those articles that are not at the top citation listings. Our results permit us better understand and depict the extant international business research and, to some extent, its evolution thus far.info:eu-repo/semantics/publishedVersio

Forest property insurance: an application to Portuguese woodlands

Fire is the biggest forest hazard, especially in Mediterranean climate countries, leading to desertification and collapse (Naveh, 2007). Wildfire is among the most dramatic threats to forests (Goldammer, 2004). In many countries, it is not easy to find companies that want to insure forests stands. This can be explained by the following reasons. Firstly, in many countries, forest insurance is not mandatory; so many farmers do not make it. Secondly, insurance companies need to have models based on desegregated and reliable data to estimate the probability of fire occurrences. Finally, it is very difficult for the insurer to estimate the real value of the stands because their values vary with the species, the stand age and market prices. The main objective of this paper is to present simple models that help to estimate ‘fair’ insurance risk premiums, contributing, in this way, to make forest business more appealing and sustainable

Software development for forest growth models and management. CORKFITS: web based growth simulator

New methods of forest management and the study of their impact on sustainability are strongly dependent on realistic mathematical modelling. The complexity of the models however, makes the use of computational power, and thus the incorporation of knowledge from computer science and research, indispensable. In this paper we wish to demonstrate the development of a simulator for the growth and production of cork oak woodlands – montados. The software is divided into three sub-modules, sharing a common core, with functions and mathematical operations. The desktop client allows for repeated operations for more intense calculations, and statistical operations for modelling purposes. The web version is intended to be used by final users in forest practice. It permits simulation of inventory data based on individual tree measurements, and inventory data based on plot description with a reduced amount of detail (number of trees per ha, diameter structure, etc.) The last module allows the incorporation of the cork model into other software by means of SOAP protocol, via web services. It conforms to the WS-I Basic Profile 1.1, to ensure interoperability among the largest number of clients. This module allows other developers to use the cork oak growth-model in their software, and the developers from other areas of expertise (management optimisation, decision support...) have the opportunity to test their techniques on real stands, with the most recently-updated model versions

Mergers & acquisitions research: A bibliometric study of top strategy and international business journals, 1980–2010

Mergers and acquisitions (M&As) are important modes through which firms carry out their domestic and international strategies and have been noted as the CEOs favorite strategy. As a significant field of study, M&Aresearch has accumulated substantial knowledge. This bibliometric study examines the extant strategy and international business literature on M&As. Methodologically, we examined a sample of 334 articles published in sixteen leading management/business journals, during a 31 year period — from 1980 to 2010. The results provide a global perspective of the field, identifying the works that have had the greater impact, the intellectual interconnections among authors and works, the main research traditions, or themes, delved upon on M&Arelated research. Structural and longitudinal analyses reveal the changes in the intellectual structure of the field over time. A discussion on the accumulated knowledge and future research avenues concludes this paper.info:eu-repo/semantics/publishedVersio

Observations on 3-dimensional crown growth of Stone pine

In this work we wish to demonstrate the possibility of a reconstruction of the 3D growth of the Stone pine (Pinus pinea L) crown. The crowns of two samples were digitized in segments corresponding with individual years, which allowed us to reconstruct length-growth and 3D shape over the last 5 years. Due to the low sample amount, we limited ourselves to observations and methodology-descriptions instead of overall conclusions. We were able to observe diminished height-growth in year 2006, which is the year after a severe drought. However, this was not observed in the total length-growth of the crown. It is possible to see that the growth of 2006 is not dominant at the top of the crown, as it would have been in normal years. The year of the drought, 2005, is visible in the annual rings, but the shoot length of 2005 is not visibly lower than expected