Browsing by Author "Borges, J.G."
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- An approach to cork oak forest management planning: a case study in southwestern PortugalPublication . Costa, A.; Oliveira, A.C.; Vidas, F.; Borges, J.G.This paper presents results of research aiming at the development of tools that may enhance cork oak (Quercus suber L.) forest management planning. Specifically, it proposes an hierarchical approach that encompasses the spatial classification of a cork oak forest and the temporal scheduling of cork harvests. The use of both geographical information systems and operations research techniques is addressed. Emphasis is on the achievement of cork even flow objectives. Results from an application to a case study in the Charneca Plioce´nica of Ribatejo in southern Portugal encompassing a cork oak forest extending over 4.8 thousand ha are discussed. They suggest that the proposed approach is capable of effective spatial classification of cork oak management units. They further suggest that it may be used to select optimal cork even flow scheduling strategies. Results also show that the proposed approach may lead to a substantial increase in net present value when compared to traditional approaches to cork oak forest management planning.
- Assessing forest management strategies using a contingent valuation approach and advanced visualisation techniques: a portuguese case studyPublication . Madureira, Lívia; Nunes, Luís C.; Borges, J.G.; Falcão, André O.The assessment of alternative forest management strategies should account not only for the private benefits to forest landowners but also for the ecological, environmental and economic benefits valued by society. There are a number of empirical valuation methods that may contribute to that assessment. These methods involve several steps: data acquisition, model specification and estimation. In this paper, this approach is illustrated in the context of a survey regarding alternative management strategies for a forest area in Central Portugal by implementing a contingent valuation experiment where an advanced landscape visualisation technique is employed to generate the visual information conveyed in the valuation scenarios. Several econometric model specifications are considered as well as alternative approaches to handle zero willingness to pay values and protest responses. The results obtained suggest the potential of the proposed approach for an effective comparison of alternative forest management strategies
- Assessing impacts of Common Agricultural Policy changes on regional use patterns with a decision support system. An application in Southern PortugalPublication . Borges, P.J.; Fragoso, R.; Borges, J.G.; Marques, S.A.; Lucas, M.R.This paper discusses research aiming at assessing Common Agricultural Policy impacts on agriculture and forestry. For this purpose an approach is developed that includes a linear programming model to estimate the Positive Mathematical Programming production cost function coefficients of current agricultural– forestry activities. It further includes a heuristic — simulated annealing — to generate solutions for each policy scenario. This model base approach is integrated within a decision support system (DSS) for testing purposes. The DSS further encompasses a relational database that stores agricultural–forestry technical and economic data and a geographic information system that stores topological data of regional farm-type land units. The DSS Graphical User Interface provides tabular and geographical reporting capabilities. Results are discussed for an application to the Alentejo region in Southern Portugal. Results demonstrate the usefulness and relevance of the proposed approach to assess the impact of changes in prices and in agricultural policy on land use patterns and on forestry
- Assessing wildfire occurrence probability in Pinus pinaster Ait. stands in PortugalPublication . Marques, S.; Garcia-Gonzalo, J.; Botequim, B.; Ricardo, A.; Borges, J.G.; Tomé, Margarida; Oliveira, M.M.Maritime pine (Pinus pinaster Ait.) is an important conifer from the western Mediterranean Basin extending over 22% of the forest area in Portugal. In the last three decades nearly 4% of Maritime pine area has been burned by wildfires. Yet no wildfire occurrence probability models are available and forest and fire management planning activities are thus carried out mostly independently of each other. This paper presents research to address this gap. Specifically, it presents a model to assess wildfire occurrence probability in regular and pure Maritime pine stands in Portugal. Emphasis was in developing a model based on easily available inventory data so that it might be useful to forest managers. For that purpose, data from the last two Portuguese National Forest Inventories (NFI) and data from wildfire perimeters in the years from 1998 to 2004 and from 2006 to 2007 were used. A binary logistic regression model was build using biometric data from the NFL Biometric data included indicators that might be changed by operations prescribed in forest planning. Results showed that the probability of wildfire occurrence in a stand increases in stand located at steeper slopes and with high shrubs load while it decreases with precipitation and with stand basal area. These results are instrumental for assessing the impact of forest management options on wildfire probability thus helping forest managers to reduce the risk of wildfires
- Computer-based tools for supporting forest management. The experience and the expertise world-widePublication . Borges, J.G.; Nordstrom, E.M.; Garcia-Gonzalo, J.; Hujala, T.; Trasobares, A.Computer-based tools for supporting forest management. The experience and the expertise world-wide answers a call from both the research and the professional communities for a synthesis of current knowledge about the use of computerized tools in forest management planning. According to the aims of the Forest Management Decision Support Systems (FORSYS) (http://fp0804.emu.ee/) this synthesis is a critical success factor to develop a comprehensive quality reference for forest management decision support systems. The emphasis of the book is on identifying and assessing the support provided by computerized tools to enhance forest management planning in real-world contexts. The book thus identifies the management planning problems that prevail world-wide to discuss the architecture and the components of the tools used to address them. Of importance is the report of architecture approaches, models and methods, knowledge management and participatory planning techniques used to address specific management planning problems. We think that this synthesis may provide effective support to research and outreach activities that focus on the development of forest management decision support systems. It may contribute further to support forest managers when defining the requirements for a tool that best meets their needs. The first chapter of the book provides an introduction to the use of decision support systems in the forest sector and lays out the FORSYS framework for reporting the experience and expertise acquired in each country. Emphasis is on the FORSYS ontology to facilitate the sharing of experiences needed to characterize and evaluate the use of computerized tools when addressing forest management planning problems. The twenty six country reports share a structure designed to underline a problem-centric focus. Specifically, they all start with the identification of the management planning problems that are prevalent in the country and they move on to the characterization and assessment of the computerized tools used to address them. The reports were led by researchers with background and expertise in areas that range from ecological modeling to forest modeling, management planning and information and communication technology development. They benefited from the input provided by forest practitioners and by organizations that are responsible for developing and implementing forest management plans. A conclusions chapter highlights the success of bringing together such a wide range of disciplines and perspectives. This book benefited from voluntary contributions by 94 authors and from the involvement of several forest stakeholders from twenty six countries in Europe, North and South America, Africa and Asia over a three-year period. We, the chair of FORSYS and the editorial committee of the publication, acknowledge and thank for the valuable contributions from all authors, editors, stakeholders and FORSYS actors involved in this project.
- A decision support system for a multi stakeholder's decision process in a portuguese National ForestPublication . Garcia-Gonzalo, J.; Palma, J.H.N.; Freire, J.P.A.; Tomé, Margarida; Mateus, R.; Rodriguez, L.C.E.; Bushenkov, V.; Borges, J.G.Aim of study: In this paper, we present a decision support system (DSS) to support decision making where different stakeholders have to generate landscape and forest level strategic plans. We further present an interactive approach that may take advantage of a posteriori preference modelling (i.e. Pareto frontier technique) to facilitate the specification of the levels of achievement of various objectives. Area of study: The approach was applied to one planning cycle of a real world study case, the Leiria National Forest in Portugal. The Leiria National Forest, a managed area of approximately eleven thousand hectares in which 8,679 hectares are even aged stands of maritime pine (Pinus pinaster Ait) aimed at the production of wood. Material and methods: The interactive approach, at first, tries to generate Pareto efficient frontiers for different objectives. Then, multiple decision makers are involved in the process to seek an agreement towards the definition of a consensual strategic plan. Main results: The system developed in this article integrates an information management subsystem, a module to generate alternative management regimes, growth model routines and a decision module that generates and solves mathematical formulations. It also provides a module to display reports and view the resulting solutions (management plans). We also build the Pareto frontier for different criteria. The results show that the proposed DSS can help solve strategic planning problems subject to sustainable management constraints where people organize themselves and participate jointly to manage their natural resources. Research highlights: The interactive approach facilitates the involvement of multiple stakeholders in the decision making process
- Improving management decisions in portuguese forests through fire behaviour modeling: guidelines to support a sustainable landscapePublication . Botequim, B.; Fernandes, P.M.; Borges, J.G.Understanding wildfire behavior at the landscape-level is critical to address wildfire impacts in Portuguese forest management planning. Thus, fire spread was simulated in three forested landscape to assist forest managers in identifying high-risk areas for actively integrating stand-level fuel treatments with explicit landscape-level management planning and develop fire prevention priorities. Specifically, several modeling applications to detect significant fire-landscape interactions between stand-level features and fire behavior were fitted to classify Portuguese forests to fire risk levels and create guidelines to support hazard-reduction silvicultural practice
- A new mixed-integer programming model for harvest scheduling subject to maximum area restrictionsPublication . Constantino, Miguel; Martins, Isabel; Borges, J.G.Forest ecosystem management often requires spatially explicit planning because the spatial arrangement of harvests has become a critical economic and environmental concern. Recent research on exact methods has addressed both the design and the solution of forest management problems with constraints on the clearcut size, but where simultaneously harvesting two adjacent stands in the same period does not necessarily exceed the maximum opening size. Two main integer programming approaches have been proposed for this area restriction model. However, both encompass an exponential number of variables or constraints. In this work, we present a new integer programming model with a polynomial number of variables and constraints. Branch and bound is used to solve it. The model was tested with both real and hypothetical forests ranging from 45 to 1,363 polygons. Results show that the proposed model’s solutions were within or slightly above 1% of the optimal solution and were obtained in a short computation time.
- Sistemas e tecnologias de informação em gestão do ecossistema montado/dehesaPublication . Borges, J.G.; Loff, J.F.
- A three-step approach to post-fire mortality modelling in maritime pine (Pinus pinaster Ait.) stands for enhanced forest planning in PortugalPublication . Garcia-Gonzalo, J.; Marques, S.; Borges, J.G.; Botequim, B.; Oliveira, M.M.; Tomé, J.; Tomé, MargaridaMaritime pine (Pinus pinaster Ait) is a very important timber-producing species in Portugal with a yield of ~67.1 million m3 year21. It covers ~22.6 per cent of the forest area (710.6 × 103 ha). Fire is the most significant threat to maritime pine plantations. This paper discusses research aiming at the development of post-fire mortality models for P. pinaster Ait stands in Portugal that can be used for enhanced integration of forest and fire management planning activities. Post-fire mortality was modelled using biometric and fire data from 2005/2006 National Forest Inventory plots and other sample plots within 2006–2008 fire perimeters. A three-step modelling strategy based on logistic regression methods was used. Firstly, the probability of mortality to occur after a wildfire in a stand is predicted and secondly, the degree of mortality caused by a wildfire on stands where mortality occurs is quantified. Thirdly, mortality is distributed among trees. The models are based on easily measurable tree characteristics so that forest managers may predict post-fire mortality based on forest structure. The models show that relative mortality decreases when average d.b.h. increases, while slope and tree size diversity increase the mortality