Designing decision support tools for Mediterranean forest ecosystems management: a case study in Portugal

Original ArticleThe effectiveness of Mediterranean forest ecosystem management calls for the conceptualization and implementation of adequate decision support tools. The proposed decision support system encompasses a management information system, a prescription simulator, a constraint generator and a set of management models designed to solve decision problems. Emphasis is on the architecture of the prescription simulator and its linkage to the three other modules, as well as on methods for reporting and visualizing solutions. Results are discussed for a real world test case – Serra de Grândola, a management area with about 18 600 ha comprising 860 cork oak (Quercus suber L.) land units. Cork oak silviculture adds complexity to the traditional forest management problem. Results show that the devised system is able to address effectively the integration of ecosystem data, silviculture, growth-and-yield and management models. They further suggest that the proposed system architecture may help address the complexity of Mediterranean ecosystem management problemsinfo:eu-repo/semantics/publishedVersio

Appraisal framework for actor interest and power analysis in forest management - insights from northern Portugal

Forest management is currently challenged by the need to address an increasing demand for a wide range of ecosystem services. Addressing this challenge requires landscape-level supply approaches that may bring together multiple interests and goals of forest actors. Characterizing these interests and the corresponding forest management context is thus a prerequisite for an effective landscape-level approach. In this manuscript we develop actor analysis to characterize a forest management context. We implement and test the analysis in Vale do Sousa, in North-Western Portugal. The analysis encompassed the identification of key actors and 40 interviews. Results show that the analysis provides a thorough diagnosis of the current forest management context in Vale do Sousa. The findings give a snapshot of the actors and factors – interests, influential actors, conflicts, problems and power resources – that frame forest decisions. Specifically, results show the keen interest of all groups on wood provisioning and on regulating wildfires. However, actors have also revealed a strong interest in water quality, soil erosion prevention, biodiversity, landscape aesthetics and environmental education. Thus, there is a significant interest in the diversification of the provision of ecosystem services. Almost half of the actors have identified the multifunctional forest as being the ideal forest management framework for Vale do Sousa. Findings thus evince the potential of a participatory approach to negotiate a consensual landscape-level solution that may integrate the different actors' interests and provide a wide range of ecosystem services. This may be facilitated by another finding from actor analysis. A regional Forest Owners Association was recognized as the most influential actor and may support the development and negotiation of multiple objective landscapelevel forest ecosystem management plans. In summary, these results may contribute to a better understanding of the forest management context in Vale do Sousa and to supporting the effectiveness of forest management planning. They may contribute further to anticipate problems and conflicts and to develop with actors from Vale do Sousa participatory processes to address theminfo:eu-repo/semantics/publishedVersio

Usefulness and perceived usefulness of decision support systems (DSSs) in participatory forest planning: the final user's point of view

In recent decades, the focus of forestry Decision Support Systems (DSSs) has expanded to consider the social dimension of forestry and to support participatory decision-making. A large number of models and tools have become available to solve forest management planning problems. The Usefulness of a DSS depends on the range of tools that it incorporates, and many researches have been developed to evaluate DSSs using Usefulness as parameter. The assessment of Usefulness concerns the effectiveness of a DSS. Furthermore, most assessments take into account the degree of Perceived Usefulness, which is considered an indicator of the impact a system has on job performance. The present study focuses on the analysis of final users’ point of view on the Usefulness and Perceived Usefulness of DSSs in participatory forest planning. The research investigates how forest users’ characteristics and context influence their views on the potentialities of DSSs to enhance both the various phases of the participatory planning process (Usefulness) and job performance (Perceived Usefulness). The study is based on quantitative data collected through two questionnaires e-mailed to a sample of 150 DSSs end users. The questionnaires focused on Usefulness and on Perceived Usefulness topics, respectively. Results indicate that special attention must be given to motivating respondents with a clear explanation of the survey objectives when e-mailing questionnaires. Moreover, results show that, in general, respondents consider DSSs useful at each step of the participatory process, despite differences emerge among steps. The research also shows that respondents’ Perceived Usefulness of DSSs was higher before actually engaging with DSSs. Furthermore, the results highlight differences in Perceived Usefulness to improve job performance, suggesting that the use of DSSs may actually improve job performance more than expected. Specifically, results indicate that improving the technical descriptions of methodologies incorporated in a DSS may contribute to increasing the Perceived Usefulness. The information provided within this research contributes to the advancement of knowledge regarding the Usefulness of DSSs as perceived by forest stakeholders, which in turn supports the improvement of DSS architectures and the development of participatory processes in forest management planninginfo:eu-repo/semantics/publishedVersio

Analysis of the performance of different implementations of a heuristic method to optimize forest harvest scheduling

Research ArticleFinding an optimal solution of forest management scheduling problems with even flow constraints while addressing spatial concerns is not an easy task. Solving these combinatorial problems exactly with mixed-integer programming (MIP) methods may be infeasible or else involve excessive computational costs. This has prompted the use of heuristics. In this paper we analyze the performance of different implementations of the Simulated Annealing (SA) heuristic algorithm for solving three typical harvest scheduling problems. Typically SA consists of searching a better solution by changing one decision choice in each iteration. In forest planning this means that one treatment schedule in a single stand is changed in each iteration (i.e. one-opt move). We present a comparison of the performance of the typical implementation of SA with the implementation where up to three decision choices are changed simultaneously in each iteration (i.e. treatment schedules are changed in more than one stand). This may allow avoiding local optimal. In addition, the impact of SA – parameters (i.e. cooling schedule and initial temperature) are tested. We compare our heuristic results with a MIP formulation. The study case is tested in a real forest with 1000 stands and a total of 213116 decision choices. The study shows that when the combinatorial problem is very large, changing simultaneously the treatment schedule in more than one stand does not improve the performance of SA. Contrarily, if we reduce the size of the problem (i.e. reduce considerably the number of alternatives per stand) the two-opt moves approach performs betterinfo:eu-repo/semantics/publishedVersio

An Ecological-Economic Approach to Assess Impacts of the Expansion of Eucalyptus Plantations in Agroforest Landscapes of Northern Ethiopia

The conversion of fertile croplands to Eucalyptus woodlots in Ethiopian highlands, due to its business attractiveness to smallholders, raises concerns related to food production, water resources, carbon and other ecosystem services. This study was therefore designed to examine land allocation and plantation management decisions. Our emphasis was on the analysis of tradeoffs between the economic gains obtained from harvesting Eucalyptus timber and food production, carbon and water use. For that purpose, we considered a 1987 ha agroforest landscape in the Amhara region, Northern Ethiopia. With a planning horizon covering nine one-year periods, we developed and used nine Model I single objective linear programming (LP) models, and analyzed tradeoffs between objectives (e.g., land expectation value (LEV), Carbon, volume of ending inventory (VolEI), crop production and water use) using an LP-based Pareto frontier approach. The study revealed that the objective of maximizing the total economic gain from the sale of Eucalyptus wood poles favored a complete conversion of the available cropland into Eucalyptus woodlots. To meet the minimum annual crop production/consumption/requirements of households in the study area, the land under Eucalyptus should be limited to 1772 ha, with a sequestration potential of 1.5 to 1.57 × 107 kg yr−1 of carbon in the aboveground biomass. However, this land cover limit should be decreased to 921 ha so as to limit the total annual water use (for biomass production) below the amount available from rainfall (11,000 m3 ha−1 yr−1). Moreover, the study highlighted that maximizing the harvested wood volume or LEV would come at the cost of a decreased aboveground carbon stock and volume of ending inventory and higher total water use. It also provided alternative optimal Pareto-front points, among which decision makers will be able to select their preferred targets. The current study also showed the potential for the application of Pareto frontier approaches to support the development of effective ecological/economic management strategies and the design of land use policies in an Ethiopian context

An average linear time algorithm for web data mining

In this paper, we study the complexity of a data mining algorithm for extracting patterns from user web navigation data that was proposed in previous work.3 The user web navigation sessions are inferred from log data and modeled as a Markov chain. The chain's higher probability trails correspond to the preferred trails on the web site. The algorithm implements a depth-first search that scans the Markov chain for the high probability trails. We show that the average behaviour of the algorithm is linear time in the number of web pages accessed

Ground-motion simulation in the Lower Tagus Valley Basin

Throughout history, the Lower Tagus Valley (LTV) region has been shaken by several earthquakes, including some with moderate to large magnitudes and with sources located inside the basin, for example the 1344 (M6.0) and 1909 (M6.0) earthquakes. Previous simulations (Bezzeghoud et al. Natural Hazard 69: 1229–1245, 2011) have revealed strong amplification of the amplitude waves in the region, because of the effect of the low-velocity sediments that fill the basin. The model used in those simulations was updated in this work by including new high-resolution geophysical and geotechnical data available for the area (seismic reflection, aeromagnetic, gravimetric, deep wells, standard penetration tests, and geological data). To contribute to improved assessment of seismic hazard in the LTV, we simulated propagation of seismic waves produced by moderate earthquakes in a 3D heterogeneous medium by using elastic finite-difference wave propagation code. The method, successfully used by Grandin et al. (Geophys J Int 171: 1144–1161, 2007), involves evaluation of the seismic potential of known faults in the area studied and three-dimensional seismic ground motion modelling by use of finite difference methods. On the basis of this methodology, we calculated the ground motion for the April 23, 1909, Benavente (Portugal) earthquake (Mw = 6.0) in dense grid points, then computed the synthetic isoseismic map of the area by use of appropriate relationships between seismic intensity (MMI) and peak ground velocity (PGV). The synthetic results, in contrast with available macroseismic and instrumental data, enable validation of the source models proposed for the area, identification of the sources of historical earthquakes, and could also indicate which areas are more exposed to seismic ground motion

A stochastic dynamic programming approach to optimize short-rotation coppice systems management scheduling: An application to eucalypt plantations under wildfire risk in Portugal

This article presents and discusses research with the aim of developing a stand-level management scheduling model for short-rotation coppice systems that may take into account the risk of wildfire. The use of the coppice regeneration method requires the definition of both the optimal harvest age in each cycle and the optimal number of coppice cycles within a full rotation. The scheduling of other forest operations such as stool thinning and fuel treatments (e.g., shrub removals) must be further addressed. In this article, a stochastic dynamic programming approach is developed to determine the policy (e.g., fuel treatment, stool thinning, coppice cycles, and rotation length) that maximizes expected net revenues. Stochastic dynamic programming stages are defined by the number of harvests, and state variables correspond to the number of years since the stand was planted. Wildfire occurrence and damage probabilities are introduced in the model to analyze the impact of the wildfire risk on the optimal stand management schedule policy. For that purpose, alternative wildfire occurrence and postfire mortality scenarios were considered at each stage. A typical Eucalyptus globulus Labill. stand in Central Portugal was used as a test case. Results suggest that the proposed approach may help integrate wildfire risk in short-rotation coppice systems management scheduling. They confirm that the maximum expected discounted revenue decreases with and is very sensitive to the discount rate and further suggest that the number of cycles within a full rotation is not sensitive to wildfire risk. Nevertheless, the expected rotation length decreases when wildfire risk is consideredinfo:eu-repo/semantics/publishedVersio

Addressing wildfire risk in a landscape-level scheduling model: an application in Portugal

Fundamental Research - Forest ManagementThe paper presents and discusses research aiming at the development of a forested landscape management scheduling model that may address the risk of wildfires. A general indicator is built from wildfire occurrence and damage probabilities to assess stand-level resistance to wildfires. This indicator is developed to further address the specificity of each stand configuration (e.g., shape and size) and spatial context (neighboring stands characteristics). The usefulness of the development of such an indicator is tested within a mixed integer programming (MIP) approach to find the location and timing of management options (e.g., fuel treatment, thinning, clearcut) that may maximize the forested landscape expected net revenues. The Leiria National Forest, a Portuguese forest in central Portugal, was used as a case study. Results suggest that the proposed approach may help integrate wildfire risk in forested landscape management planning and assess its impact on the optimal plan. Results further show that prescriptions that include fuel treatments are often chosen over others that do not include them, thus highlighting the importance of wildfire management efforts. Finally, they provide interesting insights about the role of thinnings and fuel treatment in mitigating wildfire riskinfo:eu-repo/semantics/publishedVersio

Modelação qualitativa da sustentabilidade florestal

Congresso Florestal Nacional: A floresta e as gentes - Actas das ComunicaçõesO desenvolvimento e a implementação de sistemas de avaliação e monitorização da sustentabilidade da gestão florestal são de grande importância, não apenas para a garantia do uso sustentável dos recursos florestais, mas também pela sua contribuição para a operacionalização da certificação florestal e para a articulação entre objectivos estratégicos e operacionais do planeamento florestal. Todavia, apesar da existência de um conjunto de critérios e indicadores de sustentabilidade adaptados à especificidade dos espaços florestais europeus, ainda muitas limitações se levantam à possibilidade de se implementar este tipo de sistemas a nível nacional (e.g. falta de informação, incerteza, e inexistência ou falta de experiência de utilização de instrumentos de análise adequados). Com base em estudos publicados, é feita uma revisão crítica das abordagens metodológicas de tipo qualitativo que têm vindo a ser utilizadas na avaliação da sustentabilidade da gestão florestal. Algumas das metodologias apresentadas têm como objectivos compreender a relação entre os indicadores, avaliá-los e ponderá-los em termos da contribuição para a sustentabilidade. Esta revisão crítica será o ponto de partida para uma discussão sobre a possibilidade de se utilizar a informação disponível a nível nacional em linhas futuras de I&D, na área de aplicação de modelação qualitativa na avaliação da sustentabilidade da gestão florestal