Addressing forest ecosystem management planning concerns with linear programming. An application in Portugal. 

Olha Nahorna 2020. Addressing forest ecosystem management planning concerns with linear programming. An application in Portugal. Master Thesis.  The University of Lisbon -  School of Agriculture. 

Supervisors:

Professor José Guilherme Martins Dias Calvão Borges

Abstract
Forest management is an extremely complex process that requires the combination of various techniques, practices and methods in order to achieve given environmental, economic and social objectives. Linear programming (LP) is one of the most widely used optimization methods that assists forest managers in the process of the decision-making. The use of alternative formulations of the LP model may help acquire insights about the forest ecosystem management planning problem, may thus lead to better plans.
This work presents the study of influence of different LP model formulation on the design of the management plan and on economic values, timber flow, tree species distribution, total carbon stock, cork extracted, biodiversity and cultural services. A total of 16 model formulations (scenarios) were considered for the analysis. Scenarios were obtained by changing the objective function and by adding of management related constraints. The set of objective functions included the minimization of costs, the maximization of the net present value (NPV) over the planning horizon, the ending inventory value (EIV), and the total present value (PVFI = NPV + EIV). The set of constraints included 10% timber even-flow constraints and timber targets per period and per tree species. The study area was Vale do Sousa, Portugal.
The results of the study demonstrated that the LP model formulation has a substantial influence on the proposal of management plan. It allowed to check the trade-offs between economic criteria and changes in timber flows, tree species distribution, extracted cork and carbon stock. Biodiversity and cultural services remained at the same level across scenarios. Results suggest the importance of using alternative formulations to acquire information about the management plan and to explore responses to alternative scenarios and to make better decisions.