## Materials and Methods
### Approach and Model Development  
Heuristics, \"a strategy that ignores part of the information with the goal of making decisions more quickly, frugally, and/or accurately than more complex methods\" [33], provides solutions to complex problems that cannot be solved in any other way, for example by structuring these problems into simple divisions of parts with a defined goal [34]. In this study, the problem consisted of assessing spatial and temporal interactions of actors (forest industries) with resources (forest biomass) in a defined area (Nordeste, Portugal). We assumed this complex system to be made up of three components:  
1. [label=()]
2. Supply, or how much and where the resource (forest biomass) is available in the region;
3. Demand, or what characteristics of the resource are of interest to the users (forest industry);
4. The interactions between supply and demand in the study area.  
To address this problem, we used AppTitude(r), a FMDSS tool developed with the aim of supporting forest mobilization in the Nordeste region, that applies the rationale and the methodological framework followed in this study [35] (Figure 2).  
Figure 1: Location of the study area, the Nordeste region (in red), in Portugal (in white).  
AppTitude(r) combines a set of methods in a complex decision support system applied in a 5-step protocol to define scenarios, inputs, and restrictions and to reach goals, targets and objectives in order to find a satisfactory solution for a given problem (Figure 3). It was used in this study to address the effects of forest industries on forest resources and the interactions among competing industries and to select the best industry scenarios for the region. The procedures for ranking and selecting solutions are based on a series of objectives (Table 1). These particular objectives are of two types: necessary and priority. Necessary objectives are mandatory and take into consideration the sustainability of activities and resilience of the region to absorb management operations of all industries in the region (Objective 1), from the point of view of supply, or resource availability and the of operations of each industry throughout the simulation period (Objective 2), from the point of view of demand. The priority objectives are not mandatory but are used to rank the results of the model to select the best scenarios. We considered in this study as priority objectives, from the point of view of demand, to maximize volume harvest (Objective 3) and to maximize valorisation of maritime pine in the region (Objective 4) and, from the point of view of the supply-demand iteration, to maximize the managed area (Objective 5), the lowest competition among industries (Objective 6) and to decrease forest fires (Objective 7). These objectives were monitored and verified through a series of indicators (Id) that will be described in the following sections.  
Figure 2: Flow diagram of the simulation procedure applied in for supply, demand, and supply–demand interactions assessment. AppTitude® implements quantity, value and price models to define scenario conditions required for the linear programming matrix that is iterated and solved annually for a 20-y period applying forest growth models in the area of study.