1. Overview
1.1. Introduction
The Wood Supply Simulation System (ws3) is an open-source Python software
package that is designed to model wood supply planning problems (WSPP) (i.e., a
forest estate model), in the context of forest resource analysis in support of
sustainable forest management planning.
A WSPP consists of determining the location, nature, and timing of forest management activities (i.e., actions) for a given forest, typically over multiple planning periods or rotations. The planning horizon often spans over 100 years or more. WSPP are intently complicated problems. In practice WSPP are supported by complex software models that that simulate different sequences of actions and growth for each time step, starting from and initial forest inventory. These software models are typically classified as wood supply models.
All wood supply models (WSM) require complex input data sets, which can be divided into static and dynamic components. Static WSM input data types include initial forest inventory, growth and yield curves, action definitions, transition definitions, and a schedule of prescribed activities. Dynamic WSM input data may include a combination of heuristic and optimization-based processes to automatically derive a dynamic activity schedule. The dynamic inputs get layered on top of the static activity schedule.
Given a set of static inputs, a given WSM can be used to simulate a number of scenarios. Generally, scenarios differ only in terms of the dynamic activity schedule that is simulated. Comparing output from several scenarios is the basic mechanism by which forest managers derive insight from wood supply models.
ws3 is backed by a well documented application programming interface (API), which
can be customized to control the way ws3 behaves.
1.2. About this User Guide
This guide is divided into four main sections. The first section describes general
concepts about WSM with specific linkages to the ws3 requirements. This section
covers ideas and requirements that are consistent across most WSM and is designed to
ensure proper language use and highlight commonalities. Users who are familiar with
WSM will likely find this section a review but, it will help ensure clarity for
successive sections in this guide.
The second section provides specific and detailed information about ws3 and provides
guidance on data preparation and running a wood supply simulation.
The third section provides information for connecting ws3 to libCMB, allowing for
carbon accounting to be included as a dynamic value within the WSM.
The fourth section provides information on connecting ws3 to SpaDES. SpaDES is a SPAtially explicit Discrete Event Simulation used for disturbance modelling.
1.3. About FRESH
The Forest Resources Environmental Services Hub (FRESH) is a research group at the University of British Columbia (UBC), Canada, that focuses on sustainable forest management including wood supply analysis, optimization research and supply chain analysis.
One of the primary focuses of the research group is to develop open sourced information and
software packages that increase the accessibility of higher level forest modelling including
tools used in WSPP and WSM. The ws3 package, this user guide and the API all aim to help
meet this goal.
1.4. Contact information
If you have any questions about this guide or want to ask questions about ws3, WSM or WSPP
please reach out to Gregory Paradis (see contact information below).