Forest Investment Account (FIA) - Forest Science Program
FIA Project Y072088

    Designing Simulated Experiments With TASS [Tree and Stand Simulator]
Project lead: Goudie, James
Contributing Authors: Goudie, James W.; Mitchell, Kenneth J.; Polsson, Ken R.
Imprint: [BC] :, 2007
Subject: Forest Investment Account (FIA), TASS (Computer Software), British Columbia
Series: Forest Investment Account (FIA) - Forest Science Program
Program/theme/topic This project strongly supports the research recommendations of the Timber Growth and Value Program. Topic 3.1, a funding priority for 2005/2006. It calls for the development of 'models of complex stands, including those with multiple species and stands with structural diversity'. Overview The Tree and Stand Simulator (TASS II) is a biologically-oriented model that simulates the growth of crowns and stems of individual trees in a 3-D growing space. Since the early 1980s, TASS-generated yield tables have provided most of the growth and yield projections used in BC for Timber Supply Analysis and the evaluation of silviculture predictions. TIPSY was developed in the early 1990s to manage and rapidly manipulate a large database of TASS tables to meet the needs of yield analysts and silviculturists. However, the potential of TASS II and TIPSY to address complex stands is limited to certain applications (e.g., variable retention (VR) in even-aged stands; Di Lucca et al. 2004). This proposed project will result in the integration and calibration of new and revised modules (already developed) into a new version (TASS III) designed specifically for the complex structures found in uneven-aged and mixed species stands. The modules to be integrated include: 1. A revised computer architecture for TASS canopies that accommodates multi-layered structures. The new architecture removes the limitation of a single canopy layer and permits simulation of multiple canopy layers. 2. A raster-based light model, tRAYci. tRAYci (Brunner 1998, Gersonde et al. 2004) is already integrated as a reporting tool capable of characterizing the light environment at any point in the stand. Light maps from TASS II/tRAYci have been used to facilitate the design of field installations and predictions of wildlife habitat (Goudie et al. in press). A stand visualization module, VISTAS 3. VISTAS displays 3-D images of simulated stands as they grow and allow users to implement complex silvicultural treatments and harvesting systems. The project also proposes to develop a graphical user interface based on the familiar TIPSY front end. Clients will use this interface to describe the stand and treatment conditions to TASS, specify the outputs desired, and control the overall execution. In effect, TIPSY will retrieve information directly from TASS instead of a database of TASS yield tables. All component models have been developed; this project will integrate them into an advanced version of TASS.
Related projects:  FSP_Y061088FSP_Y083088


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