Using Lego© Blocks to Demonstrate Concepts of SDI and Relative Density

Abstract

The concepts of density and stocking are critical to understanding silvicultural techniques. A variety of measures and approaches are used, including Reineke’s Stand Density Index (SDI) and Relative Density (RD). In order to teach these concepts and their applications, the dynamics and interaction of trees within stands were modeled using Lego© blocks. Small boards were filled with Lego© blocks representing various tree sizes to show how RD is used to determine critical stocking levels. Students used a randomly drawn configuration of blocks to investigate stocking reduction options and resultant SDI distributions among size classes. A web-based, interactive program was used to “thin” sample stands. The Landscape Management System was used to predict the long term results of students’ proposed thinnings and harvests. This approach effectively furthers students’ understanding of SDI, RD and their applications.