Forestry – Lidar: Quadratic Mean Diameter (in)

This data is a Lidar-derived estimate of the quadratic mean diameter (QMD) at breast height (in inches) of the average tree in a stand. It was developed by the Minnesota Department of Natural Resources using Lidar data that was collected as part of the Minnesota 3DEP USGS Lidar program, along with Plot Based Inventory (PBI) data. The QMD is derived based on basal area per acre and stems per acre values (QMD = sqrt (basal area/number of stems*0.005454)). The QMDs were calculated for each of the 120 sample plots, and the Lidar-derived metrics for the plots were used as predictors to build a relationship (linear regression model) that was finally extended over the entire area of interest using selected Lidar predictors at 20 meter spatial resolution. This information can provide foresters a better understanding of the landscape and how it should be managed.