F 321 – Lab Exercise #2

Variable Plot Sampling Refresher

1. Limiting Distance (Individual)
Along the south side of the lagoon stand, you will find two stations marked with pin flags. Select one of the stations and collect the necessary information to calculate limiting distance and determine if the trees would be “in” or “out” of your plot with a 20 BAF device. Start from north and proceed clockwise.

2. Angle Gauge (Groups of 3)
For each of the marked sample points to the west of the water canal on the west side of the lagoon stand, determine how many “in” trees you should have with a 10, 20, and 40 BAF angle gauge.

What is your average basal area per acre for each of the different BAFs?

What do you notice about the relationship between the number of “in” trees and the BAF?

2. Variable Plot Sampling (Group)
Four variable radius sampling points have been located within the lagoon stand with a ________ BAF. Using the provided instruments at each sampling point, determine how many “in” trees should be counted. For your “in” trees, measurements should be taken starting from north and rotating clockwise, record DBH for all trees and height for the first 3 trees at each sample point. From your plots, calculate the quadratic mean diameter and average height, then calculate the basal area per acre and trees per acre using your BAF.