Workshop participants in Oaxaca use their thumbs as an angle gauge (BA Factor 2) to count the number of competing trees sharing the ecological neighborhood of the sample tree being cored or measured for growth, i.e. the pine tree behind them. [NOTE: Thumbs work great for this. Inexpensive and you never lose them. A simple formula calculates the basal area factor of your thumb based on it's width. With your thumb and a Biltmore stick (see Biltmore Stick) you can do some very sophisticted data collection].