and you selected a Basal Area Factor (BAF) of 4. If your first tree had a diameter at breast height (DBH) of 14cm, then the standard way of calculating how much of 1ha was covered by tree area (scaling up from that tree to the hectare) would be: (BAF/((DBH+0.5)² × π/4))) × 10,000 BAF, in this case 4, is the BAF selected for the sampling technique. DBH, in this case 14 (this uses an assumed diameter, when actually used is the radius perpendicular to the tangent line) The + 0.5 allows under and over measurement to be accounted for. The π/4 converts the rest to the area. In this case this means in every Ha there is 242m² of tree area according to this sampled tree being taken as representative of all the unmeasured trees. Fixed area plot It would also be possible to survey the trees in a Fixed Area Plot (FAP). Also called a Fixed Radius Plot. In the case that this plot was 100m². Then the formula would be (DBH+0.5)²X π/4 References R. Hédl, M. Svátek, M. Dancak, Rodzay A.W., M. Salleh A.B., Kamariah A.S. A new technique for inventory of permanent plots in tropical forests: a case study from lowland dipterocarp forest in Kuala Belalong, Brunei Darussalam, In Blumea 54, 2009, p 124–130. Published 30. 10. 2009. Forest modelling Measurement Forest ecology