Estimation of Crown Cover in Interior Ponderosa Pine Stands: Effects of Thinning and Prescribed Fire

We evaluated the relationship between crown cover measured with a vertical sight tube and stand basal area per acre in treated (thinned, burned, and thinned and burned) and untreated interior ponderosa pine (Pinus ponderosa P. & C. Lawson) stands in northeastern California. Crown cover was significantly related to basal area at the plot level and stand level. In addition, the relationship was not affected by two extremely different thinning regimes. However, the predicted crown cover was generally lower, for a given level of basal area, in a recently thinned stand than in a stand that had not been recently thinned. Prescribed fire had no detectable effect on the relationship. The maximum measured value of stand level crown cover in untreated stands in this study was about 60 percent. West. J. Appl. For. 20(4): 240–246.