890 JOURNAI, OF FORESTRY 



These figures indicate that the bishop pine in the Humboldt County 

 extension of its range is a tree of good proportions and rapid growth, 

 which because of the strength and hardness of its timber, may well 

 be considered for propagation as a secondary species in redwood stands. 



GROWTH OF BISHOP PINF NEAR INVERNESS, MARIN COUNTY 



As an indication of the more usual growth of the bishop pine, the 

 following figures taken by students in silviculture during November, 

 1920, may be of interest. A temporary sample plot was laid out in a 

 typical pure stand of this tree on a northeast exposure near Inverness, 

 California. The pine here occupies patches of the slopes of the Point 

 Reyes peninsula on the side toward Tomales Bay and protected from 

 the ocean winds which prevent the growth of any trees on the slopes 

 facing the ocean. The pine of this region is usually found in pure 

 stands on the ridge top or, following severe fires, on the lower slopes. 

 Its gregarious habit is here well illustrated as it mixes very little with 

 other trees found on the peninsula. These include California laurel 

 (Umbellularia calif ornica), coast live oak {Quercus agrifolia), occa- 

 sional trees of Douglas fir {Pseudotsuga taxifolia), and minor hard- 

 wood species. All of the trees when young have excessive competition 

 from a number of shrubby chaparral species which form dense, almost 

 impenetrable thickets. On the plot under consideration there were 

 under the pines a large number of wild huckleberry bushes. 



Area of sample plot J4 acre 



Average age of trees 30 years 



Range of diameters 3.7 inches-15.8 inches 



Average diameter 8.4 inches 



Range of heights 34 feet— 66 feet 



Average height 50 feet 



Form factor used 0.45 based on measurement of one tree. 



Number of trees per acre 440 



Volume per acre ., .4,300 cubic feet 



Mean annual growth per acre 143 cubic feet 



This growth compares very favorably with that of a pure stand of 

 western yellow pine near Meadow Valley on the Plumas National 

 Forest measured in June, 1920, which at 56 years of age showed a 

 mean annual growth of 117.9 ctfbic feet per year, and is much greater 

 than the growth for western yellow pine in even aged stands at 30 

 years (W. K. Gallaher, Forestry Quarterly, Vol. XI, 1913, page 533), 

 which is given as 2,800 cubic feet per acre; a mean annual growth of 



