i8 9 9- 



AMERICAN FORESTRY ASSOCIATION. 



55 



begins much later. Observers testify that varying greatly in size and age. Under 

 it bears fruit every year, but that in some such conditions two and sometimes three 

 years the production of seed is more generations of trees are necessary to seed 



abundant than in others and that fre 

 quently the cones are barren. It is cer- 

 tain, however, that seed is produced 

 abundantly and at short intervals, and 

 that the tree continues to bear late in 

 life. Very old trees, such as the veterans 



the ground densely enough to establish 

 . a forest equal to the original growth. 



GROWTH. 



In order to determine the rate of 

 growth, the following method was em- 



on the slopes of the Coast Range, repro- ployed: Sample plots were measured off 

 duce themselves sparsely. Trees bear in second growth which had come up in 

 more plentifully on rich than on meagre regular even-aged stands. All trees on 

 soil; in open places than in dense stands; these plots were counted and their diam- 

 and at low than at high elevations. eters measured at breast height. The 

 In the dense forest young seedlings average diameter was then determined, 

 are practically wanting, but where the and a sample tree of this diameter and 

 stand is broken groups of small trees are apparently of average height, was felled, 

 abundant. A certain amount of light is, and measurements were taken to deter- 

 therefore, necessary for the germination mine its contents and rate of growth, 

 of the seed. The second essential con- This average tree was used as a basis 



dition of germination is a good seed-bed. 

 Young seedlings are found in largest 

 numbers on ground which has been 

 broken so that the mineral soil is ex- 

 posed. A matting of leaves or a firm 



for the computation of the total contents 

 of all the trees on the sample plots and 

 of the average growth in height and 

 diameter. 



The writer was fortunate in finding a 



sod, on the other hand, seems unfavor- number of even-aged groups of nearly 



able to the reproduction of the tree. 

 When the upper layer of humus has 

 been burned off the reproduction is ex- 

 cellent. This is the reason that fires are 



pure second-growth Douglas in the San- 

 tiam and Willamette Valleys on what 

 had been grass prairies before the coun- 

 try was settled. The repeated fires, 



often followed by a magnificent growth of probably set by the Indians, had pre- 



young Douglas Spruce. Near seed trees vented new growth from coming up; 



the second growth is usually very dense, but when the fires were checked by the 



but where a tract has been stripped by whites, the few scattered Douglas which 



fire, and seed has to be borne from a con- had survived from a former forest seeded 



siderable distance, the result is an irreg- the ground rapidly to young timber, 



ular, rather ragged, growth of trees, There were measured, in all, nine sam- 



TABLE No. 1 Summary of Measurements of Nine Sample Trees. 



