INTRODUCTION 



Farmers' woodlots play an important role in the timber production of the Inland 

 Empire (northeastern Washington, northern Idaho, and western Montana). Small, privately 

 owned timberlands total nearly 2 million acres in this territory, but their importance 

 is even greater than the acreage indicates. They generally occupy productive sites 

 located at lower elevations on gentle terrain and are easily accessible. Logging 

 operations have been concentrated on these accessible pine lands since the first settle- 

 ments were established by white men in the Inland Empire.^ 



Considerable logging of second-growth ponderosa pine ( Pinus ponderosa Laws.) 

 occurred in the years during and immediately following World War 11. Many stands were 

 partially cut shortly after trees reached merchantable size. Most of the cuttings were 

 heavy, removing the largest trees and drastically reducing the growing stock at a time 

 when the stands had just begun a period of rapid growth of sawtimber. Many foresters 

 believed it would be beneficial to delay cutting to take advantage of the rapid saw- 

 timber growth, but in many cases the landowners wanted an immediate income from their 

 young stands and were not willing to wait. Another alternative would have been a 

 moderate commercial thinning to stimulate the growth of the better trees in the stand 

 while retaining sufficient stocking to capture most of the growth potential of the site. 



A series of experiments (designed and established by Donald W. Lynch, USDA Forest 

 Service, Pacific Southwest Forest and Range Experiment Station) was started in 1950 to 

 provide comparisons of growth responses and volume production following the usual 

 "heavy cutting" versus a moderate "commercial thinning." These experiments also 

 demonstrate to landowners the returns in terms of immediately harvestable volume and 

 subsequent growth and production of residual stands following each type of cutting. A 

 third treatment, "no cutting," was also included in the study to show growth and 

 production as a result of holding the timber for future harvest. 



STAND DESCRIPTION 



In the Inland Empire ponderosa pine grows on the lower slopes of the mountains and 

 on valley floors at altitudes of 1,500 to 3,500 feet. Precipitation ranges from 15 to 

 30 inches per year. The pine grows on coarse and well drained soils such as sandy 

 alluvium, gravelly or sandy till, and loams with high stone content. 



Ponderosa pine grows in pure stands on the relatively warm, dry sites where 

 timberline borders on the prairie. The more moist sites occur farther up the mountain 

 slopes. On these cooler, more moist sites ponderosa pine is commonly associated with 

 one or more tree species, including Douglas-fir (Pseudotsuga menziesii var. glauca 

 (Beissn.) Franco), lodgepole pine (Pinus contorta Dougl.), western larch ( Larix 

 occidentalis Nutt . ) , and grand fir (Abies grandis (Dougl.) Lindl.). Stocking is 

 irregular with dense clumps, sparse stands, and openings occurring in uneven patterns, 

 especially on the poorer sites. 



METHODS 



Study areas were located in five widely scattered ponderosa pine stands of north- 

 eastern Washington and northern Idaho. Three plots, variable in size but ranging from 

 2 to 6 acres, were laid out at each study area and one of the following treatments was 

 randomly assigned to each plot: 



Behre, C. Edward. Preliminary yield tables for second growth western yellow pine 

 in the Inland Empire. The University of Idaho Bull. 23 (20), 19 pp. 1928. 



