The young ponderosa pine stands were established naturally 

 following logging between 1885 and 1915. The trees are about 

 80 years old and the average d.b.h. ranges between 8 and 

 10 inches (20.3 and 25.4 cm). Most of these second-growth 

 stands are overstocked, with basal areas in excess of 150 ft^ 

 (13.94 m-) per acre. 



An outbreak of the mountain pine beetle (Dendroctonus 

 ponderosae Hopk.) started in the area about 1972. Since that 

 time the insect has attacked and killed a large number of trees 

 of various diameters. The infested area, covering about 2,000 

 acres (809.4 ha), contains numerous patches of dead trees rang- 

 ing from 1 to 10 acres (0.4 to 4.05 ha) in size. 



Cutting in these stands has had several objectives: (1) to 

 remove and utilize the dead trees; (2) to remove green trees 

 considered to be attacked by the insects, thereby controlling, to 

 a certain extent, the insect population; and (3) to reduce the 

 basal area to about 90 ft' (8.3 m-) or less per acre, a more 

 satisfactory level for growth and prevention of insect attack. 

 Other benefits included easier re-entry for salvage and harvest- 

 ing and improved forage production for grazing. 



STUDY 1 



Increasing demand for wood products, concurrent with de- 

 creasing sawtimber supplies, is requiring the processing of 

 smaller trees. Relatively high costs of harvesting small trees us- 

 ing conventional equipment have made operators hesitant to 

 work in such stands. The objective of this study was to develop 

 information on various systems that might be applicable to 

 young, second-growth timber. Two groups of problems — forest 

 management and harvesting — were addressed. 



Some aspects of the forest management problem included: 

 sanitation cutting, thinning, postharvest cleanup, residual tree 

 response, and regeneration. Some harvesting facets examined 

 were: felling and skidding equipment, skidding methods, log- 

 making site, and slash disposal method and location. 



Equipment used in the study consisted of gasoline-powered 

 chain saws, a Melroe Bobcat (Model 1075) feller buncher (fig. 

 2), a rubber-tired Allis Chalmers farm tractor (Model 180) 

 equipped with a rear-mounted homemade grapple, a John 

 Deere rubber-tired skidder (Model 540) equipped with chokers 

 (fig. 3), a Farmhand tractor with a hydraulic lift fork, and a 

 Morbark chipper (Model 22). 



Figure 2.— Shearing head on the Melroe feller buncher. 



Figure 3. — Farm tractor with homemade grapple attached. 



Cutting Units 



Four 2.5-acre (1.0-ha) units were used in the study. The 

 detailed description of the procedure used on each study unit is 

 as foOows: 



Unit 1. — On this unit all trees over 1 inch (2.5 cm) that showed 

 signs of insect attack were felled and removed from the stand; 

 healthy trees were not cut. The feller-buncher was used to shear 

 (fig. 4) and group the trees for skidding. Trees too large for the 

 shear were felled with a powersaw. Whole trees were grapple 

 skidded to the landing where they were limbed and bucked into 

 logs and fenceposts. Posts were made from those trees too 

 small for stud logs and from tops between 6 and 3 inches (15.2 

 and 7.6 cm) in diameter. Saw logs were 33 ft (10. 1 m) long. 

 Unusable tops, branches, and small unmerchantable trees were 

 chipped at the landing. 



Unit 2. — This unit was logged conventionally. Powersaws were 

 used to fell the trees, which were choker skidded. One skidder 

 was used. Again, whole trees were moved to the landing where 

 limbing and bucking took place. As in unit I, saw logs, stud 

 logs, and fenceposts were cut at the landing and the unusable 

 tops and branches were chipped. The minimum d.b.h. of the 

 felled trees was 9 inches (22.9 cm). 



Figure 4. — Sheared tree being lowered to the ground. 



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