The experimental design for the study is a randomized complete block with 4 replications of the 12 treatments. Each treatment and measurement plot is 30x85 m [0.25 ha (0.63 acres)] and 15x70 m [0.10 ha (0.26 acres)], respectively.

Eight of the treatments form a 4 x 2 factorial in organic matter removal (4 levels), and fertilizer (2 levels) under a weed control regime. These treatments will be used to determine the implications of different levels of woody-biomass removals.

Treatments 1, 2, 9, and 10 form a 2x2 factorial with fertilizer (2 levels) and weed control (2 levels) under the cable-harvested conventional bole-only utilization regime. These treatments will be used to determine the growth potential enhancements from full site resource allocation to the crop and the addition of nutrient amendments.

Treatments 11 and 12 will be compared with treatment 2 to determine the impacts of mechanical harvesting on soil properties and stand productivity, and the amelioration potential of tillage, all under the conventional bole-only harvest plus weed control and fertilization regime.

Site Selection and Experimental Design:
We are conducting this study on a Douglas-fir Site II soil, which is commonly intensively managed for Douglas-fir. All four blocks have been established in the McDonald Tree Farm SW Washington on the Boistfort or Melbourne soil series. Boistfort series are deep, well-drained reddish-brown Lateritic soils developed from Eocene volcanic rocks. Melbourne series consists of deep, well-drained, fine-textured reddish-brown lateritic soils developed in residuum from Eocene shales. In both soils, site index averages 130(II+) on slopes of <40%. Soils are susceptible to productivity impairment when compacted.

Treatments:
The study design consists of four blocks of twelve treatment (Table 1) plots (Fig. 1) which are 0.63 acres in size and internal measurement plots which are 0.33 acres in size to ensure that valid long-term productivity trends (i.e. with fertilization or possibility for thinning) can be monitored.

Design advantages: 
The previous design did not have an adequate range of organic matter management treatments 

The study also contributes to:
a database determining full growth potential of Douglas-fir due to weed control and fertilizer.
a unit-area disturbance database for ground-based logging soil disturbance impacts and amelioration guidelines.
Subsets of this design can be replicated elsewhere to expand the database to develop more region-wide guidelines on organic matter management, vegetation control and logging disturbance impacts on Douglas-fir growth.