Multifactor manual brushing studies in the Nelson Forest Region

Project number: EP 1199

District: Selkirk Forest District

Objectives

The objectives of this study are to determine the effects of timing, opening size, and duration of manual brushing, on crop seedlings and competing vegetation.

This was the first of several planned sites, designed to optimize expenditures of $4.5 million in manual brushing operations, then underway in the Nelson Forest Region. Vegetation was be cut by hand in 1994 - 1996 and the growth and physiological responses of the seedlings were measured.

The large number of treatments would have suggested an "optimal", economic treatment combination, if it existed.

Treatment

Factor	Levels
Timing	6 Combinations (one control with no cutting, three single cuttings timed for early, mid & late summer, and two  2-entry cuttings, consisting of early/mid summer, and early /late summer cuttings)
Duration	1, 2 and 3 years
Opening size	0.5m, 0.7 m and 1.0 m radius
Replications	20
Design	Completely randomized
Crop species	Engelmann spruce

Layout

The completely randomized design consisted of staked, tree-centred circular plots with unique numbers on aluminum tags. There were 1080 tree-centred plots in this component of the study. An additional 600 plots containing a subset of the treatments comprised an ecophysiology study being conducted by George Harper (Research Branch, Victoria). These trees were components of the main study randomization.

History

• Fall 1993 baseline assessment of seedlings
• Summer 1994 baseline assessment of vegetation, first year manual cuttings
• Summer 1995 second year manual cuttings and assessment
• Summer 1996 third year manual cuttings and assessment
• Fall 1998 final assessment and report

Publications

Harper, G.J. 1998. Hybrid spruce response to time of manual brushing in the ICHmw - a detailed growth analysis. Final Report (Physiology Component ) of EP 1199. Unpublished Report, B.C. Ministry of Forests Research Branch, Victoria, BC.

Thompson, C.F. 1999. The effect of timing, duration and intensity of manual brushing on the early growth of an Engelmann spruce plantation in the Interior Cedar-Hemlock zone of southeastern British Columbia.  Final Report (Tree Component) of EP 1199. Report submitted to Science Council of BC for Project FR96/97-495 and Forest Renewal BC Research Award KB96050-RE.

Comments

All treatments had a significant effect on the growth of Englemann spruce, but the magnitude of the response was too small to be of operational significance.