EP1135.04

Subproject Summary

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Subproject:

Vegetation Management Options for Establishment of Hybrid Poplar Plantations

Project Number:

EP1135.04

District(s):

Campbell River

Location:

Menzies Bay Hybrid Poplar Plantation

Project Leader(s):

Keith Thomas, B.C. Ministry of Forests, Research Branch, Victoria

Contact:

E-mail:	Keith.Thomas@gems8.gov.bc.ca
Phone:	(250) 356-1127

Introduction:

Why grow hybrid poplars?

Demand for wood fibre has led to an increased interest in the short rotation and intensive culture of hybrid poplar. The rotation length ranges from 8 to 25 yr on the South coast of BC and depends on a number of factors including management regime, climate, and site: the more intensive the management the shorter the rotation. Due to its white fibres hybrid poplar is used primarily in the production of paper pulp because it requires little or no bleaching and can be substituted for hemlock or balsam fir. There is, however, increasing interest in using hybrid poplar for manufacturing other wood products including lumber and plywood.

Vegetation control is necessary

Hybrid poplars are very sensitive to competition from surrounding vegetation and the successful establishment of plantations requires intensive site preparation and post-planting weed control for several years. This control is beneficial to the trees and can substantially increase survival, and growth.

Options for vegetation control

Cultivation between planting rows provides some control of competing vegetation and tree growth is greater than in non-cultivated areas. However limitations with equipment preclude cultivation in close proximity to the tree stems leaving surrounding vegetation to compete with poplars for soil moisture and nutrients.

Herbicide is another tool that can be used alone or combination with cultivation. Although herbicides are effective, there is growing reluctance to use them and application is constrained in areas close to streams or standing water. In addition, permits and training are required prior to application.

Opaque polyethylene mats are an alternative to herbicide which can provide effective weed control. The mat is anchored to the ground around the stem of the tree and acts as a both a mechanical and a photosynthetic barrier to vegetation established under the mat. These mats also slow evaporation of soil moisture and increase soil temperature that can be conducive to tree growth.

Presently, there is limited information on the efficacy of opaque polyethylene mats on weed control, survival and growth of hybrid poplars in coastal BC.

This study is comprised of three experiments, and was initiated in April 1995 to document the effects of vegetation control on hybrid poplar growth and the impacts of these treatments on site nutrient cycling.

Objectives:

To evaluate the effectiveness of polyethylene mulch mats and VISIONŽ herbicide treatment on hybrid poplar growth and survival.
To evaluate different sizes of mulch mat to determine an optimum mat size which would promote maximal tree growth.
To evaluate the impact of different vegetation management regimes on site nutrient cycling over the course of one rotation.

Studies:

Menzies Bay Plot Photo (130k gif)

References and Publications (Click on the Highlighted Reference to Obtain an Electronic Copy in PDF Form):

Thomas, K. 1996. Vegetation management options for establishment of hybrid poplar plantations and their effect on nutrient cycling (E.P. 1135.04). In Mixedwood Management Research in British Columbia: A Summary of Research Initiatives., FRDA Research Memo No. 240., Page 19., B.C. Min. For., Victoria, B.C.

Thomas, K.D., P.G. Comeau, and C. van Oosten.Vegetation management options for establishment of hybrid poplar plantations. E.P. 1135.04. Establishment and First Year Progress Report. B.C. Ministry of Forests, Research Branch, Victoria. MacMillan Bloedel Ltd.

To obtain any publications that are not highlighted click here.

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