Best Practices for Native Stand Christmas Tree Silvopastures

Research and many years of practical experience have shown that Christmas-tree management in silvopasture settings is compatible with achieving multiple values, to the benefit of industry and conservation goals.  With funding from the BC Agroforestry Industry Development Initiative, Kootenay Tree Farms has refined silvopasture techniques for enhanced production of forages for both wildlife and cattle, and, tree management for rhabdocline (Rhabdocline pseudotsugae) disease control.

Forage Production

Forages are a key consideration in any silvopasture operation.  In the context of Christmas tree silvopastures in the East Kootenay region, they have direct relevance to livestock production potential, and also are a variable of consideration for land use decisions and wildlife enhancement.

The Kootenay/Boundary Land Use Plan recommends periodic entries of prescribed burning, thinning and partial-cutting to maintain open forest conditions and rangeland values.  And, ecosystem restoration projects are currently underway in several areas of the region.  To date however, no projects have compared the effects of different types of Christmas tree management systems on forage production.

One of the objectives of this operational trial was to demonstrate that a silvopasture system will benefit forage production, improve forage quality and increase the grazable area of a pasture.  Treatments (with untreated controls) were installed, representing the effect of the silvopasture management system on plant communities that are dominated by native and domestic vegetation, respectively.  The first post-treatment monitoring took place in 2013.  Preliminary results have shown that forage cover, production and species diversity increases with decreasing overstory, under a silvopasture scheme.  The long-term suitability of silvopastures to contribute as an ecosystem restoration / forage enhancement land management tool will require additional monitoring to see if these trends hold.

Economics

A production system cost-benefit analysis has been developed based on the project results with regional Christmas tree production and market information.  The production model, which Kootenay Tree Farms has evolved is based on years of practice in the East Kootenay region, is rooted in the philosophy of ‘doing it the best way for the greatest return’.  Underlying this management concept is a goal of providing agroforestry management options to producers which enhance producer and ecological sustainability, while complementing larger landscape-level management strategies. 

The review gathered economic and production data for a hypothetical Christmas tree enterprise in the East Kootenay region of BC.  It was undertaken primarily for Christmas tree producers and those potentially interested in becoming a Christmas tree producers, and was designed to provide a starting point for them to assess the potential of a Christmas tree enterprise.  The analysis provides a beginning economic assessment from which to consider one's own notions about production and economic factors, and the potentials and pitfalls of a Christmas tree enterprise in this region.

Disease Control

Christmas trees have been pruned for a long time to improve tree quality but never to control disease.  In this project component, Kootenay Tree Farms investigated different management methods to control or eliminate Rhabdocline disease in Douglas-fir Christmas trees.  The results indicate that techniques that build the soil duff layer, improve soil fertility, or reduce surface temperatures or humidity can contribute to significant reductions in disease levels in the trees.   Using pruning and tree thinning methods that improve air flow through the production site, together with practices that improve the health of the trees are key.

Cariboo Silvopasture Demonstrates Profitable Sustainability

Zirnhelt Ranch is a family owned and operated ranch located in the Beaver Valley of the Cariboo region of British Columbia.  The Zirnhelt family believes in sustainable food production and use farming methods that minimize the impact on the natural environment.  As well, the family ranch manages a woodlot and operates a timber frame building company located on the ranch.

Over the past few years, timber and livestock producers have faced depressed commodity prices and volatility due to fluctuating demand and exchange rates, pest outbreaks, and regulatory changes.  Additionally, the mountain pine beetle epidemic has created unprecedented social and economic challenges for communities in the region.  As part of a toolkit to address sustainable diversification, agroforestry systems such as silvopasture can help agricultural producers respond to these socio-economic and resource management challenges.

The Cariboo silvopasture demonstration at the Zirnhelt Ranch is an operational agroforestry approach implemented on a recently timber-harvested site and managed under high-intensity, short-duration grazing.  The long-term objectives of this demo are to determine the integrated forage and timber production, soil moisture response and the economic cost-benefits of a silvopasture approach under these conditions.

Bale grazing to help reduce unwanted brush

Establishing the silvopasture has involved brushing of unwanted shrub and tree regeneration, fencing and water developments.  And the Ranch has utilized innovative, low-cost methods to implement the silvopasture treatments with an eye towards short and long-term profitability.  For example, winter feeding of cattle over the untreated forest regeneration successfully reduced brush without damage to crop trees and created better conditions for grass and forb production.

In other areas, a silvicultural contractor spaced crop trees (a mix of fir, pine, spruce, aspen and birch) and a crew of three hand-piled the slash for later burning.  Zirnhelt Ranch bought this land after the trees had been harvested, and it was a full nine years post harvest before the silvopastures were implemented.  Ideally, for silvopastures created through logging and brushing, early introduction of cattle after logging, and in sufficient numbers to have a desired landscaping effect of trampling and stirring up the soil surface, to facilitate seeded forage establishment.

Thinning and piling to create a silvopasture

In the grazing season, cattle are used for additional brush control through their browsing.  The native shrubs that dominate the site have enough nutritional value for maintenance, but not large weight gains.  The silvopasture therefore has limits for backgrounding or finishing cattle at least in early years of development.

The Ranch has found temporary electric fencing (multi-strand electric wire and step-in posts) ideal for the silvopasture.  Major subdivision of pastures were created by running permanent cross fences from the top of the hills to the bottom, which allowed additional temporary fencing to be installed for frequent (daily to weekly) moves of livestock to follow the contours of the land.  They also found  that for any water supply it is a good idea to have a permanent electric mainline close by so that the water source can be enclosed with a charged (hot) fence to protect the water developments from excess trampling.  Locating permanent subdivision fences and travel corridors close to the water supplies is important in keeping maintenance costs down.