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Ecological Restoration of Red Spruce in Central Canada
Dr. Alex Mosseler, Canadian Forestry Service, News Brunswick
S&W Report Fall / Winter 1998 (Volume 13)
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Red Spruce, Picea rubens, has declined to an estimated 15 to 20% of its former distribution in Eastern North America as a result of environmental deterioration (e.g. atmospheric pollution) and improper forest harvesting practices (e.g. clear - cutting of red spruce dominated forests - particularly in areas with continental climates). The existing population consists of widely scattered isolated forest remnants associated with montane environments along the Appalachian Mountain chain and in coastal areas of the Maritime Provinces of Canada. Some red spruce is also found as small, stands in the Algonquin highlands of Ontario, isolated from its main range. The protection of his distinct population has become a conservation issue in Ontario because of the rarity of species, continuing threats to its existence, and the importance of red spruce as wildlife habitat and as a potential source of wood fiber.
Red spruce is one of the only two (e.g. eastern hemlock, Tsuga canadensis) highly shade tolerant conifers associated with relatively undisturbed, “old growth” forest conditions in the Great Lake-St. Lawrence region of Canada. Because of their requirements for protection from desiccation, such species have been adversely affected by clear cutting.
Red spruce provides important winter habitat for moose and deer, which require protection from deep snow during the winter. Easter hemlock and eastern white cedar, Thuja occidentalis, also provide the required habitat conditions. However, deer browsing has put intense pressure on the natural regenerations of these species to the extent the hemlock stands are aging but no longer adequately regenerating themselves. Consequently, there is a growing concern that hemlock is also facing serious decline. Evidence shows that red spruce provides similar habitat conditions to that provided by eastern hemlock bit it is not browsed to the degree that natural regeneration is adversely affected. By restoring red spruce habitat through artificial regeneration, the threat to eastern hemlock form browsing may be reduced allowing both species to recover their former status. By using alternatives to clear-cut harvesting in forests composed of such shade tolerant species (e.g. shelterwood and group or individual species harvesting systems) and under planting with red spruce where appropriate, these forest habitats can be maintained and restored.
However, red spruce has declined to such an extent that we can no longer be confident in the ability of these species to regenerate naturally in many areas of its former range. Preliminary evidence from our reproductive assessments shows reduced seed yields and seed quality in small isolated populations. A certain amount of artificial regeneration will be necessary to restore red spruce and the habitat that it represents. Where do we collect seed for this restoration effort? In Ontario, we have identified only seven viable populations of red spruce; many of which are found either within ecological reserves in and around Algonquin Park or on private property. These populations are largely inaccessible - and may not be suitable - for operational seed collection for restoration purposes. Also, black spruce (Picea mariana) hybridizes naturally with red spruce. Although, Ontario red spruce populations look like pure red spruce they may be experiencing some hybridization with black spruce. The extent to which this is happening is difficult to determine. However, DNA technology provides a potential means for quantifying this, and then assessing its ecological impact.
The main objectives of our research are (i) to provide information on the genetic and reproductive status of the remnant and reproductive status of the remnant natural populations of red spruce in Ontario, (ii) too develop silvicultural protocols for artificial restoration, and (iii) to establish seed orchards that will provide suitable seed sources for species restoration. This information will allow the Forest Gene Conservation Association in collaboration with the Eastern Ontario Model Forest to develop a conservation strategy based on sound scientific information on the genetic and reproductive status of red spruce. These organizations can also provide the necessary linkages for transferring results to landowners and resource managers through workshops, demonstration areas, and publication reports.
Scientists at the University of Alberta (Edmonton) and the Canadian Forest Service (CFS) - Atlantic Forestry Centre (Fredericton) will provide the scientific expertise, laboratories, and propagation facilities to conduct the necessary assessments of genetic and reproductive status of the species. Several land management agencies (Ontario Ministry of Natural Resources (OMNR) and Sustainable Forest Management Licenses) will provide sites for establishing genetic and silvicultural tests, assist in tests analysis, and develop seed orchards for species restoration.
If you have any questions about this work or red spruce in general please contact Cathy
Neilson OMNR, Kemptville (613) 258-8238 or Barb Boysen Forest Gene Conservation Authority (705) 755-3284.
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