The State of BC’s Forests The Indicators Genetic diversity — PDF print version

Indicator 6 – Genetic diversity

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Why is this important?

Genetic diversity, a fundamental component of biological diversity, is required for adaptation and evolution.

Overview

• Genetic diversity refers to genetic variation within individual organisms, within populations and among populations of a species.
• British Columbia’s forests are genetically diverse, with over 40 native tree species that grow in a wide range of environmental conditions.
• Most of this natural genetic diversity is intact for B.C.’s tree species. Management of protected areas and sound reforestation practices ensure genetically adapted, healthy and ecologically resilient forests.

STATE

good

TREND

mixed

INFORMATION

adequate

Questions about genetic diversity

6-1	How well conserved are the genetic resources of trees?
6-2	What genetic variation exists in unmanaged and managed forests?
6-3	What proportion of reforestation uses select seed?
6-4	Where is select seed planted?
	Ministry of Forests and Range’s assessment

Related indicators

• Agricultural and urban development, logging, planting and climate change are changing the genetic diversity of tree species (see Ecosystem diversity, Timber harvest, Silviculture, Greenhouse gases).
• Seed use strategies may help mitigate the effects of climate change (see Greenhouse gases) and increase benefits from investments in reforestation (see Silviculture).
• Management responses include reserves (see Protected forests, Timber production forests), forest genetics research, tree breeding, seed use regulation, and monitoring of genetic gain (see Silviculture) and the effectiveness of regulations for ensuring genetic diversity (see Law).

Indicator 6-1

How well conserved are the genetic resources of trees?

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Why is this important?

Conservation of genetic resources maintains the capacity for local adaptation, and the rare but potentially important genes for disease and pest resistance.

State and Trend

• Protected areas provide in situ reserves that conserve genetic resources. All of B.C.’s commercial tree species are represented in protected forests. Representation varies by species, biogeoclimatic zone, seed planning unit, and the number and size of reserves.
• For example, western redcedar, the province’s official tree, is protected in all four of its biogeoclimatic zones. By zone, the portion of its range that is protected is 10% (CWH and ICH), 6% (IDF) and 3% (CDF).
• Currently, no commercial tree species lacks protection in any of its seed planning units. Since 1991, the area protected in the 10 least protected seed planning units increased by a factor of 22. More in situ reserves are considered desirable in a small number of seed planning units.
• Ex situ genetic conservation consists of trees planted in installations for genetic research and tree breeding, and seed collections.
• B.C. has six genetic resource archives and hundreds of provenance and progeny test sites around the province, providing ex situ conservation for 19 commercial and 3 non-commercial species.
• Seed collections for commercial use, genetic archives and research exist for most species, with over 8,000 seedlots in long-term storage.
• Maps: Predominant Tree Species (PDF), Protected Areas (PDF), Biogeoclimatic Zones (PDF), Natural Stand Seed Planning Zones (PDF)

Information

• Maps and statistics of in situ reserves are published for 49 species.
• Spatial data relevant to genetic resources are available from the land resource data warehouse (LRDW).
• References: Range maps, LRDW, BC Parks
• Related international and national indicators: MP (none); CCFM 1.3.2

Indicator 6-2

What genetic variation exists in unmanaged and managed forests?

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Why is this important?

A planted forest should be at no greater genetic risk than a naturally regenerated forest.

State and Trend

• After fire or harvest, reforestation occurs by natural regeneration (from roots or naturally available seed), or by planting. Seed used for planting may be from natural forests or from seed orchards.
• The genetic variation among trees in reforested areas depends on the number of, and variation among, parent trees.
• Analysis of spruce in B.C.’s Interior shows that expected and observed genetic variation, as measured by heterozygosity, is similar in planted and naturally regenerated forests.
• Unmanaged (naturally regenerated) forests can be expected to have similar genetic variation as the original forest. Planted forests grown with select seed from seed orchards can be as or more genetically variable due to mixing of diverse individuals and overcoming inbreeding.
• In B.C., minimum genetic diversity standards, as measured by effective population size, must be met in order to register seed from natural and seed orchard sources for use in reforestation on public land.
• Maps: Natural Stand Seed Planning Zones (PDF)

Information

• Genetic diversity information (seed source, number of seed source trees, effective population size) are stored in the Seed Planning and Registration system (SPAR).
• Standards established to maintain genetic diversity and productivity are published in the Chief Forester’s Standards for Seed Use.
• References: SPAR, Chief Forester’s Standards for Seed Use
• Related international and national indicators: MP (none); CCFM 1.3.1

Indicator 6-3

What proportion of reforestation uses select seed?

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Why is this important?

Use of select seed is expected to yield substantial ecological, forest health and economic benefits over the long term.

State and Trend

• Reforestation is achieved with natural regeneration and tree planting.
• Wild seed from natural forests is used for natural regeneration and planting. Select seed from seed orchards and natural forests with superior genetic traits is increasingly used for planting.
• Between 1985 and 2000, reforestation by planting was increased to reduce accumulated not satisfactorily restocked areas.
• The proportional area reforested by planting increased from an estimated 28% in 1970–1974 to over 77% in 1998/99–2002/03.
• Operational use of select seed, particularly orchard seed, began in the 1980s. Legislation requiring use of the best genetic material increased the use of select seed from 10% of the area reforested in 1995/96 to 41% in 2002/03.
• The average genetic gain in select seed increased from 3% in 1994/95 to 11% in 2005/06. Further gains are expected. Gains in some species are substantially higher (e.g., 32% in western larch). By 2002/03, seed with genetic gain of 5% or more was planted on 18% of the area reforested.
• Maps: Natural Stand Seed Planning Zones (PDF)

Information

• Silvicultural information about area planted and associated genetic source (species, seedlot) is available in the provincial Reporting Silviculture Updates and Landstatus Tracking System (RESULTS).
• Information about the seeds’ genetic source, genetic gain and areas of use is stored in the Seed Planning and Registry system (SPAR).
• Spatial seed use reports are available in the SeedMap system.
• References: MFR’s Annual Reports, SPAR, RESULTS, SeedMap
• Related international and national indicators: MP (none); CCFM 1.3.1

Indicator 6-4

Where is select seed planted?

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Why is this important?

Areas reforested with select seed are expected to have improved productivity and forest health.

State and Trend

• Select seed, where available, may help mitigate timber supply shortfalls and impacts of climate change, and provide a satisfactory return on investment.
• The use of select seed aims to increase growth potential, and improve disease and pest resistance, tree form and wood quality. Faster growth rates allow increased harvest levels and lower minimum ages for harvesting. Disease and pest resistance reduces growth losses and loss of ecosystem functions. Improved tree form and wood quality increase the value of wood products.
• The select seed used operationally comes from seed orchards based on breeding programs (10 species) and selected provenances (2 species), and from natural forests of superior provenances (4 species).
• The area reforested with select seed in 2002/03 was about 16,000 ha in tree farm licence areas and 42,000 ha in timber supply areas, or 33% of the 178,000 ha reforested in the two main types of forest management units. Reforestation with select seed was proportionally higher in tree farm licences (57%) than in timber supply areas (28%).
• Maps: Natural Stand Seed Planning Zones (PDF), Forest Management Units (PDF)

Information

• Planting and associated genetic source information (species, seedlot, selection and transfer) are available in RESULTS, SPAR and SeedMap.
• At the time of analysis, 2002/03 was the most recent year for which all reforestation data had been entered in the RESULTS database.
• References: MFR’s Annual Reports, SPAR, RESULTS, SeedMap
• Related international and national indicators: MP (none); CCFM (none)

 

Indicator 6 – Genetic diversity Ministry of Forests and Range’s assessment State good The maintenance of genetic diversity is critical to the continued productivity, adaptation and evolution of forest tree populations. With the systematic expansion of the protected areas in the 1990s, forest tree genetic resources are currently well represented in protected areas. Standards for minimum genetic diversity of seedlots ensure adaptation and productivity on public land. Tracking systems for seed use are in place. Forest genetics research and tree breeding are well established, and gene conservation issues are being addressed. Related climate change issues are being actively considered, and a provincial strategy for the management of the province’s genetic resources is being developed. Trend mixed The area reforested by planting, the number of species and total area planted with select seed, and the genetic gains in those seeds have all increased. Seed production and genetic gain forecasts will continue to be considered for decision-making in silviculture planning and timber supply analyses. Advanced-generation breeding programs will continue for the major commercial species, and selection will factor in more tolerance to climatic changes, diseases and pests. Some in situ reserves and forest genetics installations have been damaged by insects and fires, and more losses are anticipated due to climate change. Information adequate B.C.’s forest tree genetic resources have been catalogued by the Ministry of Forests and Range and the University of British Columbia’s Centre for Forest Gene Conservation. The SPAR system is a provincial genetic resource registry for tree seeds and their sources. It is also a fully integrated seed and seedling request management and reporting system. Integration of data from SPAR with silvicultural data from RESULTS enables seedlot and genetic gain tracking from seed collection to planting. Stakeholder input in the provincial gene resource management program is supported by the Forest Genetics Council of British Columbia.