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

Indicator 14 – Silviculture

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Why is this important?

Silvicultural choices shape forests and their future contributions to the environment, economy and communities.

Overview

• Silviculture is the art, science and practice of growing and cultivating trees in forests to meet the objectives and values of the landowner.
• With British Columbia’s high level of public ownership, most silvicultural activities in B.C. have depended on government policies or funding.
• Changes in silvicultural practices over the past 30 years have increased reforestation, improved conservation of biological diversity, and increased the volume and value of future timber supplies.

STATE

good

TREND

mixed

INFORMATION

partial

Questions about silviculture

14-1	Are appropriate silvicultural systems used?
14-2	How much is reforested after disturbances?
14-3	What other silvicultural treatments have been done?
14-4	What gains do silvicultural investments yield?
	Ministry of Forests and Range’s assessment

Related indicators

• Silvicultural choices are often influenced by natural disturbances, public expectations and market demands (see Ecosystem dynamics, Public involvement, Certification).
• Silvicultural practices affect many aspects of forest ecology (see Ecosystem diversity, Species diversity, Genetic diversity) and can create short-term and long-term economic opportunities for rural communities (see Jobs and communities).
• Management responses to improve silvicultural practices include new government policies (see Law).

Indicator 14-1

Are appropriate silvicultural systems used?

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Why is this important?

Silvicultural systems are chosen to achieve specific environmental, economic and social objectives over the life of a stand.

State and Trend

• A silvicultural system is a planned program of activities that encompasses how trees are harvested, regenerated and managed over time. Selection of a silviculture system depends on the ecological traits of the tree species, and on balancing the objectives of the landowner.
• From 1970–1996, clearcutting systems were applied on 87% of the area harvested on public land; and various partial cutting systems on 13%. Clearcutting systems were chosen for their low logging costs, worker safety near large trees, and efficient reforestation; partial cutting for the ecological characteristics of drier forests in the Interior of the province.
• A shift in the balance of objectives towards conservation of biological diversity led to the use of clearcutting with reserves and variable retention systems, which by 2005/06 accounted for 58% and 6%, respectively, of the area harvested on public land. These systems can provide¹⁵ greater stand structure and diversity that better emulates natural disturbances, conserves wildlife trees and increases stand-level biodiversity while enabling acceptable volume growth of new trees.
• Social concerns about large cutblocks led to a decrease in average size of cutblocks¹⁶ on public land from 45 ha in 1989 to 26 ha in 2003.
• Maps: (none)

Information

• Detailed silvicultural records are stored in the Reporting Silviculture Updates and Landstatus Tracking System (RESULTS).
• Private land accounts for 9% of the total area harvested in the province between 1983/84 and 2005/06. Earlier data are not available.
• Related sources: MFR’s Annual Reports, RESULTS, Silviculture
• Related international and national indicators: MP (none); CCFM 2.3

Indicator 14-2

How much is reforested after disturbances?

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Why is this important?

Prompt reforestation increases future timber supplies and can help prevent soil erosion and restore wildlife habitats.

State and Trend

• Forests disturbed by timber harvests and other causes reforest naturally over time. Silvicultural investments can accelerate reforestation and thereby increase timber supplies and restore ecological services sooner.
• The area deemed not satisfactorily restocked (NSR) after timber harvesting and other disturbances increased over several decades until 1988/89, due to the gap between disturbances and reforestation.
• This gap was closed during the 1980s with increasing investments in site preparation, research that led to better planting methods, planting, backlog planting and brushing to ensure free growth of desired trees.
• The explicit reforestation obligations on public land introduced in 1987 led to planting of a greater proportion¹⁷ of current harvest areas.
• By 2002/03, the backlog of economically treatable NSR area¹⁸ was reduced to 0.07 million ha.
• Catastrophic wildfires in 2003 and 2004, and the mountain pine beetle epidemic, may add large new NSR areas¹⁹ over the next several years.
• Fewer obligations apply on most private land²⁰. Reported planting decreased from 6,000 ha annually in the 1970s to 1,000 ha since 1993.
• Maps: NSR Areas Harvested Pre-1982 (PDF) and 1982-1987 (PDF)

Information

• Reported disturbances and reforestation²¹ on public land are published annually (since 1989/90). Data are incomplete²² since 1998/99: Completion of data acquisition and data entry is under way.
• Owners of private land outside tree farm licences are not required to report NSR data. Reporting of areas planted is voluntary and incomplete.
• Related sources: MFR’s Annual Reports, RESULTS, Silviculture
• Related international and national indicators: MP (none); CCFM 2.3, 2.5

Indicator 14-3

What other silvicultural treatments have been done?

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Why is this important?

Silvicultural treatments are investments in future timber production and environmental benefits from forests.

State and Trend

• In addition to reforestation activities, several other silvicultural treatments can also increase timber quantity and quality, and improve habitats, water management and visual landscapes. They can also be used to create employment opportunities for First Nations and others affected by changes in the forest industry.
• Treatments on public land totalled 1.6 million ha (an individual site may be treated more than once).
• Between 1976 and 2005/06, investments to improve the growth and quality of future crop trees included fertilizing (0.2 million ha), pruning (0.06 million ha) and spacing (0.7 million ha) and use of select seed for planting (0.6 million ha).
• Public funding of the first three treatments was largely discontinued in recent years.
• Public funding is continuing for research, production, storage and monitoring of select seed use on public land.
• By increasing the rate of tree growth, use of select seed can increase future timber volume, reduce constraints on harvesting adjacent areas and reduce the need for (and cost of) brushing.
• Maps: Use of Select Seed (PDF)

Information

• Treatments are tracked in RESULTS and in MFR Annual Reports. Recent data for fertilizing may be incomplete.
• Private landowners are not required to report treatments.
• Related sources: MFR’s Annual Reports, RESULTS, Silviculture
• Related international and national indicators: MP (none); CCFM (none)

Indicator 14-4

What gains do silvicultural investments yield?

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Why is this important?

Investments in silviculture depend on clear objectives and adequate expected gains.

State and Trend

• Gains in timber volume, quality and timing of harvests are usually the primary objectives. Short and long-term employment opportunities and various conservation values are at times the main objective. Economic returns on investment are usually considered and often disputed²³.
• Compared with natural regeneration, planting increases harvestable volume by about 15%, and about 25% with the use of select seed.
• Recent levels of planting increase future harvests by at least²⁴ 6 million m³ per year, and use of select seed adds about 2 million m³ per year. The annual gain of 8 million m³ per year amounts to 12% of the average annual harvest of 66 million m³ on public land during the 1990s.
• Cumulative volume gains²⁵ 65 years after investments in reforestation and other treatments since 1970 are estimated at 266 million m³, based on planting (95 million m³), backlog planting (142 million m³), fertilizing (6 million m³), spacing (11 million m³) and select seed (11 million m³).
• Other gains from silvicultural treatments include increased short and mid-term timber supply, accelerated development of mature or old growth forest characteristics where needed for wildlife or biodiversity, higher wood quality (e.g., by pruning) and more pleasing visual landscapes. These are measured in different ways that cannot be readily summed.
• Maps: Use of Select Seed (PDF)

Information

• Volume gains were estimated with the Performance Measures Calculator used for results published in Forest Renewal BC’s Annual Reports.
• Genetic gain data are in the Seed Planning and Registry system (SPAR).
• Related sources: MFR’s Annual Reports, RESULTS, SPAR
• Related international and national indicators: MP (none); CCFM (none)

 

Indicator 14 – Silviculture Ministry of Forests and Range’s assessment State good Silvicultural systems and treatments are dependent on government policies and funding in most of British Columbia. Policies have evolved to reflect changing public priorities and new scientific information. The dominant silvicultural system is now clearcutting with reserves for maintaining stand-level biodiversity. Past shortfalls in reforestation after logging have been corrected with policy changes and large investments in planting during the 1980s and 1990s. Currently, virtually all logged areas are reforested within allowable timeframes. Reforestation and other silvicultural investments in 1970–2005/06 increased future timber volumes by an estimated 266 million m3 (equivalent to four years of the provincial harvest from public land), and improved other timber and non-timber values. Trend mixed The use of clearcutting with reserves and variable retention has increased since the late 1990s, and the average size of clearcuts decreased, improving the balance of environmental and economic objectives. Improved practices increased the success rates for natural regeneration and planting, and reduced failures by 90% since 1989. The quantity and quality of select seed used are expected to increase over time. Silvicultural investments increased in the 1980s; however, public funding for several treatments has been largely discontinued in recent years. The mountain pine beetle epidemic is creating substantial reforestation challenges and loss of silvicultural investments. Information partial Research has greatly improved the effectiveness of silvicultural activities. Large amounts of operational data are collected in the RESULTS database to track silvicultural activities on public land. Data on seed selection, planned use and seedlot genetic quality are tracked in the SPAR database. Information from RESULTS and SPAR is used for policy development, strategic planning, silvicultural investment decisions, predicting timber supplies, supporting AAC decisions, habitat modelling and effectiveness monitoring at the management unit level. Most silvicultural information is not available for private land. Completion of data entry for reforestation on public land is being addressed.