5. 0 - Silviculture Systems Flashcards
Where did the term Silviculture emerge from?
Northern Europe, ~200 years ago
What is the simple term of Silviculture?
Tree Culture
What was the initial concept of silviculture?
To tend forests for various benefits, but wood fibre mostly.
What are the two key focuses of Silviculture?
- Trees
- Timber Production
What are the 4 main goals of Timber Production?
- Improving Efficiency
- Protecting Site Productivity
- Shortening Rotations & Increasing Yields
- Selecting Valuable Species
Define Silviculture:
Using ecological, economic, and social knowledge to manipulate a forest ecosystem to achieve specific sustainable benefits specified for it.
Define a Silviculture System:
A process whereby stands are tended, harvested and replaced, resulting in a forest of distinct form/type and structure
What are the 4 steps in a Sustainable Forestry Cycle?
- New Forest
- Thinning
- Stand Management Protection
- Harvest Planning
What are the 5 activities involved in producing Tree Crops?
- Site Preparation (Before or after harvest)
- Seedling Establishment
- Intermediate Harvests (Thinning)
- Preparation for next tree crop
- Final Harvest
What are the set of activities in producing tree crops also known as?
The “Rotation”
What is a Silviculture System classified by?
Reproductive method used since method employed dictates forest structure and form/type over the rotation
What is the key consideration in Silvical practices?
Tree Species’ Needs
What are the 5 “Tree Species’ Needs” for Silvical considerations?
- Ability to grow in pure or mixed stands
- Degree of tolerance of shade
- Growth in even or uneven-aged tree stands
- Relative ease or difficulty of reproduction
- Windfirmness of root system
Review the “Regeneration Needs & Systems Choice” table (Slide 10)
What is the principle unit of silvicultural practice?
Stand
What is the classification of a “Stand”?
Distinguishable from surroundings based on 1 or more attributes
Forest management includes collective application of silvicultural practices to all stands in a __________________-.
management unit
What are the 2 Reproductive Methods?
- Even-aged Management
- Uneven-aged Management
What 4 types of practices are included in Even-aged Management?
- Clearfelling
- Shelterwood Cut Systems
- Seed Tree Cut Systems
- Thinning
What is the one practice included in Uneven-aged Management?
Individual tree selection and selection cut
What type of patterns does Clearfelling produce? (5)
- Alternate strip cut & progressive strip cut
- Block Cut
- Clearcut
- Clearcut with standing residuals
- Patch Cut
Early forest clearance practices produced even aged stands suitable for ________________.
clearfelling practices
In even-aged management, difference between youngest and oldest trees _______% rotation age
+/-20%
Define Clearfelling / Clearcutting:
Removal of all trees from an area in one cut to produce even-aged stand.
In Clearfelling / Clearcutting, identify which is the harvesting system and which is the result:
Clearfelling = Harvesting System
Clearcutting = Result
Clearfelling / Clearcutting has the highest volume _________ growth & lowest ___________ cost.
yields, harvesting
What is the size classification of a clearcut?
Any area with greater or equal to 2 hectares (ha)
Clearcut with residuals of 15 - 22 live or dead residuals are used to _____________.
Mimic fire impacts on wildlife
What is a Block Cut defined by?
<2ha in a square shape with ‘hard’ lines
What is a Patch Cut defined by?
<2ha with an irregular shape and ‘soft’ lines
An Alternate Strip-cut is equal to = _____________
Width of Seedling distance of standing trees; <100m
What are the four tree classifications based on its position in the stand?
- Co-dominant
- Dominant
- Intermediate
- Suppressed
______________________Tree Classification: wide crowns, above level of canopy, receives sun from above and sides
Dominant (D)
_________ Tree Classification: large-crowned at general level of canopy sharing space with immediate neighbours, sun from above and partly sides, smaller than dominants, healthy
Co-dominant (CD)
________ tree Classification: crown below general level or pinched, receives sunlight from above, crown affected by codominant
Intermediate (I)
________________ Tree Classification: crown developed under canopy; receives no full direct sunlight
Suppressed (S)
Clearfelling / Clearcutting is done on trees with these characteristics:
- Declined Shrub Invasion
- Even-aged Stands
- Full Sunlight
- Open site
- Shallow-rooted / Wind exposure
- Wildlife presence
What is the United States Department of Agriculture (USDA) rule of thumb? Explain.
3/2/2 Rule of Thumb
- 3 live standing
- 2 dead standing
- 2 felled trees left
What is the USDA rule of thumb not to be confused with?
Liquidation cuts that leave low value and damaged trees behind.
Seed Tree (Even Aged Management) uses a variation of __________.
Clearfelling
What kind of trees are left for seeding in Seed Tree Management?
- Scattered
- Wind-firm
- Mature Trees
When can seed trees be removed?
When regeneration establishes
What does Shelterwood Even-aged Management allow for?
Partial harvesting for new stems to grow up under an overstory of maturing trees.
When can Shelterwood be removed?
At a later date (5 - 10 years)
In Uneven-aged Management, what to logging methods are used?
Selective Harvesting:
*Group Selection Logging
*Individual Tree Selection Logging
What type of group is used in Group Selection Logging?
Groups 3 - 4 overstory trees removed and understory trees.
What does Group Selection Logging produce?
- Patchwork
- Uneven-aged Forest
Describe the Single Tree Selection Logging of Uneven-aged Management?
Single trees selected for removal due to high value, over maturity, poor form, disease, or other reasons.
What does Single Tree Selection Logging produce?
- Good Site Protection
- Market Sensitive
- Small Openings
Single Tree Selection Logging is _____________
expensive
What are some of the ecological downsides of clear cutting? **
- Change in Temperature
- Change in Soil Conditions
- Change in Soil Organisms and Macro Flora and Fauna
- Loss of Overstory Structure
- Potential for change in Water Balance
What are some of the ecological upsides of clear cutting? **
- Ability to Resynchronize Systems
- Harvest could benefit some species
- System recovery ability to resume natural successional pathway may be higher
What are some species that could benefit from clearcutting?
- Trees that need direct sunlight
- Shrubs, herbs, grasses, browsers, pollinators
Provide an example of system recoveries ability to resume natural successional pathway:
Riding Mountains over-mature pine stands
What four factors are considered in Harvest vs. Natural Disturbance?
- Fire (Type, severity, and duration)
- Insects & Disease (Large-scale change or gap creation, or pathway to fire impacts)
- Ageing and Replacement of Dominant Species
- Physical Changes (Wind, water, etc.)
Foresters must balance harvest type with needs of the forest at the __________ and __________ level.
Stand, landscape
What must foresters consider when balance harvest type with needs of the forest?
- Biodiversity of flora and fauna at the species and community level
- Ecosystem Classification
- Frequency and Scale of natural disturbance
- Rate and Ability of System Recovery
Provide the three main views of Environmental Perspective:
- Ecosystem-Centered View
- Environmentalist View
- Utilitarian View
Which type of Environmental Perspective considers “vigorous trees, low insect and disease presence, and high biomass”?
Utilitarian View
Which type of Environmental Perspective considers “late seral stages, gaps, high downed woody debris load, multi-layered canopy, high in rare and endangered species”?
Environmentalist View
Which type of Environmental Perspective considers “Diverse, fully functioning and balanced forest community with high renewal capacity”?
Ecosystem Centred View
What are the four characteristics of a healthy forest?
- Diversity of seral stages for species and ecological processes to function normally
- Landscape level resistance to disturbance and ability to recover on stand or site level
- Sufficient abiotic and biotic resourcesand inputs for growth and development
- Structure and Function operate within natural parameters.
What are the two perspectives of forest health?
- Unhealthy Forest: An “unhealthy” forest is considered one which is outside the natural ecological range
- If a forest is within its natural ecological range, ecosystem based harvesting systems will not impair overall forest functions and processes.
_____________ management is most applicable in northern / boreal regions.
Even-age
________________ management is best suited for temperature hardwood.
Uneven-aged
What twelve factors must be considered when choosing a harvesting system?
- Access Constraints
- Biodiversity
- Wood quality and quantity
- Habitat Requirements
- Road Network Requirements
- Recreation Uses
- Soil, nutrients
- Social Requirements, Cultural Requirements
- Stand Condition
- Stand Age and Age Class Distribution
- Silvics
- Topography
Silvicultural Systems are based on what features?
- Access Restrictions
- Clearfelling Area Size
- Exclusion Period for Adjacent Areas
- Number of Entries to an area
- Rotation Age
Which type of Forest Management is more commonly used, even-aged or uneven-aged?
Even-aged management (Clearcutting)
What are the two core motivations for increasing Indigenous involvement in forest management?
- to regain control over Indigenous lands and direct land use and
- to increase land and resource benefits to reverse the effects of past exclusion.
What are the three main types of forest tenure in Manitoba?
- Forest Management License Agreements (FMLs)
- Timber Permits
- Timber Sale Agreements (TSAs)
Under what legal provision of The Forest Act are Community Timber Allocations (CTAs) granted?
The Forest Act Part II 11(1) (b) (ii), which aims to provide employment in low-employment areas and enhance the social and economic well-being of the community.
At what levels of decision-making (strategic, tactical, operational) do Indigenous communities have control through the CTA?
The operational level
What are the three main categories of benefits associated with CTAs?
- capacity building
- community engagement
- environmental benefits
Define the CTA:
Community Timber Allocation (CTA), is a type of forest tenure in Manitoba that provides Indigenous communities with access to timber on Crown land.
Define Capacity Building:
Developing the skills, knowledge, and resources of individuals and communities