Lecture 9 - Chapter 10 Flashcards
Forests cover about 31% of Earth’s land surface:
– Provide habitat, maintain soil, air, and water quality, and play key roles in biogeochemical cycles.
True or false?
True
Trees Have Several Basic Requirements, what are this requirements?
• For photosynthesis to occur
• Macronutrients
• Micronutrients
• Transpiration
Trees Have Several Basic Requirements, what happens • For photosynthesis to occur?
– An amenable temperature
– Air
– Light
– Soil
– Water
Trees Have Several Basic Requirements, what happens in • Macronutrients?
Required in large amounts (N, P, K, Mg,
Ca, S, C, etc.)
Trees Have Several Basic Requirements, what happens in • Micronutrients?
Required in small amounts (Fe, Zn, Cu, B, Mo, etc.
Trees Have Several Basic Requirements, what happens in • Transpiration?
water loss from leaf surface, cools theplant as well as assisting in the movement of nutrients
– Water drawn up through xylem by adhesion and cohesion
– Useful to plant trees in close proximity to crops to make water more accessible to crops
What Is Canopy?
Upper level of leaves
What is Woodland?
Area has a more open canopy, allowing more light to penetrate to the forest floor.
What Are the Three Major Groups of Forest
Biomes?
- Boreal forest
- Temperate forest
- Tropical forest
What is Boreal forest?
Is Characterized by evergreen trees usually in:
– High-latitude forest
– Cold, dry climates with short growing seasons
– Stretches across Canada, Russia and Scandinavia
What is Temperate forest?
– Mid-latitude forest (Eastern North America, North-eastern Asia, and Western and Central Europe)
– Seasonal climate (winter season vs. summer growing season)
What is Tropical forest?
– Equatorial-latitude forest (South and Central America, equatorial Africa, and Indonesia and Southeast Asia)
– Wet, tropical climate
What are some examples of Drylands?
- Shrublands = wooded areas covered by shrubs and occasional taller trees (e.g.
tundra) - Savannah = open area dominated by grasses with widely scattered trees
- Grasslands = lands dominated by grasses and non-woody vegetation
Are Forests Grade into Open Wooded Lands
Called Drylands, true or false?
True
Canada Is a Steward for Much of the
World’s Forest
• Canada’s 348 million hectares of forested and other wooded land is
– 25% of the world’s natural forest
– 9% of the world’s forest cover
• Canada has the highest amount of forested land per capita in the world
• More than 50% of Canada’s primary forest remains more or less intact
True or false
True
Canada’s Forests Are Varied, what are they?
• Forests of the north: – Boreal forest (taiga) is the largest forested region of
Canada
– Every province except Nova Scotia and Prince Edward Island
• Forests of the west: – Forest regions:
*Subalpine,
* montane forest region in BC, e.g.
– Rocky mountain douglas fir,
* Columbia.
– E.g. Engelmann spruce, alpine fir, lodgepole pines etc.
* Coastal
• Forests of the east:
– Forest regions covered by:
– Deciduous forests of
* Great-Lakes-St. Lawrence,
* Acadian
* Carounian
Forests Are Ecologically Valuable
• One of the richest ecosystems for biodiversity are?
– Structural complexity houses great biodiversity.
– Some animals adapted for living in canopy, others specialize on the subcanopies.
– Shrubs and groundcover plants of the understory are home to still more organisms.
– Fallen leaves and branches called litter, house still others.
– Forest edge can be quite different from habitat in the forest core.
A forest provides many
ecosystem services, what are this ecosystem services?
– Stabilizes soil and prevents erosion
– Slows runoff, lessens flooding, purifies water
– Stores carbon, releases oxygen, moderates
climate
What are some Forest Products Are Economically Valued?
• Benefits: fuel, shelter, transportation (ships), paper
• Helped society achieve a high standard of living
• Softwood = timber harvested from coniferous trees
• Hardwood = timber harvested from deciduous trees
• NTFPs = non-timber forest products such as medicinal, herbal, decorative and edible products
Timber Is Harvested by Several Methods, what are this methods?
• Clearcutting method
• Selection systems
Timber Is Harvested by Several Methods, what is • Clearcutting method?
All trees in an area are cut, leaving only stumps
– most cost-efficient
– greatest impacts on forest ecosystems
– mimics natural disturbances such as
fires
– enhances soil erosion
Timber Is Harvested by Several Methods, what is • Selection systems?
Only select trees are cut
– Single tree selection = widely spaced trees are cut
– Group tree selection = small patches of trees are cut
Timber Is Harvested by Several Methods
• Clearcutting method & • Selection systems but do they disturb the habitat?
All methods disturb the habitat
– Change forest structure and composition
– Increase erosion, siltation, runoff, flooding, landslides
What is Reforestation?
planting of trees after logging
What is Afforestation?
planting of trees where forested cover has
not existed for some time
What is Even-aged trees?
all trees are the same age
What is Maximum sustainable yield?
cutting trees shortly after
they have gone through their fastest stage of growth, and
trees often grow most quickly at intermediate ages
Land Conversion and Deforestation, what is Deforestation?
The clearing and loss of forests
– People have cleared forests for millennia
– Clearing of land for
* farming is one of the first significant human environmental impacts
* Urbanization- settlements
– Alters landscapes and ecosystems
How was The Growth of Canada Was Fueled by land Clearing and Logging?
• Deforestation propelled growth throughout North America
• cleared for farming
• wood used to fuel furnaces of industry
• Principal cause of deforestation in Canada is agriculture
- Agriculture Is the Major Cause of
Conversion of Forests and Grasslands
• Agriculture covers more of the planet’s surface than forest
– Principal driver of land conversion today
• Swidden agriculture = small area of forest cleared and crops planted
– sustains only one or two seasons of planting
– soil depleted quickly
– 7 years required to replenish soil in original clearings to support crops or forests
• Most cattle today raised in feedlots, but have traditionally been raised by grazing on open rangelands
• Grazing can be sustainable if done carefully and at low intensity
• Poorly managed grazing impacts soil and grassland ecosystems
• Ranchers and environmentalists have joined to preserve ranchland against development and urban sprawl
- Pest Infestations Have Become
Increasingly Problematic
• Canada has many insect pests, some of the worst are invasive species
• Scientists say there are two primary reasons for outbreaks
– forest management producing even-aged forests
– plantation forests dominated by single species
Deforestation Is Most Rapid in Developing
Nations, for a Number of Reasons, what are the reasons?
• Uncut primary tropical forests still remain in many developing countries
• Advanced technology has allowed the exploitation of resources faster than in the past
• Often these countries impose few or no restrictions on logging
• Often timber is extracted by foreign corporations
• Deforestation has altered the landscapes and ecosystems of much or our planet
• Forest can be harvested sustainably but it hasn’t always happened
• Impacts are greatest in tropical areas and in dryland regions
• Deforestation also adds carbon dioxide to atmosphere
• Fastest rates of deforestation are in tropical rainforests of Latin America and Africa
What are Forest Management Principles?
• Forestry (silviculture)
• Harvesting
What is Forest Management Principle
• Forestry (silviculture)?
a professional field of managing forests by balancing forests as
– ecosystems and
– sources of wood products
What is Forest Management Principle
• Harvesting ?
The removal of material from the resource
– Should not occur at a rate that exceeds the capability of the resource to replenish or regenerate itself
Public Forests in Canada Are Managed for
Many Purposes, what are this purpose?
• Canadian Forest Service preserves timber on Crown lands
• Crown land used for timber and non-timber forest products
• Multiple use = policy where forests were to be managed for
– recreation
– wildlife habitat
– mineral extraction
– various other uses
Many Forest Managers Practice Adaptive
and Ecosystem-Based Management, what is Ecosystem-Based Management?
Managing the harvesting of resources to minimize impact on the ecosystems and ecological processes
– carefully managing ecologically important areas
– protecting some forested areas
It is challenging for managers to determine how to implement this type of management
– Ecosystems are complex, and our understanding o how they operate is limited
Many Forest Managers Practise Adaptive
and Ecosystem-Based Management, what is Adaptive management?
systematically testing different management approaches and aiming to improve methods
– Monitoring results and adjusting methods as needed
– A fusion of science and management
– Time-consuming and complicated
A guiding principle for forest management in Canada
Why does Fire Management Has Stirred Controversy?
• Many ecosystems depend on fire
• Ecosystems dependent of fire are adversely affected by its suppression
• Ground fires = the litter layer itself burns, as opposed to crown fires
• Crown fires = the upper tree canopy is ignited
• For over 100 years, all forest fires were suppressed
– But many ecosystems depend on fires
– Fire suppression allows woody accumulation, which produces kindling for future fires
• Housing development near forests and climate change will increase fire risk
• Prescribed (controlled) burns = burning areas of forests
under carefully controlled conditions
– effective
– may get out of control
– impeded by public misunderstanding and political interference
• Removal of dead trees following a natural disturbance
• Seems logical, but is really destructive
– Snags (standing dead trees) provide nesting cavities for countless animals
– Removing timber from recently burned areas increases erosion and soil damage
– Promotes future fires
Climate Change Poses New Forest
Management Challenges, what are those challenges?
• Remains to be seen if changes occur in
– fire extent,
– frequency, and
– behaviour will become established
• Changes in precipitation will have impacts worldwide
• Climate change will benefit some species and hurt others
• Natural range of trees is changing, moving northward
Sustainable Forestry Is Gaining Ground, what is Sustainable Forestry certification?
only products produced sustainably can be certified
– International Organization for Standardization (ISO)
– Forest Stewardship Council (FSC) have different standards
– Consumers look for logos to buy sustainably produced timber
– Companies such as Home Depot sell sustainable wood
*encourages better logging practices
