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UNIT 3 - FORESTRY. TOPIC 7 – FOREST SUCCESSION . TOPICS RELATED TO SUCCESSION. Why do Forests Change over Time? Human and Natural Disturbances Seasonal Changes Ecological Succession Climax Community Pioneer Species 2 Types of Succession Primary and Secondary - PowerPoint PPT Presentation
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UNIT 3 - FORESTRY
TOPIC 7 – FOREST SUCCESSION
TOPICS RELATED TO SUCCESSION Why do Forests Change over Time?Human and Natural Disturbances
Seasonal Changes Ecological Succession
Climax CommunityPioneer Species
2 Types of SuccessionPrimary and Secondary
The Role of Fire in Succession
WHY DO FORESTS CHANGE OVER TIME? Forests may be altered or disturbed
over time due to 2 MAJOR FACTORS:HUMAN DISTURBANCESNATURAL DISTURBANCES
HUMAN DISTURBANCES Logging Activities
Clearing land (ex: farming, cabins, roads)
Pollution (ex: acid rain, air pollution, garbage)
Global warming (changes in weather and climate)
Ozone Depletion (more sun exposure)
HUMAN DISTURBANCES
NATURAL DISTURBANCES Natural climate change
Species extinction
Volcanic Activity
Floods
Forest Fires
NATURAL DISTURBANCES
SEASONAL CHANGES WHAT ARE THEY?
Short-term Changes that Occurs from Year to Year
WHAT ARE SOME EXAMPLES?Losing leaves in fall, build-up of snow in forest in winter, changes in temperature and daylight hours, etc.
FOREST SUCCESSION
WHAT IS FOREST SUCCESSION? It is the natural series of LONG-TERM
ecological changes that occurs in a forest after a significant disruption.
Unlike seasonal changes, succession changes a forest so that it is never the same again.
There are two stages to the succession process:
PIONEER SPECIESFIRST STAGE
CLIMAX COMMUNITYLAST STAGE
PIONEERING PLANTS
After a disturbance, a new forest begins!
PIONEERING PLANTS The first organisms to grow in an area which
has been disrupted.
They require a lot of light and generally short-lived.
These pioneers provide nutrients for other organisms to come and form habitats in the area.
Examples include: Lichen Grass Moss Raspberries/Blueberries
CLIMAX COMMUNITY
CLIMAX COMMUNITY After undergoing a series of successions over
time, the CLIMAX COMMUNITY is formed.
They are slow-growing and long-lived.
It is the FINAL, STABLE, COMPLEX, and SUSTAINABLE community of dominant organisms in an area.
It is the LAST stage of succession.
In a boreal forest, these are generally SOFTWOOD species.
2 TYPES OF SUCCESSION
PRIMARY SUCCESSION SECONDARY SUCCESSION
PRIMARY SUCCESSION
PRIMARY SUCCESSION
PRIMARY SUCCESSION
This type begins in an area where there is NO SOIL nor PREVIOUS LIFE.
Examples of areas: Lava field Sand dune After a glacier After an earthquake
Could take 300 y to reach climax community!
PRIMARY SUCCESSION STAGES
SECONDARY SUCCESSION
SECONDARY SUCCESSION
BEFORE AFTER (2 y)
SECONDARY SUCCESSION
This type occurs in an area that has been cleared of vegetation, but STILL HAS SOIL at the start.
Examples of areas: Clear-cut Over-browsing by
Animals Insect Damage Forest fire
Could take 75 y to reach climax community
SECONDARY SUCCESSION
SECONDARY SUCCESSION STAGES
FIRE IN FOREST SUCCESION How long does it take for a forest to
recover from a fire?75 Years
IT IS natural, especially in boreal forests.
FOREST FIRE POSITIVE EFFECTS IT CREATES
REGENERATION OPPORTUNITIES Large areas of land
opened up for growth
Old unhealthy trees are destroyed
Nutrients back to soil
Some species (ex: black spruce) need soil to regenerate
Creates new habitat
FOREST FIRE NEGATIVE EFFECTS Threatens human
communities Could eliminate
trees used for harvesting operations
Destroy habitat and food sources of some Species
Could change the Natural Age/Mix of Forest
UNIT 3 - FORESTRY
TOPIC 8 – OLD GROWTH FORESTS
OUTLINE DEFINITION and TYPES
CHARACTERISTICS
IMPORTANCE/VALUE
OLD GROWTH FORESTS in NL
WHAT IS AN OLD GROWTH FOREST? Old Growth Forests are
not simply “old.”
DEFINITION:A Forest that has had NO RECENT HUMAN OR NATURAL DISTURBANCE (such as harvesting, fire, insect damage, wind throw)
AKA “Ancient Forest”
TWO TYPES OF OLD GROWTH FORESTS Type One - PRIMARY
NOT INFLUENCED OR DAMAGED by humans
TWO TYPES OF OLD GROWTH FORESTS TYPE TWO - SECONDARY
DISTURBED by humans
OLD GROWTH CHARACTERISTICS
OLD TREES
MULTIPLE AGE TREES
NO SIGNS OF RECENT DISTURBANCE
MULTI-LAYERED
PRESENCE of SNAGS AND DEADFALLS
OLD TREES
Trees are close to MAXIMUM life expectancy
Old trees does not necessarily mean LARGE trees!
Often WIDELY spaced.
MULTIPLE AGE TREES Although old trees are dominant, there
is a MIX of trees of different ages.
NO RECENT DISTURBANCE The forest has passed through the NATURAL
DISTURBANCE PERIOD, which means there has not been a major fire or insect infestation.
MULTI-LAYERED Lower LOGS Middle SHRUBS Upper TREES
This layering is called STRATIFICATION
SNAGS AND DEADFALLS Old growth forests have an
abundance of fallen logs, leaning trees, stumps and snags.
Standing dead trees are called SNAG.
Large logs or bits of wooden debris on the ground are called DEADFALL.
WHY ARE OLD GROWTH FORESTS IMPORTANT?
ECOLOGICAL VALUES
ECONOMIC VALUES
SOCIAL VALUES
ECOLOGICAL VALUES VALUE 1 - Old growth forests are habitat for
wildlife.
EXAMPLESNL MARTEN
Prefer thick, shady old growth forest to hide from predators and easily find prey.
ECOLOGICAL VALUES . . . EXAMPLES . . .
SPOTTED OWLRequires snags that are
common in old growth forest for nest habitat
http://archives.cbc.ca/environment/endangered_species/clips/8982/
BOREAL FELT LICHENPrefers coniferous old
growth forestThreatened in NL by
logging and air pollution from Holyrood Generating Plant
ECOLOGICAL VALUES . . . VALUE 2 - Old growth forests are CARBON
SINKS.
They store carbon for long periods of time, keeping this carbon out of the atmosphere.
The cutting of these trees increases Atmospheric Carbon Dioxide.
ECOLOGICAL VALUES . . . VALUE 3 – RESEARCH VALUE
Old growth forests provide SCIENTIFIC information about the understanding of forest processes that humans have not influenced.
ECONOMIC VALUES Medicinal and Botanical
products
Ecotourism
Timber-related products
SOCIAL VALUES Old growth forests have AESTHETIC value,
where we want to protect nature as it stands without disturbance.
SOCIAL VALUES . . . Old growth forests have SPIRITUAL value,
especially to groups such as First Nations people who have deep and historical attachments to nature.
http://archives.cbc.ca/IDC-1-75-679-3926/science_technology/clearcutting/clip11
HOW MUCH OLD GROWTH IS LEFT?
OLD GROWTH IN NL Old growth forests in NL
are classified as WET BOREAL
They are unique because of high MOISTURE levels, and thus very rare FOREST FIRES.
They are dominated by CONIFEROUS trees.
Trees can range from 100 to 250 years of age.
Main River: Old Growth balsam fir forest at the base of the Great Northern Peninsula
Map: http://www.aquatic.uoguelph.ca/rivers/main.htm
FUTURES FROM FORESTS: FOREST ECOLOGY IN NEWFOUNDLAND AND LABRADORFUTURES FROM FORESTS: OLD GROWTH FORESTS
Main River was depicted on one of five stamps in Canada Post's 1991 Canada's River Heritage series
MAIN RIVER
FUTURES FROM FORESTS: FOREST ECOLOGY IN NEWFOUNDLAND AND LABRADORFUTURES FROM FORESTS: OLD GROWTH FORESTS
Source: Parks and Natural Areas, Department of Environment and Conservation, Canadian Heritage River System
Newfoundland and Labrador’s first Heritage River (designated in 2001)
Located at the base of the Great Northern Peninsula, and it joins White Bay near Sop’s Arm
Flows south-easterly 57 km from headwaters through expanses of Boreal forest and lush island meadows, known locally as the Big Steady
FUTURES FROM FORESTS: FOREST ECOLOGY IN NEWFOUNDLAND AND LABRADORFUTURES FROM FORESTS: OLD GROWTH FORESTS
Source: Parks and Natural Areas, Department of Environment and Conservation; Photos: Lem Mayo, Canadian Heritage River System
The watershed contains a diversity of vegetation ranging from shrub barrens and wetlands to old growth forest, providing habitat to a variety of waterfowl and wildlife including the Newfoundland marten
Managed by Parks and Natural Areas Division of the Department of Environment and Conservation
To protect the fragile Main River ecosystem, guidelines have been established by the Department of Environment and Conservation:
MAIN RIVER GAP REPLACEMENToccurs here
INDIVIDUAL OR SMALL GROUPS OF TREES die and leave small openings in the forest canopy
This increased SPACE allows small trees to grow and develop, a process known as RELEASE.
BALSAM FIR AND BLACK SPRUCE are two trees that “lie in wait” for many decades for the chance to crop up in these openings.
As a result, trees may be OLD BUT NOT TALL.
OLD GROWTH IN NL MAIN RIVER INDICATOR
SPECIESTwo species living in NL old
growth forests are thought to be INDICATOR SPECIES, species that indicate the OVERALL HEALTH of the ECOSYSTEM THEY OCCUPY
The two species are: BLACK-BACKED
WOODPECKER NL MARTEN
MAIN RIVER Much controversy has surrounded Main
River, since it is many things to many people:
A majestic old growth forest region.
A habitat to the at risk NL marten.A unique Canadian Heritage River.A logging ground for CBPPL.A tourist attraction.http://archives.cbc.ca/environment/envir
onmental_protection/clips/3936/
Source: Parks and Natural Areas, Department of Environment and Conservation; Photos: Canadian Heritage River System
FUTURES FROM FORESTS: FOREST ECOLOGY IN NEWFOUNDLAND AND LABRADORFUTURES FROM FORESTS: OLD GROWTH FORESTS
Activities not permitted
• Timber harvesting• ATV use• New cottage
development• Mineral exploration
Activities Permitted• Salmon and trout
fishing• Hunting - big and
small game• Snowmobiling• Outfitting and
adventure tourism• Backcountry hiking
and camping• Canoeing/ kayaking
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