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