Transcript Notes: Succession (11/18) - Liberty Union High School District

Succession
Monday, November 14th, 2016
Forest Fires
‣ Forest fires are a natural
forest development and may
naturally occur as a result of:
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lightning strikes
concentration of heat on dry
tinder.
or fire services start
controlled burns to remove
dry tinder and material that
could lead to potentially
uncontrollable fires in the
future.
Photo: CA
‣ In some situations, forestry
Surface fires
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Types of fires
Burns undergrowth and leaf litter
Kills seedlings & small trees
Stimulates germination for some species (giant sequoia & Jack Pine)
Crown fires
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Occurs in forests that have not had surface fires for a very long time
Extremely hot!
Leap from treetop to treetop
Kills wildlife & increases soil erosion
Ground fires
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Occur underground, burn partially decayed leaves
Common in peat bogs
Difficult to extinguish
Ecological Succession
‣ Succession proceeds in several
Pioneer community, Hawaii
stages, until the formation of a
climax community, which is stable
until further disturbance.
‣ Early successional (or pioneer)
communities are characterized by:
Simple structure, with a small
number of species interactions
Broad niches
Low species diversity
Broad niches
Climax Communities
‣ In contrast to early
successional communities,
climax communities
typically show:
Complex structure,
with a large number of
species interactions
Climax community, Hawaii
Narrow niches
High species diversity
Large number of species interactions
Primary Succession
‣ Primary succession refers to
colonization of a region where
there is no pre-existing community.
Examples include:
Newly emerged coral atolls &
volcanic islands
Newly formed glacial moraines
Islands where the previous
community has been extinguished
by a volcanic eruption
Paved Parking lots
Remember: No soil!
Hawaii: Local plants are able to rapidly
recolonize barren areas
Primary Succession
‣ A classical sequence of
colonization begins with lichens,
mosses, and liverworts, progresses
to ferns, grasses, shrubs, and
culminates in a climax community
of mature forest.
In reality, this scenario is rare.
Bare rock
and lichens
Ferns, grasses
and herbaceous
Pioneer species.
plants
Mosses and
liverworts
Shrubs and
fast growing
trees
Mature, slow
growing trees
Why lichens are awesome…
http://youtu.be/Te4qnLkHnS4
Secondary
Succession
‣ Secondary succession
occurs where an existing
community has been
cleared by a disturbance
that does not involve
complete soil loss.
Cyclone
‣ Such disturbance events
include cyclone damage,
forest fires and landslides.
Forest fire
Secondary Succession
‣ Because there is still soil present, the
ecosystem recovery tends to be more rapid
than primary succession, although the
time scale depends on the species
involved and on climatic and
soil factors.
Mature forest
Bare land
Grasses and
herbaceous plants
Pioneer community
(annual grasses)
Shrubs and
small trees
Young fast
growing trees
Gap Regeneration
‣ The reduced sunlight beneath
large canopy trees impedes the
growth of the saplings below.
‣ When a large tree falls, a crucial
hole opens in the canopy
(gap), allowing sunlight to reach
the saplings below.
‣ The forest regeneration
following the loss of a
predominant canopy tree is
called gap regeneration.
‣ Gap regeneration is an example
of secondary succession.
Wangari Maathari and Kenya’s
Green Belt Movement
‣ Green Belt Movement: 1977
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Self-help group of women in Kenya
Success of tree planting
50,000 members planted 40 million trees
Women are paid for each tree that survives
Slows soil erosion
Shade and beauty
Combats global warming
Nobel Peace Prize: 2004
A History of Parks
‣ 1864 – Yosemite was the first designated
national park in the world.
‣ 1872 – Yellowstone was established and was
the first park to be called a “National Park”
•A national park not only provides public access but it affords
protection of nature. In the 20th century conservation became
the focus of national parks worldwide.
•Additionally keep in mind that a goal of park and nature
preserve management is maintaining biodiversity in national
parks for recreation such as hunting.
Who is in charge?
‣ Dept of Interior
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Bureau of Land
Management (BLM)
Division of Fish and
Wildlife (F&W)
National Parks Service
(NPS)
‣ Dept of Agriculture
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US Forest Service