Transcript Tree Physiology, Forestry and Fire Ecology

Tree Physiology, Forestry, and
Fire Ecology
• Angiosperms – commonly known as
hardwoods:
– Produce flowers
– Protect their seeds inside a fruit
– Are pollinated by insects and other animals
• Gymnosperms – commonly known as
softwoods:
– Protect their seeds on cone scales
– Are pollinated by wind
Monocots and Dicots: Read Only
Monocots
• 1 cotyledon
• parallel veins
• scattered vascular bundles
• flowers with 3 petals or multiples
• fibrous root
Dicots:
• 2 cotyledons
• branched veins
• vascular bundles in rings
• flowers with 4 or 5 petals (or multiples)
• tap root
Tree Physiology
• Deciduous trees lose their leaves in the
fall. Without leaves, the tree is less likely
to suffer ice and wind damage during the
winter, but it is unable to produce food.
Parts of a Tree
• Outer Bark - protects trees from the elements
(dead phloem cells).
• Phloem – inner bark – pipeline that delivers food
(made in the leaves) to other parts of the tree.
• Cambium – living cell layer of the tree which adds
cells to the outside (which become phloem) and
to the inside (which become xylem).
• Xylem is composed of sapwood and heartwood
• Xylem – pipeline where water is moved from
the roots to the leaves.
– Sapwood is the new wood which transports water.
As new layers of sapwood are laid down, inner
layers lose their vitality and turn to heartwood.
– Heartwood – is the central, supporting pillar of the
tree. It is composed of dead xylem cells.
A.
B.
C.
D.
E.
Bark
Phloem
Cambium
Sapwood
Heartwood becomes darker
b/c the xylem
gets clogged up
Photosynthesis
___CO2 + ___ H2O ↔ C6H12O6 + ___ O2
Cellular Respiration
Paper Plate
• Draw rings to correspond to your age.
• List ten events that impacted your life:
– You will number them on the rings
– Then list them on the back of the plate.
Forestry Definitions
• Forest – area where predominant cover is trees.
• Forestry – practice of planting, tending, and
managing forests for timber production.
• Sustainable forestry – managing forests to meet
the needs of the present without compromising
the needs of future generations.
• Renewable resource – a resource that has the
ability to replenish itself through natural
processes (within our lifetime).
• Sustainable yield – the maximum rate at which
people can use a renewable resource without
reducing its ability to renew itself.
• Stand – a group of trees that are similar in age
and in species composition.
SC Forests
• 12.3 million acres of South Carolina’s land area
are forested. That is 64% of it’s 19 million
acres.
• Timber is the #1 cash crop in SC.
• Wood products industry employs 50, 000
people in SC.
Who Owns SC Forests?
National
forest
5%
Nonindustrial
private
74%
Forest
industry
16%
Other
public
5%
South Carolina
Forest Type Distribution
12.3 Million Acres*
Bottomland
Hardwood
20.3%
Upland
Hardwood
19.4%
Oak-Pine
11.7%
Pine
Plantations
24.8%
Natural Pine
23.8%
BMPs
• Best Management Practices – set of voluntary
guidelines designed to limit negative impacts on
the land during forestry operations in
accordance with Section 404 of the Clean
Water Act.
• SMZs – stream management zones – specific
BMPs that are a set of guidelines to protect
riparian areas (strips of vegetation along
watersheds) from sedimentation during forestry
operations.
Harvesting Methods
• Clear Cut – the practice of removing an entire
stand of trees in one harvest.
• Seed Tree – is very similar to clear cutting
except that a few seed-producing trees are left.
These trees are removed after the stand is
regenerated. This method is reserved for tree
species whose seeds are dispersed by wind.
– 10-15 mature trees are left per acre
Clear Cut
Seed Tree
• Shelterwood – process of regenerating a stand
through a series of two or three cuts. The first
cut removes 50% of the stand. The second cut
removes half of the remaining stand. The third
cut removes the rest of the mature trees.
• Shelterwood cuts provide wildlife with both
food and cover while regeneration occurs. It is
also more aesthetically pleasing than a clear cut.
Shelterwood
• Group selection cuts involve removing clusters
of trees in an area less than 2 acres. Openings
should be at least two times as wide as the
height of surrounding trees to allow sunlight to
penetrate the forest floor and stimulate
regeneration and growth of shade-intolerant
trees and herbaceous growth.
• Single tree selection – involves removing
individual trees. This method is labor intensive
but forest communities remain relatively
unchanged.
Site Prep
• Mechanical Site Preparation – involves the
physical disturbance of a site by machinery to
reduce undesirable plant competition.
Mechanical Site Prep
• Raking – done to control debris
• Plowing – done to till soil so that seedling
roots are free to grow.
Plow Blades
• Bedding – increases seedling survival.
• Shearing vegetation and piling debris is called
windrowing. When windrows are not burned,
they create cover for deer, rabbits, birds, snakes
and other wildlife as well as produce food.
Dozer with Sear Blade
Site Prep
• Chemical Site Preparation – involves the use of
herbicides to reduce the unwanted vegetation
that competes with newly planted trees.
• In many cases, after herbicides are used, the site
is also burned to further reduce competition
and improve soil nutrients. This is called
brown and burn
Regeneration
• Artificial Regeneration – planting seedlings or
distributing seeds directly on a recently cleared
forest site – typically after a clear cut.
• The most common problem with direct seeding
(spreading seeds) is regulating the density and
spacing between seedlings.
• Planting seedlings is more common for
southern pine regeneration
Regeneration
• Natural Regeneration – re-establishment of pine
stands from standing trees left on the site.
– Seed tree: 10 - 15 mature seed-producing trees are
left per acre.
– Shelterwood: 20 – 40 mature seed-producing trees
are left per acre.
Natural vs. Artificial Regeneration
Natural
Adv: Lower costs
Adv: Less labor intensive
Adv: Less soil disturbance
Adv: More aesthetically
pleasing
Dis: Less spacing control
Dis: Greater seed loss
Dis: Don’t use genetically
improved seedling
Dis: Irregular stands led to
difficult harvest
Artificial
Adv: Control of seed spacing
Adv: Use genetically improved
seedlings
Dis: Higher costs
Dis: Higher erosion from site
prep
Dis: Less aesthetically pleasing
Forest Measurements
• Site Index: the height a tree will attain on a
given site at a given age – usually 50 years.
• DBH – Diameter at Breast Height – diameter
of the tree taken at 4.5 feet from the base.
• Chain – unit of measure used by foresters that
equals 66 feet. 10 square chains = 1 acre
(An acre is 209 feet by 209 feet)
(A circular acre has a radius of 117.75 feet)
Forest Measurements
• Board foot - unit of wood 1 foot by 1 foot by 1
inch often used to describe the volume of wood
produced from a log.
• Log – 16.3 foot section of newly harvested tree.
• Cord – a measure of wood volume described as
a stack 4 feet high, 4 feet wide, and 8 feet long.
Dendrochronology
Dendrochronology is the dating of past
events (climatic changes) through study of
tree ring growth
The shallow roots of the longleaf pine absorb surface water, which is affected by
precipitation. Hurricanes produce large amounts of precipitation with a distinctly lower
oxygen isotope composition than that in dew or smaller storms. Tracing tree-rings that
contain these lower isotope compositions unveils a record of hurricanes that both
supports and surpases the present historical record. The current study looks at a 220year-old record and suggests data up to 400 years can be accessed in future studies.
Annual
rings:
spring
wood (light)
and
summer
wood
(dark)
Douglas
fir in
New
Mexico
Ponderosa
pine with
multiple
fire scars
Long leaf
pine with
fire scar
Fire scars
on a Giant
Sequoia
White
spruce
struck by
a snow
avalanche
Ponderosa
pine
growing
alongside a
river with an
impact scar
from a flood
Assume all trees were cut in
2010
Age
1.
2.
3.
4.
5.
6.
Yr it started growing