Download Exotic

Forest Plants
Much like wetlands, forests also have plant
species that are native and exotic.
•If a plant is native to a particular area, then it is
originally from that area (prior to European
settlement).
•Native plants provide food and habitat for
native animals. Without this, the native
animals may be forced to migrate to areas.
•Native plants also keep local genes viable and
in the gene pool.
• Exotic plants were not originally in the area
and have been carried to the area in some
way.
• Exotic plants can become invasive where they dominate
the ecosystem preventing opportunities for growth for
the native plants.
• Exotic plants also out grow native plants because they
have no native predators
• Invasive exotic species are the second leading cause of
native species extinction (habitat loss being number
one)
(Center for Applied Ecology, 2007)
• Exotic plants were not originally in the area and have
been carried to the area in some way
• Exotic plants can become invasive where they
dominate the ecosystem preventing opportunities
for growth for the native plants.
• Exotic plants also out grow native plants because
they have no native predators.
• Invasive exotic species are the second leading cause
of native species extinction
(habitat loss being number one)
(Center for Applied Ecology 2007)
Forest Quality
1. Tree size
• A rough estimate of the forests’ age can be
determined by measuring tree size
2. Size of the forest
• Large forests ecosystems are more stable
3. Diversity of native species
• Forests benefit from a large diversity of native
species
Forest Quality
4. Percentage of exotic plants
• Exotic species can dominate native species preventing their
growth and survival
5. Rare species or potential for their existence
• Rare species are generally indicators of a healthy ecosystem
6. Adjacent forest buffer
• A forest patch that is bordered by another forest benefits from
the neighboring forest.
• A forest may not have a buffer because of deforestation
(Center for Applied Ecology, 2007)
Deforestation- the destruction of a forest as a result of
human activity. (DuBay, Lapinski, Schoch, & Tweed, 1999)
Conservation
• Many forests are being cut down
because of the need for lumber,
space, or other human requirements.
Ecologists see the need to keep the
forests everywhere. (Center for
Applied Ecology, 2007)
What would CAE do?
• The Center for Applied Ecology does
many things to ensure forest
conservation. Depending on the
circumstance, they can improve the
quality of an existing forest or create the
conditions for a forest in an area that
currently not forested.
– Step one
• Determine forest quality by using the “Forest
Quality Rapid Assessment Method”. This method
looks at the 6 indicators listed above under “forest
quality ”.
– Step two
• A prescription is created based on the quality of
the existing forest.
• Low quality forests require CAE to focus on
invasive exotic species control. Once this is
complete, they can focus on planting native
species.
• Medium quality forests may require some
invasive exotic control and minimal planting.
In this type of forest, native species will begin
to grow once the exotics are controlled.
• High quality forests may have small areas that
need species control. Mostly, CAE focuses on
maintenance of these systems, keeping them at
a high quality.
• If a forest does not exist, CAE will undergo a
complete restoration where they must develop
a list of plants and trees to introduce into an
area based on the soils.
o Dry soils require hardwoods such as oak and maple trees
o Bottom lands where there is moisture require trees such as
sycamore and cottonwoods.
o Mesic hardwood forests contain trees such as beech and
maple
• In all cases CAE removes trash and unwanted
materials from the conservation area
(Center for Applied Ecology, 2007)
Leaves
o Vary in size (giant Victoria water lily in
Guyana has leaves 2m long)
o Some leaves attach directly to the
stem (grass) and some are connected
with a stalk (petiole)
o The petiole has tissue that extends
from the stem to the leaf to form veins
o Different shapes
• Simple leaf- has a single blade
• Compound leaf- has leaflets
attached to the petiole
o Arrangement on stem
 Opposite leaves- when two
leaves are arranged in pairs on
the stem
 Alternate leaves- when only
one leaf is present at each
point on the stem
 Whorled leaves- three or more
leaves at the same place on the
stem
• Leaf Structure
1. Cuticle- waxy layer that covers the tops and
bottom of the leaves (helps keep the water
in)
2. Upper and lower epidermis- a layer of tightly
packed cells that cover and protect all young
parts of the plant (like the “skin” of the plant)
3. Mesophyll- photosynthetic tissue of a leaf
a. Palisade mesophyll- column shaped cells containing
chloroplasts (where most photosynthesis takes place)
b. Spongy mesophyll- loosely packet cells with air spaces
that allow carbon dioxide, water vapor, and oxygen to
circulate around the cells
4. Stomata- openings in the cuticle that control gas exchange (also on stems)
5. Guard cells- control the opening and closing of the stomata
a. When the cells fill with water, the pressure causes them to change
shape and open. When they are not filed they are flat and closed.
b. Loss of water through the stomata is called Transpiration
6. Vascular bundle
a. Contains two types of cells
that transport material
i. Xylem- transports
water an d minerals
upward from roots
ii. Phloem- transports
food made in the
leaves down to the
stem and to the
shoots to make more
leaves and fruits
Roots
o underground part of plants the anchor them to the ground
oAbsorbs water, nutrients , and minerals form the soil and transports them up
the stem
o Some plants store food in their roots (carrots, radishes)
o Three main types of roots
 Tap root- central fleshy root that grows deeper than the rest
with smaller roots growing around it
 Fibrous root- numerous roots branching from a central point
 Aerial roots- roots that cling to objects such as walls for
support
Root structure
1. Epidermis- outer layer of cells
2. Root hair- a tiny extension of a single epidermal cell that increases the
surface area of the root with the soil. (absorb water, oxygen, and
dissolved minerals)
3. Cortex-transports water and ions to the center of the root. Made up of
parenchyma cells that can sometimes store food and water.
4. Endodermis- single layer of cells that forms a waterproof seal that
surrounds the root’s vascular tissue.
5. Root cap- tip of the root that is covered by a tough protective layer of
parenchyma cells- cells that haven’t decided which part of the plant they
are going to
6. Apical meristem- where cells are produced that cause the root to
increase in length
7. Xylem and Phloem- see leaves
8. Pericycle – within the endodermis, tissue that lateral roots come from
(roots that shoot out of the sides)
Root structure
Stems
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Above ground portion that supports leaves and flowers
Are either herbaceous (like flowers) or woody stems (like tree trunks)
Transport water, mineral ions, and sugars to form leaves and roots
Stores food so plants can survive drought, cold, or seasons with shorter
amounts of sunlight
o Tuber- a swollen underground stem or leaf (like the sprouts on
potatoes)
Stem Structure (Similar to a root)
1. Vascular bundles-made of xylem and phloem and are in small separate rings
that go around the stem.
2. Cortex- makes up the center of the
stem
Woody Stems
• As stems grow in height, they also
increase in thickness
• Wood is actually xylem tissue
• Growth rings can determine the
size of the tree
• Bark is actually phloem cells and the cork
cambium (layer under the phloem layer)
Flowers
• Flowers are how
plants sexually
reproduce
• Usually contains both
male and female
parts
Parts of a Flower
• Flowers are considered complete or incomplete.
oComplete flowers have all the parts listed above
oIncomplete flowers are lacking one or more of these parts
1. Petal- Leaf like, usually colorful structure arranged in a circle
around the stem
• Usually brightly colored and often have perfume or
nectar to attract pollinators
• Provides a landing place for pollinators
• Can be fused to form a tube
2. Sepal- Leaf like, usually green and circle around the stem underneath the
petals
• Are a protective covering for the flower bud
3. Stamen- the male reproductive structure of the flower. Made of two parts.
a. Filament- Structure that supports the anther.
b. Anther- at the tip of the filament, produces pollen which contains sperm
• When pollen grains mature in the anther, it cracks open
allowing the pollen to escape
4. Pistil- female structure of the flower. The bottom part of the pistil enlarges to
form an ovary that contains an ovule (or egg).
5. Style- an extension of the ovary
6. Stigma- the tip of the style (pollen must land here for reproduction to occur)
•Has a pollen tube that grows down the style and into the ovary so
pollen can reach the ovule (or egg)
• Flowers that have both stamens and pistils are
called perfect even if it is incomplete because
of it lacks sepals or petals. An imperfect flower
is incomplete because it is missing stamens or
carpals
• Monoecious- plant that has both male and
female parts
• Dioecious- a plant that has separate male and
female plants