Download Ecology Chapter 9 Notes Forests Voc. List: Coniferous Forest

Ecology Chapter 9 Notes
Forests
Voc. List: Coniferous Forest, softwood, cones, evergreens, needles, litter layer, polar zone, temperate
zone, tropical zone, deciduous forest, hardwood, humus, dormant state, canopy layer, understory layer,
forest floor layer, lianas, epiphytes, arboreal, nurse logs, and buttresses
Section 9.1-Coniferous Forests
The word coniferous means cone-bearing
o So, in a Coniferous forest the trees produce cones
 The cones hold seeds of the tree
Most coniferous or conifers are also evergreens
o Species include different types of pine, hemlock, fir, spruce, and cedar
 Usually only a few species of trees present
o Evergreens are trees that do not lose all their leaves at the same time.
 Exception-Bald Cypress loses its leaves in the Fall
Conifers have unique leaves called needles
o Needles are long, thin, thick, waxy green leaves that help the tree conserve water and
shed snow off of in the winter. –Needles can turn brown and drop to the ground
 A litter layer of needles are often deep, poorly decomposed, acidic, and often
poor in nutrients
 Mites and fungi decomposers are common in these litter layers
Conifers are generally shaped in a triangular form to help allow the snow to fall off the tree to prevent
damage to the tree structure.
There are a few species with broad-leaf such as aspen and birch present along with other plants such as
ferns, lichen, and sphagnum moss that can be found in a Coniferous Forest
Locations:
 Subarctic regions of North America, Europe, and Asia
 In the Southern Hemisphere these forests are often found on high mountainous areas
Climate:
There are three climate zones: Tropical, Polar and Temperate zones
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This climate zone is polar: 60-80o N or S Latitude
 The summers are warm, lasting 2-5 months
o Lots of precipitation in the form of rain
 The winters are long, cold, and dry
o Often precipitation is in the form of snow
 Snow is essential to the ecosystem because it acts like an insulating blanket
that keeps the heat in and prevents the ground from forming permafrost.
 Snow also protects the roots of trees so such animals as mice can for
underneath the ground for warmth.
Precipitation ranges: 40-200 cm-Least of the three types of forests
Temperatures: Lowest temps of the three types of forests
Limiting factors: Harsh winters and nutrient-poor soil
 The soil is poor and acidic because of the conifer needles
 Decomposition of materials is slow so nutrients have trouble getting into the soil
Animals
Small herbivores include: mice, squirrels, and birds
 They feed on seeds and/or the bark of plants
Larger herbivores include: moose, elk, beaver, and snowshoe hares
Predators include: grizzly bears, wolves, lynxes
Problem: Logging –Soft wood trees are great for building materials
Specific Coniferous Forest
I. Boreal (northern) forest or Taiga (Russian for Coniferous)
 Four bands of communities include
1.) Forest/Tundra ecotone (stunted spruce, lichen, and moss)
2.) Open boreal woodland (lichen and black spruce)
3.) Main Boreal forest (continuous conifers except early successional
communities of poplar and birch)
4.) Boreal/mixed forest ecotone (conifers grade into mixed hardwoods of
southern Canada and Northern USA)
II. Montane Coniferous forest
 Higher elevations than Boreal and longer winters and more snowfall
III. Southern pine forest
 Located on coastal plains
 Nutrient poor
 Well-drained coastal sands
 Fire adapted: Some seeds germinate after fire, others simply benefit from more sun
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Located as far North as the NJ Pine barrens: Dwarfed Pitch Pine and Blackjack Oak
It takes 20 years for a forest to grow to maturity –A Loblolly Pine grows 18 meters
tall and 20 cm in diameter-heavily timbered
Section 9.2-Deciduous Forests
A deciduous tree is a tree with broad-leaf leaves that fall off the tree in the Fall.
 The leaves that fall quickly decompose enriching the soil
o The decaying leaves form a deep, rich layer of soil called humus
 The humus is home to many insects and other invertebrates that feed on the
material
o These areas have very rich soil and are fertile-great for farming
Deciduous forests grow in lower latitudes than Coniferous forest.
 Locations stretch out in parts of Europe (virtually gone now though), China, parts of South
America, Middle American Highlands, and Eastern United States
 Typically undergo succession including a pine stage
Climate:
 Climate zone is temperate
 There are four well-defined seasons
 Summer temperatures can reach 30oC
 Winter temperatures can get to -30oC
 The growing season is roughly six months (Spring and Summer)
 A tree grows quickly and produces and stores large amounts of food by
photosynthesis
 During the Fall there are cooler temperatures and shortening amounts of
daylight.
 Both these changes trigger the leaves fall to the ground
o It helps trees conserve water and prepare for winter-dormant
state
 Precipitation falls as rain or snow depending on the temperature and the season
 Range: 50-300 cm per year
Deciduous Forest species include: Many varieties of maple, oak, beech, hickory, ash, and birch
A Deciduous Forest has three distinct vegetation layers
1. Canopy- The highest layer where direct sunlight is trapped in the chlorophyll of the
leaves
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2. Understory-Middle layer where the younger and smaller trees than canopy trees grow
which does include shrubs
3. Forest Floor-Bottom layer where leaves fall and plants like moss and ferns grow.
Organisms include fungi and other decomposers, insects, invertebrates, birds, mice, small mammals,
deer, reptiles, and amphibians
 Predators include foxes, birds, mountain lions, and wolves
Specific types of Eastern North America Deciduous Forests
I. Northeastern forest
 South to the Mid Atlantic: Beech maple dominate
II. Mid Atlantic
 Down to Southern Appalachians: Oaks and Hickories dominate
Problems: Farms, orchards, and urban development are replacing the native deciduous forest of North
America and Europe
 Hardwood trees are great for building furniture and flooring and a great heat source
Limiting Factor: Temperature is not warm enough for a 12 month a year growing season (usually 6
months)
9.3 Rain Forests
o Only 6% of the Earth’s surface is covered in Rain Forest but contains 50% of the world’s plant life
(biomass) and up to 70% of all terrestrial species -Most diverse biome in the world
o Adaptation other than tree trunks:
 Woody vines called lianas grow up the sides of tree trunks to reach the sunlight
at the canopy
 Epiphytes are plants such as orchids, and bromeliads, that live entirely on the
other trunks or limbs of trees or other plants
 They absorbing airborne nutrients and moisture
Types of Rainforest
I.
Temperate Rain forests
o Found along Pacific Northwest and in Canada and Alaska
 Ketchikan, Alaska has the most rain in North America
 2/3 found in USA along the Pacific Northwest
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 In Pacific Northwest the coastal mountain traps air masses full of moisture
that rise from the Pacific Ocean
60-200 inches of rain (5-16 feet per year)
Seasons: Long wet Winters and Springs and dry foggy Summers
 Temperatures rarely drop to freezing and Summers rarely exceed 80oF
Covers only 75 millions acres of Earth
Have the largest biomass because of the giant redwoods in California
 Forests include only Giant Redwood trees and a mix of only 3 or 4 other
species on tall conifer trees
Layers
 Canopy-Tops of trees with only a few animals (mainly birds)
 The Understory-Leafy, delicate trees (dogwoods and maples) and scrubs
 Forest Floor
 Soil is rich
 Thick layer of mosses and nurse logs (fallen trees that nurture young trees
to grow on top their mossy surfaces)
 Most of the wildlife are found in these areas
II. Tropical Rain Forests
o 30-40 types
o Generally located in the tropical zone (Climate zone) near the equator
o Average temperatures are 25oC year round
o Growing season is year round
o Lots of rain: 200-450 cm per year (More precipitation than any other land biome)
o Most of the of a Rain forest wildlife occurs in the trees especially in the canopy level
 Tree –dwellers also called arboreal are organisms that never touch the ground
o 1000’s of species of trees
 Like the deciduous forest it has a canopy, understory, and forest floor
level
o Decomposition and recycling occur very fast so the nutrients are in the top 5cm of soil.
 Because of the quick decamping and recycling tree trunks widen at their
bases, with ridges of wood called buttresses that support the trees
 Some areas have poor soil nutrients where completely blocked by sunlight
Problem: Deforestation and Global Warming
Helpful: Scientists have found secretions and plants themselves that are now being used to discover
new medicines.
Limiting Factor: Soil nutrients are low in a few areas of the Rain Forest
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