chapter 4: kinds of ecosystems section. 4.1: forests
TRANSCRIPT
Chapter 4: Kinds of Ecosystems
Section. 4.1: Forests
What are biomes?
Biomes are areas that have distinctive climates and organisms.Biomes are usually named for there plant life, because the plants dictate what other life lives there.
What dictates plant life in a certain area?
The main deterrent is climate – refers to weather conditions in an area over a long period of time.Typically precipitation and temperature are the most important factors in a regions climate.
What dictates plant life in a certain area?
The main deterrent is climate – refers to weather conditions in an area over a long period of time.Typically precipitation and temperature are the most important factors in a regions climate.The soils of biomes are different.
Because climate largely defines biomes,
latitude and altitude are important
defining these regions as well!
The same biome often occurs in several places on Earth.
Although they may have different species of plants and animals, they have similar characteristics and niches.
Forest Ecosystems
Forest ecosystems cover areas with relatively high average yearly rainfall.
Different types of forest biomes:
Tropical Rain Forest
Tropical Rain Forest Characteristics
They cover large areas on both sides of the equator.
Tropical Rain Forest Characteristics
They cover large areas on both sides of the equator.Hot and humid all year around.High average rainfall – receive about 100 inches a year.Strong sunlight year around with little seasonal change.
Tropical Rain Forest Characteristics
Vegetation grows in distinct layers.*Lower layer plants are
adapted to receiving less light.*Examples: Broad leaves, and
the ability to use vines to climb up other plants.
Tropical forest soil is very poor and at times are less than a few inches deep.
Tropical Rain Forest Characteristics
Tropical forest soil is very poor and at times are less than a few inches deep.
*Heavy rainfall washes away the soil too fast for decomposition to
replace.*Plants tend to have root systems
that spread across the top of the soil rather than under the soil.
Tropical Rain Forest
The most important characteristic of the tropical
rainforest is the diversity of life!
1 hectare of temperate forest = 10 species1 hectare of tropical rain forest = 100 species
Threats to Tropical Rain Forest
Use to cover 20% of the Earth’s surface….now they cover 7%.Logging operations destroy large areas. Land cleared slash and burning for farming.
Different types of forest biomes:
Tropical Rain ForestTropical Deciduous Forest/Scrub Forest
Tropical Deciduous Forest/Scrub Forest
Tend to have less water than the rain forest.Tend to have most of their rain during 1 season rather than all year round.The trees tend to lose their leaves during the dry.
Different types of forest biomes:
Tropical Rain ForestTropical Deciduous Forest/Scrub ForestTemperate Deciduous Forest
Temperate Deciduous Forest Characteristics
They are found in moist areas with long, warm summers and cold winters.Precipitation is moderate and regular throughout the year (30-100 inches)Typically occur between 30 and 50 degrees north latitude.Typically dominated by five species of trees:
1. Oaks
2. Maples
3. Hickory
4. Beech
5. Sycamore
Temperate Deciduous Forest Characteristics
Trees of the forest are deciduous meaning that their leaves turn brilliant colors of red, gold, orange in the fall; drop off; and then grow back in the spring.Many of the large predators of the deciduous forest have died or been killed off.
Temperate Deciduous Forest Characteristics
Today the forest is dominated by bears, deer, squirrels, rabbits, raccoon and opossum.
Major Threat to Temperate Deciduous Forest
Most of the old growth forests have been destroyed by lumbering, urbanization and farming.
Different types of forest biomes:
Tropical Rain ForestTropical Deciduous Forest/Scrub ForestTemperate Deciduous ForestTaiga
Taiga Characteristics
Stretches in a large band across the northern hemisphere just below the Arctic Circle.Evergreen conifers are dominant tree species.The leaves of the conifer are thin, needle-like leaves with a waxy coating.They include:
Red Pine
White Pine
Taiga Characteristics
The leaf structure offers protection against the cold and holds moisture.Typically these forests have long winters – 6-10 months.They are extremely cold at times the temperature plummets below –20 C.The growing season may be as short as 50 days.
Taiga Characteristics
Constant daily during summer that accelerates the growing season.Most precipitation falls as snow.