Kinds of Ecosystems
Environmental Science
Chapter #4
Mr. Garretson
Biomes are…
Areas that have distinct climates and organisms.
Environments that contain many different ecosystems.
Mainly determined by their Climate…or the weather conditions in an area.
Temperature
Precipitation
Humidity
Winds
Major Land Biomes
Tropical Rain Forest
Temperate Rain Forest
Temperate Deciduous Forest
Taiga
Tropical Savanna
Temperate Grassland
Desert
Tundra
Mountains
Tropical Rain Forest
Characteristics: High humidity…100 in.+ rain per year. Thin soil, easily eroded,
nutrients constantly recycled into growing canopy.
Location: Equatorial and Sub-Tropical regions.
Plant Modifications: Canopy 100 ft. blocks out 95% of sunlight. Large leaves, lush
growth and many epiphytes.
Animal Modifications: High degree of diversity and specialization. Very specific
niches to avoid predation, aid in food gathering and insure survival.
Threats: Mining, Logging, Deforestation for farming. We destroy hundreds of acres
everyday. Loss from 20% of Earth’s surface to only 7% in last century.
Temperate Rain Forests
Characteristics: Cool and humid. Rain 80 in.+. Usually associated with ocean currents
effecting weather patterns.
Location: North and South America, New Zealand and Australia. In U.S. the Pacific
Northwest.
Plant Modifications: 300 ft. evergreens covered with moss and lichen due to high
moisture.
Animal Modifications: High diversity…many animals are supported due to abundant
plant growth.
Threats: Logging of the evergreen forests has been a controversy for years. (Ch.#8-10)
Spotted Owl controversy has divided population in the Pacific Northwest.
Temperate Deciduous Forest
Characteristics: Moderate temperatures. 30 to 100 in. precipitation per year.
Location:
Middle latitudes. Found on most continents. (30-50 degrees latitude)
Forests have very rich humus due to extensive organic material decaying in soil.
Plant Modifications: Deciduous trees are predominant. Cold hardy plants (perennials
and rhizomes) survive cold winters.
Animal Modifications: Abundant wildlife…summer nesting site for birds…In winter,
hibernation, migration or the adaptation of permanent residents allow them to survive
cold winters.
Threats: Destruction due to urbanization. Logging, Strip mining and Insect pests also
threaten the limited forests that are remaining. Ohio’s only “old growth forest” is a few
acres in Hocking Hills State Forest.
Taiga
Characteristics: Coniferous forest dominant. Sparse vegetation on forest floor. Very
cold with long Arctic winter. 20-25 in. precipitation per year, mostly as snow.
Location: Northern Hemisphere in the Sub-Arctic regions.
Plant Modifications: Needle bearing trees resistant to cold, predominate. They acidify
the soil and limit forest “under story” growth.
Animal Modifications: Abundant lakes attract birds and insects during short growing
season. Large mammals have adapted coats for insulation and camouflage. Smaller
animals hibernate or migrate.
Threats: Oil exploration, mining and aggressive logging threaten the Taiga.
Tropical Savannas
Characteristics: Extensive grasslands with an abundance of grazers and predators.
Warm climate and moderate rain 20-40 in. per year.
Location: Found in the tropic regions, near the equator.
Plant Modifications: Mostly heat and fire hardy grasses. Grow from their base to
sustain pressure of grazing animals.
Animal Modifications: Mostly grazers and the predators that feed on them. Young are
born in rainy season when food is most available.
Threats: Used for farming. Domestic livestock pressure wildlife. Poaching, mining
and privatization threaten migrating animals.
Temperate Grasslands:
Prairies, Steppes and Pampas
Characteristics: Tall grass, fertile soil, very moderate water and 42% of Earth’s land.
Location: Interior of continents where rain is sparse. May be influenced by mountains.
Plant Modifications: Perennial grasses form thick soil mats. Few trees due to low
water and constant winds.
Animal Modifications: Abundance of burrowing animals. In the past, Bison herds
numbered in the millions and grazed the prairie.
Threats: Plowing and cultivation make the soil erode easily by wind and water.
Overgrazing of livestock also shortens grass and makes it less resistant to drought, and
more easily eroded.
Deserts
Characteristics:
The driest places on the face of the Earth. They get less than 10 in. of
rain per year. They can be hot or cold. Soil is high in minerals but lacks organic material
due to slow decomposition.
Location: Sub-tropical regions…effected by dry winds and sometime the effect of
mountains.
Plant Modifications: Water conservation and drought resistant methods include needle
leaves, water storage stems and roots and soil toxins that prevent rival plant growth.
Animal Modifications: Most have a thick covering to protect from heat. They are active
in mornings and evenings. Estivation helps cold blooded life survive.
Threats: Encroachment of residential developments. All-terrain vehicles damage plants
and animal habitats.
Tundra
Characteristics: Treeless expanses of permafrost. Short summers and limited plant life.
Many bogs and swamps. Very cold year round with only 5-10 in. of precipitation per
year, mostly snow.
Location: Polar regions of the Earth, mostly areas around the North Pole.
Plant Modifications: Mosses and Lichens predominant. Stunted forms of shrubs hug
the ground due to constant wind, snow and cold.
Animal Modifications: Birds and insects during the short summer. Permanent residents
must be adapted to cold. Rodents and caribou feed on the lichens. Predators feed on
these herbivores
Threats: Environment is fragile and slow to recover. Oil drilling and the construction
of access roads and pipelines has been an ongoing concern for the past few decades.
Freshwater Ecosystems: Lakes and Ponds
Shallow littoral zone holds most of the nutrients. Plankton provides base for food
chain. Deep water benthic zone contains decomposers and filter feeders.
Cattails and algae make up the producer species. Fish, birds, insects and various
invertebrates inhabit the waters.
Eutrophic lakes develop when a large amount of decaying material accumulates. The
bacterial life uses all of the oxygen and the other pond life suffers. Eutrophication can
also be stimulated by sewage, fertilizers and animal wastes polluting the waters.
Wetlands: Swamps and Marshes
These areas are covered with water for most of the year. They perform important
functions:
Spawning and feeding ground for game fish.
Provide a habitat for wildlife.
Trap CO2 that would normally go into the atmosphere.
Removes pollutants and acts as a natural water filter.
Important as a reservoir for flood control.
Wetlands have been reduced in Ohio by 95%. Most have been destroyed by draining
for industrial or residential sites. We now know that our water quality is directly
dependent on the filtering effect of wetlands.
Riparian Habitats: Rivers
Rivers
originate at headwater areas and change character as they move towards the
ocean. Oxygen content is dependent on the turbulence of the water.
They are fueled by runoff water. This not only gives them nutrients and and sediment,
but it also brings in pollution.
The health of the river is dependent on the watershed it drains.
Anchored algae,and aquatic plants are the riparian producers. Fish, frogs, reptiles and
various invertebrates inhabit the moving waters.
For years rivers have been used to “take away” sewage, garbage and toxic chemicals.
Fertilizer, pesticide, herbicide, and animal wastes increasingly run into the river from
farmland. Dams alter river flow, and effect the breeding habits of riparian life.
Marine Ecosystems
Estuary…an ecosystem where a fresh water river mixes with a salt water ocean.
Nutrients settle out an are trapped at the mouth of the river.
Estuarine life is very tolerant. It is diverse with an abundance of filter feeders and
anchored plants and animals.
Estuaries occur near some of the world’s most populated cities. Pollution is
widespread and in some cases dredging destroys the ecosystem.
Coral Reefs
Built by coral polyps. The most diverse aquatic ecosystem.
They can only grow in warm, tropical waters so most are near the equator.
They provide a rich habitat for the feeding, breeding and housing of small fish. This
draws the larger predators and adds to the reef’s diversity.
The reef a very fragile environment. Changes in water temperature, salinity or turbidity
effect growth. (El Nino)
Pollution and over fishing have reduced diversity. Tourists collecting coral have
reduced the reef significantly. Nearly half of the coral reefs on Earth are in a state of
rapid decline.
Earth’s Oceans
Oceans cover one third of the earths surface.
Only the areas where sunlight penetrates can support life. Continental shelf and
shallow, open ocean are the most prolific.
Phytoplankton is the main ocean producer. Most algae has oil drops to keep them
afloat. In deep waters, decomposers and filter feeders thrive. Dead organisms deposit
their oil drops in the rich sediment.
Aquatic life in prolific and is concentrated in the areas the light penetrates. Vertebrates
and invertebrates are equipped with unique systems and strategies for survival.
Oceans collect all of the pollution from the land. They are increasingly endangered.
Off shore drilling for oil and oil spills contribute to increased pollution. Over fishing is
becoming a more urgent concern. Improper fishing kills many dolphins and endangered
turtles every year.
Polar Ecosystems: A New Concern
North and South are similar in that they get nutrients form phytoplankton and are
mostly ice covered.
The South Pole is an ice covered land mass surrounded by an ocean. This area is
mostly used as a research area. The wildlife depends on phytoplankton from the ocean.
Many whales, fish and birds live there. It is the only place where penguins live in
abundance.
The North Pole is an ice covered ocean surrounded by a land mass. Its shallow ocean
environment support diverse aquatic life. Surrounding land predators like the polar bear
depend on aquatic animals for food.
Oil and mineral exploration threaten both environments. Increased tourism has become
a problem. Wastes and garbage are difficult to dispose of because nothing will
decompose in the cold temperatures.