Download Chapter 34 The Biosphere 34.1 The biosphere is the global

Chapter 34
The Biosphere
34.1 The biosphere is the global ecosystem
I. The Study of Ecology
A. ecology: scientific study of the interactions among organisms and between
organisms and their environment
B. biotic factor- any living part of an environment, ex: prokaryotes, protists, animals,
fungi, and plants. abiotic factor: nonliving physical or chemical condition in an
environment.
C. Ecologists study the relationships among biotic and abiotic factors at five
increasingly broad levels: organisms, populations, communities, ecosystems, and
the biosphere.
D. individual organism: the smallest unit of ecological study, ex: blue sweetlip fish
in a coral reef environment.
E. population: a group of individual organisms of the same species living in a
particular area, Ex: A group of sweetlip fish in the reef environment
F. community: all the organisms living in an area, Ex: All living things in a coral reef
including fish, coral animals, microscopic algae, and all other organisms that live in
and around the reef.
G. ecosystem: community of living things plus the nonliving features of the
environment that supports them, Ex: Coral reef’s living and nonliving inhabitants
H. biosphere: all the parts of the planet that are inhabited by living things; sum of all
Earth's ecosystems, broadest category,
1. Closed system where nothing enters or leaves except light and heat.
II. Patchiness of the Biosphere
A. The biosphere is not spread out uniformly around the planet.
B. All these environmental variations are due mainly to differences in abiotic factors
such as temperature, soil type, and the availability of water and light.
C. habitat: an organism's specific environment, with characteristic abiotic and biotic
factors
III. Key Abiotic Factors
A. Sunlight - the sun provides light and warmth, and is the energy source for almost all
ecosystems on Earth. The sunlight powers photosynthesis in land and in the water
(only on top layer).
B. Water – All organisms contain water (human contain 70%), water can dissolve
gases and solutes such as salt, terrestrial (land) organisms have adaptation to control
water (pine tree needles), water organisms must control osmosis (movement of
water)
C. Temperature – most life between 00C – 500C, too low and metabolisms slow, too
high and enzymes denature (lose shape), except for some prokaryotes (deep-sea
vents)
D. Soil – product of abiotic forces such as ice, rain, wind. Allows only certain adapted
plants to grow
E. Wind – effects distribution and activity of organisms, Ex: stirs up lakes, pollinates
plants
F. Severe Disturbances – fire, hurricane, drought, floods, volcanoes, etc. allow some
organisms to adapt Ex: brush growing after a fire
34.2 Climate determines global patterns in the biosphere.
I. Uneven Heating of the Earth’s Surface
A. because of Earth's spherical shape, different locations on Earth's surface receive
different amounts of solar energy
1. Close to equator – low latitudes, high angle sun rays, absorb more heat, higher
temperatures
2. Farther from equator – high latitudes, low angle sun rays, reflect more heat,
lower temperatures
B. tropics: regions between 23.5° N latitude and 23.5° S latitude; warmest
temperature zones on Earth
C. polar zones: the regions north of the Arctic Circle (66.5° N) and south of the
Antarctic Circle (66.5° S), that receive the smallest amount of direct sunlight yearround
D. temperate zones: latitudes between the tropics and polar regions in each
hemisphere (most of the US), moderate
II. Wind, Precipitation, and Ocean Currents
A. Uneven heating causes wind and precipitation. Near the equator more heat means
more moisture and rising air, lots of rainfall
B. After losing moisture over the equator, dry air spreads from the equator and
descends at about 300N and 300S latitudes where most deserts are located.
C. Rising, falling air masses and Earth’s Rotation cause predictable wind patterns
which combine with the uneven heating of the Earth and the shapes of the
continents create currents – river-like flow pattern within a body of water,
circulates water back and forth from poles to equator
III. Local Climate
A. Large bodies of water can hold heat and cause stable temperatures. Rock and soil
absorb/lose heat quickly. Ex: Great Britain has mild temperatures
B. Mountains causes the temperature to drop as elevation increases (60C every
1000m), also block moisture from the air as it moves across (causes some deserts)
IV. Microclimate
A. microclimate: climate in a specific area that varies from the surrounding climate
region, ex: organisms thriving under a fallen log
34.3 Biomes are the major types of terrestrial ecosystems.
I. What is a Biome?
A. biome: major type of terrestrial ecosystem that covers a large region of Earth
(abiotic and biotic), related to latitude
II. Tropical Forest
A. tropical rain forest: type of forest near the equator that receives as much as 350
cm of rainfall yearly, tall broad-leaved trees create a canopy where little light
reaches the ground
B. Plants adapt to shade, many mosses and vines grow on trees
C. Animals are tree-dwellers as well, including monkeys, birds, snakes, and bats.
D. Contains 50% of all species, most diverse, Ex: Madagascar, Amazon
E. Clearing forests is a conservation problem (mining, lumber, farms)
III. Savanna
A. savanna: grassland with scattered trees; found in tropical regions of Africa,
Australia, and South America
B. Animals, such as zebras, wildebeest, antelope, and, in Australia, kangaroos, as well
as numerous insects, also are burrowing animals, and predators (lions, cheetahs,
etc.)
C. Warm climate with alternating wet and dry seasons, droughts are common, animals
often migrate
IV. Desert
A. desert: land area that receives less than 30 centimeters of rain per year,
temperatures varies greatly; often have less plant life, Ex: Sahara, Gobi
B. Cactus adapt by storing water, kangaroo rat has a burrow for shade
V. Chaparral
A. chaparral: temperate coastal biome dominated by dense evergreen shrubs, mild,
rainy winters, hot, dry summers, brush fire common to climate Ex: Mediterranean,
California coast
B. Animals of the chaparral include deer, birds, and rodents that feed on the shrubs and
their seeds, as well as lizards and snakes.
VI. Temperate Grassland
A. temperate grassland: biome characterized by deep, nutrient-rich soil that supports
many grass species, colder winter than savannah, seasonal droughts, height of
vegetation depends on yearly rainfall
B. North American grasslands (also known as prairies, Midwest) include grazing
mammals such as bison and pronghorns, as well as coyotes, snakes, lizards, worms,
arthropods, rodents, and insects.
VII. Temperate Deciduous Forest
A. temperate deciduous forest: forest in a temperate region, characterized by trees
that drop their leaves annually, large trees, winters cold, summers hot (parts of
Ohio, eastern forests of US)
B. deciduous trees such as maples, oaks, beeches, and hickory shed their leaves in
autumn, which helps reduce evaporation during the winter
C. Microorganisms, fungi, and arthropods live in the soil; Mammals found in the
temperate deciduous forests of eastern North America include deer, squirrels,
chipmunks, foxes, and bears. During the cold winter, many of these animals
conserve energy by greatly reducing their activity levels
VIII. Coniferous Forest
A. coniferous forest: forest populated by cone-bearing evergreen trees; mostly found
in northern latitudes, northern regions are called taiga, long cold winters, heavy
snowfall, Ex: Canada lower latitudes
B. conical shape of tree needle (leaf) limits snow from piling on trees, and limits
evaporation during dry periods
C. Typical taiga animals include hares, moose, elk, wolves, and bears.
IX. Tundra
A. tundra: biome in the Arctic Circle or on high mountaintops, characterized by
bitterly cold temperatures and high winds, Ex: Northern Canada, Alaska, Siberia,
and Arctic
B. permafrost: permanently frozen subsoil, shallow topsoil, mosses, lichens, grasses
thrive, no large plants
C. Lemmings, caribou, and reindeer eat the tundra ground cover, some animals like the
snow owl change color
34.4 Aquatic ecosystems make up most of the biosphere.
I. Ponds and Lakes
A. Freshwater bodies of water with little dissolved salts, Ex: Great lakes
B. photic zone: regions of a body of water where light penetrates, enabling
photosynthesis, and lakes are divided into zones by depth
C. phytoplankton: microscopic algae and cyanobacteria that carry out photosynthesis
in photic zone
D. aphotic zone: deep areas, no photosynthesis
E. benthic zone: bottom of an aquatic ecosystem; consists of sand and sediment and
supports its own community of organisms
II. Streams and Rivers
A. Flowing freshwater usually empties to lake or ocean
B. near source low in nutrients, cold, major producer is algae, downstream is warmer
and larger, supports more life including phytoplankton
C. trout, frogs, worms, insects, etc.
III. Estuaries
A. estuary: area where fresh water from streams and rivers merges with salty ocean
water; productive ecosystem, Ex: Chesapeake Bay, parts of Florida
B. Have changes in salt concentration and temperature, very productive, lots of
nutrients, many fish and birds, crabs, oysters, clams. Etc.
IV. Ocean Zones
A. Oceans are divided 4 zones based on depth and distance from shore
B. pelagic zone: open water above the ocean floor
C. intertidal zone: area of shore between the high-tide and low-tide lines
D. neritic zone: area of ocean that extends from the low-tide line out to the edge of the
continental shelf
E. oceanic zone: Vast open ocean from the edge of the continental shelf outward,
includes zooplankton: microscopic animals that swim or drift near the surface of
aquatic environments
V. Coral Reefs
A. very diverse, like the rainforest of ocean, coral is an animal that builds upon hard,
dead external skeletons, can be poisonous, Ex: Great Barrier Reef
B. including sponges, sea anemones, worms, sea stars, and mollusks, sea turtles, and
fishes
VI. Deep-sea Vents
A. hydrothermal vent: opening in the ocean floor where hot gases and minerals
escape from Earth's interior, producers (prokaryotes) use chemical energy (eat
sulfur) because of no light, Ex: Mid-Atlantic Ridge