Ch. 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.
The Study of Ecology
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 living in and
around the reef.
The Study of Ecology
G. ecosystem: community of living things plus
the nonliving features of the environment that
support 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)
Key Abiotic Factors
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
Uneven Heating of the Earth’s Surface
B. tropics: regions between 23.5ｰ N latitude
and 23.5ｰ S latitude; warmest temperature
zones on Earth
C. polar zones: the regions north of the Arctic
Circle (66.5ｰ N) and south of the Antarctic
Circle (66.5ｰ S), that receive the smallest
amount of direct sunlight year-round
D. temperate zones: latitudes between the
tropics and polar regions in each hemisphere
(most of the US), moderate
The Sun & Earth Climate
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 - riverlike flow pattern within a body of
water, circulates water back and forth from poles to
equator
Ocean Currents
Local & Microclimate
III. Local Climate
A. Large bodies of water can hold heat and cause
stable tempertures. 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
Terrestrial Biome
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
Tropical Forests
II. Tropical Forest
A. tropical rain forest: type of forest near the
equator that receives as much as 250 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)
Savannas
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 burrowing animals, and
predators (lions, cheetahs, etc.)
C. Warm climate with alternating wet and dry
seasons, droughts are common, animals often
migrate
Desert
IV. Desert
A. desert: land area that receives less than
30 centimeters of rain per year,
temperatures vary greatly, often have less
plant life, Ex: Sahara, Gobi
B. Cactus adapt by storing water, kangaroo
rat has a burrow for shade
Chaparral
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.
Temperate Grassland
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.
Temperate Deciduous Forest
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
Coniferous Forest
VIII. Coniferous Forest
A. coniferous forest: forest populated by conebearing 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.
Tundra
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, 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
Terrestrial Biomes
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, lakes
are divided into zones by depth
C. phytoplankton: microscopic algae and
cyanobacteria that carry out photosynthesis in
photic zone
Ponds and Lakes
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.
Ocean Zones
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
Ocean Zones
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: MidAtlantic Ridge