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Ch. 52 Warm-Up
1.
2.
3.
Name examples of biotic and abiotic factors in the
environment surrounding PPHS.
Which biomes can be found in Colorado?
Define the following terms:
 population
 community
 ecosystem
 biosphere
CHAPTER 52
An Introduction to Ecology and the Biosphere
You Must Know



The role of abiotic factors in the formation of
biomes.
Features of freshwater and marine biomes.
Major terrestrial biomes and their characteristics.
Ecology: the scientific study of the interactions
between organisms and the environment


“Richness of the biosphere”
These interactions:
 Determine
both the distribution of organisms and their
abundance
 Where
are.
organisms are found and how many of them there
What is ecology?

Ecology is both observational/descriptive and
experimental
Observational - what’s there and how does it change.
 Experimental - rigorous due to mathematical modeling of
populations and ecosystems which relies on innovative
experimental design and statistical inferencing.


Changes in Ecological time (minutes, months, years)
result in changes in Evolutionary time (decades,
centuries, millenia +)

Predators eat prey, kills off individuals which lowers the
population size (ecological effect) and changes the gene
pool (evolutionary effect)
Environmental Factors

The ecological study of species involves biotic and
abiotic influences.
 Biotic
= living (organisms – behaviors & interactions
between organisms)
 Abiotic = nonliving (temp, water, salinity, sunlight, soil)
Can you list 3 biotic and 3
abiotic components in this picture?
Biogeography: geographic distribution of
species

Factors:
 Dispersal – movement away from area of origin
 Behavior – habitat selection
 Biotic factors – other species, food resources,
competition, pollinators, predators
 Abiotic factors – temp, water, oxygen, salinity,
sunlight, rocks & soil
Dispersal


Dispersal - the movement of individuals
away from their area of origin or from
centers of high population density.
Natural range expansion
Cattle egrets
 Early humans “out of Africa”
 Different from migration.


Species transplants

Potential vs. actual ranges
Where organisms could be versus where they
are.
 Invasive/introduced species.
 Asian Carp in Mississippi threaten Great
Lakes

Environmental Factors Example
Affect the
Distribution
and
abundance
Of organisms

Southern Australia has
cool, moist winters and
warm, dry summers.
Climate in northern Australia is
hot and wet, with seasonal
drought.
Red kangaroos
occur in most
semiarid and arid
regions of the
interior, where
precipitation is
relatively low and
variable from
year to year.
Tasmania
Environmental Factors Example
From this figure, you can
predict that kangaroos:
A. eat plants.
 b. prefer a hot dry climate.
 c. don’t like saltwater.
 d. prefer to live in
areas where people don’t live.
 e. are more abundant in
some years than in other
years.

Southern Australia has
cool, moist winters and
warm, dry summers.
Climate in northern Australia is
hot and wet, with seasonal
drought.
Red kangaroos
occur in most
semiarid and arid
regions of the
interior, where
precipitation is
relatively low and
variable from
year to year.
Heirarchy

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Organisms/Species: group of interbreeding
individuals that can produce fertile offspring
Population: group of individuals of same species
living in a particular geographic area
Community: group of populations of different
species in an area
Ecosystem: community of organisms + physical
factors
Landscape: mosaic of connected ecosystems
Biosphere: global ecosystem
Climate: long-term prevailing weather conditions in
a particular area


Climate = temperature + precipitation + sunlight +
wind
Macroclimate vs. microclimate:
 Macro:
work at seasonal, regional or local level
 Micro: small-scale environmental variation (eg. under a
log)

Climate change: some species may not survive
shifting ranges
Global Climate Patterns:
Latitudinal Variations in Sunlight intensity
• Earth’s curved shape
causes latitudinal variation
in the intensity of sunlight
• Because sunlight strikes the
equator perpendicularly,
the most heat and light per
unit of surface area are
delivered there
• At higher latitudes, sunlight
strikes Earth at an oblique
angle, and thus the light
energy is more diffuse on
Earth’s surface
Global Climate Patterns:
Air Circulation & Precipitation Patterns
Global Climate Change: Seasonal
Variation in Sunlight Intensity
Global Climate Patterns:
Ocean Currents
Global Climate Patterns:
Mountains affect rainfall
Which side of the canyon has more plants? Why?
Biomes: major types of ecosystems that occupy
very broad geographic regions
Figure 34.7C
Climate and elevation determine biomes
Figure
34.12
Figure
34.12
Climograph: plot of temperature & precipitation in a
particular region
Tropical Forest
• distribution: equatorial
• precipitation: very wet
• temperature: always
warm
• characteristics: many
plants & animals, thin soil
Desert
• distribution: 30°N & S
latitude band
• precipitation: less than 30
cm per year
• temperature: variable daily
& seasonally, hot & cold
• characteristics: sparse
vegetation & animals, cacti,
succulents, drought tolerant,
reptiles, insects, rodents, birds
Savanna
• distribution: equatorial
• precipitation: seasonal,
dry season/wet season
• temperature: always
warm
• characteristics: fireadapted, drought
tolerant plants,
herbivores, fertile soil,
between a desert and
rainforest
Chaparral
• Distribution: little bit of most of the
continents , coastal
• Precipitation: seasonal, drought common
• Temperature: very hot and dry.,
Characteristic: Most of the plants have
small, hard leaves which hold moisture. Some
of these plants are poison oak, scrub oak,
Yucca Wiple and other shrubs, trees and cacti.
The animals are all mainly grassland and
desert types adapted to hot, dry weather.
coyotes, jack rabbits, mule deer, alligator
lizards, horned toads, praying mantis, honey
bee and ladybugs.
Temperate Grassland
• distribution: mid-latitudes,
mid-continents
• precipitation: seasonal,
dry season/wet season
• temperature: cold
winters/hot summers
• characteristics: prairie
grasses, fire-adapted,
drought tolerant plants;
many herbivores; deep,
fertile soil
Northern Coniferous Forest/ Taiga
• distribution: highlatitude, northern
hemisphere
• precipitation: adequate
to dry (temperate rain
forest on coast)
• temperature: cool year
round
• characteristics: conifers;
diverse mammals, birds,
insects, etc.
Temperate Broadleaf Forest
• distribution: mid-latitude,
northern hemisphere
• precipitation: adequate,
summer rains, winter snow
• temperature: moderate
warm summer/cool winter
• characteristics: many
mammals, insects, birds,
etc.; deciduous trees;
fertile soils
Artic Tundra
• distribution: arctic, highlatitude, northern
hemisphere
• precipitation: dry
• temperature: cold year
round
• characteristics: permafrost,
lichens & mosses, migrating
animals & resident
herbivores
Alpine Tundra
• distribution: high
elevation at all latitudes
• precipitation: dry
• temperature: cold year
round
• characteristics:
permafrost, lichens,
mosses, grasses;
migrating animals &
resident herbivores
Marine/Aquatic Biomes
coral reef
benthos
intertidal
Aquatic/Marine Biomes

Account for the largest part of the biosphere in
terms of area
 Can
contain fresh (aquatic; less than 1% saline),
brackish, or salt (marine; ≈ 3% saline) water

Oceans
 Cover
about 75% of Earth’s surface
 Have an enormous impact on the biosphere
 Evaporation
provides majority of Earth’s rainfall
 Ocean temperatures affect climate and wind patterns
 Algae and photosynthetic bacteria provide oxygen and
consume CO2
Zonation


Are stratified into zones or layers defined
light penetration, temperature, and depth
Thermoclines - Narrow vertical zone of
abrupt temperature change.
Zonation

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Photic Zone – sufficient light for photosynthesis
Aphotic Zone – little light penetration
Benthic Zone – bottom substrate composed of sand, organic, and
inorganic materials (ooze)

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Benthos – Organisms that live in the benthic zone
Detritus – dead organic matter that rains down from the productive photic zone.
In aquatic communities organisms are distributed according to:
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water depth
light penetration
distance from the shore
open water versus benthic zone
Nutrient Turnover
Lakes and other marine/aquatic biomes experience turnover.
Lakes
• Oligotrophic - nutrient
poor, oxygen rich
• Eutrophic - nutrient
rich, oxygen poor
• Periodic oxygen
depletion; large amount
of decomposition
• Biota - fish,
invertebrates
depending on O2
levels, phyto- and
zooplankton.
Wetlands
• Inundated with water at
least periodically
• Plants adapted to watersaturated soil
• Highly productive
• Important filters and
breeding grounds
• Birds, carnivores,
crustaceans, plants,
reptiles.
Streams & Rivers
• Current with lots of
aeration
• Aquatic plants and
phytoplankton, fish,
invertebrates, etc.
• Ex. Potomac and
Anacostia rivers,
Rock and Sligo
creeks, Chesapeake
Bay watershed.
Estuaries
• Transition between rivers
and sea - brackish water
with flow between the
two.
• Variable salinity depending
on temperature, depth,
and tides.
• Worms, oysters, crabs,
fish, etc.
• Highly productive and
important in filtering
water.
Intertidal Zones
• Periodically submerged
and exposed.
• Physical environment
varies vertically, so
species range varies
vertically.
• Oxygen and nutrients
renewed tidally.
• Sea grass, algae, worms,
crustaceans, crabs, etc.
Oceanic Pelagic Zone
(Open Water)
• Open ocean, particularly deep
water.
• Driven by currents - lots of light
and oxygen. Large photic zone.
• Experience nutrient turn over depends on temperature.
• 70 percent of world’s surface
• Phytoplankton and
photosynthetic bacteria - makes
our oxygen!
• Zooplankton, fish, cephalopods,
marine mammals, etc.
Coral Reefs
• Formed from coral
“skeletons”
• Photic zone zooxanthellae need light
for photosynthesis;
sensitive to change in
temperature
• Fringing reef --> barrier
reef --> atoll island
• Unicellular algae, coral
animals, fish and
invertebrate diversity.
Marine Benthic Zone
• Below neritic (near, coastal)
and pelagic (noncoastal,
open water) zones.
• Deep benthic = abyssal
zone; deep sea vents with
chemoautotrophs.
• Shallow benthic - oxygen
from algae and seaweed.
• Chemo- or
photoautotrophs; worms,
arthopods, echinoderms,
etc.
Warm Up Questions
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Dead organic matter that rains down from the
productive photic zone.___________________
The movement of individuals away from their area
of origin or from centers of high population
density___________________________
Nutrient rich, oxygen poor lake.________________
Long term weather patterns on a global, regional
and local level. ____________________________
Warm Up Questions

What are the 4 factors that affect aquatic
communities distribution of organisms