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SCI 160 Week 5
• The Final Frontier…
• Things we’ve skipped in the text:
•
•
•
•
•
•
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Plant Form and Function
Plant Life Cycles
Animal Bodies and Functions
Circulation & Respiration
Nutrition, Digestion & Excretion
Defenses Against Disease
Chemical Control in Animals –
Endocrine Systems
• The Nervous System
• Animal Reproduction
Tonight…
• Chapters 27 to 30 - The BIG picture
•
•
•
•
Population Growth
Community Interactions
How Ecosystems Work
Earth’s Ecosystems
Chapter 27
• Population Growth
Ecology
• We are now concerned with ecology – the study of
organisms’ interactions with each other AND
nonliving parts of their environment.
• Some more definitions (small to large):
• A population – all members of a particular species
who live in a particular area
• A community – all interacting populations of
different species who live in a particular area
• An ecosystem – all communities within a defined
area along with their non-living components
How Are Populations
Distributed in Space and
Time?
• Individuals in Many Populations Clump
Together in Groups
– Advantage: can search for food together,
reduces the odds of being eaten by
predators, improves mating possiblilities
– Figure 27.1 Population distributions (p.
548)
clumped
Even Steven
• Uniform distributions –keep a relatively
constant distance between each other.
• Can defend territories from invading
species
• Can escape destruction by local
disasters (fire/flood)
uniform
Random Distributions
• The species don’t need social groups
• And/or and resources are not scare
random
How Do Populations Grow?
• Births, Deaths, and Migration Determine Population
Growth
– Population Growth Can Be Expressed As a Rate
• Like a velocity
• Simple even if you bury it in math
Factors Affecting Population
Numbers
Locally…
Growth…
• A Constant Growth Rate Increases Population Size
Rapidly
Biotic Potential
The Biotic
Potential is the
maximum rate
at which a
population
could increase
under ideal
conditions.
Different species have different biotic
potentials..
How fast is fast?
• A Population’s Growth Rate Depends on Patterns of
Reproduction
– Some Species Produce Large Numbers of Offspring Quickly
– Other Species Produce Fewer But Longer-Lived Offspring
• Figure 27.2 J-shaped exponential growth curves (p. 551)
bacteria
Exponential
growth curves
are J-shaped.
time (minutes)
number of
time
(minutes) bacteria
0
1
20
2
40
4
60
8
80
16
100
32
120
64
140
128
160
256
180
512
200
1024
220
2048
eagles
Reproduction
begins at
4 years.
time
(years)
0
2
4
6
8
10
12
14
16
18
20
22
24
26
28
30
Reproduction
begins at
6 years.
time (years)
number of number of
eagles (i) eagles (ii)
2
2
2
2
4
2
8
4
14
8
28
12
52
18
100
32
190
54
362
86
630
142
1314
238
2504
392
644
4770
9088
1066
17314
1764
How Do Populations Grow?
– Delayed Onset of Reproduction Slows
Population Growth
• Are Americans having children later?
– Death Rate Also Influences Growth Rate
• Figure 27.3 The effect of death rates on
population growth (p. 552)
bacteria
no
deaths
10% die
between
doublings
25% die
between
doublings
time (hours)
How Is Population Growth
Regulated?
• Rapid Growth Cannot Continue Indefinitely
– Some Populations Fluctuate Cyclically
• Figure 27.4 A boom-and-bust population cycle (p.
552)
• Figure E27.1 Population cycles of predators and
prey (p. 554)
• Figure E27.2 Experimental predator–prey cycles
(p. 554)
• Figure 27.5 Lemming population cycles (p. 553)
Nutrients are depleted.
Favorable growth
conditions occur.
hares (prey)
lynx (predator)
year
bean weevils (prey)
branconid wasp (predator)
generation
approximate number of lemmings per acre
How Is Population Growth
Regulated?
– Why are the peaks and valleys above not always
the same?
• Ecosystem Changes May Allow Temporary Rapid
Growth
– Extra food and water/Less food or water
– A new species invading the area = an exotic species
• Environmental Resistance Limits Population
Growth
– You can get a stable population
– Birth rate is balanced by death rate
– Figure 27.6 The S-curve of population growth (p.
553)
number of individuals
(environmental resistance)
carrying capacity
equilibrium
(biotic
potential)
rapid
growth
time
How Is Population Growth
Regulated?
– Density-Independent Factors Limit
Population Size
• Natural disasters, weather, human activities
– Density-Dependent Factors Have Greater
Effect As Population Density Increases
• Predator and prey cycles
• OR parasite and host
• Figure 27.7 Predators help control prey
populations (p. 555)
How Is Population Growth Regulated?
– Predators Exert Density-Dependent Controls on
Populations
• The more prey there is, the more frequently the predators find
them
– Parasites Spread Faster When Host Population Density
Is High
• In the same way, when there are more hosts, the parasites
spread more easily
– Populations Can Soar or Crash When Predator–Prey
Relationships Are Disrupted
• Break the natural cycle, and numbers can get out of hand!
– Competition for Resources Helps Curb Population Size
• Then starvation is needed to control numbers
How Is the Human Population
Changing?
• Is it creepy thinking of humans in the
same way we think of
animals/plants/parasites?
The same rules can apply.
• Figure 27.8 Human population growth
(p. 557)
Agricultural advances
billions of people
bubonic plague
Technical and cultural advances
Industrial and
medical
advances
How Is the Human Population Changing?
• Technological Advances Have Increased Earth’s
Carrying Capacity for Humans
– Early Tools Allowed Human Populations to Spread and Prosper
• There was a cultural revolution when fire was discovered
• Tool, weapons, shelter, protective clothing
– Agriculture Fostered Population Growth
• 8000BC crops and domesticated animals replaced hunting and
gathering
– Explosive Growth Began with the Industrial Revolution
• bacteria, smallpox etc.
• Population Growth Continues Today But Is Unevenly
Distributed
– All countries are not reproducing equally
– Population in developing vs. developed countries (p. 558)
population (billions)
2004: 6.3 billion
developing countries
developed countries
How Is the Human Population
Changing?
• The Age Structure of a Population
Predicts Its Future Growth
– Broken into pre-productive, reproductive,
and post-productive slices
– The overall shape tells you if the population
is growing, steady, or shrinking
– Age structure diagram (p. 558)
postreproductive
(46-100 years)
reproductive
(15-45 years)
prereproductive
(0-14 years)
expanding
stable
shrinking
27.4 How Is the Human
Population Changing?
– 27.4.3.1 Almost All Future Population
Growth Will Be in Developing Countries
• Figure 27.9 Age structures compared (p. 559)
• Figure 27.10 Population growth by world
regions (p. 560)
Developed countries
2003
age
postreproductive (45-79 yr)
reproductive (15-44 yr)
prereproductive (0-14 yr)
millions of people
2025
age
Developing countries
millions of people
World average 1.3%
Developing countries 1.6%
World regions
Africa 2.4%
Latin America/Caribbean 1.7%
Asia (excluding China and Japan) 1.6%
China 0.6%
Developed
countries 0.1%
N. America 0.5%
Europe -0.2%
annual natural increase
How Is the Human Population
Changing?
– Fertility in Europe Is Below Replacement Level
– More deaths than births!
But…
• The U.S. Population Is Still Growing Rapidly
– Natural increase of 0.6%/year
– With immigration  1.4%
– Example: In 2002: 4.1million more that year,
11,000 more a day
– 2050 could be 420 million (up from 295 million
presently)
– Figure 27.11 U.S. population growth (p. 560)
U.S. population (in millions)
(1790-2004)
year
Chapter 28
• Community Interactions
Why Are Interactions in
Ecological Communities
Important?
• An ecological community consists of all the
interacting populations in an ecosystem.
• Can be beneficial, harmful, or have no effect
on any two interacting populations
• Table 28.1 Interactions within Communities
(p. 568)
Why Are Interactions in
Ecological Communities
Important?
• Community Interactions Help Limit
Population Size
– This can be messed up when members of
foreign populations are introduced
– Completion goes out of balance  no
natural predators for introduced species
– Figure E28.1 Exotic species (p. 570)
Zebra Mussels
Kudzu
Water hyacinths
The rosy wolf snail attacks Hawaii’s native snails
Why Are Interactions in
Ecological Communities
Important?
• Community Interactions Influence
Evolutionary Change
• Wolf and Deer again
• Wolves prey on the weakest deer and
the weakest deer can’t catch fast deer
• This concept is called coevolution
What Are the Effects of Competition
among Species?
• When you have interspecific competition,
you have different species competing for the
same resources
• Each Species Has a Unique Place in Its
Ecosystem
– Those places are referred to as niches
– A niche can be defined by
•
•
•
•
•
range of temperature
moisture
available nutrients/food/prey
time of day food/moisture is available
even soil pH (acidity)
Niches
• BUT The Ecological Niches of Coexisting
Species Never Overlap Completely
• Often, one survives (a slightly wider range of
flexibility) and the other dies out.
• Example: two paramecium in a flask…
P. aurelia
P. caudatum
grown in
separate
flasks
grown in
the same
flask
Healthy competition
• Critters (species) can coevolve to
decrease competition (greater chance
of survival that way)
• Called resource partitioning
• The ones that don’t compete as much
as the rest of the species has the
greater food/resource supply and
survives and reproduces better
Warblers as
examples of
Resource
Partitioning each species
spends at least
50% of foraging
time in
designated areas
What predators and prey do to
each other …
• We see the current state of a long playing arms
race.
Camouflage assists predators
• Where ARE the kitties?
• and Figure 28.6 (p. 574)
Warning coloration
– Animals with bright coloration are often
poisonous
– Figure 28.7 (p. 574)
Warning mimicry
• Harmless animals may look like harmful ones
(Coral Snake and Mt. King Snake)
• Distasteful species may end up looking like one
another…a universal sign of bad taste
(Monarch and Viceroy butterflies)
• Or prey can mimic another predator (snowberry
fly mimics the jumping spider)
• Or they can startle- reveal what looks like large
eyes that would belong to a big predator
Chemical warfare
• Skunks!
• Other examples:
• Bombardier sprays a hot toxic brew
(pictured)
• and Monarch caterpillars feed on milkweed
that contains a powerful toxin
• Figure 28.11 (p. 576)
Symbiosis – working together
• Parasites – harm, but don’t immediately kill the
host (if their life cycle is short, what do they
care?)
• How does that apply to diseases?
– Ebola?
– Flu?
– AIDS or mad-cow disease?
• Lichen = Fungi + Algae (Fungus= protection, Algae
= photosynthesis/food
• Cows and termites can only digest cellulose
containing plant tissue due to protists and bacteria
in their guts (you too for many vitamins and
digestion)
• Figure 28.12 Mutualism (p. 577)
Eyelash Mites
Keystone species
• The controller of other species in a
region/habitat/niche
• Remove it and other populations explode
or crash
• Figure 28.13 (p. 577)
– The starfish Pisaster controls mollusks
– The elephant feeds on small trees and bushes,
preventing the encroachment of the forests,
preserving the grasslands for everything else
All good things must come to
and end Jean Luc…
• When something disastrous happens to a region,
life ‘rushes’ in to grab hold again.
• Pioneers (hardy organisms) lead the way
• Then it progresses to a stable climax community
eventually results
• Figure 28.14 New life emerges after disruption
(p. 578)
Successions…
• Figure 28.15 Primary succession (p. 579)
– Starts with bare rock, sand or a clear glacial pool
• Figure 28.16 Secondary succession (p. 580)
– Starts after an existing ecosystem is disrupted or
destroyed (farm land or volcanic eruption)
• Example: Figure 28.17 Succession in a
freshwater pond (p. 581)
lichens and moss
on bare rock
0
bluebell, yarrow
blueberry,
juniper
time (years)
jack pine, black spruce,
aspen
balsam fir,
paper birch,
white spruce,
climax forest
1000
plowed
field
0
ragweed,
crabgrass
and other
grasses
asters,
goldenrod,
broom sedge
grass
blackberry
time (years)
Virginia pine,
tulip poplar,
sweet gum
oak-hickory climax
forest
200
Chapter 29
• How Do Ecosystems Work?
• Biosphere 2
–
–
–
–
–
–
–
(What was Biosphere 1?)
1991: a 3 acre glass and steel ‘greenhouse’
900,000 gallon ocean
8 people for 2 years at a time sealed in
CO2 (rich soil and concrete)
Nitrous Oxide (rich soil)
Ants (stressed all vertebrates, ended pollination
etc.)
– Ultraviolet (photosynthesis not as efficient)
– Yams did well… with strange side effects
How Do Ecosystems Obtain
Energy and Nutrients?
• Energy flows through the Earth system
• Nutrients are cycled around (reused)
• Trivia: Has anyone else breathed the air or
drunk the water you are breathing and last
drank?
• Figure 29.1 Energy flow, nutrient cycling,
and feeding relationships in ecosystems (p.
588)
HEAT
producers
Energy from
sunlight
HEAT
NUTRIENTS
primary consumers
detritus feeders
and decomposers
HEAT
solar energy
heat energy
energy stored in
chemical bonds
higher-level
consumers
nutrients
HEAT
How Does Energy Flow
through Ecosystems?
• Energy Enters Ecosystems through
Photosynthesis
– After reflection, absorption, hitting a plant and making it
to the chlorophyll, about 1% of the sunlight that makes it
here can be used in photosynthesis. Then only about
3% of that is actually made into sugars/energy
containing molecules
– = 0.03% of the sunlight becomes food for the earth
– Everything is either a producer or a consumer. Which
are you? Which is your brother-in-law?
– Figure 29.2 Photosynthesis (p. 589)
Energy is
captured
from
sunlight.
Carbon dioxide
is absorbed
from the air.
photosynthesis
Water is absorbed
from soil, used in
photosynthesis, and
stored in cells.
Oxygen is
released.
Sugar is
synthesized
and used in
plant tissues.
plant
tissues,
growth
Inorganic mineral nutrients
(nitrate, phosphate) are
absorbed from soil and
used in plant tissues.
How Does Energy Flow
through Ecosystems?
• Energy Captured by Producers Is
Available to the Ecosystem
– Called the biomass
– Produces oxygen as a byproduct (the only
thing putting oxygen in the atmosphere)
– Figure 29.3 Ecosystem productivities
compared (p. 590) in grams of organic
material per square meter
tundra
(140)
tropical
rain forest
(2200)
open
ocean
(125)
continental
shelf
(360)
estuary
(1500)
coniferous
forest
(800)
temperate
deciduous forest
(1200)
grassland
(600)
desert
(90)
How Does Energy Flow
through Ecosystems?
• Energy Passes from One Trophic Level to Another
– Primary consumers eat plants (herbivores –plant eaters)
– Secondary consumers (carnivores- meat eaters)
– A tertiary consumer is a carnivore that eats carnivores
• Feeding Relationships within Ecosystems Form
Chains and Webs
– We can picture these levels in a more complex way…
– Figure 29.4 Food chains (p. 591)
– Figure 29.5 A food web in a shortgrass prairie (p. 592)
TERTIARY CONSUMER
(4th trophic level)
PRIMARY CONSUMER
(2nd trophic level)
PRODUCER
1st trophic level
SECONDARY CONSUMER
(3rd trophic level)
SECONDARY CONSUMER
(3rd trophic level)
Phytoplankton
PRODUCER
(1st trophic level)
Zooplankton
PRIMARY CONSUMER
(2nd trophic level)
TERTIARY CONSUMER
(4th trophic level)
How Does Energy Flow
through Ecosystems?
• Detritus Feeders and Decomposers
Release Nutrients for Reuse
– Then everything dies and decomposes
– Detritus feeders – tiny animals and protists
that feed on dead things
– Then the fungi and bacteria break it down
further to just nutrients = decomposers
Passing on the energy
• Energy Transfer through Trophic Levels Is
Inefficient
– Only 1/10th of the energy consumed by one level
is available to the next level that eats it
– Waste heat/energy is what keeps you warm and
alive, but is lost to the environment as you live
– Figure 29.6 Energy transfer and loss in a forest
(p. 593)
HEAT
heat
energy
stored in
chemical
bonds
producer
primary consumer
detritus feeders and decomposers
secondary consumer
How Does Energy Flow
through Ecosystems?
• Energy Pyramids Illustrate Energy
Transfer between Trophic Levels
– Remember 90% is lost each level (1/10th or
10% is available to the next level)
– Figure 29.7 An energy pyramid for a prairie
(p. 593)
– Figure 29.1 The price of pollution (p. 594)
tertiary consumer
1 calorie
secondary consumer
10 calories
100 calories
1000 calories
primary consumer
producer
How Do Nutrients Move
within and among
Ecosystems?
• Remember, energy flows through (from the
sun, to the Earth, is used for a bit, then goes
back to space)
• Carbon Cycles through the Atmosphere,
Oceans, and Communities
– Fossil fuels ADDS OLD carbon to the systemmaking a NEW balance in the system
– Figure 29.8 The carbon cycle (p. 596)
reservoir
processes/locations
CO2 in
atmosphere
trophic levels
burning of
fossil fuels
fire
respiration
CO2 dissolved
in ocean
producers
consumers
wastes, dead
bodies
soil bacteria
and
detritus feeders
fossil
fuels
limestone
How Do Nutrients Move
within and among
Ecosystems?
• The Major Reservoir for Nitrogen Is the
Atmosphere
– But it can’t be used by plants directly
– Needs to be ‘fixed’ in the soil for root
uptake
– Ammonia produced by bacteria (symbiosis
again!)
– Figure 29.9 The nitrogen cycle (p. 597)
reservoir
processes/locations
trophic levels/organisms
electrical storms
produce nitrate
nitrogen in
atmosphere
burning produces
nitrogen oxides
fertilizer
factories
consumers
producers
wastes, dead
bodies
denitrifying
bacteria
uptake
by
plants
soil bacteria
and
detritus feeders
ammonia and
nitrate in soil
and water
nitrogen-fixing
bacteria in
legume roots
and soil
How Do Nutrients Move
within and among
Ecosystems?
• The Major Reservoir for Phosphorus Is
Rock
– Worn down through erosion
– Bacteria in the soil
– And the return of phosphorous from waste
or dead organisms (fertilizer!)
– Figure 29.10 The phosphorus cycle (p.
598)
reservoir
processes/locations
trophic levels
geological
uplift
phosphate
in
rock
runoff
from rivers
consumers
producers
runoff from
fertilized
fields
phosphate
in
water
detritus
feeders
phosphate
in
soil
phosphate
in
sediment
How Do Nutrients Move
within and among
Ecosystems?
• The Hydrologic Cycle does the major moving
• WATER again! Very important for large scale
life and us on our own.
• Water Remains Unchanged During the Water
Cycle
– Just goes through phase changes
– Figure 29.11 The hydrologic cycle (p. 599)
reservoirs
processes/locations
water vapor
in atmosphere
evaporation from
land and
transpiration
from plants
evaporation
from
ocean
Precipitation
over
ocean
precipitation
over
land
lakes and
streams
water in
ocean
surface
runoff
groundwater
What Is Causing Acid Rain
and Global Warming?
• The earth CAN absorb some of ANY
pollutant…but when we exceed the rate it
can break down/take up/utilize (biotic and
abiotic systems) then we have too much of a
‘normal’ substance. = Pollution.
• Figure 29.12 A natural substance out of
place (p. 599)
• (There ARE microbes that can break down
oil…just slowly.)
What Is Causing Acid Rain
and Global Warming?
• Overloading the Nitrogen and Sulfur Cycles
Causes Acid Rain
– Primarily from the combustion of fossil fuels –
coal is really bad unless cleaned before of after
combustion
– About 20 million tons of sulfur dioxide emitted in
the US
– Volcanoes do too, but not as consistently.
– Combines with water (droplets or drops) in the
atmosphere  acid rain
– 29.4.1.1 Reactions in the Atmosphere Form Acid
Deposition
• Figure 29.13 Acid deposition is corrosive (p. 600)
What Is Causing Acid Rain
and Global Warming?
– In the Adirondack Mts. – acid levels of about 25%
of the lakes is too high for fish to live
– Forests harmed
– Acidic water dissolves lead in old piping solder =
high lead levels in your drinking water
– Acid Deposition Damages Life in Lakes, Farms,
and Forests
• Figure 29.14 Acid deposition can destroy forests (p.
600)
What Is Causing Acid Rain
and Global Warming?
• Disruption of the Carbon Cycle Contributes to Global
Warming
– Release of OLD carbon from oil/coal upsets the normal
levels
– Deforestation removes the things that can uptake the
carbon (remember: trees etc. are just solidified atmospheric
carbon dioxide!)
– Greenhouse Gases Trap Heat in the Atmosphere
• More like a THERMAL BLANKET than a Greenhouse, but the
name has stuck.
• Figure 29.15 Increases in greenhouse gas emissions contribute to
global warming (p. 601)
• Figure 29.16 Global warming parallels (p. 603)
heat radiated
into space
sun
outer space
sunlight
CO2
CFCs
methane
nitrous oxide
atmosphere
heat trapped
in atmosphere
volcano
forest
fires
factories
vehicle
emissions
houses
cows
average world temperature (°C)
CO2 concentration
(parts per million by volume)
CO2
temperature
The famous carbon graph
Back in time…
And back and back…
What Is Causing Acid Rain
and Global Warming?
– Global Warming May Have Severe
Consequences
• Polar ice cap and glacier loss
• Rising sea levels (NOT from ice, but from
ocean EXPANSION)
• Spread of tropical diseases
• Change of economies/farming regions
• And more?
Only you can prevent…
• Our Decisions Make a Difference
– We are ~5% of the worlds population but
produce 20% of it’s carbon dioxide
– If we all switched to low power florescent
light bulbs (now coming in more natural soft
colors) we can reduce energy consumption
– Will the leveling off of oil production and it’s
increase cost change this via market
pressure?
• Are SUV’s as popular now as they were?
Chapter 30
• Earth’s Diverse Ecosystems
What Factors Influence
Earth’s Climate?
• Both Climate and Weather Are Driven
by the Sun
– What causes the seasons?
– We are close to the sun at one time of the
year and further from the sun at anther
time.
– Which times of the year are we closest or
further?
The reason for the season
– We are closest to the sun Jan 5th
– We are further from the sun July 11th (give
or take a few days)
– IT IS NOT THE SUN EARTH DISTANCE!!
So what is it?
What Factors Influence
Earth’s Climate?
• Sunlight Strikes Earth at Various Angles
– Gives us the seasons AND the hottest time
of the day and coolest time of the night
– Figure 30.1 Earth’s curvature and tilt
produce seasons and climate (p. 610)
sunlight
sunlight
The Earth at 23.5O Tilt
Seasonal Variation.
What Factors Influence
Earth’s Climate?
• Air Currents Produce Regional
Climates
– Figure 30.2 Distribution of air currents and
climatic regions (p. 612)
Air Mass Formation
General Air Patterns
Atmospheric Circulation Pattern
The sun, through heating of land and air,
drives the earth’s patterns of rains, winds,
and ocean currents.
Air on the move
Coriolis
Effect
Cell Names…
http://goes-rap.cira.colostate.edu/GOES-10/GEMS/Original/JPEG/Current/fulldisk_c01.jpg
Global Patterns of Air
Circulation/Precipitation
• Air rises at the equator (equator = hot) First
convection cell is highest because most energy
• Adiabatic cooling
• Rain occurs (cool air holds less water).
• Air from the North and South comes in to replace it.
• Coriolis effect - air is deflected because of
momentum.
Air Pressures
Areas of High and Low Pressure
Generate Surface Winds
cold, dry
air falls
rain
forest
cool, moist
air rises
(rain)
60º N
warm, dry
air falls
30º N
desert
rain
forest
0º
hot,
moist
air rises
(rain)
desert
30º S
warm, dry
air falls
60º S
cold, dry
air falls
cool, moist
air rises
(rain)
South African
Desert
Sahara
Desert
Arabian
Desert
Coriolis
Effect
Coriolis
Effect
Responsible
for where
wind blows
from; wind
patterns
influence
regional
weather.
Winds
Wind is the horizontal movement of air from areas
of high to low pressure.
High pressure regions are dominated by cold,
descending air, while low pressure areas are
associated with warm, rising air masses.
Winds blow from high pressure to low pressure.
Winds are deflected from their course by the
Coriolis Effect (to the right in the Northern
Hemisphere)
Ocean Currents Due to Coriolis Effect
and Land Masses
Ocean waters
warmed in
the equatorial
regions
transport heat
energy to
other parts of
the globe.
Circulation of Warm and Cool
Ocean Waters has a Moderating
Effect on Coastal Cities
Effects of
Upwelling and
Downwelling
on Currents
When the wind blows
parallel to a Northern
Hemisphere coastline and
the ocean is to the right of
the wind direction,
upwelling can result. Wind
in the opposite direction
produces downwelling.
Upwellings Bring Nutrients to
Surface
ENSO (El Niño – Southern
Oscillation)
The Southern oscillation is a phenomenon that refers
to the see-saw effect of surface air pressures in the
Eastern and Western Pacific Ocean. For Example,
when air pressure recordings are high in Tahiti, they
are low in Eastern Australia.
Also noted was a cycle of varying Pacific Ocean
temperatures which occurs annually on a small scale.
This was recognized by Peruvian fishermen who
called it El Niño (Christ Child) because it occurred
during the winter close to Christmas.
Normally, have
warm waters and
heavy
precipitation in
the western
Pacific.
El Niño, have
warm waters
migrate to the
eastern Pacific
along with the
convective cell
and increased
rainfall.
El Niño and La Niña
La Niña (cold conditions)
Normal Conditions
El Niño (warm conditions)
Climate Changes Associated with
ENSO (El Nino in the media)
http://proa.accuweather.com/www/phoenix2/includes/professional/misc/misc-sst.htm
30.1 What Factors Influence
Earth’s Climate?
• 30.1.4 Ocean Currents Moderate
Nearshore Climates
– Figure 30.3 Ocean circulation patterns (p.
612)
Greenland
Eurasia
Eurasia
North
America
Africa
South
America
Australia
Antarctica
Antarctica
What Factors Influence Earth’s Climate?
• Continents and Mountains Complicate
Weather and Climate
– Figure 30.4 Effects of elevation on
temperature (p. 613)
– Figure 30.5 The rain shadow of the Sierra
Nevada (p. 613)
rock, snow, and ice
tundra
coniferous
forest
deciduous
forest
tropical
forest
equatorial
regions
Latitude
polar
regions
average annual
precipitation (cm)
altitude (m)
winds
west
Where do you find places like this in the US?
east
What Conditions Does Life
Require?
• Nutrients from which to construct living tissue
• Energy to power that constuction
• Liquid water in which metabolic reactions can
take place
• Appropriate Temperatures
• What about mushrooms?
• Figure 30.6 Environmental demands mold
physical characteristics (p. 614) – nearly identical
but widely separated evolutionary areas…
How Is Life on Land
Distributed?
• Terrestrial Biomes Have Characteristic Plant
Communities
– Biomes are the regions with similar temperature,
nutrient supply, etc.
– Biomes are typically named by the major type of
vegetation found there
– Figure 30.7 The distribution of biomes (p. 614)
– Figure 30.8 Rainfall and temperature influence
biome distribution (p. 615)
60º N
30º N
0º
(equator)
30º S
60º S
tropical forest
chaparral
grassland
desert
temperate deciduous forest
coniferous forest
savanna and tropical
shrub forest
temperate rain forest
tundra and alpine vegetation
ice
low
Temperature
tundra
coniferous forest (taiga)
cool
desert
high
warm
desert
low
cool
grassland
warm
grassland
temperate
rain forest
temperate
deciduous forest
savanna
Rainfall
tropical
deciduous forest
tropical
rain forest
high
A quick survey…
How Is Life on Land
Distributed?
• Tropical Rain Forests
– Temperatures 77 to 86F; little seasonal variation
– 100-160 inches of rain a year!
– Highest biodiversity on the planet
• Picture of Tropical rain forests (p. 616)
• Figure 30.9 The tropical rainforest biome (p. 616)
• Human Impact: Deforestation…
• Figure 30.10 Fire engulfs a tropical rain forest in
Brazil (p. 617)
How Is Life on Land
Distributed?
• Tropical Deciduous Forests
– Slightly further from the equator
– A definite wet and dry season
– Plants usually drop their leaves in the dry season to
conserve water
• Tropical deciduous forests (p. 618)
How Is Life on Land
Distributed?
• Savannas
– Moving away from tropical deciduous forests, trees
get more sparse
– Rainy season with 12 inches/year or less
• Figure 30.11 The African savanna (p. 618)
• Human impact: poachers
• Figure 30.12 Poaching threatens African
wildlife (p. 618)
How Is Life on Land
Distributed?
• Deserts
– Usually at about 30 degrees N and S of the equator
– Less than 10 inches of annual rainfall
– Often hot, but can be very cold
» The Gobi Desert in Asia = temperature below freezing
for half the year
– Plants adapted to harsh low water environment
• Human Impact – off road damage to delicate life Web
• Figure 30.13 The desert biome (p. 619)
• Figure 30.14 The Sonoran Desert (p. 619)
How Is Life on Land
Distributed?
• Chaparral
–
–
–
–
Coastal regions that border deserts
Vegetation called chaparral
Annual rainfall as much as 30 inches
Wet winters, hot dry summers
• Figure 30.15 The chaparral biome (p. 620)
How Is Life on Land
Distributed?
• Grasslands
–
–
–
–
•
•
•
•
Located in the center of continents
10-30 inches of rain typically
Warm/hot summers, cold winters
Fires are important to life cycles
Human impact: Grazing and Farming
Figure 30.16 Tallgrass prairie (p. 620)
Figure 30.17 Shortgrass prairie (p. 621)
Figure 30.18 Sagebrush desert or shortgrass
prairie? (p. 621)
How Is Life on Land
Distributed?
• Temperate Deciduous Forests
– More precipitation than grasslands – 30-60 inches a
year
– Cold winters!
– Trees drop leaves during cold weather.
– Many insects and arthropods to feed on biomass
• Human Impact: Hunting of predators/deer etc.
• Figure 30.19 The temperate deciduous forest
biome (p. 622)
How Is Life on Land
Distributed?
• Temperate Rain Forests
–
–
–
–
–
Mountains on the western (upwind) side of continents
Up to 160 inches of rain a year
Mild temperatures year round
No need to shed leaves
Fog is common
• Figure 30.20 The temperate rainforest biome
(p. 623)
How Is Life on Land
Distributed?
• Taiga
–
–
–
–
–
North of grasslands and temperate forests
Also called northern coniferous forest
Slow growth trees – conifers
Harsh cold winters
Large game, bear, moose, caribou etc.
• Human Impact: The lumber industry
• Figure 30.21 The taiga (or northern coniferous
forest) biome (p. 624)
• Figure 30.22 Clear-cutting (p. 624)
How Is Life on Land
Distributed?
• Tundra
–
–
–
–
–
The last biome before the polar ice cap
Winters often reach –40F or below
Strong winds
Average less 10 inches a year  freezing deserts
Permafrost = permanently frozen soil usually about
1.5 feet below the surface
– Roots limited to a shallow soil layer
– Short growing season
• Human impact: Any human changes last for
centuries, little grown to erase scars.
• Figure 30.23 The tundra biome (p. 625)
How Is Life in Water
Distributed?
• Freshwater Lakes Have Distinct Regions of
Life
– Life Zones Are Determined by Light and Nutrients
• Littoral zone = shallows, plants can anchor, lots of
sunlight and nutrients
• Limnetic zone = Enough light penetrates to allow some
photosynthesis
• Profundal zone = No light, dead stuff falls to feed
bottom dwellers
• Figure 30.24 Life zones of a lake (p. 628)
– Freshwater Lakes Are Classified by Nutrient
Content
littoral zone
limnetic zone
profundal zone
How Is Life in Water
Distributed?
• Marine Ecosystems Cover Much of Earth
– Photic zone = depth sunlight penetrates to
support photosynthesis
– Aphotic zone = too dark for direct production of
energy from sunlight
– Upwelling is needed to bring nutrients from the
deep to fish and creatures in shallow (warmer)
water
– Figure 30.25 Ocean life zones (p. 630)
intertidal
zone
near-shore
zone
dry land
open ocean
photic
zone
200 m
aphotic
zone
How Is Life in Water
Distributed?
– Coastal Waters
•
•
•
•
•
Support a LOT of life
Nutrients are available
Tides move nutrients and oxygen around
Salt marshes and estuaries
protect the shore in storms and provide for
much life
• Human Impact: Hotels, recreation, oil spills
etc.
• Figure 30.26 Nearshore ecosystems (p. 631)
How Is Life in Water
Distributed?
–
–
–
–
Coral Reefs
Water about 72-82F
In the photic zone – less than 130 feet deep
Build up from carbon fixed in carbonate shells
over long periods of time
– Wide diversity of life
– Human Impacts: Over fishing, river pollution,
many are getting ‘sick’ presently
• Figure 30.27 Coral reefs (p. 632)
How Is Life in Water
Distributed?
– The Open Ocean - about 65% of the planet
– Food Web depends on phytoplankton
• Things that swim (surface is far far below, outside of
the reach of sunlight)
• A strange variety of deep see creatures – much to be
discovered
• Human Impact: Over fishing (whales etc.) and
pollution.
• Figure 30.28 The open ocean (p. 634)
How Is Life in Water
Distributed?
– Hydrothermal Vents
• Discovered in 1977
• Superheated volcanically warmed water rises from the
ocean floor
• Supports a wide variety of life – blind, no
photosynthesis, sulfur and other chemical reactions
power life
• Some can survive in water up to ~250F!
• Figure 30.29 Hydrothermal vent communities (p. 635)
Finis!
• You’ve now been from atoms to life
across the planet and through time.