Transcript Temperate deciduous forest

Mrs. Daniels
Advanced Biology
April 2005 (revised April 2008)
Population Ecology - Ch. 51
• The study of the numbers of individuals of a
particular species at a given time and
location
• Includes interactions of that population with
other populations and the environment
Density and Dispersion
• Density: the # of individuals of a particular species per
unit of space
• Dispersion: the spacing of those individuals
• Uniform evenly
distributed
• Random - lack of • Clumped - most
interaction between common; patchy
indiv.
– Result of uneven
distribution of
resources or asexual
reproduction
Dispersion of individuals within a
population
bluestripe snappers (Lutjanus kasmira)
Schooling of some fish is an example
of clumped dispersion
Cape gannets (Morus capensis)
These birds space their nests out evenly
Growth Rate
• r = growth rate in a population
• Takes into consideration birth rate (natality)
and death rate (mortality)
• No population can increase exponentially
indefinitely
• Limiting factors become important
• Carrying capacity (K): the largest
population that can be sustained for an
indefinite period of time
Exponential population growth
Number of bacteria (N)
1,200
1,000
800
dN
= rN
dt
600
400
200
0
0
2
4
6
Hours
8
10
12
Carrying capacity and logistic population growth
Number of individuals (N)
Carrying capacity of
the environment (K)
dN
= rN
dt
Time
K–N
K
(
)
Strategists
• r-strategists: high r, small size, large # of
offspring, may live in unpredictable habitats
• K-strategists: have a population size near
K, are larger in size, have fewer offspring,
may care for their young
• Which type are humans?
Survivorship curves
1000
Figure 51-8
Page 1013
Number of survivors (log scale)
Type I
100
Type II
10
1
Type III
0.1
Young
Old
Total life span
Survivorship Curves
• Type I: the young and those at reproductive age
have a high probability of surviving while
probability of surviving decreases with age
• Ex. Humans and bison
• Type II: probability of survival does not change
with age; no age bias
• Ex. Some lizards
• Type III: the young are less likely to survive
than those of increased age
• Ex. oysters
Population Size
• Regulated by density-dependent and densityindependent factors
• Density-dependent: factors that increase
proportionally with population size
• Ex. Competition
• Density-independent: affect population
regardless of size
• Ex. Climatic factors
Competition
• Intraspecific: between members of same
species
• Interspecific: between members of
different species
Human Populations
• Population statistics - demographics
• Not all countries have the same growth rate
• Less developed countries have the highest growth
rate
• Developed countries have a higher degree of
industrialization and prosperity and have a lower
growth rate
• Environmental degradation is a result of
overpopulation and resource consumption
• Overpopulation causes over-consumption and overutilization of resources
Human population growth
Figure 51-13
Page 1016
Human population (billions)
6
5
1999: 6 billion
4
3
2
Black Death
1
8000
6000
4000
Time (years)
2000
BCE CE
2000
Human Population Growth
• Do all countries/areas of the world have the same
population growth rate?
• Why or why not?
• Have we reached carrying capacity on the Earth?
• Scientists actually calculate K for this planet to be
____________...IF all resources were being
utilized equitably
Birth and death rates in Mexico, 1900 to 2000
50
Rate per 1000 population
Birth rate
40
Overall population
increase
30
20
Death rate
10
1900
1925
1950
Time (years)
1975
2000
Age structure diagrams
Slow population growth
United States
Male
Female
Decline in
population growth
Germany
Female
Male
12 10 8 6 4 2 0 2 4 6 8 10 12
12 10 8 6 4 2 0 2 4 6 8 10 12
4 3 2 1 0 1 2 3 4
Number of people
(in millions)
Number of people
(in millions)
Rapid population growth
Age
Nigeria
80+
75–79
70–74
65–69
60–64
55–59
50–54
45–49
40–44
35–39
30–34
25–29
20–24
15–19
10–14
5–9
0–4
Male
Female
Number of people
(in millions)
Community Ecology - Ch. 52
• In a community, populations interact in a variety
of ways
• NO species exists independently of other species
• Niche - a species role in the community
– All aspects of the organism’s existence, not
just habitat
– May be influenced by resources: biotic and
abiotic
Resource partitioning
Figure 52-5
Page 1028
Cape May warbler
Blackburnian
warbler
Bay-breasted warbler
Yellow-rumped
(Myrtle) warbler
Black-throated
green warbler
Avoiding Competition
Percentage of individuals of each size class
G. fuliginosa
G. fortis
Bill depth
40
20
0
8
10
12
14
8
10
12
14
40
20
0
40
20
0
8 10 12 14
Bill depth (mm)
• Character
displacement:
adaptation of
characteristics that
average bill depths of
enables interspecific
G. fuliginosa
competition to be
reduced
average bill depths of
G. fortis
• (ex. Darwin’s
finches)
Effect of competition on an organism’s realized niche
Species 1
Niche
overlap
Species 2
Niche dimension (habitat)
Brown anole (Anolis sagrei)
Resource use
Resource use
Green anole (Anolis carolinensis)
Species 1
Species 2
Niche dimension (habitat)
Predation
• Predator: consumes members of another species
• Prey: is hunted or consumed by members of
another species
• Defenses:
• Plants - chemical (ex. Monarch’s)
• Animals – “cryptic” warning coloration
– mimicry
Müllerian mimicry
Monarch
Viceroy
Two species which are both harmful, poisonous, or distasteful
resemble each other for an added effect of safety. Because both
species are dangerous, the predators learn to avoid them much
more quickly.
Batesian mimicry
Scarlet king snake
(Lampropeltis triangulum elapsoides)
Eastern coral snake
(Micrurus fulvius fulvius)
A defenseless species (scarlet king snake ) gains protection
from predation by resembling a dangerous species (Eastern coral snake)
• Herbivore• Carnivore• Omnivore-
•
•
•
•
ProducerConsumerPrimary, secondary, tertiary, etc.
Decomposers-
Food Chains and Webs
Quick review from elementary and middle school…
Symbiotic Relationships
• Symbiosis: bio - live sym - together
• Mutualism - both benefit
– Ex. Myccorrhizae facilitate mutualistic
relationship between fungi and roots of some
plants
• Commensalism - one takes without harm
– Ex. Epiphytes living on tropical trees
– Spanish moss pictured to the right
• Parasitism - one benefits at the
other’s expense
– Ex. Tracheal mite seen here 
Biodiversity
• Biodiversity of the community is a measure
of the relative importance of each species in
the community
• Not to be confused with species richness,
which is the number of different species
within a community
Succession
• The process of developing a community over
time
• One species is replaced by another
• Primary - develops in a “lifeless” environment
– On newly formed volcanic lava and recently glaciated
rock
• Secondary - a community develops where a
previous community existed
– Ex. Areas that have been denuded or modified by fire
or agriculture (the soil remained after the fire…it
was not completely barren)
Ecosystems and the Biosphere Ch. 53
• We’ve already touched on part of this
chapter when we dealt with food webs
• We’ll continue this discussion and then
focus on the BioGeoChemical cycles
• Carbon, Nitrogen, Phosphorus, and Water
Cycles are central to life on Earth
Energy flow through ecosystems
Energy
from
sun
First
Second
Third
Fourth
trophic level: trophic level: trophic level: trophic level:
producers
primary
secondary
tertiary
consumers
consumers consumers
Heat
Heat
Heat
Heat
Decomposers
(saprotrophs)
Heat
A food web at the edge of an eastern deciduous forest
Figure 53-2
Page 1046
Pyramids of biomass
Secondary consumers (1)
Saprotrophs (10)
Primary consumers (4)
Producers
(40,000)
Tropical forest in Panama
Primary consumers (21)
Producers (4)
Plankton in English Channel
Pyramid of energy
Tertiary consumers (21)
Secondary consumers (383)
Saprotrophs (5,060)
Primary consumers (3,368)
Producers (20,810)
Notice that there is roughly a 90% reduction in energy
with each consecutive trophic level
A simplified diagram of the carbon cycle


Air (CO2)
750

Animal
Soil

and plant microorganism Decomposition
respiration respiration
Photosynthesis
by land plants
560

Combustion
(human and natural)
6
Marine
Partly
decomposed plankton
Soil
remains
Coal
1500 plant remains
 Natural gas

Coal
Oil

Dissolved
Erosion of CO in water
2
limestone to
38,000
form dissolved
CO2
Burial and
 compaction
to form rock
(limestone)
Carbon Cycle
• Carbon dioxide is the pivitol molecule of
the carbon cycle
• Carbon is present as:
• Carbon dioxide in the atmosphere
• Carbon dioxide, carbonate, and
bicarbonates in aquatic habitats
• Carbonates in rocks such as limestone
• Carbon fixation is done during
photosynthesis by plants, protists, and
photoautotrophic bacteria
• Organic molecules are stored in plants,
consumers, or as fossil fuels.
• Combustion of fossil fuels releases carbon
dioxide into the atmosphere
• Cellular respiration releases carbon dioxide
also
• We’ll discuss human impact on global
climate change later…
A simplified diagram of the nitrogen cycle
Atmospheric
nitrogen (N2)


Biological nitrogen
Nitrogen fixation
fixation (nitrogenfrom human activity
fixing bacteria in
100
root nodules and soil)
140

Denitrification
(denitrifying bacteria)
≤ 200

Decomposition
(ammonification by
ammonifying bacteria) Plant and animal proteins
Internal cycling
Assimilation
(nitrification, assimilation,
(nitrates, ammonia, or
ammonification on land) ammonium absorbed by roots and
1200
Ammonia (NH3)
used to make organic compounds)
+
and ammonium (NH4 )


Nitrification
(Nitrifying bacteria)
Nitrate (NO3–)
Nitrogen Cycle
• Bacteria can “fix nitrogen” which means they
break apart nitrogen gas and convert it into
ammonia or ammonium.
• Decomposition also results in ammonia products
and is called ammonification
• Nitrification converts ammonia into nitrates and
nitrites which can be used by plants to make
organic compounds.
• Denitrifying bacteria convert nitrates back into N2
Nodule
Root nodules and
nitrogen fixation
A simplified diagram of the phosphorus cycle

Phosphate
rocks
10,000 (mineable)

Geologic processes
(e.g., uplift)
Phosphate
rocks
Burial and compaction
to form rock
Phosphate
mining

Erosion of calcium
Fertilizer
containing
phosphates
phosphate minerals
Excretion and
Animals, crops
decomposition
Internal Dissolved
cycling phosphates

Internal
1000
90,000
cycling
Marine
60
organisms
Erosion
 Marine
sediments
Soil phosphates
9
4 x 10
200,000
Animal waste and
decomposition
Phosphorus Cycle
• Has no gaseous component (from land to sediment
and back to land only)
• Erosion releases phosphate into the soil where it
can be used by plants
• It is returned to the soil via decomposers
• Deposited in oceanic sediment – unavailable for
years
• Fertilizers, run off containing animal wastes, and
sewage introduce it into aquatic ecosystems
A simplified diagram of the hydrologic cycle
Movement of
moist air
Condensation
40,000
Atmosphere
(cloud formation)
13,000


Precipitation
on land
111,000

Percolation
 through soil
and porous rock
Evaporation
from ocean
425,000
71,000*
Evaporation from
soil, streams, rivers,
and lakes


Precipitation
to ocean
385,000
Transpiration

from vegetation Runoff
to ocean
40,000
Ocean
1,350,000,000
Groundwater
15,300,000
Water Cycle
• Let’s just review…
Focus On 1
Page 1056
A hydrothermal vent community
The fate of solar radiation that reaches Earth
30% reflected back
into space
immediately
Figure 53-11
Page 1057
Less than one billionth of the
sun’s total energy
reaches Earth’s outer
atmosphere.
Less than 1%
drives the
winds and
ocean currents
47%
absorbed
by the
atmosphere
23% runs the
hydrological cycle
All solar
energy is
ultimately re-radiated
to space as heat
0.02% captured by
photosynthesis
Seasonal changes in temperature
Figure 53-12
Page 1058
Vernal
equinox
March 21
Summer
solstice
June 21
Winter
solstice
December 21
Circle of
illumination
Day
Sun’s rays
Night
Earth’s orbit
Sun
Night
Arctic
Circle
Day
Autumnal equinox
September 22
Atmospheric circulation
Figure 53-13
Page 1059
Polar
easterlies
60°N
Westerlies
30°N
Trade winds
0
Trade winds
30°S
Westerlies
60°S
Polar
easterlies
Geographic Ecosystems - Chapter 54
Biomes - large terrestrial regions characterized by
similar climate, soil, and living things
• Tundra
• Taiga
• Temperate Rain
Forest
• Temperate
Deciduous Forest
•
•
•
•
Grasslands
Deserts
Savanna
Tropical Forests
(dry and rain)
Using precipitation and temperature to identify biomes
Figure 54-1
Page 1066
Annual precipitation (cm)
400
Tropical
rain
forest
300
Temperate
rain
forest
200
Temperate
deciduous
forest
100
Taiga
Temperate
grassland,
chaparral
Tropical
dry
forest
Savanna
Desert
Tundra
0
–10
0
10
Average temperature (°C)
20
30
ELEVATION
ZONES
High elevation
LATITUDE
ZONES
North Pole
Snow/ice
Polar region
Alpine tundra
Subalpine coniferous
forest
Deciduous forest
Low elevation
Comparison of elevation
and latitude zones
Arctic tundra
Taiga
Temperate forest
Mid-latitudes
Average monthly Average monthly
precipitation (cm) temperature (°C)
Significance of precipitation in temperate biomes
28
24
20
16
12
8
4
0
–4
14
12
10
8
6
4
2
J F MAM J J AS OND
J F MAM J J AS OND
Month
J F MAM J J AS OND
Temperate deciduous forest
(Nashville, Tennessee)
Temperate grassland
(Lawrence, Kansas)
Temperate desert
(Reno, Nevada)
The world’s major biomes
Equator
Tundra
Taiga
Temperate deciduous forest and
temperate coniferous forest
(includes temperate rain forest)
Temperate grassland
Desert
Chaparral
Mountains with complex zonation
Savanna
Tropical dry forest
Tropical rain forest
Arctic tundra
Tundra
•
•
•
•
•
•
•
Cold, boggy plains of the far north
Seasonal snow melts
Very little precipitation
Nutrient-poor soil lies over permafrost
Lichens, mosses, grasses, and sedges
Rodents and hares; insects in the summer
Migratory birds
Figure 54-5
Page 1070
Taiga
Taiga
• An evergreen forest of the north
• a.k.a. - boreal forest
• Longer growing season, but little
precipitation
• Some deciduous trees; dominated by
conifers
• Yields much lumber and pulpwood
Temperate
rain forest
Temperate Rain Forest
• Cool weather, dense fog, high precipitation
• NW US, SE Australia, southern South
America
• Dominated by conifers
• Yields much lumber and pulpwood
Temperate
deciduous forest
Temperate Deciduous Forest
• Dense canopy of broad-leaf trees
• Trees overlie saplings and shrubs
• Great seasonal variation in temperature and
moderate precipitation
• Has been converted to agriculture in much
of the world
Temperate
grassland
Grasslands
• Temperate areas with moderate precipitation
• Dominated by grasses
• Most native grasslands have been converted
to agriculture; well-suited to raising cereal
crops
Chaparral
Chaparral
• Thicket of evergreen shrubs and small trees
• California, Western Australia, Chile, South
Africa, Mediterranean area
• Dominated by drought-resistant shrubs and
scrub and has adapted to fire
Desert
Deserts
• Both temperate (cold deserts) and
subtropical and tropical regions (warm
deserts)
• Low precipitation
• sparse vegetation - small in size
Savanna
Savanna
• Tropical grassland with scattered trees
• Africa, South America, West India, and
Northern Australia
• Greatest abundance of hoofed mammals
• Often converted to rangeland for
domesticated animals
Figure 54-12
Page 1074
Tropical rain forest
Tropical Forests
•
•
•
•
•
•
•
•
Tropical Dry Forests:
Have both a wet and dry season
Tropical Rain Forests:
High temps and high precipitation
Soils have little organic matter
Unrivaled in plant and animal diversity
Plant community is characterized by layers
Biome is threatened by overpopulation of indigenous
people and exploitation of resources by developed
countries
What do aquatic ecosystems all
have in common?
WATER!!!
Water IS the habitat
• What type of characteristics does water have?
• High Sp. Heat, Surface Tension, Density…
Aquatic Ecosystems: occupy most of Earth’s
surface
• Marine - salt water
– Dominate Earth’s surface
• Freshwater - include flowing-water, standingwater, and wetland ecosystems
• Estuaries - occur where freshwater and saltwater
meet
Marine Ecosystems
• 1. Intertidal zones - btwn land & ocean
– Between low and high tides
– Highly productive, but very stressful habitat
• 2. Benthic environment - the ocean floor
– Seagrasses, kelps, coral
• 3. Neritic area - consists of shallow waters close to shore
– Depths less than 200 m
• 4. Oceanic provinces - comprises most of the ocean
– Depths of over 200 m
– Abyssal zone - benthic area from 4000-6000m
– Hadal zone - benthic area deeper than 6000 m
Classifying Aquatic Ecosystems
• Aquatic ecosystems can be classified according to
abiotic factors OR types of organisms
• Types of Organisms:
Benthos
Periphyton
Plankton
Nekton
Neuston
• BENTHOS:
– Bottom dwellers
– Ex. Microbes, worms, clams, some crustaceans
• PERIPHYTON:
– Attach or cling to other structures
– Ex. Aquatic plants, zebra mussels, Stentor
• PLANKTON:
– Microorganisms that float (phyto- or zoo-)
• NEKTON:
– Large swimming organisms (ex. Fish)
• NEUSTON:
– Live at the surface
– Ex. Water striders, snails, other aquatic insects & larvae
Estuaries
• Where saltwater and freshwater meet
• Organisms living here have adapted to
being able to withstand constant changes in
their environment
(ex. salinity and
temperature)
Freshwater Ecosystems
• Lotic - Rivers and Streams
• Lentic - Lakes and Ponds
• Wetlands - Bogs, Fens,
Swamps, & Marshes
LOTIC SYSTEMS
• “Body of water in motion”
• Ex. Rivers and Streams
• Current is the most important feature
– It is constant
– And it shapes all features of the stream
• Small Streams:
• Headwater, typically cold, shallow, and
fast-moving
• Highly oxygenated
• Depend on detritus as a primary energy
input: allochthonous
• Rivers:
• Deeper, slower flowing, less dissolved
oxygen ; autochthonous
LENTIC SYSTEMS
• Standing or still water contained within a
basin
• Ex. Lakes and ponds
• The difference?
• Lakes are deeper and have thermal
stratification
• Large Lakes are divided into the littoral,
limnetic, and profundal zones
Epilimnion 22-25 degrees
Thermocline 10-20 degrees
Hypolimnion 4-5 degrees
Thermocline:
Zone of rapid
temperature change
Turnover
Organisms In Lakes
•
•
•
•
•
Controlled by many factors:
Temperature
Light
Nutrient availability
Oxygen availability
• Affects many factors:
• Nitrates, nitrites, ammonia, dissolved oxygen,
turbidity, etc.
WETLANDS
• Defined by soil which is saturated with water for at
least 6-9 months of the year
• These are natural filters and are very important to
the health of other habitats
• 5 major types:
• Marine - salt water
• Estuarine - salt marshes & brackish wetlands
• Lacustrine - associated with lakes
• Riverine - associated with rivers, sometimes
floodplains
• Palustrine - the wetland IS the major feature
Palustrine Wetlands
• Major Non-Forested Wetlands
–Marshes
–Shrub-swamps
–Peatlands : Bogs and Fens
WETLANDS
Wetlands are areas where
The soil is saturated with
water for a significant
portion of the year.
They serve as natural filters
and are important in the
health of other habitats.
Wetlands
• Wetlands can be freshwater OR saltwater,
but in Michigan they are FRESH water
• Where do they come from?
• 1. From other wetlands
• 2. From glaciers, river, or lakes.
• There MUST be hydric soil.
Major Palustrine Wetlands
• 1. Marsh:
a shallow basin of standing
water with vegetation from shore to shore
• Extremely productive habitat
• Most dominant plant is the CATTAIL, but
also has a lot of rushes, reeds, and other softstemmed plants.
• Many are related to grasses. You can
identify grasses by the unique characteristic
of being hollow.
• 2. Shrub-swamp - a wetland thicket dominated
by 10-15 foot shrubs and young trees.
• Often flooded areas
• Interesting organism that lives here is the skunk
cabbage. Why so interesting?
• Many animals USE this habitat
• 3. PEATLANDs made up the final type we’ll
examine. A BOG and a FEN are classified as this
Peatlands
• 3a. Bog: has a floating mat of sphagnum moss
(peat) and acidic water.
• Plants get their nutrients from their surrounding
habitats…not from the acidic water, which is
nutrient poor
• Plants must adapt to conserve water and some
have adapted to become carnivorous
• Ex. Leatherleaf, sundew, pitcher plants
• Few animals actually LIVE here, but many visit
and use this habitat
• 3b. Fen: alkaline peatland
• Has some sphagnum, but is not the
dominant plant
• Alkaline water
• Many sedges, grasses, and small plants
• Usually attached to flowing water
•
•
•
•
Bog - acidic, stagnant
Fen - alkaline, flowing
Swamp - alkaline, flowing
Marsh - neutral, stagnant
Sand Dunes
• What do sand dunes have to do with
wetlands?
Chapter 55 – Human Impact
•
•
•
•
•
•
•
•
Let’s discuss:
Pollution
Overuse
Overharvesting
Destroying habitat
Deforestation
Global warming
Ozone depletion
Enhanced greenhouse effect
Figure 55-12
Page 1101
Sunlight
Atmosphere
Much heat radiated
from Earth is redirected
back to Earth
Only some of the
heat radiated from
Earth escapes to
space
Carbon
dioxide
Heat
Heat
Surface of Earth
Ultraviolet radiation and the ozone layer
Ultraviolet solar radiation
Ozone
Stratosphere
Oxygen
Troposphere
Surface of Earth
Surface of Earth
Ozone present at normal levels
Ozone present at reduced levels
Ozone thinning
Figure 55-15
Page 1105
Ozone (Dobson Units)
100
200
300
400
500
What can YOU do to help?
• Conservation efforts: