Download Ecology

What is ecology?
Ecology:
scientific study of interactions
between organisms and their
environment.
Populations vs. communities
 PopulationA
population is all the
organisms that both belong to the same
species and live in the same place at the
same time.
 Communitya
group of multiple species
that live in the same place and interact
with one another.
Vocabulary
 Ecosystems
the living and non living environment
 Habitat place where organism lives
 Biomes large region characterized by a specific
kind of climate and certain animal and plant
communities
 Biodiversity variety of organisms living in an area
 Climate average weather conditions in an area
over a long period of time
 Weather Current conditions-temp, precipitation,
humidity, cloud cover.
Ecosystems
 Living
and non-living things in the
environment
 Many different populations, therefore,
many different species all living in the
same ecosystem.
 Can be small or big
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Populations of many tiny insects called
aphids can live on a single leaf of a single
tree for many years yet each aphid is a
host for many different bacteria
That same tree is part of the forest
ecosystem
In other words, an ecosystem is relative to
what organism(s) you are talking about
Ecosystems
 Important
things to consider when
studying ecosystems:

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
Size
Organisms and their relationships
Relationships between organisms and the
environment
Human influences or interference
The entire ecosystem must be studied not
just the individual species or population
Habitat
 Where






an organism lives
House for humans
Backyard for a dog
Field of grass for crickets
Mouse-hole
Ant-ant mound or hill
Bird in a nest
Niche

A niche is very different than a habitat
 Habitat  place where an organism lives

Niche includes physical home, environmental
factors necessary for survival, and all of the
interactions of other organisms
 ex: A lion den, grass, antelope, climate,
vegetation

Usually expressed as a range
 A certain range of temperatures can be
tolerated, a certain habitat can be tolerated, or
a certain food source can be used as
acceptable
Biome Map
Abiotic vs. Biotic factors
Biotic
Abiotic
 non
living things in
environment that
may affect a
population.
 Water, nitrogen,
oxygen, pH, soil
nutrients,
temperature,
amount of sunlight,
amount of
precipitation


living things in
environment that
may affect a
population
Plants, animals, fungi,
and bacteria are all
biotic or living
factors.
Biomes
 Give
me three
examples of
Biomes and
describe each
Abiotic vs
Biotic
1.
2.
3.
4.
5.
6.
Temperature
Trees
Rainfall
Soil nutrients
Squirrel
Amount of oxygen
Water cycle
 Evaporation
 Condensation
 Precipitation
Nitrogen (N2) cycle
 78%
of atmosphere is nitrogen gas(N2)-plants cannot
use.
1) Nitrogen fixation Bacteria helpsto convert Nitrogen
gas (N2) into ammonia (NH3). It does this by splitting
N2 into N(nitrates) + NH3.
2) Then plants absorb Nitrates (N), (nutrient) fertilizer
3) Animal eats plant, then defecates
4) Bacteria then turns waste back into Nitrogen (N)
(nitrates) for plants
5) Left over ammonia gets converted back to Nitrogen
gas (N2) and returns to atmosphere
 The nitrogen cycle is of particular interest to scientists,
because nitrogen availability affects plants. Without
plants, nothing else lives.
Carbon-oxygen cycle
 Plants
(autotrophs)-take in
CO2 and release O2
 Animals (heterotrophs)take in O2 and release CO2
 Combustion-release CO2
 Death of animals and
plants and waste products,
decomposers turn
everything back into soilhelps plants grow, and
start again
Energy Flow
 Producers
(also called autotrophs) get
their energy from the sun through
photosynthesis
 Consumers (also called heterotrophs)
eat food to get energy. Can get food
from producers, or other consumers



Carnivores-eat meat only
Herbivores-eat plants only
Omnivores-eat both meat and plants
 Decomposers
eat dead things, and turn
them back into soil or dirt
Producers
Consumers
Proboscis monkey
Decomposers
Food Webs

Trophic (energy) levels
 First level-producers and
decomposers
 Primary consumers-usually
herbivores
 Secondary consumersusually omnivores
 Tertiary consumers-usually
carnivores
 Food
webs/chains
 10% rule only 10% of
the energy in each level
continues in the food
chain-from predator to
prey is only 10% of the
energy is transferred
Energy pyramid
 Represents
the energy
available for each
trophic level in an
ecosystem
 Energy needs increase
as you travel “up” the
pyramid
 Only about 10% of the
energy available is used
by organisms while the
other 90% is lost to the
environment
Biomass Pyramid
Pyramid of numbers
Ecological relationships

Predation the act of one organism killing another.



Can have a large affect on both predator and prey populations
Coevolution "the change of a biological object triggered by
the change of a related object.
Types of Symbiosis relationships between two or more
species
 Parasitism when one organism lives and feeds off another
with no benefit for the host


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Ex: Ticks, fleas, tapeworms, pinworms, many bacteria
Mutualism when both organisms benefit equally from the
sharing of food, shelter, etc.
 Ex: clownfish and anemone
 Humans and E. Coli bacteria
Commensalism When only one benefits, but the other
neither benefits nor is harmed.
 Owl and a tree
Predator/Prey graph
Succession
 Succession
the replacement of one community
by another at a single place over a period of time.
 Primary succession occurs in an area that has not

previously been inhabited
Secondary succession begins in an area where
there was a preexisting community and well-formed
soil: for example, abandoned farmland, vacant lots,
clear-cut forest areas, or open areas produced by
forest fires.
 Lichens
(half fungus, half algae) and moss are the
first species to inhabit new area
Global warming-a theory


Global Warming gradual increase in global temperature
 Car on a hot sunny day
Greenhouse Effect warming of the surface and lower
atmosphere of earth that happens when greenhouse gases in
the air absorb and reradiate heat.

Ozone makes up the ozone layer. Getting smaller every
year.

CO2 production has increased steadily for the last 50 or so
years

Acid rain precipitation that has an unusually high
concentration of sulfuric and nitric acids which is caused by
pollution

What can humans do to help?
Videos
 http://www.theguardian.com/environme
nt/video/2009/oct/14/arctic-sea-icecoverage
Solutions for global warming
How to “fix” Global Warming
 Conservation
the science of the
protection, restoration, and
management of biodiversity.
 Restoration cleaning up and
restoring damaged habitats.
 Recycling the reuse of “waste”
products.
 Renewable energy sources
energy sources that are naturally
produced and are recyclable.
Human Populations
Population Density
 Population density number of individuals per unit
area or volume. Basically, how crowded an area is.
 Ex: number of people per square mile
 Number of Catfish per cubic foot of water in Lake Hartwell
 Population dispersion is the relative distribution
or arrangement of its individuals within a given
amount of space
 Even
 Clumped
 Random
Regulation of Population
Two types
 Density dependent when many individuals are
dying due to an increase in population density
 Increases in population leads to increases in:
 Overcrowding
 Competition
 predation
 widespread famine
 Density independent decreases in population
not do to a change in numbers of individuals
 Natural disasters, severe weather, war
How does a population grow
Change in pop size= birth rate-death rate
 In order to grow, birth rate must be higher than
death rate
On average, for every two adults at least
two offspring must be produced to maintain
a population
 The assumption is that the parents will die
sometime after reproduction, so they need two to
replace themselves
What limits population growth
 Carrying capacity
 Resource limits
 Competition
Population growth
 Carrying Capacity the maximum population size of the species that
the environment can sustain for a long period of time, given the food,
habitat, water and other necessities available in the environment.
Demography
 Study of populations, usually human populations
 Demographers use historical data on size and makeup of a
population, current conditions, and resource data in order to
make comparisons and predictions
 Developed country a country that tends to be on the wealtheir
side, and already has a stable economy that can survive a
recession.
 Higher incomes, slower population growth, and diverse economies
 Ex: US, Japan, China, UK, Germany, France, others
 Developing country a country that tends to be on the poorer
side, and in the process of reaching economic stability
 Lower incomes, faster pop growth, and more agricultural based
economy that relies on agriculture as major income
 Ex: African countries, SA countries
Predicting Population Size
 Age structure distribution of ages in a specific population at
a certain time
 Survivorship percentage of members of a group that are
likely to survive to an given age
 “what is the survivorship of young males to survive until they are
60”
 Fertility Rates number of babies born each year per 1000
women in a population
 Migration movement of individuals in a population
 Immigration-movement into a pop
 Emigration-movement out of a pop
Continued
 Death Rate number of individuals that die per 1000 living
individuals
 Decreased dramatically in recent years – adequate food, shelter,
water, vaccinations, and sewage disposal
 Life Expectancy average number of years a person is likely
to live
 Affected greatly by infant mortality rate
 Steadily increased over the last few centuries