ECOLOGY!

ECOLOGY!

What is Ecology? - study of the interactions

among organisms and between organisms and their environment.

Some Vocabulary Review!

What is EcologyBIOTIC FACTORS – all living

things in an environmentEx: plants and animals

ABIOTIC FACTORS – all the non living things (physical and chemical)

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VocabularySmallest unit in

Ecology….Individual Organism –

one organism in an ecosystem

Population – group of individuals of the same species living in a particular area.

EcologyCommunity – two or more different

populations living together

Ecosystem – all abiotic and biotic factors in an area

EcologyBiosphere – the sum of all Earth’s ecosystems

EcologyMain ABIOTIC factors to know!

SunlightWaterTemperatureSoilWindSevere disturbances

Different environments on Earth : CLIMATE

What is climate? - usually look at the temperature

and rainfall of a particular area

- Different patterns due largely to the uneven heating of the Earth

Uneven heating patterns

Because the earth is a sphere – the sun’s rays hit it at different angles causing the different climate zones

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Wind and Rain patterns

Food Webs and Energy

• Review:– Autotrophs- producers– Heterotrophs- consumers and decomposers– Herbivores- primary consumers (eat plants)– Carnivores- secondary consumers (eat

herbivores)– Decomposers- consume organic wastes and

dead organisms.

Food Webs and Energy

• 10% rule- each level of the food pyramid receives 10% of the energy from the level below it.

Hawk (8 kcal)Snakes (80 kcal)Herbivores (800 kcal)Grasses (8,000 kcal)

Hawks need to eat a lot more to get the energy they need

Food Web and Energy

• Biomass- the total quantity of living matter at each trophic level.

• Just like available energy decreases, so does biomass at each level.

Relationships in Ecosystems

• Predation- one species (predator) consumes another (prey).

• Competition occurs when two species are consuming the same prey.

Relationships in Ecosystems

• Niche- particular combination of resources that a species is adapted to.

• Example: A niche is available in forests for an animal that can live in the treetops and eat fruit.

Relationships in Ecosystems

• Symbiosis- Relationships in which species live together – Mutualism- both species benefit– Parasitism- one organism gains at the expense of the

other– Commensalism- one organism benefits and the other

is unaffected

Limiting Factors

• Factors that limit productivity in an ecosystem– Supply of water for desert plants– Supply of light – Supply of iron for algae– Supply of nitrogen in the soil– Temperature

Limiting Factors

• Productivity and population size of other species– Population size of birds is limited by

productivity of insects that they eat– Or by the availability of nesting sites

Population Dynamics

• Two types of population growth– Exponential- growth under ideal conditions. Will result

in enormous numbers of individuals.– Logistic- At first grows normally but slows down as

competition and other factors limit reproduction and survival.

Carrying capacity

• The largest population of a species that the environment can support. – Are not stable– Invention of fertilizers led to more crops which

led to more humans. The increase in crops could support a higher carrying capacity for humans.