ECOLOGY Chapter 20 WHAT IS ECOLOGY Ecology the

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ECOLOGY Chapter 20

ECOLOGY Chapter 20

WHAT IS ECOLOGY? ? Ecology: the study of how living things interact with their

WHAT IS ECOLOGY? ? Ecology: the study of how living things interact with their environment.

Habitat: SECTION 1: LIVING THINGS & THE ENVIRONMENT – Where an organism lives that

Habitat: SECTION 1: LIVING THINGS & THE ENVIRONMENT – Where an organism lives that provides the things it needs to survive – Different organisms need different habitats – One area may contain many habitats – Food, water & shelter are provided in an organism's habitat.

BIOTIC FACTORS • All the living things in an environment.

BIOTIC FACTORS • All the living things in an environment.

ABIOTIC FACTORS • All the nonliving things that affect organisms in their environment •

ABIOTIC FACTORS • All the nonliving things that affect organisms in their environment • Examples include: – Water – Soil – Sunlight – Temperature & – Oxygen

LEVELS OF ORGANIZATION IN AN ECOSYSTEM:

LEVELS OF ORGANIZATION IN AN ECOSYSTEM:

 • The smallest level in an ecosystem is an organism (1 individual). •

• The smallest level in an ecosystem is an organism (1 individual). • All the individuals of one species living in a certain area is called a population.

 • All the different populations of species in an area make up a

• All the different populations of species in an area make up a community. • To be considered a community, populations must live close enough together to interact. • Ex) Eat the same food, prey or be preyed on by other species, use the same resources (water, etc. ) to

ECOSYSTEM: THE COMMUNITY OF ORGANISMS THAT LIVE IN A PARTICULAR AREA, ALONG WITH THEIR

ECOSYSTEM: THE COMMUNITY OF ORGANISMS THAT LIVE IN A PARTICULAR AREA, ALONG WITH THEIR NON-LIVING SURROUNDINGS.

WHAT MAKES AN ECOSYSTEM DIFFERENT FROM THE OTHER LEVELS? • Organisms, populations & communities

WHAT MAKES AN ECOSYSTEM DIFFERENT FROM THE OTHER LEVELS? • Organisms, populations & communities are all made up of biotic factors, factors or living things! • An ecosystem contains both biotic AND abiotic factors, factors or non-living things in a particular area.

POPULATION SIZE There are 4 ways to determine population size: 1. Direct Observation: count

POPULATION SIZE There are 4 ways to determine population size: 1. Direct Observation: count all the members of a population. 2. Indirect Observation: looking at signs of organisms instead of actual numbers • Example: looking at swallow mud nests, count the number of entrance holes- on average each nest has 4 swallows- multiply

3. Sampling: if population is large or spread over a large area you can’t

3. Sampling: if population is large or spread over a large area you can’t count them all, you have to make an estimate based on reasonable assumptions.

4. Mark and Recapture Studies: Studies Capture animals and mark them. Then come back

4. Mark and Recapture Studies: Studies Capture animals and mark them. Then come back two weeks later and capture again. Count how many marked and unmarked that you count. Use a mathematical formula to calculate the estimated total population.

CHANGES IN POPULATION SIZE Birth & Death Rate: • birth rate higher then death

CHANGES IN POPULATION SIZE Birth & Death Rate: • birth rate higher then death rate- population gets bigger • Death rate higher then birth rate= population gets smaller

CHANGES CONTINUED… • Population size changes when animals move in and out of the

CHANGES CONTINUED… • Population size changes when animals move in and out of the population. • Emigration is moving OUT of a population • Immigration is moving INTO a population

POPULATION DENSITY • How many organisms there are in a certain amount of area

POPULATION DENSITY • How many organisms there are in a certain amount of area • Pop. Density= # of individuals/ Unit area • Example: 20 butterflies in 10 square meters of area, population density would be 2 butterflies per meter squared.

LIMITING FACTORS • An environmental factor that prevents a population from increasing. • These

LIMITING FACTORS • An environmental factor that prevents a population from increasing. • These environmental factors include: • • Food & water Space Temperature Rainfall

CARRYING CAPACITY The largest population that an area can support.

CARRYING CAPACITY The largest population that an area can support.

EXPONENTIAL GROWTH • With unlimited resources, populations will grow. • This is called exponential

EXPONENTIAL GROWTH • With unlimited resources, populations will grow. • This is called exponential growth and is represented by a “J-Shaped” curve.

LOGISTIC GROWTH • Occurs when there are limiting factors that keep population growth balanced.

LOGISTIC GROWTH • Occurs when there are limiting factors that keep population growth balanced. • called an “S-Curve”

INTERACTIONS AMONG ORGANISMS

INTERACTIONS AMONG ORGANISMS

PREDATOR VS. PREY • Predator An animal that hunts, kills, and eats another. •

PREDATOR VS. PREY • Predator An animal that hunts, kills, and eats another. • Prey An animal that is killed and eaten by a predator.

ADAPTATIONS FOR FEEDING • Ambush (camouflage) • Teeth • Night vision • Echolocation

ADAPTATIONS FOR FEEDING • Ambush (camouflage) • Teeth • Night vision • Echolocation

DEFENSE STRATEGIES • Camouflage • False coloring- false eyepredators think organisms head is someplace

DEFENSE STRATEGIES • Camouflage • False coloring- false eyepredators think organisms head is someplace else • Warning coloration: Bright colors to tell predators they are poisonous • Protective covering: porcupine

MIMICRY The resemblance of one organism to another or to an object in its

MIMICRY The resemblance of one organism to another or to an object in its surroundings for protection from predators.

SYMBIOSIS • A relationship between organisms of different species in which at least one

SYMBIOSIS • A relationship between organisms of different species in which at least one organism benefits. • Three types of symbiotic relationships: – Mutualism – Commensalism – Parasitism

MUTUALISM • BOTH species benefit from living together • Examples: – Shark & teeth

MUTUALISM • BOTH species benefit from living together • Examples: – Shark & teeth cleaning fish – Crocodiles & cattle egrets – Moray Eel & Cleaner Fish *Moray Eel gets a clean mouth *Cleaner Fish gets a meal

COMMENSALISM • One species benefits, other is neither harmed nor benefitted • Example: Clown

COMMENSALISM • One species benefits, other is neither harmed nor benefitted • Example: Clown Fish & Anemone • Clown fish gets protection • Anemone is

PARASITISM • One species benefits and the other is harmed Taenia worm in human

PARASITISM • One species benefits and the other is harmed Taenia worm in human eye • Examples: – – – Leeches Ticks Hookworms Tapeworms botfly • Worm infects human blood stream • Human may go blind

COMPETITION • When a resource is limited organisms must compete for it (due to

COMPETITION • When a resource is limited organisms must compete for it (due to limiting factors) • Usually the organism that competes the best reproduces more often & passes on those genes that allow it to be more successful- NATURAL SELECTION

NICHE • The role of an organism in its habitat, or how it makes

NICHE • The role of an organism in its habitat, or how it makes its living. • Different from habitat (where it lives)

SUCCESSION • Series of predictable changes that occur in a community over time

SUCCESSION • Series of predictable changes that occur in a community over time

PRIMARY SUCCESSION • Occurs in an area where NO soil or organisms exist •

PRIMARY SUCCESSION • Occurs in an area where NO soil or organisms exist • Ex: Volcano erupting, resulting in an area of land

 • The 1 st species to populate that area is called a pioneer

• The 1 st species to populate that area is called a pioneer species • Examples: Moss or lichen • Break up the rocks and provide nutrients to the soil • Over time seeds land in the soil and grow • Grasses and shrubs often replace the pioneer plants

SECONDARY SUCCESSION • Series of changes that occur in an area where the ecosystem

SECONDARY SUCCESSION • Series of changes that occur in an area where the ecosystem has been disturbed, BUT soil and organisms are still present • Natural disturbances: fire, flooding, tornado, etc. … • Human disturbances: logging, farming…