Population Ecology ch 4ish Population Curves Succession Resource partioning

Land SUCCESSION Pond Succession One thing leads to another

What is succession? What is a climax community? What are pioneer plants? What is primary succession? What is secondary succession?

SUCCESSION The replacement of one community by another

PIONEER PLANTS The first plants to appear in a community For example, lichens are often the first plants to appear on bare rock

PRIMARY vs. SECONDARY SUCCESSION PRIMARY SUCCESSION/ BARE ROCK SUCCESSION: Succession on land where there was no previous growth SECONDARY SUCCESSION: Growth on land where there has been previous growth, such as abandoned fields or forest clearings

Succession

Climax Community : Last stable stage of succession.

Succession to a climax community

Puffer protection pufferfish.flv antlion death trap.flv antlion anatomy.flv Peacock spider

How Ecosystems change

Ecology Population Biotic potential -The maximum reproductive rate and all live and reproducedBiotic potential

Lemmings migration

Rat population

Rabbit can multiply

POPULATION ECOLOGY

Over reproduction (Biotic potential)

Biotic Potential maximum rate at which a population could grow given optimal conditions (food, water, space) Factors that influence biotic potential: (Environmental Resistance) 1. age of reproduction 2. frequency of reproduction 3. number of offspring produced 4. reproductive life span 5. average death rate under ideal conditions

Environmental Resistance: Factors that Decrease the birth rate, or increase death rate, related to environmental conditions, such as food & space. Density Independent Factors: weather and other natural disasters Density Dependent Factors: food, space, water, parasitism, competition

Ecology Population Environmental resistance –factors that reduce population growth rates –disease, predation, weather… dragonfly1.flv

Ecology Population Carrying capacity – the maximum number of individuals of a population an area can support in terms of food, space and shelters. Birth – death = pop.

Population Growth When is population growth zero? G=growth r= rate of reproduction N= number of individuals K=carrying Capacity

r-selection=Reproduction/short life cycle ; no parental care k selection = low offspring production, parental care

. R Unstable environment, density independent K Stable environment, density dependent interactions small size of organismlarge size of organism energy used to make each individual is lowenergy used to make each individual is high many offspring are producedfew offspring are produced early maturity late maturity, often after a prolonged period of parental care short life expectancylong life expectancy each individual reproduces only once individuals can reproduce more than once in their lifetime type III survivorship pattern in which most of the individuals die within a short time but a few live much longer type I or II survivorship pattern in which most individuals live to near the maximum life span

Carrying Capacity- Carrying Capacity- The maximum number of individuals and area can support in terms of resources

Population Graph

What is happening in phase A? What is happening in phase B?

Human population Growth

Human Population based on a Fossil Fuel Economy

Predator / Prey Populations

The Abiotic factors affect populations

Rabbit Myxoma virus

Habitat Formation A) Competition –Intraspecific -same species –Interspecific - different species B) Coevolution -two or more species ‘evolve’ in response to each other (insects & flowers) Predator/Prey relationships –Plant defenses –Animal defenses –Animal deceptions –mimicry

Niche ‘Way of life” in a specific habitat COMPETITIVE EXCLUSION PRINCIPLECOMPETITIVE EXCLUSION PRINCIPLE Niche overlap increases competition and leads to a ‘realized niche’ –area that the organism actually occupies

Kangaroo Island

koala over population.flv Koala activity