Community Interactions

QUICK REVIEW What is community? What is population?

What is community?

What is population?

Community Interactions Powerfully affect an ecosystem Include: Competition Predation Symbiosis

Powerfully affect an ecosystem

Include:

Competition

Predation

Symbiosis

Competition When organisms of the same or different species attempt to use an ecological resource at the same place and the same time Resource  any necessity to life Plants and animals compete Winner and losers

When organisms of the same or different species attempt to use an ecological resource at the same place and the same time

Resource  any necessity to life

Plants and animals compete

Winner and losers

Interspecific competition Competition between same two species When 2 or more species rely on same limited resource in a community Ex. African savannah

Interspecific competition

Competition between same two species

When 2 or more species rely on same limited resource in a community

Ex. African savannah

Rules, rules, rules Fundamental rule in ecology Competitive Exclusion Principle Russian biologist G.F. Gause Paramecium caudatum vs. Paramecium aurelia 2 species so similar in requirements that the same resource limits both population’s growth, and one species may succeed over another No two species can occupy the same niche in the same habitat and the same time Prevents competition

Fundamental rule in ecology

Competitive Exclusion Principle

Russian biologist G.F. Gause

Paramecium caudatum vs. Paramecium aurelia

2 species so similar in requirements that the same resource limits both population’s growth, and one species may succeed over another

No two species can occupy the same niche in the same habitat and the same time

Prevents competition

Niche Each species unique living arrangement in a community “ Role” Ex. Lizards in a rainforest Includes: Habitat Food sources Time of day organism is most active

Each species unique living arrangement in a community

“ Role”

Ex. Lizards in a rainforest

Includes:

Habitat

Food sources

Time of day organism is most active

Predation Interaction where an organism captures and feeds on another organism Predator Organism that does the killing and eating Prey Organism that is being killed and eaten (victim)

Interaction where an organism captures and feeds on another organism

Predator

Organism that does the killing and eating

Prey

Organism that is being killed and eaten (victim)

Predator Adaptations Speed Agility Coloring/camouflage to ambush prey Packs/teams Ex. Wolves Acute senses Ex. Rattle snake heat sensor organs Claws, teeth, fangs, stingers, poison

Speed

Agility

Coloring/camouflage to ambush prey

Packs/teams

Ex. Wolves

Acute senses

Ex. Rattle snake heat sensor organs

Claws, teeth, fangs, stingers, poison

Prey adaptations Safe locations Flee Coloring/camouflage to hide Defensive coloration “ warning coloration” Mimicry Organisms imitate dangerous organisms by appearance and actions Hawk moth larva Plants Thorns, spines, poisonous chemicals

Safe locations

Flee

Coloring/camouflage to hide

Defensive coloration

“ warning coloration”

Mimicry

Organisms imitate dangerous organisms by appearance and actions

Hawk moth larva

Plants

Thorns, spines, poisonous chemicals

Symbiosis Any relationship where two species live closely together Symbiosis literally means “living together” 3 main types Parasitism Mutualism commensalism

Any relationship where two species live closely together

Symbiosis literally means “living together”

3 main types

Parasitism

Mutualism

commensalism

What type of relationship is this? Who is helping who?

Who is helping who?

Mutualism Both species benefit from the relationship A Happy couple Flowers and bees Flowers need bees for pollination, bees need flowers nectar

Both species benefit from the relationship

A Happy couple

Flowers and bees

Flowers need bees for pollination, bees need flowers nectar

What type of relation ship is going on here? Who is helping who?

Who is helping who?

Commensalism One member of the relationship benefits while the other is neither harmed nor helped One-sided Food or shelter Barnacles on whale

One member of the relationship benefits while the other is neither harmed nor helped

One-sided

Food or shelter

Barnacles on whale

Ants and aphids

What type of interaction is going on here?

Parasitism One organism lives on or inside another organism and harms it Parasite obtains all or part of its nutrients from the other organism Host Organism that is harmed in relation ship; the one that provides the nutrients to the parasite Parasite Organism that gets its nutrients from the host Do they want to kill their host? No, because they need them…they will weaken or hurt the host in some way

One organism lives on or inside another organism and harms it

Parasite obtains all or part of its nutrients from the other organism

Host

Organism that is harmed in relation ship; the one that provides the nutrients to the parasite

Parasite

Organism that gets its nutrients from the host

Do they want to kill their host?

No, because they need them…they will weaken or hurt the host in some way

Recap What are the three types of interactions in a community? Competition Predation Symbiosis What types do we have? Mutualism Commensalism Parasitism

What are the three types of interactions in a community?

Competition

Predation

Symbiosis

What types do we have?

Mutualism

Commensalism

Parasitism

Ecological Succession Do all ecosystems stay the same all the time? What are some things that cause changes to ecosystems? Natural and unnatural Quickly and slowly

Do all ecosystems stay the same all the time?

What are some things that cause changes to ecosystems?

Natural and unnatural

Quickly and slowly

Ecosystems are constantly changing in response to human and natural disturbances. As an ecosystem changes, older habitants die out and new organisms move in, causing more change

Ecosystems are constantly changing in response to human and natural disturbances.

As an ecosystem changes, older habitants die out and new organisms move in, causing more change

Ecological Succession Series of predictable changes that occur in a community over time Physical environment Natural disturbance Human disturbance

Series of predictable changes that occur in a community over time

Physical environment

Natural disturbance

Human disturbance

Primary Succession Succession on land that occurs on surfaces where no soil exists Volcanic eruptions Glaciers melting

Succession on land that occurs on surfaces where no soil exists

Volcanic eruptions

Glaciers melting

Stages of Primary Succession Start with no soil, just ash and rock First species to populate this area “ pioneer species” For example, pioneer species on volcanic rock are lichens (LY-kunz) Lichens  made up of fungus and algae that can grow on bare rock When lichens die, they for organic material that becomes soil…now plants can grow

Start with no soil, just ash and rock

First species to populate this area

“ pioneer species”

For example, pioneer species on volcanic rock are lichens (LY-kunz)

Lichens  made up of fungus and algae that can grow on bare rock

When lichens die, they for organic material that becomes soil…now plants can grow

Secondary Succession Succession following a disturbance that destroys a community without destroying the soil Natural hurricane fires Human disturbances Farming Forest clearing

Succession following a disturbance that destroys a community without destroying the soil

Natural

hurricane

fires

Human disturbances

Farming

Forest clearing

Succession in Marine Ecosystems Deep and dark Can succession happen? 1987 dead whale off of California Unique community of organisms living in remains Represents stage in succession in an otherwise stable, deep-sea ecosystem Whale-fall community

Deep and dark

Can succession happen?

1987 dead whale off of California

Unique community of organisms living in remains

Represents stage in succession in an otherwise stable, deep-sea ecosystem

Whale-fall community

Whale-Fall Succession Begins when large whale dies Sinks to barren ocean floor Scavengers and decomposers flock to carcass , our first community Amphipods Hagfish sharks After a year, most tissues have been eaten Now, second small community of organisms live here Body is decomposing, releasing nutrients into the water Small fishes Crabs Snails worms Only skeleton remains… Third community moves in Heterotrophic bacteria Decompose oil in bones  release of chemical compounds Who uses these chemical compounds? Chemoosynthetic autotrophs In come the crabs, clams, and worms that feed on this bacteria

Begins when large whale dies

Sinks to barren ocean floor

Scavengers and decomposers flock to carcass , our first community

Amphipods

Hagfish

sharks

After a year, most tissues have been eaten

Now, second small community of organisms live here

Body is decomposing, releasing nutrients into the water

Small fishes

Crabs

Snails

worms

Only skeleton remains…

Third community moves in

Heterotrophic bacteria

Decompose oil in bones  release of chemical compounds

Who uses these chemical compounds?

Chemoosynthetic autotrophs

In come the crabs, clams, and worms that feed on this bacteria

Human Activity and Species Diversity Land clearing Farmland Diverse forest replaced with single crop Decreases species diversity Introduced species Humans move a species from its native land to a new location, intentionally or accidentally

Land clearing

Farmland

Diverse forest replaced with single crop

Decreases species diversity

Introduced species

Humans move a species from its native land to a new location, intentionally or accidentally

Teacher, Study Chapter 35, Population Ecology and Community Interactions