COMMUNITIES

COMMUNITIES All populations interacting at any particular

time in a defined habitat.

- Give me an example?

COMMUNITIES All populations interacting at any particular

time in a defined habitat. Some are temporary (eg. a rotting log) and

some last a long time (eg. Forests)

Other examples?

COMMUNITIES All populations interacting at any particular

time in a defined habitat. Some are temporary (eg. a rotting log) and

some last a long time (eg. Forests) Three characteristics common to most

communities:- The more different species in a community,

the more stable it is = species diversity. And vice versa. Eg. Tundra – unstable b/c low species diversity, rainforest – stable.

Three characteristics common to most communities:

- A few organisms are present in a large number or great biomass (weight of living matter). These dominate the community.

Three characteristics common to most communities:

- A few organisms are present in a large number or great biomass (weight of living matter). These dominate the community. A great number of other organisms are relatively rare, but they can play an important role.

Three characteristics common to most communities:

- A few organisms are present in a large number or great biomass (weight of living matter). These dominate the community. A great number of other organisms are relatively rare, but they can play an important role.

- EG. A beetle that only eats one plant may keep it in check.

Three characteristics common to most communities:

- Always more producers (usually plants) than consumers. (One exception – the sea). Phytoplankton don’t have higher numbers than animals that eat it, yet they reproduce so quickly they can keep up.

Three characteristics common to most communities:

- Always more producers (usually plants) than consumers. (One exception – the sea). Phytoplankton don’t have higher numbers than animals that eat it, yet they reproduce so quickly they can keep up.

- ** Communities are named from the highest biomass – eg a kauri forest.

COMPOSITION OF A COMMUNITY All organisms can be grouped according to

their feeding or trophic levels.1. Producers –

COMPOSITION OF A COMMUNITY All organisms can be grouped according to

their feeding or trophic levels.1. Producers – make their own foodPhotosynthesisers = take energy from

sunlight. Together with water and C02 they make glucose.

COMPOSITION OF A COMMUNITY All organisms can be grouped according to

their feeding or trophic levels.1. Producers – make their own foodPhotosynthesisers = take energy from

sunlight. Together with water and C02 they make glucose.

Chemosynthesisers = usually bacteria. Same thing but energy from chemical reactions.

CHEMOSYNTHESIS

2. Consumers – can’t make own food.

2. Consumers – can’t make own food.- Herbivores = animals that eat all parts of

plants. Sap, leaves, roots, pollen etc.

2. Consumers – can’t make own food.- Herbivores = animals that eat all parts of

plants. Sap, leaves, roots, pollen etc.- Carnivores = animals that eat other animals.

Predators – hunt, kill, and eat.

2. Consumers – can’t make own food.- Herbivores = animals that eat all parts of

plants. Sap, leaves, roots, pollen etc.- Carnivores = animals that eat other animals.

Predators – hunt, kill, and eat.- Scavengers – live off dead animals killed by

something else.

2. Consumers – can’t make own food.- Herbivores = animals that eat all parts of

plants. Sap, leaves, roots, pollen etc.- Carnivores = animals that eat other animals.

Predators – hunt, kill, and eat.- Scavengers – live off dead animals- Parasites – live in or on living host. Endo-

inside, and Ecto-outside.

ENDO/ECTO

2. Consumers – can’t make own food.- Herbivores = animals that eat all parts of

plants. Sap, leaves, roots, pollen etc.- Carnivores = animals that eat other animals.

Predators – hunt, kill, and eat.- Scavengers – live off dead animals- Parasites – live in or on living host. Endo-

inside, and Ecto-outside. - Decomposers = bacteria and fungi that break

down dead bodies to release the nutrients.

INTRA-SPECIFIC RELATIONSHIPS Either cooperative or aggressive.

INTRA-SPECIFIC RELATIONSHIPS Either cooperative or aggressive. Cooperative – includes courtship, looking

after young, hunting in packs, defending the group.

INTRA-SPECIFIC RELATIONSHIPS Either cooperative or aggressive. Cooperative – includes courtship, looking

after young, hunting in packs, defending the group.

Aggressive – fighting for mates, territory, keeping up pecking order etc.

INTER-SPECIFIC RELATIONSHIPS Mutualism – both partners benefit.

(lots of examples which we have already discussed/watched jot down some)

INTER-SPECIFIC RELATIONSHIPS Mutualism – both partners benefit. Commensalism – one species benefits while

the other is unaffected. EG. A fish called a remora. Hitches a ride on a

shark, and when the shark attacks the remora feeds on scraps then hitches another ride. The sharks are indifferent, yet the remora gets lots of food and doesn’t use energy.

INTER-SPECIFIC RELATIONSHIPS Mutualism – both partners benefit. Commensalism – one species benefits while

the other is unaffected. Antibiosis – one species is harmed and the

other is indifferent.

EG. Blue green mould on rotting oranges/lemons is penicillum – which produces a chemical called penicillin which inhibits bacteria. Hence, antibiotics.

INTER-SPECIFIC RELATIONSHIPS Mutualism – both partners benefit. Commensalism – one species benefits while

the other is unaffected. Antibiosis – one species is harmed and the

other is indifferent. Exploitation – One species benefits, while the

other is harmed.

EG. Most examples of herbivores, carnivores, and parasites etc.