Ecosystems1.2

1. Explain various relationships with respect to food chains, food

webs, and food pyramids, including:

producer

consumer (herbivore, carnivore, omnivore)

predation (predator‐prey cycle)

decomposers

symbiosis (mutualism, commensalism, parasitism)

2. Describe the relationships between abiotic and biotic elements within

an ecosystem, including air, water, soil, light, temperature (abiotic)

and bacteria, plants, animals (biotic)

3. Design and analyse experiments on the effects of altering biotic or

abiotic factors (e.g., nutrients in soil: compare two plant types with

the same nutrients, compare one plant type with different nutrients)

Ecosystem

Habitat

Community

Species

Population

Symbiosis

Mutualism

Commensalism

Parasitism

Predation

Niche

Competition

Predator

Prey

Biodiversity

By studying past and present ecosystems, we can better understand what may happen in the future. Historical ecology is the

study of natural and written materials to better understand the ecology of a certain area.

Many First Nations sources provide detailed knowledge of plants, animals, and natural occurrences of an area.

An ecosystem is made up of many parts. Abiotic (non-living)

factors include air, water, soil, nutrients, and light.

Biotic (living) factors include plants, animals, and micro-organisms.

Ecosystems can take up many hectares of land or can be small, such as a tide pool or a rotting log.

A habitat is where an organism lives.

The habitat of the red fox often includes the edges of

forests or marshlands.

HABITATS

There are all sorts of different

‘habitats’ that different species

occupy:

The Blind Flatworm

& the eyeless shrimp

Live in dark caves. They are

called “troglobites” (cave-

dwellers). They have adapted to

darkness - do not require eyes...

White-Spotted Puffer Fish

Lives in coral reefs (in tropical waters)

Second most poisonous vertebrate in the world...

It’s muscles, skin, liver and ovaries contain toxin 3x deadlier than cyanide.

The Rattle SnakeOccupies different habitats depending on the

time of year...

Open grassland (areas with high rodent

density)

Hibernating dens (rock fissures or caves)

The abiotic components are what allow the biotic components to survive in an ecosystem Abiotic factors include oxygen, water,

nutrients, light and soil. Oxygen is produced by the green

plants and certain micro-organisms and is used by animals and most other micro-organisms.

An example of a micro-organism thatproduces oxygen is cyanobacteria. They are found in oceans, rivers, bare rocks, and soil. “Blue-green algae”

Water is necessary for all life.

Nutrients often enter the food chain with plants and are very important for growth.

Light is required for photosynthesis, which is the process in plants that converts and stores the Sun’s energy into starches and sugars.

Soil not only contains water and nutrients

but also is home to many plants and animals.

Earthworms in soil

A community = all the organisms that interact within an ecosystem.

A species refers to all of the organisms within an ecosystem that have the same structure and that can reproduce with each other.

A population refers to all of the members of a certain species within an ecosystem.

Symbiotic relationships are the interactions between members of two different species that live together in a close association. Commensalism – one species benefits, one is

not affected Example: the barnacles on a whale

Mutualism – both species benefit Example: a bee gathering nectar from a flower

Parasitism – one species benefits, the other is harmed Example: hookworm living in dogs

Mutualism Video

COMMENSALISM(Biological hitch-hiking)

The Imperial shrimp hitches a rideon a large sea cucumber. It ridesalong through areas of potential food, at no cost to the other organism.

Anyone home?The pearlfish is a small fish (5-10cm) that livesinside a seacumber in the day and at night, exits through the anus of the seacumber to feed.

MUTALISM

Leaf Cutter AntsThese ants

cultivate (grow) a fungus. They

feed the fungus and the fungus serves as their

food!

Cut the leaf..

Chew into a pulp

Store the pulp with ant feces

and fungus spores

Fungus begins to grow...

Teachers' Domain: Ancient Farmers of the Amazon

MUTALISM

LICHEN = algae + fungus

The algae

provides food

(glucose) for

the fungus

through

photosynthesis.

PARASITISM

HOOK WORMS

The common way for hook worms to enter is through the skin (walking barefoot)...

A parasitic worm that lives inside the

intestines of its host (mammal). These

worms such blood from the host’s intestinal walls ...this leads to

anemia (iron deficiency).

M

O

U

T

H

PARASITISM

The Pine Beetle

The pine beetle has infested lodgepole pine trees in BC’s Central Interior.

Burrows in the tree, feeds on trees phloem

(nutrients) and lays its eggs.

The Pine Beetle’s Legacy....

In B.C., the provincial government estimates the beetle's spread will have economic implications for 30 communities and will impact 25,000 families whose livelihood depends on the pulp and paper industry.

The environment is also affected: trees normally capture CO2 (greenhouse gas) – but the death of more trees has instead released carbon into the atmosphere, according to a study published in April 2008 in the journal Nature.

A niche refers to the role an organism has within an

ecosystem, physically, chemically and biologically.

Within the niche, an organism interacts with other

individuals of the same species or with individuals of

other species

Competition occurs when a resource is

needed by two or more individuals.

Competition usually means resources are limited.

This limits the size and health of that individual

and perhaps that population.

Examples of resources that organisms compete over

include food, water, and mates

Predation is the relationship between the“eaters” and the “eaten”.Predators have adaptations to help them

catch their prey.Prey have adaptations to help avoid

predators.Examples of adaptations include spines and shells,

camouflage and mimicry.

The numbers of predators and prey influence each other.

Biodiversity refers to the variety and number of

different individuals and species in an ecosystem.

Healthy ecosystems generally have high biodiversity.

Most biodiversity losses occur from the loss of habitat.

Humans often have a negative impact on biodiversity.

Many efforts are now made to lessen this impact in order to maintain biodiversity.

Ecological management programs try to balance human progress with maintaining biodiversity.