Chapter 9

Habitats and Environment

WEEK 8: Habitats and EnvironmentLEARNING OUTCOMESBy the end of this week, you should:have developed a knowledge and understanding of

habitats and environments that exist in them,be able to identify major factors that produce the

environments of various habitats and distinguish between biotic and abiotic factors,

have explored technologies used to record environmental factors and track distribution of species within their habitats.

Key Terms1. Habitat2. Microhabitat3. Range4. Community 5. Niche 6. Biotic factors7. Abiotic factors8. Qualitative 9. Quantitative10. Micro-environment11. Tolerance range12. Limiting factor

Complete the card sort of key terms

Now use your textbook to find and describe some examples for

each of the definitions to fill out your knowledge!

Habitat: The location or place where an organism lives at any

given time is known as its habitat.Many habitats can be described in general terms as

being Terrestrial (e.g. deserts, grasslands, forests etc)Aquatic, which includes freshwater, marine and estuarine.

Members of one species do not live in isolation in a habitat.

For example: Ragged-Finned Lionfish – tropical waters around coral reefs in the Great Barrier Reef.

MicrohabitatsA microhabitat is a more localised or specialised

part of a general habitat.For example, in a freshwater pond, some

organisms may occupy the soft sediment at the bottom, while others may live among the aquatic plants. These are twodifferent of many microhabitats

NICHE refers to the ‘way of life of a species’ OR the role of a species in a community OR the status or role of an organism in its habitat

A niche can be explained using the example of a human population within a city.- groups of people are identified by their way of life, e.g. educator, surgeon, security guard, etc- each group can then be subdivided, e.g. the educator role includes: pre-school teachers, biology teachers, etc

A niche can be identified in terms of the degree of use of resources e.g. where it lives, what it eats, when it feeds

Niche

Environmental FactorsThe various factors that produce the particular

conditions in a habitat are called environmental factors.

BIOTIC or living factors relate to other living organisms in the environment and include factors such as the presence of predators, parasites and competition between members of one species.

ABIOTIC are non living factors relating to aspects of soil, water, light, shelter, temperature etc.

Biotic & Abiotic Factors Affecting A Crocodile

Soil and water chemistry

SalinityCompetitors

Humans

Air temperature

Relative humidity

Solar radiation Atmospheric

gases

Day length

Parasites

Prey

Environmental factors in water

Micro-environmentsConditions in a small region of habitatMany of these can be found within an environment

For exampleIn Arctic winterair temp above snow-covered may be colder than the tempwithin the snowlayer...forming differentmicro-environments

RangeThe geographic area that encloses all the

habitats where the species lives denotes the range or distribution map of the species.

Present range of

the Numbat

(Myrmecobius

fasciatus). Their

range is shrinking

because of

feral predators.

Tolerance RangeConditions in which an organism can

survive. Beyond these conditions are detrimental.

The tolerance range of organism affects an organisms distribution.

Tolerance Range

Limiting FactorsA requirement that is in short supply can

affect the organisms survival and reproduction of an organism.E.g. Light, water, oxygen, carbon dioxide

Describing environmental conditionsAn environment can be described in

qualitative terms, such as ‘warm and humid’ where ‘warm’ refers to the air temperature and ‘humid’ refers to the water vapour content of the air.

An environment may also be described in quantitative terms where a numeric value is stated, such as, ‘the air temperature is 23°c’.

When scientists measure environmental factors in a habitat, they usually express their findings in quantitative term. Some of the devices are shown on the next slide.

Devices for measuring the physical factors in the field include the following meters:

Quantum light meterDissolved oxygen Oxygen meterpH meterTotal dissolved solids (TDS)

meterCurrent meterMulti-purpose meterHygrometer Wind meterOther equipment includes:

Secchi discs Nansen bottles

Monitoring Physical Factors

Pasco datalogger with attached sensor

Pho

to: C

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esy

PA

SC

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cien

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FOR THE NEXT SLIDES:What is the habitat? Microhabitat?

Community? Niches? Biotic factors? Abiotic Factors? Limiting factors?

EcosystemsAn ecosystem consists of a

community, its physical surroundings and the interactions within and between them.

The living community in every ecosystem differs in their physical, biochemical and behavioural adaptations.

A biome is a large geographical region comprising natural units called ecosystems.An ecosystem encompasses the physical environment and the community.

Components of an Ecosystem

Community

Physical environment

Physical environment

Community

Abiotic factorsatmosphere,soil,water,wind speed wind direction,current velocity

Biotic factorscompetitors, symbionts, predators, parasites, pathogens

Ecosystem

Ecosystems Light intensity varies

Flow rate varies

Rainfall level varies

There are many different sorts of ecosystems from natural to artificial, and they range in size from large to small.

Still water habitat

Fast flowing water habitat

Rock habitatStream bank

habitat

Australian Ecosystems 1

Shrublands are widespread over much of inland Australia, in arid and semi-arid regions.

There are several different types including mulga, mallee, and bridalow, each with different dominating species.

Heathlands are found in highland areas where the increase in altitude creates conditions that lowland species find difficult to tolerate.

Mulga scrubland

Heathland, Tasmania

Australian Ecosystems 2

Deserts are rich and varied in Australia. They are generally defined as having an annual rainfall of less than 250 mm in the south and less than 500 mm in the north.

The desert regions range from large areas of active dunes to eroded outcrops, such as Uluru.

Australian Ecosystems 3Sclerophyll forests (top, right) in regions of higher rainfall on the east coast of Australia possess a single canopy layer of eucalyptus trees with a lush undergrowth.

Rainforests (bottom, right) are found in warm regions of high rainfall. With fewer eucalypts, the trees form a dense canopy with several understorey layers.

Australian Ecosystems 4Rock platforms occur on exposed coasts where wave action erodes the rock strata.

Coral reefs are found in the warm waters of the northern Australian coastline. The Great Barrier Reef extends 2000 km along Queensland’s coast and encompasses many individual reefs and islands.

The reefs, composed of hard corals, provide an immensely diverse range of habitats for many other kinds of marine organism.

GroupingsFind definitions and examples for the

following:AutotrophProducerHeterotrophConsumer

HerbivoreCarnivoreOmnivoreDetritivore

Decomposer

Producer?Consumer?Detritivore?

Producer?Consumer?Detritivore?

Producer?Consumer?Detritivore?

True or false?1. A producer organism in an ecosystem

must be a flowering plant.2. Different ecosystems have different

communities.3. Ecosystems can function without producer

organisms.4. Decomposer organisms are important in

breaking down organic matter to its more simple constituents.

Interactions within Ecosystems

Fill in the table for interactions within ecosystems using your textbook and

the Internet.