Ch 3: Biodiverse Ecosystems

Question 1

What does endemic mean?

Answer 1

a species that i native to a particular geographic region (not introduced)

Question 2

What is a biological hotspot?

Answer 2

a reservoir of the mos diverse, yet most threatened, sites of biodiversity on the planet.
The are extremely important to conserve due to the large number of endemic species found in the area.

Question 3

What is a biome?

Answer 3

the main category of an ecosystem across a large geographical area

Question 4

What are the defining features of terrestrial biomes?

Answer 4

✿ major variations in vegetation types
✿ climate
✿ topography (the arrangement of both natural and artificial physical features of an area)
✿ soil type
i.e. tropical rainforest, desert, grassland

Question 5

What are defining features of aquatic biomes?

Answer 5

✿ how permanent the body of water is
✿ salinity
✿ depth
✿ nutrient availability

Question 6

How are environments classified?

Answer 6

environments are classified based on their biotic and/or abiotic factors

Question 7

List and define some biotic factors

Answer 7

presence/absence of other living organisms that affect an organism
✿ members of their own species
✿ competitors
✿ collaborators
✿ predators
✿ disease-causing organisms
✿ parasites
✿ availability of mates

Question 8

List and define some abiotic factors

Answer 8

physical or chemical factors
✿ temperature
✿ light intensity
✿ texture and pH of soil
✿ concentration of significant gases in water/air
✿ availability of water

Question 9

Why is it important to identify the physical and chemical factors of soil when classifying an environment?

Answer 9

understanding the features of the soil helps determine which plants will grow best in a particular region

Question 10

What is soil type determined by?

Answer 10

✿ location
✿ depth
✿ texture
✿ colour
✿ porosity
✿ pH
✿ water carrying capacitiy
✿ nutrient status

Question 11

What is the distribution of terrestrial environments based on and list elements of climate?

Answer 11

based mainly on climate variation
elements of climate
✿ temperature
✿ light
✿ water
✿ wind

Question 12

What mainly defines aquatic environments?

Answer 12

Concentration of sodium chloride (salt
✿ 3%- marine
✿ less then 1%- fresh water
✿ fluctuating- estuaries

Question 13

How are ocean environments defined?

Answer 13

✿ depth
✿ distance from the shoreline
✿ way they are formed

Question 14

How are freshwater environments defined?

Answer 14

according to production of organic matter
✿ standing (still) bodies of water
✿ moving bodies of water
✿ ✿ large deep rivers tend to be nutrient poor while shallow lakes nutrient rich (but can develop eutrophication)

Question 15

How are ecosystems classified compared to environments?

Answer 15

environments can be classified based on their biotic and abiotic factors, ecosystems can also be classified by these factors but are largely classified by their dominant species

Question 16

What is generally the component species of an ecosystem?

Answer 16

some variety of plant
Vegetation is classified according to
✿ the % of ground shaded/covered by the tallest layer of vegetation
✿ the form (i.e. tree, shrub or grass) of the tallest layer

Question 17

What is the likeliness of an ecosystem being closed and why?

Answer 17

ecosystems are rarely closed, in neighbouring ecosystems, physical conditions (soil type, temp) gradually change/merge and the ecosystems overlap
it can be hard to notice where one ends and the other begins. Some animals (birds) will be part of multiple communities as they move from one area to another- these ecosystems are open

Question 18

What is a fundamental and realised niche?

Answer 18

an organism has a fundamental niche that it could potentially inhabit were no predators, competitors or parasites involved, and a realised niche, that they do inhabit due to the organism’s inability to exploit the resources of its habitat because of restrictions caused by other organisms

Question 19

How do organisms within an ecosystem deal with the fact they cannot feed on the same food sources at the same time?

Answer 19

they generally differ in the food source they prefer, their use of space and the timing of their activities

Question 20

What are the components to talk about when talking about a niche?

Answer 20

✿ Lives- spatial habitat, features and why this animal lives in this and how it is advantageous
✿ Eats- feeding activity
✿ Relates- interactions with other organisms (members of the community)

Question 21

List some relationships and interactions between living things

Answer 21

✿ competition
✿ collaboration
✿ predator-prey
✿ disease causing organism and host
✿ parasitism
✿ mutualism
✿ commensalism
✿ ammensalism

Question 22

How does predator-prey relationship affect biodiversity?

Answer 22

✿ prey population is always affected which leads to a subsequent change in predator population.
✿ when prey population decreases, predators can turn to alternative prey species and affect population severely
✿ seed predators effect plant population and their distribution as they cause seeds to become unviable/damaged when digested
✿ release of nutrients into soil caused by decomposing animal carcasses left behind by predators, allows for micro-organisms to survive

Question 23

How doe a disease causing organism relationship with its host affect biodiversity?

Answer 23

if it causes disease in an introduced species, the biodiversity of an ecosystem with native species would be higher. However if it affected a native species i.e. Koala and chlamydia the biodiversity of an ecosystem would be lower

Question 24

What are pollinators?

Answer 24

major type of mutualistic relationship
essential for many flowering plants to reproduces. Pollinators benefit from feeding on nectar while plants benefit from being pollinated i.e. pygmy possums

Question 25

What are seed dispersers?

Answer 25

another major type of mutualistic relationship
mammals and birds that eat fruit and seeds for nutrition, when the animal defecates, it deposits the seeds, undamaged and unviable, in a new location where it can germinate and grow i.e. cassowary and Queensland rainforest ecosystem

Question 26

What would happen in the absence of pollinator and seed disperser relationships?

Answer 26

many species would become threatened/extinct and diverse ecosystems would not be built

Question 27

What is a keystone species?

Answer 27

a species of relatively low abundance that is seen to have a large influence over lower trophic levels to allow the coexistence of these species. The ecosystem depends on it for its survival- all members of an ecosystem depends on this species directly/indirectly for its survival
✿ prevents any organism from monopolising food resources and space and allows for richer biodiversity
i.e. purple sea star or cassowary

Question 28

What is the niche of a African lion?

Answer 28

Lives- inhibits grassland and open woods, allows it to be hidden when seeking out prey
Eats- feeds on large hoofed animals like gazelles, zebras,, impalas and wildebeest, will eat smaller prey if necessary, hunting takes place at night and early morning, often hunt in groups which allows it to prey on animals bigger than itself, has different hunting style/preferences to other predators which allows all to feed equally
Relates- male lion’s mane makes it conspicuous so females do most of the hunting, lives in pride, sleeps 20 hours of the day, is one of the top predators so does not have other animals to worry about

Question 29

What are the features of Mulga Shrub Ecosystem?

Answer 29

✿ widespread over much of inland Australia- arid and semi-arid regions
✿ mulga is dominant species
✿ low rainfall and altitudes
✿ high summer and moderate winter temp

Question 30

What are the features of a Highland Heathland Ecosystem?

Answer 30

✿ high altitude and rainfall (>1600mm)

✿ moderately cool temp (5-22C)

Question 31

What are the features of a Rock Platform Ecosystem?

Answer 31

✿ substrate made of rock that is exposed to mod-strong wave action

Question 32

What are the features of Tropical Rainforest Ecosystem?

Answer 32

✿ warm temp
✿ high rainfall
✿ trees form a dense canopy with several understorey layers

Question 33

What are the features of West Sclerophyll Forest Ecosystem?

Answer 33

✿ low rainfall and temp than those necessary for a tropical rainforest
✿ single canopy layer of eucalypt trees with lush undergrowth

Question 34

What are the features of Desert Ecosystem?

Answer 34

✿ low rainfall (

Question 35

What are the features of Coral Reef Ecosystem?

Answer 35

✿ warm water and temp (20C-35C)
✿ clear water
✿ less than 50m deep