Lecture 2 - DA

Question 1

What defines a woodland?

Answer 1

Trees with non-overlapping crowns.

Question 2

What defines an open forest?

Answer 2

Tall trees giving only a single stem.

Question 3

Where are forests usually localised? What about woodlands?

Answer 3

Forests are near coastlines.

Woodlands take transition zone between forests and grasslands/shrublands.

Question 4

How tall are trees in woodlands, generally?

Answer 4

10-30m

Question 5

What is the canopy and spacing of trees like in woodlands? What about their branching?

Answer 5

Large, open canopy.

Trees are widely spaced, and have more extensive branching.

Question 6

What 3 factors shaped most woodland communities?

Answer 6

Fire, climate, and human activity.

Question 7

Which biome is the most endangered and vulnerable in Australia?

Answer 7

Woodlands.

Question 8

What percentage of Australia is an open forest currently? What was it like in precolonisation times? Where are open forests confined to?

Answer 8

5%, confined to higher rainfall areas near the coast.

Current cover is only 60% of precolonisation times.

Question 9

What are open forests dominated by?

Answer 9

Eucalypts.

Question 10

Where are Australian alps found?

Answer 10

Southeast Australia only.

Question 11

What are 2 ways plants can be sampled? What do they record?

Answer 11

Done by pins, or by eye.

Will record species, density, and cover/abundance.

Question 12

What are 4 methods of surveying an ecosystem?

Answer 12

Transects
Quadrats
Plotless sampling
Aerial survey

Question 13

When sampling plants vs animals, what is one advantage of plants?

Answer 13

Plants are static.

Question 14

What are recordings of plant species during a survey specific to? Is this true of animal species?

Answer 14

Time of the recording, some plants can be seasonal.

Some animals come out at certain times only, such as nocturnal animals.

Question 15

When is a structural survey done?

Answer 15

When comparing different geographical regions.

Question 16

What does a structural survey reveal? Is it necessary to identify species?

Answer 16

Shows a mix of trees, shrubs, or ground covers.

No need to identify species.

Question 17

What can a structural survey allow you to compare?

Answer 17

Allows for site comparison, even if species differ.

Question 18

What are 2 disadvantages of structural surveys?

Answer 18

Not very informative

No record of the species

Question 19

What is a presence/absence survey?

Answer 19

A list of species, recording all those found.

Question 20

Name 5 disadvantages of a presence/absence survey.

Answer 20

• Hard to be thorough
• Time intensive
• Seasonal changes means needing >1 visit
• High cost
• Difficult to have accurate identification

Question 21

What is a density survey?

Answer 21

Counting the number of individuals per area.

Question 22

What are 2 problems with a density survey?

Answer 22

Defining an area

Defining an individual - especially plants, such as moss or multistems.

Question 23

What is a cover/abundance survey?

Answer 23

Estimation of the proportion of area covered by a species.

Question 24

What is an advantage of a cover/abundance survey? What 2 organisms is it good for?

Answer 24

They are quick.

Good for plants, and colonial animals.

Question 25

What are two disadvantages of a cover/abundance survey? Are they objective or subjective?

Answer 25

Variation between individuals - subjective

Time consuming - objective

Question 26

What is a solution to the disadvantages of a cover/abundance survey?

Answer 26

Use standardised broad scales.

Question 27

When are transects used? How are the samples taken?

Answer 27

Used if there are obvious patterns or clines.

Systematic samples are taken along the transect.

Question 28

How are samples taken if there are no obvious patterns?

Answer 28

Use random points.

Question 29

What is needed to average out the variability of sampling using a quadrat?

Answer 29

Using a large number of quadrats.

Question 30

What are the axes of a graph from a quadrat’s results?

Answer 30

Mean no. of plant species per quadrat vs quadrat area.

Question 31

What are nested quadrats?

Answer 31

Small quadrats that progressively get bigger, within a large master quadrat.

Question 32

What are quadrats good for?

Answer 32

Understory and midstory.

Question 33

Plotless sampling is also known as?

Answer 33

Point-quarter sampling.

Question 34

What is plotless sampling mainly used for?

Answer 34

Trees with scales too big for quadrats.

Question 35

What does plotless sampling measure?

Answer 35

Individual counting to measure density.

Question 36

Density in plotless sampling is obtained from 2 measurements. Describe them.

Answer 36

Point-to-plant distance using tapes/measures.
Diameter at breast height over bark - dbhob
-Also circumference at breast height

Question 37

How is plotless sampling carried out?

Answer 37

From a random point, divide the area to 4 quarters.
Measure distance to the nearest individual of species in each quarter, and average it.
Do the same with DBHOB, to get its average.
Allows calculation of density and dominance.

Question 38

What does DBHOB allow you to estimate? How is canopy cover usually estimated in plotless sampling?

Answer 38

Canopy cover. Cover is assessed visually.

Question 39

Describe the braun-blanquet cover abundance scale.

Answer 39

+ 1 2 3 4 5
+ - sparse, very small cover
5 - >75% cover

Question 40

What are aerial surveys good for? What is needed in addition to an aerial survey?

Answer 40

Good overview, reveals patterns if there. Will need to visit the area however, to confirm findings.

Question 41

What is a berlese funnel, what is it used for, and how does it work?

Answer 41

A trapping method for invertebrates.
A known area of litter is collected, spread on a mesh, with mild heat applied.
Invertebrates within will fall through the mesh to escape, and fall to ethanol below.
The individuals can then be counted.