L6 Synecology

Question 1

What effect does sepentine soil have on the boundaries between plant communities

Answer 1

Creates more abrupt boundaries and lack of ecotones

Question 2

What does serpentine soil contain lots of

Answer 2

Heavy metals

Question 3

What are ecotones

Answer 3

Transitional areas - the gradual blending of two communities

Question 4

What effect do humans have on the boundaries between vegetation

Answer 4

Humans also cause abrupt boundaries

Question 5

Plants are only a subset of the community, what other subsets are there

Answer 5

Herbivory
Disease
Pollinators
Mycorrhizal associations

Question 6

Define plant community

Answer 6

The collection of plant species growing together in a particular location that show a definite assocation or affinity with each other

Question 7

How many recognised plant communities are there in the UK

Answer 7

286

Question 8

How are oundaries of plant communities defined

Answer 8

Based on changes in abundance of dominant or common species

Question 9

When sampling a plant comunity, which areas should be avouded

Answer 9

The edges / near the boundaries

Question 10

What is a stand in terms of sampling

Answer 10

Local area treated as a unit for the purpose of describing begetation

Question 11

What are the 2 questions that arise in sampling the plant community

Answer 11

How large should the area be?
Where (precisely) should the sample be?

Question 12

What are 2 ways quadrats could be assigned a location

Answer 12

Subjective - positioning in ‘typical vegetation’
Objective - positioning by randomisation

Question 13

What was Clements view of the plant community

Answer 13

Superorganismic, holistic view of ocmmunity structure

Question 14

What was Clements view of the plant community

Answer 14

Superorganismic, holistic view of ocmmunity structure

Question 15

What was Gleasons view on the plant community

Answer 15

Individualistic, reductionist

Question 16

What are the 2 main differences in Clemets and Gleasons arguments

Answer 16

The importance ascribed to biotic versus abiotic factors
The predictable versus unpredicatble pprocesses

Question 17

Who of Gleason and Clements is more likely correct
Where is the modern view

Answer 17

Gleason more likely correct
Modern view is somewhere in the middle

Question 18

Where did Clements study

Answer 18

North America

Question 19

What is the climax community in the UK

Answer 19

Temperate woodland

Question 20

What did Clements believe was responsible for the nature of the climax community

Answer 20

Climate

Question 21

Clemets believed that the life history of a community was…

Answer 21

A definite and predictable process

Question 22

What did Clemets believe was the singular factoe determining community structure

Answer 22

Only species interactions

Question 23

How did Clements break up commuities in North America
How many climax communities did he recongise
What were they
What were they divided into
What were these further divided into

Answer 23

Recognised 3 climax communities
Grassland, scrub and forest
Subdivided into formations
Further subdivided into associations

Question 24

What is the modern name given to what Clements identified as ‘associations’

Answer 24

= communities

Question 25

What 3 things did Gleason believed formed the individualistic community

Answer 25

The result of interactions between individual species and the environment (biotic and abiotic) In combination with change historical events

Question 26

What 2 things did Gleason believe were responsible for determining community structure

Answer 26

Biotic and abiotic interactions

Question 27

What did Gleason believe happened at boundaries between communities Do all species experience the same boundaries

Answer 27

Different species have different boundaries at different places along an environmental gradient Changes are gradual, not abrupt transitions

Question 28

What 4 things did Gleason think could affect heterogeneity of community structure

Answer 28

Accidents of seed dispersal Minor variations in environment Different abundances of parent plants Brevity of periods (length of time) between disturbances

Question 29

What did Clements believe occured between two plant communities

Answer 29

An abrupt boundary

Question 30

What did Whittaker belive the pattern was When was this What was his theory called

Answer 30

Mosaic climate pattern 1956 Community-unit theory

Question 31

What kind of gradients did Whittaker belived played a role in establighing forest communities

Answer 31

Elevational gradients

Question 32

What did Whittaker believe about the transition zones between communities

Answer 32

They were gradual changes, not abrupt transitions

Question 33

What is succession

Answer 33

The non-seasonal, directional and continuous pattern of colonisation and extinction on a site by species populations

Question 34

Where does primry succession occur and is it influenced

Answer 34

Occurs on exposed landforms Uninfluenced by a previous plant community

Question 35

Who came up with the idea of succession

Answer 35

Clements

Question 36

What did Clements believe was the end stage of succession

Answer 36

Dynamic equilibrium

Question 37

How many stages did Clements believe there was to succession

Answer 37

6

Question 38

Did frequency, strength and complexity of interactions decrease or increase throughout succession

Answer 38

Increase

Question 39

Define seres

Answer 39

The series of recognisable communities before a climax was achieved

Question 40

Did Clements believe you could predict the climax community What would determine the climax community

Answer 40

Yes they are predictable and determined by climate

Question 41

When does secondary succession occur

Answer 41

When vegetation of an area is removed but soil and seeds or spores remain and a sequence od speciew regenerates

Question 42

Is primary succession faster or slower than secomndary succession

Answer 42

Primary is slower

Question 43

What parts of Clements theory did Gleason disagree with

Answer 43

The determinism and directedness

Question 44

How did Gleason believe communities were established

Answer 44

Random elements of seed immigration and seedling establishment

Question 45

What did Gleasin believe established the end point of succession in an area

Answer 45

Initial conditions and disturbance histories

Question 46

Why did Gleason disagree with the consept of an equillibrium community

Answer 46

Communities exhibit transient dynamics Communities often change and we cannot tell if we are at the end of succession

Question 47

What did Gleason believe could cause succession

Answer 47

Distrubance Gaps = large like landslides or local like one tree being struck by lightning Wind Water Earthquakes and volcanoes Colonisation rates

Question 48

What did Clements (1916) believe about the end point of succession

Answer 48

Monoclimax theory = in a given climatic refion, a single climax will dominate

Question 49

What did Tansley (1935) believe about the end point of succession

Answer 49

Polyclimax theory = local climax governed by a combination of factors e.g. Climate, soil conditions, topography, fire

Question 50

What did Whittaker (1953) believe about the end of succession

Answer 50

Climax pattern hypothesis = continuity of climaxes along environmental gradients