patterns in space and time

Question 1

what is community ecology

Answer 1

the study of patterens in the structure and behaviour of multispecies assembalages

Question 2

what is meant by the term synergistic emergent properties

Answer 2

when the interactions of an
individual components produce new functi9nos which make the community more than the sum of its parts

Question 3

what determines the species which assemble to make a community

Answer 3

1) the habitat species pool- species which are able to survive the environmental constraints
2) the geographic species pool - species which can overcome dispersal constraints e.g. mountains etc

Question 4

if a species can overcome environmental and dispersal constraints what do they form

Answer 4

an ecological species pool which makes up the community

Question 5

how can a community be defined

Answer 5

any scale within a hierarchy of habitats

Question 6

what is species richness

Answer 6

the total number of species

Question 7

what are some of the challenges faced when describing species richness

Answer 7

1) needs skilled taxonoists
2) only a small sample is counted- therefore number of species depends on number of samples counted
3) more common species are represented first
4) when do you stop sampling

Question 8

how do you know when an appropriate number of samples has been taken when calculating species richness

Answer 8

once a plateu of species richness has been reaches then the right number of samples has been taken to represent to community

Question 9

why may species counts be misleading

Answer 9

disparities in size mean counts are misleading
- larger individuals will take up more room per square metre therefore they will be less abundnat

Question 10

what is a better technique to indentify diversity

Answer 10

biomass per speices per unit area

Question 11

what does the simpsons index show

Answer 11

the probability that 2 randomly selected individuals belong to the same species

Question 12

what is the difference between simpsons index, simpsons index of diversity

Answer 12

1) probability 2 randomly selected individuals belong to same species
2) probability 2 randomly selected individuals belong to different species

Question 13

what is shannon weiner diversity index

Answer 13

uses species richness and abundance to measure the uncertainty in predicting the species identiy of an individual taken at random

Question 14

what do rank abundance diagrams show

Answer 14

provide a more complete picture of species abundance and distribution in a community

Question 15

what does classification of species allow

Answer 15

assumes communities consist of discrete entities and groups communtites which are similar

Question 16

what does ordination of species allow

Answer 16

allows communities to be organised on a graph so most similar in species composition and abundance appear closer together

Question 17

how can boundires cause issues in the study of community ecology

Answer 17

• there are often blurred transition zones e.g. aquatic vs terrestrial which frogs move between

Question 18

what did clements mean when they said a community was a superorganism

Answer 18

that members tightly bound together now and in evolutinary history

Question 19

outline Gleasons individualistic concept

Answer 19

that relationships of coexisting species are simply a result of similarities in requirements and tolerances and chance

Question 20

when will a species only occur

Answer 20

1) if the individual is able to reach the location
2) if there are approproiate conditions
3) competiton and predation dont preclude it

Question 21

how can disturbances disrupt a community

Answer 21

• influence availability of space or food
• change physical enviro

Question 22

what is the founder controlled responce to distrubance

Answer 22

species are equallt able to colonise an opening made by disturbance

Question 23

what is dominance controlled responce to disturbance

Answer 23

when some species are competitvley superiror so an initial coloniser cant maintain its presence

Question 24

what is ecological succession

Answer 24

the non-seasonal directional and continuous pattern of colonisation and extinction on site by species populations

Question 25

what is clements monoclimax theory

Answer 25

in any given climatic region a single climax will dominate

Question 26

what is Tansley polyclimax theory

Answer 26

that local climax is governed by a combinatino of factors

Question 27

what is Whittakers climax pattern hypothesis

Answer 27

a continuity of climaxes along environemental gradients