community ecology

Question 1

what is the nature of ecological communities?

Answer 1

communities are composed of multiple species
several ways to describe this diversity in ways that integrate information in species richness and relative abundance

Question 2

what is species richness?

Answer 2

S
crude metric

Question 3

what is Shannon’s diversity index

Answer 3

accounts for both abundance and evenness of the species present
takes in account of the number of species and the abundance it is

Question 4

what is population interactions and their effects?

Answer 4

genetically based, reciprocal adaptations in species that interact ecologically

Question 5

what is an ecological niche?

Answer 5

concept to visualize populations resource use
- fundamental niche
- realized niche

Question 6

what is competition?

Answer 6

field studies can demonstrate competition between 2 species

Question 6

what is interspecific competition?

Answer 6

2 or more species using same limiting resource

Question 7

what is interference competition?

Answer 7

one species harms another species directly

Question 8

what is exploitative competition?

Answer 8

one species reduces resources availability to other
less aggressive

Question 9

what is interspecific competition?

Answer 9

can coexist at first due to an abundance of resources
more resources taken by one species, the population of the other will decrease

Question 10

what is population interactions and their effects?

Answer 10

generically based, reciprocal adaptations in species that interact ecologically

Question 11

what is resource partitioning?

Answer 11

conflict and competition reduced when different species use different resources or in different ways
subspecies use different in different ways

Question 12

what is character displacement?

Answer 12

evolution phenomenon where morphological and behavioural differences among similar species with overlapping geographic ranges
- greatest in those areas where species co-occue
- minimal in those areas where species distributions do not
overlap
- results from selection

Question 13

what is allopatry?

Answer 13

when two different species has the same niche in different areas

Question 14

what is sympatry?

Answer 14

when two different species has the same niches in different areas but when put in same area they have different environmental differences

Question 15

what is ecological succession?

Answer 15

somewhat predictable change in species composition over time
primary succession
secondary succession

Question 16

what is primary succession?

Answer 16

begins on habitats without soil

Question 17

what is secondary succession?

Answer 17

occurs where a community existed in past

Question 18

what causes succession?

Answer 18

facilitation hypothesis
tolerance hypothesis
inhibition hypothesis

Question 19

what is facilitation hypothesis

Answer 19

species modify the local environment, marking it less suitable for their continued success but more suitable for later colonizers

Question 20

what is tolerance hypothesis?

Answer 20

good dispersers colonize first and become established
slowly dispersing but strong competitors can invade and outcome the early colonist

Question 21

what is inhibition hypothesis?

Answer 21

each successional stage dominated by first colonizers
new species are actively prevented from occupying community by species already present
eventually dominate species die of old age or a disturbance reduces their numbers, creating opportunities for later