Topic 21 -Interspecific Competition

Question 1

Interspecific Competition=

Answer 1

an interaction between individuals of different species brought about by a shared requirement for a resource in limited supply

Question 2

interspecific competition brings negative effects on both species because

Answer 2

each species contributes to the regulation of the other population as well as its own

Question 3

less obvious effects than predation which are

Answer 3

reduction of growth, reproduction and survival

Question 4

fundamental niche

Answer 4

full range of conditions/resources used by a species to survive and reproduce

Question 5

realized niche

Answer 5

the portion of the fundamental niche a species actually exploits as a result of competition

Question 6

Niche overlap

Answer 6

when two or more species use a portion of the same resource (food/habitat) simultaneously

Question 7

the amount of overlap in realized niche is the degree of

Answer 7

potential competition for the resource

Question 8

Three possible outcomes when one species is introduced to another area where another species exist

Answer 8

1. Coexistence without competition (resource not limited)
2. Coexistence with competition (resource moderately limited)
3. One species is eliminated (resource extremely limited)

Question 9

Coexistence with competition results in

Answer 9

Asymmetrical competition -one species is more strongly effected

Question 10

competitively dominant

Answer 10

species least effected by competition

Question 11

Competitive exclusion principle

Answer 11

two species that have the same resource requirements cannot coexist when those resources are scarce

Question 12

root competition, occupy soil

Answer 12

water and nutrients ex rye grass outcompetes white clover in every competition

Question 13

stems and leaves occupy atmosphere, shoot competition=

Answer 13

light ex rye grass outcompetes white clover in every competition

Question 14

competitive release

Answer 14

expansion of a realized niche in the absence of another competing species

ex red-cheeked salamander is a dominant species to northern slimy salamander

Question 15

Environmental Gradients

Answer 15

abiotic factors or resources exist along a gradient (continuum)
some portion of the gradient will be optimal for a particular species but not for others
Results in one species having competitive advantages under one set of conditions but not under another

Question 16

Temporal Variations

Answer 16

temporal variations allow for competitive advantages that change over time

variation in the environment over time changes which species will be the more successful competitor

as a result no species reaches sufficient density to displace its competitor and both coexist

Question 17

Multiple resources

Answer 17

interspecific competition often involves more than one singe resource

competition for one resource can influence how organisms compete for other resources

usually occurs between related species and especially in territorial birds -compete for space (territory), food or nesting sites

Question 18

resource partitioning

Answer 18

often species can coexist by resource specialization

functionally reduce the breadth of each species niche so there is no longer as much or any overlap

reduces competition

each species exploits a portion of the resources unavailable to others