Top Posters
Since Sunday
18
17
Z
9
7
s
6
m
6
M
6
a
6
K
6
l
5
k
5
5
SlideshowReport

Indirect Interaction (Foodwebs)

Description
ndirect interactions in communities. (a) Two consumers sharing a common prey may compete indirectly via classical exploitation competition (resource depression). (b) Two prey species may only appear to compete, because if either increases, a shared predator also increases, which operates to the detriment of the other prey population (Holt 1977). (c) Populations of three species at the same trophic level, arranged so that one species, P2 is sandwiched between two others. Populations P1 and P3 are indirect mutualists because each inhibits the other's competitor -- P2. (d) A more complex four-species system that results in an indirect "mutualism" or "facilitation" (Vandermeer 1980). In this case, populations C1 and C2, which do not interact directly, but consume different prey species, interact indirectly because their prey compete: if consumer C2 increases, its prey P2 decreases, which in turn reduces competition with P1, providing more food for consumer species C1. (e) A trophic cascade, with populations of three species at three trophic levels: the plant P1 and the carnivore C1 are indirect mutualists because they share an herbivore H1. Numerous other sorts of indirect interactions are also possible.
Related Images
Commenting on this item has been disabled by the author or forum moderator.
Explore
Post your homework questions and get free online help from our incredible volunteers
  176 People Browsing
 343 Signed Up Today
Your Opinion

Previous poll results: Do you believe in global warming?