Lecture 18: Species Interactions Flashcards
Interactions between two species can…
• benefit (+),
• harm (-), or
• have no effect (0)
…on each of them.
Describe the interaction of species in competition.
-/-
Both do worse when together.
competition
resource use by ONE individual that reduces its availability for others.
Intraspecific competition
individuals of the same species compete.
Interspecific competition
individuals of different species compete.
Niche
Total range of all abiotic/biotic conditions
tolerated and all resources used
Fundamental Niche:
Niche that a species potentially could occupy
Few species actually fill their fundamental niche
Realized Niche
subset of the fundamental niche that a species actually occupies
Competitive Exclusion Principle
complete competitors cannot coexist
worst competitor would be entirely excluded.
Mutualism
positive/positive
+/+
Both species benefit (do better together).
Pollination Syndrome
Suites of floral characters associated with different modes of pollination (flower characteristics that relate to pollinator characteristics)
pollination
Act of transferring pollen grains from the male part of a flower to the female part of the flower.
• Required before fertilization to take place (i.e., to create a zygote).
Plant
provides organic carbon derived from photosynthesis
Bacteria
provide fixed nitrogen by forming nodules in plant roots
antagonist interaction
negative/positive
-/+
One does worse, one does better when together.
Forms of Antagonism
- Predation
- Herbivory
- Parasitism
- Pathogens
Stone plants make themselves less apparent to herbivores by blending in with their environment
Reduced Apparency (Herbivory Resistance)
Herbivory Resistance: Structural Defenses
a. modified stems
b. modified leaves
c. extension of the epidermis
d. trichomes (hair)
e. leaf margin
Secondary metabolites
specialized compounds not directly related to basic metabolic pathways (e.g., photosynthesis)
Herbivory Resistance
- Reduced apparently
- structural defenses
- chemical defenses
Give an example of indirect defenses against herbivory
the ants that inject other plants to kill them off and protect the main species plant and also attack other insects trying to eat the plant. In return ants get shelter.
commensalism
positive/unaffected
+/0
One does better when together; one is unaffected.
ammensalism
negative/unaffected
-/0
One does worse when together; one is
unaffected.
Describe the species interaction grid
(+/+) (+/-)
Mutualism Antagonism
(-/+) (-/-)
Antagonism Competition
(0/+) (0/-)
Commensalism Ammensalism
