Species Interactions
Define ecological community:
An assemblage of populations of different species that live close enough to interact.
What is the "red queen principle" and what does it relate to?
Continuous adaptation is needed to maintain fitness.
Antagonistic Evolution= the joint evolution of two interacting species, each in response to selection imposed by the other
What are species richness and species diversity?
Species richness: # of species that ar present in the community.
Species Diversity: # of species and relative abundance (# of individuals per species)
What are the 4 primary trophic levels?
Primary Producers
Primary Consumers
Secondary Consumers
Tertiary Consumers
SOMETIMES: quaternary consumer (orca)
1. Not eaten
2. Feces
3. Growth
4. Cellular respiration
3&4 assimilated
Define symbiosis:
when an individual of 2 or more species live in direct or intimate contact with one another
What is behavioral parasitism?
"parental care parasitism"
Interaction is behavioral, NOT physical.
EX: common cuckoo ejects egg or Reed warbler and uses the parents for foos.
What are the three primary stages of ecological succession?
Pioneer species—-->Intermediate species—--> climax community
What is the energetic hypothesis?
The length of the food chain is limited by the inefficiency of energy transfer along the chain.
More resources=more producers=longer food chain.
Only 10% of energy converted to biomass with each trophic level.
What is a climax community?
The most stable association of species is achieved following succession.
At the end of succession, the greatest heterogeneity (habitat diversity)
What is the only +/+ interspecific interaction?
Mutualism
What is an example of an ecto and endo parasite?
Ectoparasite: ticks, lice, lamprey
Endoparasite: heartworm, tapeworm, plasmodium
What are the direct and indirect species interactions?
Direct: competition=use of a resource by one species such that it is less or unavailable for other species.
Indirect: facilitation (change in soil chemistry) & inhibition (no sunlight)
How do plants and animals use energy to benefit each other?
Plants:
(CO2+H2O)----->Sugars+O2
Animals:
(Sugars+O2)------>CO2+H2O
What is secondary succession?
When EXISTING communities have been cleared by DISTURBANCE that leaves soil intact.
All of the environmental conditions and resources that an animal requires. Sum of abiotic and biotic resources used.
What are 3 different types of consumers?
Herbivory=Plants=Grazer
Granivory=Grains=Grazer or Predator (mutualism): spreading seeds)
Sanguivory=Blood=Parasite or grazer (mosquito)
Insectivory=Insects=Predator
What is a keystone species?
Influence on the community is proportionally greater than its numbers would suggest! Super competitors OR super predators. Huge impact because of the niche.
What is the bottom up effect?
Unidirectional influence from lower to higher trophic levels.
Altering biomass production at low trophic levels changes community structure.
R-selected: Increased fecundity, decreased parental care, increased reproduction rate
What are the two scales that coexistence results from when resource/niche partitioning occurs?
Spatial scale: vertical structure in tropical areas OR horizontal mosaics.
Temporal Scale: Daylight, tide, time
Can be Proximate or Ultimate cause of evolution
What does mutualistic (+/+) coevolution evolve from?
What are the 2 types of mutualism?
arises from parasite-host or predator-prey interactions.
Obligate Mutualism
Facultative mutualism
What effect would a large and close island have on immigration, extinction, and species richness compared to a small and far island?
Large island: increased immigration, decreased extinction, increased species richness.
What is trophic transfer efficiency (TE)?
TE=[Production at lower level (kcal)]/[Production at higher level]
as a percent
What are 3/4 of the human impacts on the environment?
1. deforestation (decrease biodiversity)
2. invasive species (non-native)
3. Climate change (increased temp)
4. Biological magnification (toxins)