Bio - Module 9 (Community Ecology)

community

a set of populations of different species living together in a particular area

community dynamics

how organisms are interacting and changing

community structure

interactions between organisms

competition 

— —

mutualism

+ +

antagonistic

- +

amensalism 

- 0

commensalism

+ 0

neutralism

0 0

antagonistic interactions

• predation

• parasitism

• herbivory

autotrophs 

primary producers 

heterotrophs

everything besides primary producers

issue with food chains

generally not complex enough to accurately represent the ecosystem

topology 

arrangement of trophic elements

• broad in food webs 

• narrow in food chains 

nodes

species

links

our interactions

connectance 

a quantitative measure of how complex a food web is 

trophospecies

a group of species acting as the same trophic unit

detritivores

• eat detritus (dead things)

• eaten by predators

why parasites matter 

• vectors for disease 

• important to the food web 

• often ignored 

obligate

host is required to complete their life cycle

examples of obligate parasites

• ticks

• viruses

• helminth parasites

facultative

host is not required

generalist

has many hosts

specialist

very host-specific

endoparasite

inside the host body

ectoparasite

outside the host body - the surface

directly transmitted 

don’t need a vector, there is no intermediate 

• many time they are free-living (they move around and infect as their own organism) 

trophically transmitted

• transmitted by being eaten by a host

• transmitted via trophic interactions; usually via multiple hosts

animal parasites

• insects

• helminth worms

• annelid worms

plant parasites 

mistletoe 

protozoans parasites

• plasmodium

• toxoplasm gondii

• trypanosoma

fungi parasites

• ringworm, athletes foot

• rust

types of helminth parasites 

• flatworms 

  • cestodes - tapeworm

  • trematodes - flukes

• round worms 

• thorny headed worms