Community Ecology Flashcards
Definition of Community Ecology
The study of patterns and processes involving at least 2 species of organisms at a particular location
Parasites are often only afapted to ____ or a few host species, but host species often have ____ parasite species.
one; multiple
Coevolution of host and parasite species
The host and parasite populations evolve in response to selection pressures of the other
The ____ ____ ____ abolishes the expression of the Duffy antigen receptor of chemokines on the surface of red blood cells, and confers almost complete protection from P. vivas
Duffy-negative phenotype
*Approaches fixation in western and central Africa
Each time a ____ species is lost to extinction, all ____ specialized to depend on the host species will all follow.
host; parasite
Parasites greatly increase ____ ____linkages, and makes them ____ stable.
food web; more
Lyme disease is caused by ____that is carried and transmitted by ____. White-footed mice are a primary ____ ____, and white-tailed deer are a crucial hsot for adult tick ____.
bacteria; black-legged ticks; zoonotic reservoir; reproduction
The Ecology of Lyme Disease
1st Summer: eggs hatch to larvae and infects birds and small mammals
2nd fall: Adult ticks mate and lay eggs
Why are ticks good at spreading diseases?
They spit digestive enzyme / anticoagulant which can pring pathogens into the body.
Chain reactions linking oak mast to lyme disease risk
- Deer bring in adult, gravid female ticks during mast events (t=0)
- Mice feed on acorns, increases mouse population in the following year (t=1)
- Larval ticks hatch the following spring, and feed on abundant mice (t=1)
- Many larvae feed on infected mice become infected with B. burgdorferi, molt into infected nymphs the following summer (t=2)
- Increased number of infected nymphs results in a spike in the number of human cases of Lyme disease (t=2)
Apparent competition
Occurs when a predator consumes multiple prey species
- Prey species indirectly compete with each other by increasing the numbers of their shared predator
Shared Parasitism
The parallel concept of a single parasite utilizing more than one host
*one parasite, multiple hosts
Competition
A fundamental force structuring wildlife communities
Exploitative competition
The indirect form of the interaction, whereby 2 species compete via a shared resource
Competitive exclution principle
2 species that share exactly the same resource/niche cannot persist
Parasite competition
Competition among parasites for a shared host
*Multiple parasites are often able to persist in one host via niche partitioning
*Can also result in temporal partitioning of host resources (ex. alterations between measles and whooping cough)
Key stone species
A species whose presence and role within an ecosystem has a disproportionate effect on other organisms within the system
Parasites may serve as keystone species as well, either as ____ species themselves or through their ____ on ____ species.
dominant; effect; dominant
Example of Keystone species regulating parasites
Oaks and Lyme Disease
Example of Parasites as keystone species
- Avian malaria in Hawaii
- Rinderpest
Community Ecology of Avian Malaria in Hawaii
The pathogen is unable to reproduce at elevations above 1500m due to temperature limits, which pushed the range of native birds to higher elevations.
Why does avian malaria qualify as a keystone species in Hawaii?
They have strong effects to the dominant species on the island
How might climate change affect the outcome of these interactions?
Mosquitoes will be more prevalent in higher elevations, the range of non-native birds will increase and the range of native birds will decrease
If humans can’t get Avian Malaria, how is it even a human health issue?
Physical threats: flooding, wildfire, access to clean drinking water from the ecosystem services that native birds provide; also the pollination of native plants
