Chapter 54 Flashcards
Community
Population of differnet species living in the same habitat
Interspecific interaction
Interaction between different species in the community
Competition
( - / - ) interaction that occur when individuals of different species each use a resource that limits the survival and reproduction of both individuals
Predation
( + / - ) interaction between species in which the predator kills and eats the other prey
Herbivory
( + / - )
Symbiosis
Individuals of two or more species live in direct and intimate contact with one another
Mutualism
( + / + )
Commensalism
( + / 0 ) symbiotic relationship in which one organism benefits but neither harms or helps the other
Parasitism
( + / - )
Endoparasites
Live within body of the host
Ectoparasites
parasites that feed on the skin/external surface of the host
Facilitation
( + / + ) or ( 0 / + )
Competition
Species competing for a resource that limit their growth and survival
Ecological Niche
Sum of environmental factors that a species require : habitat, food source, temperature, etc.
Fundamental niche
Niche initially occupied by a species
Realized niche
Actual niche occupied in a particular environment
Competitive exclusion principles
Devised by Russian ecologist G.F Gause
Two species with same niches can’t coexist in a community
But they can through resrouce Partitioning or differentiation of niches
Allopatric
Geographically spereate
Sympatric
Geographically overlapping
Character displacement
Tendency to diverge in order to survive in a competition
Cryptic Coloration
Camouflage, makes prey difficult to be seen.
Aposematic Coloration
Animals with effective chemical defenses often exhibit bright colors and predators avoid preys with bright colors.
Batesian mimicry
Harmless species mimics a harmful one.
Mullerian mimicry
Two or more harmless species resemble each other.
Facultative mutualism
Both species can survive independently without the other
Obligate mutualism
One species loses ability to survive without its partner
Facilitation
Interspecific interaction in which species can have positive effects without living
Spcies diversity
The variation of different species that form a community
Species richness
The amount of differnet species in a community
Relative abundance
The percentage of how much a species represents the community
Shannon diversity index
H = -(pA inpA + pB inpB + pC inpC)
Invasive species
Organisms that become based outside their domestic area
Benefits of diverse communitites
More resistant against invasive species
More effective
Able to resist disturbances better
More stable
Trophic structure
Correlation between organisms in a community in relation to food energy
Food chain
The exchange of food energy through the trophic levels
Food webs
Concept that food chains are not isolated but rather linked together in a web
Who created food web
Charles elton in 1920
Energetic hypothesis
Food chains are short because longer chains has inefficient E transfer
Dynamic stability hypothesis
Suggest longer chains are less stable, changes in lower trophic levels could be magnified
Dominant species
Species that has the largest population/biomass in a community with the ability to affect a community
Keystone species
Species that have a strong control over a community due to their niches, but doesn’t have the largest population
Foundation species
Has strong effects on its community bc/ large size, high abundance, or a pivotal role in community dynamics.
May provide significant habitat or good for other species, also may be competitively dominant in exploiting key resources.
Ecosystem engineers
Organism that influences community structure by causing physical change sin the environment
Adjacent trophic level relationships
V -> H More Veg. More herbivore
V <- H
V<–> H
Bottom up model
Shows the control that lower trophic levels have on higher trophic levels
Top- down model/trophic cascade
Shows the effect of predation in a community
Biomanipulation
Used to manipulate the environment by using the top-down model
Disturbance
Events such as a storm, fire, flood, drought, human activity
Non-equilibrium model
Describes most communities as constantly changing after being affected by disturbances.
Intermediate disturbance hypothesis
Moderate levels of disturbances foster greater species diversity, and can open up habitats for less competitive species making a more diverse community
Ecological succession
A process in which the species in the disturbed are gradually replaced by other species
Primary succession
Called primary when the ecological succession happens in a virtually lifeless environment with no soil
Secondary succession
Called secondary when the soil is present but the community ahs been cleared out by a disturbance
Why are species in tropics more abundant
More speciation events -> more diverse
Climate as a primary cause
In terrestrial communities, two main climatic factors : solar energy input and water availability -> high in tropics
Area effect
If all other factors are equal, the larger the land = the more diverse the community
Island Equilibrium model
Devised by Robert MacArthur and E.O Wilson
States species diversity depends on size of island, distance from mainland, immigration rate and extinction rate.
Used to predict the stable number of species
Higher # is great in larder island closer to mainland.
Pathogen
A microorganism, virus, viroid, or prion that is able to create a disease
Change structure of community, thrive as invasive due to no immunity
Zoonotic Pathogens
Pathogen that are transmitted from animal to human through direct contact/vector
Vector
Animal that receives a disease from one animal and passes to a human (tick, mosquito, etc)
Resource partitioning
The division of environmental resources by coexisting species such that the niche of each species differs by one or more significant factors from the niches of all coexisting species.
evapotranspiration
the evaporation of water from soil and plants, takes into account sunlight and precipitation rates
species area curve
biodiversity pattern that shows the larger than geographic area of a community is, the more species it has.
