Ecology Flashcards
Predation
Predators benefit as they feed on prey; predation affects numbers and behavior of prey
Parasitism
A parasite lives on or in a host, obtaining food from the host and harming it
Competition
A species using a resource reduces the amount available to other species using it
Mutualism
Different species living together in a close relationship, from which they both benefit
Herbivory
Primary consumers feed on plants or other producers; harms producers but reduces competition between producers
Distribution of a species
The range of places it inhabits
Ecological niche
An species spacial habitat and interactions with other species
Competitive exclusion principle
Only one species can occupy a niche in an ecosystem
Fundamental niche
Th niche that a species could potentially occupy
Realized niche
The niche a species actually occupies
Keystone species
Has a disproportionate effect on the structure of an ecological community
Net production
The amount of energy converted to biomass in an organism
Gross production
The total amount of energy in food assimilated by an animal or photosynthesis in producers
Feed conversion ratio
Th efficiency with which a species uses food
Closed cosystem
An ecosystem that does not exchange nutrients with its surroundings
Three main storage compartments of terrestrial ecosystems
- Biomass: living organisms
- Litter: dead organic material
- Soil
Taiga
Large litter, small biomass and soil
Desert
Large soil, small biomass and litter
Rainforest
Large biomass, mall litter and soil
Eutrophication
Excessive richness of nutrients in a body of water because of high levels of nitrate and phosphate, which causes a dense growth of plant life and death of animals
Ecological succession
A series of changes to an ecosystem
Primary succession
An ecosystem starting where organisms have not previously lived
Endemic species
One that naturally occurs in an area
Biological control
The use of a predator, parasite or pathogen to reduce or eliminate a pest
Biomagnification
Concentration of pollutants in the tissues of organisms
Richness
Number of different species present
Evenness
How close in numbers the different species are
In situ conservation
Conserving a species in its own habitat
Ex situ conservation
Transferring threatened populations elsewhere
Indicator species
Needs particular environmental conditions and so shows what the conditions in an ecosystem are
Diversity index
N(N-1)/sum:n(n-1)
N is total number of species
n is number of individuals per species
Capture mark release recapture
Number caught and marked initially times total number caught second time divided by number of marked second time
Population change equation
(Natality+immigration)-(mortality+emigration)
Nitrogen fixation
The conversion of atmospheric nitrogen into ammonia
Nitrogen fixing bacteria
Azotobacter: free living
Rhizobium: living in roots
Nitrification
The conversion of ammonia to nitrate
Soil bacteria for nitrification
Nitrosomonas then nitrobacter
Denitrification
The conversion of nitrate into nitrogen by denitrifying bacteria
Denitrifying bacteria
Psuedomonas
