Ecological processes Flashcards
What processes drive biodiversity patterns at spatial and temporal scales?
Oceanography, climate, productivity
What is a population?
Group of interacting individuals of the same species living together n the same area
What is a community?
Group of interacting populations living in the same location
Limiting factor
Biological or physical factor that limits an organism’s success in a community
Carrying capacity
Maximum population size that a community can reach under stable environmental conditions
What are the 4 main ecological processes?
Dispersal
Speciation
Selection
Drift
Speciation
Evolutionary process by which new species arise from existing ones
Dispersal
Spatial movement of organisms, active or passive
Drift
Random changes in species abundance
What are some stochastic (random) processes?
Birth
Death
Production rate
Selection
Deterministic fitness differences among species
What are three forms of selection?
1) Constant selection
2) Frequency- or density-dependent selection
3) Spatially- or temporally-variable selection
What are two selection mechanisms?
1) Niche filtering
2) Limiting similarity
Limiting similarity
Limit to similarity and number of competing species that can coexist
What is meant by environmental filtering?
The abiotic factors that prevent the establishment or persistence of a species in a particular location
Niche filtering
Similar species in the same environmental conditions act as a filter allowing only a narrow spectrum of species to survive
What two kinds of niches exist?
Fundamental and realized
Fundamental niche
Basic conditions under which a species can live without interference from other species
Realized niche
Conditions determined by interactions with other species
Assembly rules
Any constrain that limits number and size of species in the assemblage
How is alfa diversity used to measure biodiversity?
Number of different species within assemblage
How is beta diversity used to measure biodiversity?
variation of species composition of assemblage
How is gamma diversity used to measure biodiversity?
number of different species within ecosystem
