Define
Life history
The traits of a population that affect an organism’s schedule of reproduction and survival
ex: Max size, lifespan, age of first reproduction, survivorship curves
Also tradeoffs: size of offspring vs multiple offspring, for example
What are the two models of population growth?
Exponential (density-independent) and logistic (density dependent)
Describe
A case of exponential growth
Rebound of a drastically reduced population or a population brought into a new environment
Often followed by negative feedback: + density = + deaths
Define
Metapopulation
Group of populations that are connected by immigration and emigration
What makes a population within a metacommunity important?
- Very large (represents a large percentage of metacommunity)
- Connected to a lot of other populations by dispersal (movement is a type of dispersal, only done by organisms that can move)
Define
Ecological interactions
Interactions between species occur when the actions of individuals of one species directly/indirectly affect the vital rates (death, birth, growth) of other species
Define
Interspecific interactions
Defined by whether they help, harm or have no effect on the survival and/or reproduction of species involved
What are the two types of mutualism
- Obligate, where one species cannot live without the other (ex: lichen)
- Facultative: both species can survive alone
Define
Facilitation
(+/+ or +/0) is an interaction in which one species positively affects another species without direct contact
Define
Exploitation
One species benefits at the expense of the other
(predation, herbivory, parasitism)
Define
Aposematic coloration
Colors displayed by animals with effective chemical defenses; bright colors
Define
Parasitism
- +/-, the parasite derives nourishment from its host, which is harmed in the process
- Endoparasite: lives within host body
- Ectoparasites: live on external surface
What is the difference between predation and parasitism?
A predator kills its prey before consuming it, a parasite consumes but does not kill the host immediately
Parasitoids, on the other hand…
Define
Competition
(-/-), occurs when species compete for a resource in short supply, or when both species directly negatively affect each other’s ability to survive
Define
Fundamental niche
- Niche potentially occupied by that
species. - Range of potential abiotic and biotic
conditions and resources that would
allow the persistence and growth of
that species
Define
Realized niche
Niche actually occupied by a species when coexisting with other species in nature
Define
Species richness
- Way to measure how diverse a community is
- Total number of species in the community
Define
Evenness
- Relative abundance of species
- Community perfectly even if all species share the same % of total abundance
- Total abundance is the total number of individuals in the community
Why care about diversity?
- Can be more productive
- Can be more stable (less variable biomass)
- Can be harder to invade
*Could also be a bigger source of new pests
Define
Trophic cascade
When the changing abundance of a predator leads to its prey increasing, and that species’ prey decreasing, and so on
