Ecology Exam 2

Species interactions

relationships among organisms of different species living in the same location

Herbivores

heterotrophs that feed on plants and other primary producers

mesopredators

smaller carnivores that consume herbivores

top predators

larger carnivores that consume mesopredators and herbivores

biological controls

a method of controlling pests using other organisms

Lotka-Volterra models

models of predator-prey interactions that incorporate oscillations (and lag) in the abundances of predator and prey

joint equilibrium point

point at which equilibrium isoclines and for predator and prey cross

functional response

relationship between density of prey and an individual predator’s rate of consumption

numerical response

change in the number of predators through population growth, immigration or emigration

crypsis

camouflage that allows an organism to blend in with its surroundings or disrupt its shape

structural defenses

mechanical defenses that reduce a predators ability to capture or handle prey

chemical defenses

mechanical defenses that deter predators

aposematism

warning coloration that evolves in tandem with distastefulness

batesian mimicry

when palatable species evolve warning coloration that resemble unpalatable species

mullerian mimicry

when several unpalatable species evolve a similar warning coloration

coevolution

when two or more species affect each other’s evolutionary response

natural history

study and description of living things, with an emphasis on observation and description

food chain

linear representations of how species in a community consume each other

food web

linear representations of how species feed on each other in a community

trophic level

ranks within a food chain or food web

primary consumer

consumer that eat producers (2nd trophic level)

secondary consumer

consumer that eat primary consumers (3rd trophic level)

tertiary consumer

consumers that eat secondary consumers (4th trophic level)

omnivore

animals that include both plant and animal matter in their diet

detritivore

heterotrophic organism, which obtains its nutrition by feeding on organic matter made up of dead plant and animal material

scavenger

an organism that mostly consumes decaying carcasses

decomposer

an organism that degrade dead organic materials, returning organic constituents to principle ecological cycles

guild

group of species that exploit the sane class of environmental resources in a similar way

mutualism

type of symbiotic relationship where all species involved benefit from their interactions

commensalism

type of symbiotic relationship where one species benefits from the interaction and the other species is unaffected

parasitism

type of symbiotic relationship where one species benefits from the interactions, while the other species (host) is harmed

parasitoids

type of symbiotic relationship where one species benefits from the interaction, while the other species (host) is killed outright

Dispersal (mutualism)

transportation of gametes or individuals of another species

nutritional (mutualism)

providing of nutrients to another species

protective (mutualism)

preventing harm to another species

symbiotic

intimate interspecific association (involving strong physical connection) and prolonged interaction

Nonsymbiotic

not intimate and/or short-lived interspecific interaction

facultative

mutualism or association is essential for survival and/or reproduction

obligate

mutualism or association is essential for survival and/or reproduction

partner fidelity

positive feedbacks between species where benefits are strongly dependent on the success of the partner

partner choice

choosing the most beneficial partner at the least cost from the start of the association

partner sanctions

negative selection against less beneficial partners

Mycorrhizae

fungi that have a symbiotic relationship with the roots of many plants

sociality

intraspecific interaction- involves two or more individuals from the same species

cooperation

two or more individuals receive a net benefit, despite some incurred costs

inclusive fitness theory

relatives are likely to share more genes than non-relatives

eusociality

extreme sociality among kin

reciprocity

individuals benefit by exchanging benefits

parental investment

how much parental care does each mate provide

signaling

how organisms communicate to each other

Allocation

what investment an organism makes in certain physiological processes like growth, reproduction, cellular repair

Trade-offs

with finite resources, what physiological processes an organism ‘decides’ to invest in

Maturity

age at which an organism becomes reproductively active

parity

how many times an organism reproduces in a given time

fecundity

number of offspring produced per reproductive episode

reaction norm

observed relationship between an organism’s phenotype and the environment

phenotypic plasticity

responsiveness of a phenotype to surroundings is called

reciprocal transplant

a common garden experimental design in which different phenotypes are planted among home and away habitats

semelparity

life histories characterized by death after first reproduction

iteroparity

life histories characterized by multiple reproductive cycles over the course of a lifetime

annuals

any plant that completes its life cycle in a single growing season

perennials

any plant that persists for several growing seasons or years

senescence

gradual increase in mortality and decline in fecundity resulting from physiological deterioration

Uniformitarianism

Principle stating that present processes directly observable are a proxy for processes in deep time.

Fossil

Preserved remains of organisms older than \~10,000 years.

Stratum (strata)

Unit of rock characterized by given lithologic features.

Geologic time

Time on the scale of geologic processes

Taphonomy

The study of what happens with organisms from their death to being found in the fossil record.

Time-averaging

Process through which information about time is lost (or abbreviated) in the rock/fossil record.

Continental drift

The result of plate tectonics causing the movement (drift) of continental masses over geologic time.

Infauna

Organisms that live within the substrate (e.g. copepods in a sandy beach)

Abundance

total number of individuals in a population that exist within a defined area

Density

in a population, number of individuals (abundance) per unit area or volume

Mark/Recapture survey

method of population estimation in which researchers capture, mark, and release individuals only to capture a second subset later

Growth rate

number of new individuals that are produced in a given amount of time minus deaths

Intrinsic growth rate (r)

highest possible per capita growth rate

Geometric growth model

model of population growth that compares population sizes at regular time intervals

Doubling time

time required for a population to double in size

Density independent

factors that limit population size regardless of population density

Density dependent

factors that limit population size in relation to population density

Allee effect

when the rate of population growth increases as population density increases

Inflection point

point on a sigmoidal (S-shaped) growth curve where the growth rate is highest

Age structure

proportion of individuals that occur in different age classes

Stable age distribution

when the age structure of a population does not change over time

Net reproductive rate

total number of female offspring that expect an average female to produce over their life

Generation time

average time between the birth of an individual and the birth of its offspring

Spatial structure

pattern of density and spacing of individuals in a population

Endemic

species or populations living in a single, often isolated, location

Cosmopolitan

species with a very large geographic ranges

Dispersion

spacing of individuals with respect to one another in a geographic area

Dispersal

movement of individuals from one area to another

Habitat corridor

strip of favorable habitat located between two large habitat patches which facilitates dispersal

Ideal Free Distribution

when individuals distribute themselves among different habitats in a way that allows for maximum per capita benefit

Subpopulations

when a larger population is broken into smaller, isolated groups

Metapopulation

infrequently interacting subpopulations dispersed among patches of ideal habitat patches, isolated by unsuitable habitat

Emigration

pertains to organisms leaving one habitat with the intent of living in another place (net loss to home habitat)

Immigration

pertains to organisms arriving in a new habitat from elsewhere (net gain to new habitat)

Source (subpopulations)

subpopulations living in high quality habitats that serve as a source of dispersers to low quality habitats

Sink (subpopulations)

subpopulations living in low quality habitats that rely on outside dispersers (immigration) to maintain the subpopulation

Deterministic

models which predict results without incorporating uncertainty or randomicity in parameters