Bio 102 Exam 5- Ecology and Biogeography

Ecology

study of interrelationships among organisms and environment

Biogeography

study of how organisms are established on Earth

biotic

interactions among organisms

abiotic

interactions between organisms and non-living, physical environment

population

group of individuals of same species living in one area at same time

community

populations of different species that live/interact in same area

ecosystem

links biotic interactions among organisms and the abiotic environment

biosphere

global ecosystem including all of Earth’s ecosystems

solstice

largest/ shortest light period

equinox

apporiximately equal day-light periods

dispersal

movement of population to new area

vicariance

geographic separation of populations due to barriers or events

adoptive radiation

rapid diversification from a common ancestor

endemism

spieces restricted to particular geographic area

niche

ecological role/environmental requirements of a species

population dynamics are influence by:

1. population density

2. abiotic factors

3. life history traits

population density

# of individuals of a species in an area

population dynamics

change in # of individuals in a population over time

dispersion

distribution of individuals in a population

3 patterns of dispersion

1. clumped

2. uniform

3. random

clumped

individuals in patches/groups

uniform

result of aggressive interactions among neighbors

random

unpredictable distribution pattern

Formula for determining the rate of change

ΔN / Δt = N (b-d)

ΔN = change in # of individuals in population

Δt = change in time

N = # of individuals in existing population

b = natality

d = mortality

Formula for growth rate

r = (b-d)

r = rate

Formula for rate of change including immigration and emigration

ΔN / Δt = N (b-d) + (i-e)

carrying capacity

maximum population size that a particular environment can sustain

density dependent

birth rate and death rate change with population density

density independent

birth rate and death rate does not change with population density

guild

group of species that use same resources

functional group

species that function in similar ways but may/may not use same resources

dominant species

most abundant or have biggest biomass

keystone species

not usually abundant, but exert strong control on community structure due to pivotal ecological role

ecosystem engineers

create, modify, or maintain change in environment

ecological niche

combo of species’ physical habitat and ecological role in habitat

interspecific competition

use of needed resource by one species lowers availability of resource for other species

competitive exclusion

2 species cannot exist in a community if their niches are identical

fundamental niche

niche potentially occupied by a species

realized niche

niche occupied by a species in an environment

resource partitioning

“ghost of competition past”

Examples of predation (+/-)

1. carnivory

2. herbivory

3. parasitism

positive interaction (+/+ or +/0)

1. mutualism

2. commensalism (+/

obligate

both organisms in mutualism cannot survive without the other

facultative

one or both can survive without the other

amensalism (