BIO 1B- Ecology

traditional ecological knowledge

only organisms and abiotic/biotic environment

biome

major terrestrial ecosystem at a global scale

temperature

indicator of biomes; warmer near equator and lower elevation

precipitation

indicator of biomes; wet at equator, dry at 30, wet at 40-60; increases with elevation (besides rain shadow)

maritime climate

lower seasonal temp. fluctuations

continental climate

higher seasonal temp. fluctuations

Mediterranean climate

stable temperatures and strong seasonal precipitation

Hadley Cell

1. tropical air heats up, moisture rises and air cools down
2. cooler air precipitates moisture as rain
3. rising air is displaced north/south → creates winds and air transport
4. transported air cools down and sinks
5. dry air falls in mid-latitudes (decreased precipitation)

climate

temperature, precipitation, sunlight, and wind

species distribution

geographical distribution of occurence of biological organisms

dispersal

movement of individuals away from their original location

dispersal limitation

not all suitable habitats will be occupied by a species

biotic limit

living things in the environment

abiotic limit

non-living things in environment

performance curve

how a fitness metric varies with the abiotic environment

environmental gradient

species occur where performance is highest

indicator species

species that can only live in healthy systems

demography

births, immigration, death, and emigration

B-D Model

current size + births - deaths

Geometric growth

Nt = (1+ r)^t × N0

Exponential growth

N(t) = N0 \* e^rt

N0

initial population

r∆

change in population size

r

intrinsic rate of increase: per capita rate

per capita population growth rate

1/N \* dN/dt

density dependence

changes in per-capita growth rate with population size

equilibrium population size

per capita population growth rate = 0

logistic growth

dN/dt = r \* N (1 - N/K)

K

carrying capacity

population fluctuation

variation in immigration and emigration; density independent factors that vary over time

population collapse

population suffers large drop in carrying capacity, sometimes permanent

life history

suite of traits related to species life cycle and timing of major events

* average lifespan
* duration and investment of parental care

principle of allocation

individuals have limited amount of resources to invest in different activities and functions

* can only invest in one function (trade-off)

cost of reproduction

more reproduction in one year means less reproduction the next year

fast-slow continuum

fast: plants, bugs, smaller mammals

slow: mammals, trees

competition

A & B both try to acquire the same limited resource

predation

A kills B

herbivory

A eats B, may kill B

parasitism

A lives on/in B. may kill B

mutualism

A & B help each other

commensalism

B helps A, no impact on B

facilitation

either mutualism or commensalism

defense

physical defenses, chemical defenses.

dishonest mimicry

looks bad, but is harmless

honest mimicry

looks bad, is harmful

exploitation competition

A & B eat the same prey, if A eats more it indirectly harms B

indirect mutualism

A. B, C are predated by same species → A & B gang up on C

interaction network

diagram with arrows linking species that have a direct pairwise interaction

community

multiple species co-occuring in a place, possibly interacting with each other

coexistence

when several species co-occur together over time

scarcity

resources/prey can eventually become scarce

Lotka Volterra model

simple environment

predator kills prey, then goes extinct after food runs out

complex environment

prey are killed by predator but are fast enough to escape predator to another habitat

intraspecific competition

competition between individuals of the same species

interspecific competition

competition between individuals of different species

competitive exclusion principle

species that uses resource more efficiently will eventually eliminate the other locally

* similar to allele fixation

fundamental niche

full range of conditions or resources used in which a species could maintain a stable population in an absence of other species

realized niche

actual set of conditions or resources used in which a species could maintain population in presence of other species

niche partitioning

allows coexistence by reducing competition

* different species live on different parts of the tree

niche overlap

low overlap → low competition → potential coexistencep

play

a behavior suggestive of the absence of scarcity

cooperation

an interaction suggestive that scarcity can be avoided at some scales

community dynamics

changes the composition over time

disturbance

a change in abiotic or biotic conditions in a community

succession

community dynamics after a disturbance

primary succession

after disturbance, community is empty and any species that enters must migrate from another community

secondary succession

after disturbance, some individuals survive and species that come into community are from population growth or immigration from other communities

gap phase regeneration

dominant canopy trees fall down and open light gap areas with more sunlight and avaliable resources

early successional species

species that are good dispersers/colonizers and quickly establish themselves and complete their life cycles

late successional species

disperse/colonize slowly, and then competitively exclude early colonists

dispersal rate

species vary in when they get there

competition-colonization tradeoffq

some species are bad competitors, but good dispersers

facilitating

some species modify biotic/abiotic environment that helps other species establish

competing and inhibiting

some species modify biotic/abiotic environment that don’t help other species establish

tolerating

some species are not affected much by other species

flammability

dead tissue accumulates and promotes fire spread and kill plant’s neighbors

serotiny

reproductive parts survive fire and open/germinate immediately after a fire

disease

harmful condition affecting an individual, sometimes reducing its growth, survival, or reproduction

biological pest control

using living organisms to suppress pest population

gene drive

gene editing mosquitos so that they are unable to reproduce in further generations

biological warfare

deploying organisms to spread disease

parasite

organism that feeds on host while being in or on host

pathogen

an organism or virus that causes disease

hyperparasites

parasites get parasites too

metapopulation

many patches, each with populations, linked by immigration and emigration

environmental reservoir

locations where pathogenic species live when not parasitizing a host

biotic reservoir

locations where pathogenic species live when parasitizing a host

zoonotic disease

has non-human biotic reservoirs but can jump to a human host

contact transmission

direct movement from one host to another

vehicle transmission

indirect movement from one host to another

vector transmission

indirect movement from one host to another via another biological host species

SIR model of disease

Susceptible → Infectious → Recovered (or dead)

* epidemic occurs if # of infectious individuals increases

R0

average number of infected individuals by each sick individual

* diseases spread when >1

habitat destruction

more disease vector species encounter humans, enhancing change for zoonotic

urbanization

people contact each other more frequently, increasing spread ratesa

air travel

people move long distances more often

climate-change in disease

tropical-only diseases can affect people in all areas

photosynthesis

solar energy is captured by formation of C bonds in compounds that are stored in organism

* carbon dioxide + water = glucose + oxygen

respiration

metabolic reactions release chemical energy, and in doing so return carbon to the environment