Population is
same species
Community is
multiple species
Ecosystem is
Organisms and abiotic environment
Landscape / seascape are
Connected ecosystems
Global ecology is
the biosphere
How are terrestrial biomes classified?
dominant vegetation
What drives transitions among forested biome types?
Temperature and precipitation
What is disturbance?
an event that removes individuals from a population
What factors limit distribution?
dispersal, abiotic, biotic factors
Examples of abiotic factors
Temperature, moisture, salinity, oxygen
Examples of biotic factors
Resources, predation, competition, disease
What is an outbreak?
rapid increase in population density
Exponential growth formula
dN/dt = rN
what does dN/dt mean?
size at time 0
what does r represent
per capita growth rate
The four per capita rules are
Birth rate, death rate, immigration rate, emigration rate
Per capita growth rate formula
r = b - d + i - e
What is a closed population?
Has no immigration or emigration
What is the net per capita migration rate?
Difference between immigration and emigration rates
Open population population growth formula
r = (b - d + m)
Outbreaks are caused by what
environment change
What is gregarization?
Change from population of solitary forms to swarms
How does gregarization happen
mechanical stimulation
Hormones to serotonin
Behaviour change in hours
Colour change
What is intra-specific competition?
Competition for resources among individuals of the same species
What is carrying capacity (K)
number of individuals of a population that an environment can support
Birth rate is dependant on what?
Density dependant
What is equilibrium density?
Birth rate equals death rate
What does a regulated population have?
at least one density dependant rate
Effect of limited resources formula
(K-N)/K
What happens when N value is small
Population growth is close to exponential
What happens when N=K
Population growth is zero
What happens when N is larger than K
Population growth is negative
what are the trade-offs of reproduction?
More offspring means less energy put into each one
What is the r strategy?
Many low quality offspring due to harsh environments
What is the K strategy?
Few high quality offspring due to highly competitive environments
Ways that death rates vary
Age and Sex
What is the photic zone?
Part of ocean that receives sunlight, O2 rich, nutrient poor
what is the aphotic zone?
Part of the ocean that does not receive sunlight, O2 poor, nutrient rich
Zones of the ocean from shallow to deep
Intertidal, neritic, oceanic
What is thermocline?
zone of rapid temperature change
What does eutrophic mean?
High nutrients and productivity
What does oligotrophic mean?
low nutrients and productivity
What are interspecific competitors?
Use same resource, resource is in limited supply
what is an ecological niche?
The role a species plays in an ecosystem
Realized niche
Observed niche that occupies in the wild
Fundamental niche
Conditions in which it can survive and reproduce
How do corals benefit from zooxanthellae?
Zooxanthellae photosynthesize, feed corals
How do zooxanthellae benefit from corals?
Safe place to live, coral excretes CO2, N
What allows abundant life in low nutrient waters?
Mutualism
Colonization of new space depends on what?
Settlement rate and growth rate
What is redundancy?
Several species having similar roles in a community
What do food webs represent?
Trophic interactions
What makes a species important in the food web?
Eat most organisms and eaten by most organisms
What makes a dominant species?
High biomass
What is a keystone species?
Large impact despite low biomass and abundance
What is top down control?
Higher trophic level reduces abundance of lower trophic level
What causes regime shifts?
Removal of species, arrival of disease, climate change, nutrient inputs
How does lyme disease spread?
Migratory birds move ticks to new locations
Why is lyme disease spiking?
More forest, more deer, warmer climate, more ticks
Components of an ecosystem
Primary producers, primary consumers, secondary consumers, detritus, decomposers
Ecosystems and life are powered by what?
the sun
How do ecosystems transfer chemical energy?
Consumption
Ecosystems lose heat energy through what?
Respiration
Energy flow is entered as what?
Radiant energy
Energy flow is stored as what?
Chemical energy
What is transferred among components?
Organic Carbon
What is the rate of primary production?
Rate that primary producer biomass is built
What is the rate of secondary production?
Rate that consumer biomass is built
What is the rate of decomposition?
Rate that inorganic nutrients are released from detritus
What is Net Primary Production (NPP)
Rate that plant biomass increases in an ecosystem
What is Gross Primary Production (GPP)
Total light energy captured by plants
NPP Formula
NPP = GPP - Ra
What is autotrophic respiration (Ra)
Energy lost due to plant respiration
GPP Formula
GPP = NPP + Ra
What is Net Ecosystem Production (NEP)
Biomass accumulated in all ecosystem components
Energy is stored as what?
Biomass
What is Total Respiration (Rt)
Biomass lost from all components
NEP Formula
NEP = GPP - Rt
What does a positive NEP do?
Lowers atmospheric CO2
What limits NPP in Ecosystems?
Temperature (Latitude, Elevation), Moisture, Soil nutrients
N-fixation formula
N2 gas to Ammonium
Nitrification Formula
Ammonium to Nitrate
Denitrification Formula
Nitrate to N2 gas
What is assimilation?
Plants in cycle turn Ammonium and Nitrate to organic N
Natural sources of Nitrogen
Lightning, Bacteria
Human input of Nitrogen
Agriculture, FFs
Nitrogen effects on coastal marine environments
too many nutrients, eutrophication decomposes algae, O2 depletion
What is cooperative behaviour
Good for actor and recipient
Cooperative behaviour examples
Defence, hunting
What is selfish behaviour?
Good for actor, bad for recipient
Selfish behaviour example
Terrotoriality
What is is spiteful behaviour?
Bad for both actor and recipient
Spiteful behaviour example
Surplus killing
What is altruism?
Bad for actor, good for recipient
Altruism example
Pika alarm calls warm other but increase risk to self
What is kin selection?
Selection for an act that enhances relative’s reproductive success
What is Hamilton’s rule?
Natural selection favours an act is Cost to altruist is less that Benefit to recipient x relatedness
Cost to altruist =
Risk of dying x lost reproduction
What is r for full siblings / mother to daughter?
r = 1/2
What is reciprocal altruism?
Favour will be returned in future