Ecology

Population is

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