Biol 215 final exam

ecology

succession

sequential change in species composition of a community over time.

primary succession

establishment of substrates lacking living organisms.

secondary succession

change of an established community.

seral stage

continuous stages that each make up a sequential community.

allogenic

abiotic disturbance like fire.

autogenic

biotic disturbance like humans, pests, parasites, diseases.

biomass over time

reorganization, aggradation, transition, steady state.

stochastic event

largely unpredictable, whatever gets there first will colonize.

facilitation

species creates conditions that are favourable for a succeeding species other than itself.

inhibition

species inhibits colonization of subsequent colonists.

tolerance

members of seral stages are those that co-exist due to use of different resources.

trophic levels

sequence of steps in a food chain or pyramid.

indices of food web complexity

C=L/N

indicator or umbrella species

used for conservation decisions.

dominant species

common species with an effect on the community that is proportional to its biomass.

keystone species

species with an effect on the community that is disproportional to its biomass.

downloading

streams bring things into oceans which increases primary productivity in marine waters.

uploading

birds eat from oceans and bring nutrients to land in droppings.

riparian

forest habitat adjacent to stream that is influenced by streams parameters.

oligotrophic

low productivity lake that is clear.

estuaries

tidal mouth of a larger river, where the tide meets the stream.

intertidal zone

extends from high to low tidal zone

kelp forests

highest primary productivity, physical protection for shoreline.

pelagic

oceanic zone - not much productivity.

continental shelf

10-50km from intertidal zone.

photic zone

photosynthesis can occur - epipelagic 200m.

aphotic zone

still light but too deep for photosynthesis.

mesopelagic

200-1000m.

bathypelagic

1000-4000m

hadal

4000-6000m

benthic

seafloor

arctic

frozen ocean surrounded by land - ice cover about 3 meters thick.

antarctic

large frozen continent surrounded by oceans.

dystrophic

stained lakes with low productivity.

mesotrophic

intermediate productivity.

eutrophic

high productivity lakes.

epilimnion

top layer of lake that mixes in the summer from wind - lots of oxygen and lots of fish.

thermocline

separating layer in summer in lakes.

hypolimnnion

cold water at bottom of lake in summer with very little oxygen.

hadley cell

air rising near equator and cools descending about 25 degrees of latitude and returns to equator near surface.

ferrell cell

subsidence zones of cold dry air sinks - polar and Hadley on either side = zone of mixing.

polar cell

cold, dry, high-pressure air.

amount of biomass on earth

550 Gt of carbon.

plants biomass

450 Gt carbon

animals biomass

2 Gt carbon

latitudinal diversity gradient

diversity is higher closer to the equator.

oceanic depth biodiversity

most diversity at intermediate depths.

primary productivity

explanation for global biodiversity trends.

birds migrate to where primary productivity is highest.

temperature and rainfall.

band of productivity follows the boreal forest.

competition theory

explanation for primary productivity.

important for local scale.

spatial heterogeneity theory

mandelbrot series - diversity isn’t reduced on smaller scales.

complexity in structure correlates with higher species diversity on plants - microhabitats.

environmental age theory

more diveristy with increasing age.

diversity will also reached K and then flatten out a bit.

diversity-stability hypothesis

as the number of species goes down, stability will gradually go down with it.

rivet hypothesis

once you lose many species there is a sudden drop in species but before you reach that point it steadily decreases.

redundancy hypothesis

species = passengers - stability is the same until you lose the pilot.

features of island biogeography equilibrium #1

number of species moves towards an equilibrium between extinction and colonization as a function of island size and distance.

features of island biogeography equilibrium #2

at equilibrium, species composition is in continuous state of change as some species go extinct and new species colonize.

features of island biogeography equilibrium #3

can predict number of species but not species composition.

tripartite theory processes

immigration, extinction, speciation.

tripartite theory island characteristics

area, isolation.

ecological disharmony

non-representative proportions of species.

ex. predators normally absent from small islands because they need larger MVA.

human population growth rate

1.1 - increase of about 80 million each year with 135 million births and 55 million deaths.

major threats to earth’s ecosystems

habitat loss/modification, overfishing/overhunting, exotic species.

selective cutting

removal of single trees by helicopter.

variable retention

leave representative old growth in each cut block.

clear cutting

remove all trees in patches up to 2000ha on 80 year rotation.

how much of the world’s remaining coastal temperate rainforest is in BC?

¼

how much of the world’s coastal temperate rainforest has been cut down?

55%

fragmentation

global issue of creating islands

edge effects

leads to reduced fragment size which leads to reduced size of populations and reduced number of species.

ecotone

transition between 2 habitats.

carbon dioxide

greenhouse effect - CO2 comes from many processes but heat is trapped and reabsorbed.

evidence that global warming is caused by burning fossil fuels

burning fossil fuels does not release C14 so you can measure which areas of the atmosphere have the smallest ratios of C14 versus C12 and C13. These areas are where the most amount of fossil fuels are being burned.

black carbon

particles of soot from incomplete combustion - dominate absorber of visible solar radiation.

black carbon is responsible for how much total temperature increase in the Arctic from 1890 to 2007?

50%

methane

has 80x the effect of CO2 on warming.

nitrogen trifluoride

industrial gas used in semiconductor manufacture that has potential to be very harmful.

chlorofluorocarbons

CL breaks up O3 resulting in loss of atmospheric ozone.

sulphur dioxide

produces smog - acid rain which caused major loss of forests and aquatic ecosystems in the 80s.

still increasing in Asia and Africa.

radioactivity

nuclear power plant meltdowns cause huge loss of ecosystems and lives.

ocean acidification

carbonate ions react to make bicarbonate ion when too much CO2 is absorbed into the ocean resulting in not enough carbonate ions to make shells for corals and plankton.

oil spills

decreasing over last 30 years.

can see from space - vastly underestimated contributions to pollution.

exxon valdez

oil spill in 1989 of 10 million gallons of oil.

killed 250,000 seabirds, 2,800 otters, 300 harbour seals, 50 bald eagles, and 22 whales.

industrial chemicals and biocides

cause biomagnification so affects things further up the food chain.

10 million times increase of DDT in water to birds.

neonicotinoids

natural insecticide that binds to receptors in nervous system of animals and kills insects.

collapse of pollinators.

overfishing

fishing down the food chain.

overhunting

imports of wildlife are still increasing - $150 billion/year revenue.

how many seals are killed each year in Newfoundland

100,000 - 400,000 $30 million revenue.

level of atmospheric carbon dioxide

~420ppm

methane levels

(CH4) ~1700ppb

how many dolphins are killed each year by Japan, Peru, and Denmark

about 20,000

how much of the wolf population is the BC government planning to kill

80% using assault-style rifles.

major exporters of wildlife

argentina, australia, bolivia, brazil, canada, china, colombia, congo, honduras, india indonesia, nepal, phillippines, south korea, taiwan, thailand, us.

majro importers of wildlife

EU, UK, US, United Arab Emirates, Canada, China, HongKong, Korea, Singapore, Taiwan, Yemen.

how much wildlife do cats kill in the US each year

1.4-3.7 billion birds and 6.9-20.7 billion mammals.

how long does a species normally persist in the fossil record?

1 million years.

natural extinction

a species is usually outcompeted or replaced by a different species that is genetically related and has a similar niche.

extinction rate for a 25km sq island

10%/100 years

extinction rate for a 1km sq island

50%/100 years

how many seed bearing plants go extinct each year

3 - 500x natural rate.

what percent of north american birds have gone extinct

almost 30%