Studied by 5 people
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%
Note
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