Ecology Part II Flashcards
Major communities
Aquatic
Terrestrial
Aquatic communities
Marine
Freshwater
Marine communities
estuaries, intertidal, sub-tidal kelp beds, pelagic, deep sea, coral reefs
Terrestrial communities
tundra, temperate coniferous forests, temperate deciduous forests, grasslands, deserts, tropical forests
temperate coniferous forests
Boreal/Taiga
Estuaries are
partially enclosed body of water where freshwater flows into the ocean and mixes with salt water
Estuaries have
variable salinity, pH, sediments, nutrients, temperature
large # niches, biodiversity, productivity
important estuary ecology
major stopover for migratory birds throughout world
ex. fraser estuary
Different types of tides
MHWS, MHWN, MLWN, MLWS
Mean high/low water neap/spring
smaller high/low tides
neap tide
larger high/low tides
spring tides
Emersion curve
MHWS, MHWN, MLWN, MLWS (ft) vs. % exposure to air (0-100)
MLWS- pretty much 0%
curve tends towards 100 towards MHWS
Subtidal kelp bed ecology
high PP on planet
physical protection to shoreline communities
foraging/shelter for large # species
Types of benthic communities
Hot vents
Glass Sponge reefs
Deep water coral reefs (bioherms)
Arctic marine communities
frozen ocean surrounded by land ~4000m depth, ~3m ice upper 15m low salinity layering of Atl./Pac. water high summer plankton, cod, seals
Antarctic communities
frozen continent surrounded by ocean ~98% ice up to 2km thick mountainous- up4500m low diversity- bacteria, lichen, penguins ocean high PP and diversity
lake classifications
oligotrophic
dysotrophic
mesotrophic
eutrophic
oligotrophic
clear water - low productivity
dystrophic
stained lakes - low productivity
mesotrophic
intermediate productivity
eutrophic
high productivity
lake stratification
separation of lakes into three layers- Epilimnion, Metalimnion, Hypolimnion
due to density change with temperature
epilimnion
top of the lake
metalimnion
thermocline
middle layer- may change depth throughout the day
hypolimnion
bottom layer
dimictic lake
lake water turns over during the spring and the fall due to the higher density colder water and of 4ºC water, lower density of ice and warm water
Tundra characteristics
3-6mnths dark, north America, north Europe/Asia ice/snow/permafrost
surface soil .5m thaws in summer
3 strata
tundra strata
soild
ground
low shrubs
tundra ecology
cold-hardy plants
aquatic/terrestrial insects
shorebirds, waterfowl, seasonal
hare, fox, wolves, caribou, grizz, polar bear
Temperate coniferous forests found
central interior north america/europe/asia
temperate rainforests found
west coast NA
Temperate coniferous forest characteristics
conifers, limited shrubs, ferns, moss, limited diversity
trees- monopodial growth
4 strata
short summer, long cold winter
conifers
spruce, hemlock, fir, cedar, pine
monopodial growth
grow upward from a single point, single trunk or stem
to shed snow
temperate coniferous forest stratum
soil, ground, shrubs, trees
temperate coniferous forest ecology
slow decomposition (b/c of cold)
seasonal migrants
occasional hibernation/torpor (frozen)
temperate deciduous forest locations
below great lakes, WEurope - Italy, EChina- Japan
temperate deciduous forest characteristics
warm/wet summer, cold winter
5 strata
temperate deciduous forest stratum
upper canopy (large trees) lower canopy (small trees) shrub layer ground layer (herbs, ferns, mosses) soil (decomposer community)
temperate deciduous forest ecology
high species diversity
seasonal migrants
prairies located
near temperate deciduous forests
mid US, mid belt across Europe/Asia, SE SouthAmerica
Savannas located
southern tip of NA
belt down SA
Southern half of Africa
large parts of Australia
Grasslands
pairies
savannas
Grassland characteristics
3 strata 2m deep roots (** water is limiting resource) high evaporation long droughts soil moisture protected by mulch
grassland stratum
soil
ground
sparse trees (**important for shade, trees limiting resource)
grassland ecology
large grazers (buffalo) small burrowing mammals
desert/semi desert found
30º belt of Europe, top half of africa, small parts of America, interior of Australia
desert characteristics
low rain, high T
3 strata
desert stratum
soil
ground
cactus
desert ecology
annual plants (if rainfall), succulents, desert shrubs
small, burrowing, seed-eating mammals
lizards
**nocturnality VIP
succulents
more than normally thickened and fleshy plants, usually to retain water in arid climates or soil conditions
tropical forest location
equator- top of SA, mid Africa, SE of china, top E of Australia
tropical forest stratum
SIX strata- ABCDEF
A- emergent trees >60m (discontinuous)
B- up to 20m (discon.)
C- lowest trees (contin.)
D- shrub layer (tall herbs/ferns)
E- ground layer, herbaceous plants, seedlings
F- root/soil layer (shallow, poorly developed)
tropical forests A and E strata
connected by vines (Lianas)
tropical forest ecology
many epiphytes
high species diversity (most taxonomic groups)
high biological turnover
high nutrient recycling
tropical rainforest characteristics
incredibly rich/diverse
emergent trees have specific/unique bird/insect/epiphite communities
sympodial growth
emergent trees
grow way above other trees with unique communities
sympodial growth
outward growth (upside down triangle)
Temperate rainforest characteristics
very similar to temperate forests with oceanic processes moderating, more diversity, stabilized
Lianas
parasitic- conveyor belt of nutrients from ground to top of trees
air cells from top to bottom of globe
polar– ferrell– hadley– hadley– ferrel– polar
most important factors for predicting biodiversity
temperature, moisture
hight T, high-low moisture
Tropical rain forest– tropical forest– savanna– desert
mid T, high/mid - low moisture
temperate rain forest– temperate forest– grassland– desert
low moisture, med/low - low T
Taiga, Tundra
tundra = low T, low moisture
global trends in species abundance
taxonomic abundance and body size
aquatic vs. terrestrial
correlates of species richness– latitude, depth and altitude
communities that grow back quickly
Taiga, grassland- N2 is in soil
communities that don’t grow back quickly
savanna- N2 is above ground (trees)
tropical rainforest- latterating soil washes away in rain
poorly developed root system in tropical rainforest
soils are thin and nutrient depleted
scarify soil
lossened and broken up
needed for tropical rainforest regrowth
taiga clear cutting
20% reduction of growth after each clear cut
slow depletion of soil
subsidence zones
~30/60º - where air sinks in each cell, cold/dry air - deserts
vertebrate body mass
most abundantly small, <100g
most common body mass
.001 - .01 g (b/c of insects)
most abundant species
insects, viruses/bacteria, fungi, arachnids, protozoans, algae, plants
(smallest species)
earth areas
aquatic 71%
terrestrial 29%
earth aquatic/terrestrial species
aquatic- 2 million
terrestrial - 10 million
predicted terrestrial species based on terrestrial area
700,000
rapid cladogenesis on land?
correlation of species richness by latitude
many species much more abundant near equator (corals, fish, copepods)
don’t see large change in species abundance by latitude in
benthic species (nematodes)
richest vascular plant areas
brazil, columbia, (on/below equator)
china, mexico (above equator)
orchid species
> > > in tropics (up to 3000, compared to 40 in Canada)
tree species in NA
rely on isotherms
higher species = higher T and P
reliant on tree species diversity
high tree diversity = high insect diversity = large # amphibians
most bird rich communities
colombia, peru, brazil, indonesia, ecuador, venezuela
diversity decreases
~linearly with elevation (altitude)
plants, birds
species richness per ocean depth
intertidal richest
highest PP- arctic/antarctic
equator- high PP
algal bed/reefs, estuaries- smaller area– very high productivity
why high PP in polar regions
continual turnover of water- almost always at max density
why equator high PP
meeting of nutrient laden gyre currents
largest biome on earth
deep sea
deep sea biodiversity
among the highest, macro/meiofauna
high evenness
meiofauna
small benthic invertebrates
deep sea communities with extreme physiochemical processes
biodiversity low
abundance, biomass high
dominated by few species
peak deep sea diversity
intermediate depths
2000-3000m
high benthic diversity not recognized until
1960’s– fine mesh (250-500µm)
100 species/.25m^2 found
how far have bacteria been found
deepest layer of oceanic crust
1391m
oil drilling can reach 9km
mean net PP
g/m^2 yr algal bed, reefs- 2500 tropics- 2200 temperate forest- 1300 estuaries- 1500 very high but small areas
world net PP
10^6 tonnes / yr
tropics - 37.4
open ocean - 41.5
cont- 56, ocean - 48
world biomass
10^6 tonnes tropics- 765 open ocean - 1 algal beds/reefs - 1.2 estuaries - 1.4 cont-550, ocean-10
biological deserts
NPP < 250
desert, open ocean
cultivated land (mostly growing grasses)
phytoplankton productivity
short generation time
small PP at a snapshot in time, very high over a yr
total bacteria biomass
~= all other PP biomass
ocean productivity
highest where large turnover (cold)
terrestrial productivity
highest where warm/wet (tropics)
changes based on season
climatic variations occur due to
uneven heating of earths surface during orbit (angle of inclination)
PET
potential evapotranspirational
PET is
the amount of water that COULD be evaporated and transpired IF there was sufficient water available
PET graph
tree species richness around globe vs. PET (mm/yr)
increases up and to right
cold+dry = very few species
why is there a large spread on the high PET end of PET graph
b/c PET represents amount of water that COULD be evaporated.. doesn’t mean that much water is present..
vertebrates vs. PET
increase up and to the right like trees, fn of tree diversity and moisture and T
explanations for global species richness
PP competition theory predation theory wind/animal pollinator theory climate variability theory spatial heterogeneity theory environmental age theory geological time and cladogenesis theory
competition theory results
temperate- r-select species- broad niches, low diversity
tropic- k-seleced species- narrow niches, higher diversity
predation theory
few predators/parasites= high herbivore density = low species richness
more predators = low herbivore density = high richness
predation theory results
temperate - few predators = lots of herbivores
tropics- many predators/parasites/specialists = low herbivore= more niche space
pollinator theory
more wind = less pollinators = low diversity
pollinator theory results
temperate = more wind = low diversity, flowers work harder for species of insects
tropics- more insects, flowers pollinated by specialists (one species- climate survivable by insects all yr)
climate variability theory
temperature similarity = more specialization
larger T range = lower # species
climate variability theory tropics
less variation = more opportunity for year round specialization
spatial heterogeneity theory
on a completely smooth sphere there is low niche opportunity, variations in surface create opportunity- mandelbrot series
insects vs. architectural rating (Opuntia)
leaves perpendicular = same area, photsynthesis, more insects (more niche space)
spatial heterogeneity theory results
temperate: few plants- few herbivores- few predators
tropic: many plants- many herbivore- many predators
bird species diversity
increase with plant species diversity, but more related to foliage height diversity (more niches)
example of tropics high specificity
up to 10 different mite niches on parrot/macaw feather
environmental age theory
assembly rules: deglaciation- plant regrow- insects regrow
recolonize quickest- wind dispersal seed plants
high insect abundance = plants been around a long time
low #’s of insects after long time
represent niche spaces of plants that have recently recolonized
geological time and cladogenesis theory
geographical isolation + natural selection + geological time = cladogenesis
example of geological time and cladogenesis theory
australia
length of time for origin of a new species
~1million years
potentially as short as 10,000 years
continental explanations for difference in species richness
PP, geological time
regional explanations for differences in species richness
PP, environmental age, spatial heterogeneity
Local community explanations for difference in species richness
competition, predation, spatial heterogeneity
number of species vs. area
mainland vs. island
island- greater slope (0.2-0.4)
(mainland ~0.1)
larger areas- island populations approach mainland
small areas- island populations «_space;mainland
IBT
island biogeography
why lower # species on islands
dispersal barriers/distance from source
MVA/patch size
genetic diversity/homozygosity/extinction
lower number of species per island size
distance from sourceland
persistence of populations over 50 years based on original population size
> =100 – ~100%
51-100 – ~60%
<=50 – 0%
persistence of populations 15 or less
50% by 30 years
20% by 40 years
ecological disharmony
non-representative proportions of some species
Skewed balance of taxa relative to mainland
Superabundance of some taxa
Absence of other taxa
why ecological disharmony
different resource use
less trophic levels- unbalanced
species have different dispersals
predators- higher extinction rate
ex. ecological disharmony
amphibian niche space overtaken by other organisms (ex. birds) b/c they can’t swim throughs salt water
plant colonization graph
plant species vs. yr
wind dispersal seeds steeper sloped colonization rate
water dispersal
successive extinctions/colonizations
decrease in number species
leads to species turnover
MacArthur and Wilsons equilibrium model
rate vs. # species present immigration- decreasing extinction- increasing where lines cross- equilibrium t(0) = large event (volcano)
why immigration curve starts so high in MacArthur/Wilson model
new area = large niche space = colonization by many species
when immigration curve = 0 in MacArthur/Wilson model
immigration is still occurring but colonization is not successful
high extinctions
small population size
resource depletion
small island
inbreeding
small island =
smaller population = higher extinction
near island =
high colonization rate
far, small island
equilibrium shifts left (lower species #)
at equilibrium (MacArthur/Wilson model)
actual species composition is in continuous state of change (continual extinctions/colonizations)
MacArthur/Wilson model can predict
numbers of species but not species composition
major issue with the loss of brazil rainforest
can’t be recolonized– no more source area, Brazil WAS the source area
MacArthur-Wilson experimental equilibrium theory test (1978)
defaunated mangrove islands at different distances to sourceland, took species counts over time
experimental equilibrium theory test results
species built up quickest in closest island
not same species as originally present (at first)
later- same species assemblage as original
conclusions from experimental equilibrium theory test
can’t predict species assemblage
CAN predict species assemblage GIVEN enough time
why- give enough time- do you wind up with the same species assemblage
tolerance- only certain species can live together under certain conditions- think niche dimensions
modifications to equilibrium theory
target effect
rescue effect
tripartite theory
target effect
larger islands have higher immigration rate than expected
rescue effect
close islands have higher immigration rate– reduces chances of extinction
Tripartite theory
3D graph of immigration vs. extinction vs. speciation
area/extinction on same axis
isolation/immigration on same axis
speciation is a function of multiple factors
stability of island community structure
large island high resistance to change high resilience (ability to return to predisturbed state)
stability theories
stability vs. # species
diversity-stability hypothesis
rivet hypothesis
redundancy hypothesis
diversity-stability hypothesis
Charles Elton
function is linear increasing
loss of one species affects stability
rivet hypothesis
Paule, Anne Erhlich
fn nearly logarithmic, increasing
one-few species losses don’t effect stability (plane rivet analogy)
redundancy hypothesis
Passenger hypothesis Brian Walker reaches asymptote early species = passengers species are not equal in stability importance many species can be lost w/o effecting
stability crash in redundancy theory
only if loss of keystone/dominant species (like throwing the pilot off the plane)
world population 2013
7.1 billion
top populated countries
china 1.3 billion
india 1.1 bill
US 300 mill
most densely populated countries
bangladesh 1,002ppl/km^2
Japan 337ppl/km^2
india 328 ppl/km^2
global population growth rate
~1.1% – 75million ppl/yr
130M births, 55M deaths
largest annual growth rate is in
africa
lowest annual growth rate is in
Russia, Greenland, Canada
human population growth
exponential
~4 generations ago– lots of births– high Ro
how do we decide if the world is overpopulated
starvation
disease
conflict
starvation
> 30% undernourished
increased world hunger
increased malnourished areas
most undernourished countries
congo burundi haiti sierra leone ethiopia angola zambia zimbabwe
Disease- child mortality rates
down from 11.9 mil (1990) to 6.9mil (2011)
conflict
new war every 2yrs
~378,000 deaths/yr
common causes of war
resource constraints and conflict
ethnocentrism
Impact (I)
= PAT
P - population size
A - per-capita consumption
T - environmental damage in order to supply each unit of consumption
Highest GNP
NA, Australia, western Europe
habitats lost
forests, grasslands, estuaries, coral reefs
Deforestation
clear cutting
variable retention
selective cutting
clear cutting
remove all trees in patches
12ha - 2000ha
80 yr rotation
most invasive/widespread/profit margin/common
variable retention
leave representative old growth in each cut block
10-30% retention
WFP
world food programme
selective cutting
removal of single trees by helicopter least invasive makes small-gaps in canopy- seedlings develop similar to natural disturbance cost-prohibitive
problems with variable retention
small patches are subject to windfall- counter productive
madagascar
almost completely deforested
lateritic soil runs off into ocean
only place lemurs live
lateritic soil
soils leached of Si after deforestation
concentrated in Fe, Ni, Al, Mn
causes of deforestation in Brazilian Amazon
Cattle 65-70%
Agriculture 30-35%
Logging 2-3%
Brazil cattle herding
largest cattle herd in world
export to 170 countries
3X in past year
how do they clear cut in Brazil
slash and burn- have to burn to release nutrients
Had highest diversity of every taxonomic group on planet
Ecuador (no other source land)
countries with highest deforestation rates
Brazil- 3.5mil Ha/yr
Indonesia- 1.5 mil Ha/yr
largest changes in deforestation rates from 1990-2005
Peru- 200%
Viet Nam,Nigeria- 120%
Madagascar- 40% LESS
French Guiana, Brunei- ~10% LESS
Coastal temperate rainforest characteristics
ancient trees (1000y old, 4m) 4 strata, structurally complex species restricted to old growth species rich greatest biomass/ha of all ecosystems
coastal temperate rainforests are most productive where
on salmon rivers– nutrient transfer
coastal temperate rainforest seral stage recovery after clear cutting
1000yr
how much of worlds temperate rainforests have been cut
55%
how much of Washington’s, Organs, Californias ancient rainforests are gone
95%
BC has how much of worlds remaining coastal temperate rainforests?
1/4
Gribbell island story
30% white bears– clear cut watershed (1980s)– loss of salmon (4000–300kg/yr)– 80% reduction in major protein source for bear
Haida Gwaii deforestation
156,000 ha logged
70% of old growth gone
Prairie/Grassland human use
large increase in crop land and pasture land
Coral Reef characeristics
richest marine ecosystem
highest species diversity of vert. on planet
problems with coral reefs (the numbers)
75% globally degraded and in decline (over 30-40yrs)
80% reduction in Caribbean coral diversity
50% reduction in corals of Great Barrier Reef
why theres problems with coral reefs
warming of oceans, cyclones, ocean acidification, coliform bacteria, artisanal fishing, commercial fishing, aquaria trade
atmospheric habitat modification
CO2, water vapour, black carbon, CH4, nitrous oxide, NF3, CFCs, SO2, radioactivity
atmospheric molecules that increase global warming
CO2, H2O, black C, CH4, NO, NF3, CFCs
atmospheric molecule that reduced global warming
SO2– increases smog though
habitat loss- estuaries
very uncommon, very important
major cities
no comparable habitats for displaced species
sunlight comes in as
shortwave radiation (leaves as long wave)
Antarctic ice core oxygen isotopes
16O evaporates preferentially, snow is enriched in 18O
correlation between 18O/16O and T
[CO2] sep 2014
395ppm
when did CO2 go above 400pm
april 2013
Mauna Loa, Hawaii