ecosystem ecology Flashcards
example of a small ecosystem
tide-pool
how is “ecosystem” a flexible term?
may be large and complex OR may only have a few species
how is the earth energetically open?
- energy constantly added by sun
- energy radiated away into space
- more comes from sun
how is the earth materially closed?
- matter is not added or removed
- chemicals are not added or removed
- stuck with what we have
energy flow: conservation of energy
- comes from sun
- movement through ecosystem
- passed form organism to organism
- eventually all lost as heat
nutrients cycle: conservation of mass
- biochemical cycles
- chemicals required for life
- movement through ecosystems
- cycle: used and reused
gross primary production:
- amount of sun energy captured
- amount of sugar produced
- measure of photosynthesis
net primary production
- energy that goes into plant growth
- energy available to other organisms
net primary production forms the __ of the trophic pyramid
base: amount available affects everything in ecosystem
where is net primary production highest?
in tropical rain forests
energy is produced by the …
lowest trophic level
energy flows from …
low trophic to a higher one
much energy is used to run…
body systems: most of this is lost as heat
small fraction of energy is used for..
growth: energy available to higher trophic levels
energy and biomass ___ at higher trophic levels
decreases
most energy is lost as…
heat
-basal metabolic rate
-movement
energy used to grow is not…
lost
10% of energy is transferred to…
higher trophic levels
-the other 90% is lost
-limits the number of trophic levels (<5)
what has the most weight and energy?
plants
where are nutrients stored?
reservoirs
residence time:
length of time in reservoir
nutrient cycle:
- Organism gets nutrients from reservoir
- Nutrient moves through food web
- Decomposers return nutrient to reservoir
___ are important nutrient reservoirs
plants
__ leaves forest when trees are removed
nutrients: significant portion of the cycle gets disrupted
nutrient cycle depends on
decomposers
decomposition rates increase with…
temperature and moisture
rarest resource =
limiting factor
limiting factor example: pond algae
Limiting resource is phosphorus
Phosphorus added from fertilizer
* No longer limited
Algae growth explodes
most important water reservoir =
oceans
water cycle:
o Sun evaporates water into atmosphere
o Evapotranspiration from plants adds water to atmosphere
o Water condenses and falls as precipitation
o Ultimately runs back to ocean
water impacts net primary production:
Terrestrial net primary production
Higher precipitation correlated with higher production
Water is a critical resource for plants
most important carbon reservoir?
the atmosphere (CO2)
carbon cycle:
o Plants use carbon to make sugar
o Animals eat sugar
o Both break down sugar for energy via cellular respiration
Returns carbon to reservoir
respiration and photosynthesis should..
balance
disruption of global carbon cycle:
Earth had a balanced carbon cycle
Humans have unbalanced the carbon cycle
* Add extra carbon from fossil fuels
* Remove forests
* Burn jungle
consequences of unbalanced carbon cycle
warming temperature
acidifying ocean
___ is needed to make DNA and RNA
phosphorus
____ portion of the phosphorus cycle is very slow
inorganic
reservoir of phosphorus is?
rock:
-Bacteria degrade rock and release phosphorus
-Eventually buried and turns back to rock
-Mined for fertilizer
some ways phosphorus is added to soil
*Rock decomposition (by bacteria)
*Dissolved in water
*Blow by wind
*Animal waste
*Decomposition
some ways phosphorus is removed from soil
- Used by plants
- Soil erosion and runoff
- Sedimentation
largest nitrogen reservoir is.
the atmosphere
what is the largest component of the atmosphere?
nitrogen (78%)
__ is the limiting resource for many plants
nitrogen (N2 is not useable by plants or animals)
how do plants get nutrients from nitrogen reservoir if they are in an unusable form?
nitrogen fixing bacteria
examples of plants that are mutualistic with nitrogen fixing bacteria?
legumes (peanuts and soy) and alder trees
farming and nutrients cycle:
*plants grow using nutrients in the soil
*plants are taken somewhere else after death and do NOT return nutrients
farming depletes the soil of…
nitrogen and other nutrients
plants with______________ can be lated in nitrogen poor soil to fix nitrogen and leave extra nitrogen in soil
bacteria symbionts
how can farmers fix the nitrogen cycle?
rotate crops that remove and produce nitrogen
*Don’t have to buy as much fertilizer
*Better for the environment
how is nitrogen added to soil?
- Nitrogen fixing bacteria
- Lightning
- Animal waste
- Decomposition
how is nitrogen lost from soil?
- Used from plants
- Soil erosion
denitrification
bacteria return nitrogen to atmosphere
limiting distribution:
Organisms have a range of tolerance for each environmental factor (determines their niche)
abiotic limits:
terrestrial -
aquatic -
terrestrial: temp, humidity, precipitation, water availability, nutrients, sunlight
aquatic: temp, oxygen, salinity, nutrients, sunlight
biotic limits:
negative interactions with another species, competitive exclusion, exploitation, disease.
dispersal ability limits an organism’s…
range
meterological conditions
wind, precipitation, air pressure, temperature, cloud cover
weather
meteorological conditions on a given day
climate
long term trends in meteorological conditions
Microclimate:
local climate in a small area
macroclimate:
climate in a large area
factors that affect climate:
Solar intensity, wind, seasonality, altitude, water, global currents
solar intensity patterns:
Lower intensity at higher latitudes
Higher intensity near the equator
why is solar intensity lower at higher latitudes?
Sun passes through more atmosphere
Sunlight is spread out over more area
wind patterns:
warm, moist air rises at…
equator (due to solar intensity)
wind patterns:
wind moves __ or ___
north or south
wind patterns:
air cools as it …
rises, and loses moisture as rain
cooler air cannot hold as much…
water
dry air descends at ____ degrees north and south of …
30 degrees north and south of the equator
dry air creates
large deserts
coriolis effect
Deflects things right in the Northern Hemisphere
Deflects things left in the southern hemisphere
prevailing wind direction
Toward the west near equator
Toward the east 30 degrees N or S
seasons are due to
the tilt of the earth
seasons are more pronounced near…
the poles
mutualistic relationship between plants and nitrogen fixing bacteria
- plants provide root pouches for bacteria (protection) and they share sugar
- bacteria fix nitrogen and provide a steady supply to plants
altitude: temp is colder..
higher up
enclosed valleys may be older since…
cold air sinks (temp inversion)
rain shadow
Moisture removed as air cools over mountain
Area of little rainfall on leeward side of mountain
Water slowly ___ heat form the air in hot weather
removes
Water slowly ___ heat to the air in cold weather
releases
warmer water creates…
more storms: greater precipitation nearby
warm or cold water may…
flow to new locations
biome:
large ecosystem
abiotic factors that determine biomes
- Climate for terrestrial biomes
- Water properties and depth for aquatic biomes
disturbance
outside event that disrupts community or resource availability
3 categories of biomes
terrestrial, freshwater, marine
types of forest biomes
- Tropical rainforest
- Temperate broadleaf
- Northern coniferous
tropical forests climate
Lots of rain year round
Warm temperatures
Days mostly the same length
tropical forest: what are the plants like?
Plants have large leaves to absorb sunlight
Plants grow continually
Very abundant primary production
* Supports complex ecosystems
* High biodiversity
what are tropical forests threatened by?
deforestation: results in nutrient poor soils
savanna: climate
Tropical
Warm year round
Rainy and dry seasons
Intense sunlight and high production
* Complex ecosystems
savanna: what are plants like?
Scattered shrubs and trees
Grass adapted to constant grazing
savanna: threatened by
cattle which eat all the grass
called desertification
desert: climate
Rainfall less than 30cm per year
*Most are 30 degrees N and S of equator
*Very dry air
Hot during the day, cold at night
desert: what are plants/animals like?
Many plants have spines to protect their stored water
Plants minimize water loss
* Waxy covering
* Traditional leaves small or absent
Animals are adapted to need little water
* Kangaroo rat can live its entire life without ever drinking
deserts are threatened by…
urbanization and agriculture
chaparral is AKA
mediterranean scrub
chaparral climate
Moderate rainfall during moderate winters
Very hot, dry summers
* Burns a lot
where are chaparrals located
along the edges of continents
chaparral: what are plants like?
Drought resistant plants
* Small leather leaves
* Adapted to frequent fires
chaparrals are threatened by
urbanization
types of grasslands:
savanna and temperate
terrestrial biomes include:
forest
chaparral
grasslands
desert
tundra
temperate grassland: climate
Hot summers
Cold snowy winters
temperate grassland: plants
Nutrient rich soil
Mostly grasses (height depends on precipitation)
temperate grassland types
prairie: high precipitation, long grass
steppe: lo precipitation, short grass
temperate grassland is threatened by
agriculture
temperate broadleaf forest: climate
Moderate precipitation year round
Cold winters and warm summers
temperate broadleaf forest: what are plants like?
Plants have moderately sized leaves
Shed all their leaves in the winter
Grow new leaves in the spring
why do temperate broadleaf forest’s leaves shed in winter?
Conditions poor for growth
Little sunlight
Little access to water
northern coniferous forest: climate
Most extensive terrestrial biome
Dry, cold winters
Rains fall primarily during summer
Short growing season
northern coniferous forests is AKA
Taiga or boreal forest
northern coniferous forests: what are plants like?
Dominated by conifers
*Cone shaped to shed snow
*Waxy needles prevent water loss during winter
Often very wild
northern coniferous forests are threatened by
logging and mining
tundra: climate
Coldest biome
50-60 day growing season
Permafrost: permanently frozen soil
*Prevents water drainage leading to marshy soil
tundra: what are plants
Low clustered plants avoid cold and wind
Animals migrate elsewhere or hibernate during winter
tundra is threatened by
oil exploration and climate change
factors that influence biomes:
temperature and rainfall
types of aquatic biomes:
freshwater and Marin
freshwater biomes:
(less than .1% salt)
Lakes and ponds
Rivers and streams
Wetlands
marine biomes:
(3.5% salt)
-covers 75% of the earth’s surface
freshwater habitat zones include:
-photic zone
-aphotic zone
-pelagic zone
-benthic zone
photic zone
-near surface
-light from surface
-littoral zone if bottom of photic
aphotic zone
-little to no light rom surface
-limnetic zone if bottom of aphotic zone
___ zone above bottom
pelagic
___ zone on bottom
benthic
Seasonal vernal (spring) ponds are important for
breeding
why does surface/shore of lakes/ponds have more organisms?
Water is warm, bright, and well oxygenated
lakes/ponds: oligotrophic
few nutrients and clear water
lakes/ponds: eutrophic
many nutrients and cloudy water
lakes/ponds: eutrophication
addition of nutrients
lakes and ponds are threatened by
pollution, eutrophication, and acid rain
turnover in temperate lakes:
___ in summer
thermocline: warm surface water (high in oxygen) and cold deeper water (little oxygen)
turnover in ___ and ___
spring and fall
what is turnover?
*Mixing of deep and surface water
*Redistributes nutrients and oxygen
___ lakes often have permanent thermocline
tropical
rivers/streams: headwater
clear, cold, high in oxygen, quick flowing
Good habitat for trout and related species
headwater in rivers and streams
middle of river/stream:
slower, warmer, high photosynthesis
fish, insects, amphibians, reptiles live where?
middle of river/stream
characteristics of wetlands:
High nutrient levels
Support a huge variety of species
importance of wetlands
Slow the flow of water
*Allows pollutants to settle out
*Help prevent flooding
what are wetlands?
Standing water with plants above surface
wetlands are threatened by
destruction by drainage
marine habitat zones: ___ near surface
photic
marine habitat zones:
neritic zone ___ continental shelf
over
marine habitat zones:
oceanic zone ___ oceanic shelf
beyond
marine habitat zones:
pelagic zone
above bottom
marine habitat zones:
benthic zone
on bottom
estuaries
Area of fresh and saltwater mixing
Extremely productive and diverse habitat
why are estuaries called nurseries of the sea
Provides habitat for juveniles of many commercial fish species
estuaries are buffers that stabilize…
shoreline and prevents erosion
estuaries are threatened by…
pollution, eutrophication, and habitat destruction
tides are caused by..
gravitation pull of the moon
intertidal zone
only underwater part of the time
*Shoreline interface between land and sea
intertidal zone animals must survive…
- Temperate fluctuations
- Rough waves
- No water
- Land and aquatic predators
intertidal zones are threatened by
by pollution, habitat destruction, and overexploitation
coral reefs:
Habitat structure created by organisms themselves
Corals build skeletons from calcium carbonate
Up to 90% of energy is provided by alage that live in coral
coral reefs need..
warm, well lit water
coral reefs are threatened by
pollution, warming temperatures, and ocean acidification
open ocean pelagic zones covers __ of earth’s surface
2/3
50% of earth’s oxygen is genernated by…
photosynthetic plankton
-serve as base of ocean food chain
open ocean is threatened by
overharvesting, pollution, and garbage
open ocean benthic zone: characteristics
- Much of it receives no sunlight
- Food falls from above
- Very cold (3C)
- Extreme water pressure
- Relatively high oxygen levels
open ocean benthic zone is threatened by
by bottom trawling, oil spills, and unknown factors
hydrothermal vents: characteristics
- Very deep, no light
- Hot water spews from holes
o Volcanically heated
o Full of minerals
where does energy come from in hydrothermal vents?
Energy from bacteria: they break down sulfur compounds (rely on sulfur, not sun)
mouth of river/stream:
very slow, high sediment, lower oxygen
bottom dwelling fish (catfish and carp) live where?
mouth of river
rivers/streams are threatened by
pollution, eutrophication, and dams
