Transcript Biomes - peartreabio

Section 3.2: Biomes
*Biomes - a large group of ecosystems that share the
same type of climax community.
2 types:
1) Aquatic Biomes
2) Terrestrial Biomes
I.
Aquatic Biomes: Life in the Water
*2 types of aquatic biomes exist: freshwater and
saltwater.
A.
Marine (Saltwater) Biomes
*different parts of ocean
waters differ in physical
factors and in the
organisms found living there.
*salinity - the amount or concentration of salt in the water.
1. Biomass - the oceans contain the largest amount of
biomass compared to all other biomes; the majority of this
biomass comes form extremely small organisms such as
phytoplankton and zooplankton.
Plankton
Phytoplankton - can do
photosynthesis; very small, most
are microscopic
Zooplankton - cannot do
photosynthesis, thus they eat other
organisms, mainly phytoplankton.
2. Concept of “Zoning”
Ecologists study marine biomes by separating them into 2
main zones: Photic & Aphotic.
a) Photic Zone - zone or portion of the ocean that is shallow
enough for sunlight to penetrate through.
location - found in areas along the coastline and the
upper portions of the sea.
b) Aphotic Zone - zone or portion of deep ocean water that
NEVER receives sunlight.
location - deepest parts of the oceans
B. A Mixing of Waters: Bays & Estuaries
*rivers will often flow into the oceans and the two types of
waters will mix.
1. Estuary - a coastal body of water, partially surrounded by
land, where freshwater and saltwater merge.
a) Salinity in an estuary - salinity ranges from that of
seawater to that of freshwater. It depends on how much
freshwater is brought in by the river to the estuary.
b) organisms in estuaries - due to changes in salinity of the
estuary they are capable of supporting a large number
and wide range of organisms.
c) estuary ecosystems - salt marshes, bays
C. The Effects of the Tides
*Tides are caused by the gravitational pull of the sun and
the moon.
1. The Intertidal Zone - the portion of the shoreline that lies
between the high and the low tide lines.
The Zone size depends on:
a) the slope of the land
b) the height of the tide
2. The Intertidal Ecosystem
a) has high levels of sunlight, nutrients and O2
b) Productivity - limited by waves crashing against shore
c) Organisms:
1) “suction cup” organisms
ex) snails, sea stars
2) “glue” organisms
ex) mussels, barnacles
3) “burrowing” organisms
ex) clams, worms, crabs
Intertidal Zone Organisms:
d) waves - keeps the bottom of the ocean in constant motion
3. Tide Pools
*form when water recedes at low tide; marine “puddles”
*this land locks some organisms until the next high tide
Zoning in the Ocean:
D. In the Light (Photic Zone)
*the further out in the ocean you go, the less the ocean
bottom is affected by waves.
1. Life - abundant in the photic zone; productivity is high.
2. Plankton - represents the majority of the ocean’s
organisms. Can be autotrophic or heterotrophic.
E. In the Dark (Aphotic Zone)
*almost 90% of the ocean is more than a kilometer deep.
1. Life - depends upon plankton from above for food.
2. Adaptations to Life in the Dark
-no photosynthesis; no light, cannot make food
-special adaptations
ex) large eyes, or no eyes at all
bioluminescence
Freshwater Biomes
*examples: rivers, ponds, lakes, streams, etc.
1. Organisms - cattails, sedges,
tadpoles, aquatic insects,
worms, crayfish, fish, etc.
Freshwater Biomes
2. Abiotic Factors:
a) temperature variations:
1) upper surface of lake
is warmer than lower or
deeper portions of water.
2) the deeper you go,
the colder it gets.
Freshwater Biomes
b) light:
1) upper layer of freshwater systems receive enough
light to carry out photosynthesis.
2) deeper portions of freshwater systems do not usually
support photosynthesis.
3) not many plants can grow near the bottom if there is
no light, thus populations density is lower near the
bottom.
c) decay/ decomposition:
1) occurs on the bottom of the freshwater system;
where the dead “stuff” accumulates. “Slimy”
II. Terrestrial Biomes
*Environments change as you move N to S
*There is an observable pattern in the environments as
you move N to S
*Three (3) influential factors determine Biomes:
1) latitude
2) altitude
3) precipitation
Biome Map