Ecological Biomes
Chapter 50, 52, &
54
What you need to know
 The role of abiotic factors in the formation
of biomes
 Features of freshwater and marine
biomes
 Major terrestrial biomes and their
characteristics
Ecosystems
 A biological community
interaction/adapting to its biotic and
abiotic environment
 Types include:
 Terrestrial Biomes
 Aquatic Biomes
 Freshwater
 Marine
Biomes
 The major types of ecosystems that
occupy very broad geographic regions.
 Aquatic biomes make up the largest part
of the biosphere
Aquatic Biomes

1.
2.
3.
Broken into four layers:
Photic zone: enough light for PS
Aphotic zone: very little light
Thermoclines: mid level region with
fast temperature change (deeper 
colder)
4. Benthic zone: bottom of the biome
(sand, organic sediments, detritus)
Freshwater Biomes
1. Lakes & Wetlands


Littoral zone (shore), limnetic zone (deep water)
Oligotrophic lakes (deep lakes, nutrient poor, O2
rich), eutrophic (shallow lakes, nutrient rich, O2
poor)
2. Rivers & Streams


Defined by current, and divided among head
waters and mouth
Esutuaries are where freshwater rivers and
streams merge into the ocean
Marine Biomes
 Intertidal zone: land meets the water
(tidal regions)
 Neritic zone: shallow water
 Pelagic Biome: open blue water (most of
the ocean)
 Coral Reef: cnidarians make calcium
carbonate shells (coral); among the most
productive ecosystems
Climate
 Total annual rainfall
 Average annual temperature
Climate is largely determined by latitude,
but can be modified by mountain ranges,
trade wind patterns, and/or altitude
9 Major Biomes
1.
2.
3.
4.
5.
6.
7.
8.
9.
Tropical rain forest
Tropical dry forest
Savanna
Desert
Temperate forest
Temperate grassland
Chaparral
Taiga
Very low temp
Tundra
High temperature
Decreasing rainfall
Lower temp
Decreasing rf
Tropical Rain Forest
Tropical Rainforest





Around equator
Temperature is warm, rainfall 200-400 cm/year
Photoperiod: 10-12 hr/ year round
No/little seasonal change
Most complex terrestrial biome, many varieties
of vegetation (300 species of trees), highest
variety of species
 Highest amount of trophic levels
 Poor soil: rapid recycling rather than
accumulation
Tropical Dry Forest
Tropical Dry Forest
 Similar to rain forest but less rain
 Dryer forests in Africa and South America
Savannah
Savannas




Temp. warm, rainfall 30-50 cm year
Main vegetation: grasses
Large herbivores and their predators
Seasonal drought, fires
Desert
Desert
 Driest terrestrial biome: low and
unpredictable rainfall (less than 30
cm/year, some none in decades!)
 High temperature fluctuations
 Descending dry airmasses: 30 olatitude
 Deep rooted, water storing plants, CAM
metabolism
 Animal adapted by behavior, excretory
systems
Temperate Forest
(deciduous/broadleaf)
Temperate Forests





Midlatitude regions
Seasons, rainfall 200 cm/year
Growing season 5-6 month
Less diversity than rainforest, more open
High rates of decomposition, but low cycling of
nutrients, allows for thick layer of rich soil
 Many invertebrates (leaf litter), many bird,
rodent, deer species
 Good regeneration from human impact
Temperate Grassland
Temperate Grassland
 Similar to savanna but cold winter
 North American Prairie
Chaparral
Chaparral
 Semiarid regions, rainfall like wet desert,
but additional moisture from fog
 Dense spiny shrubs, tough evergreens
 Midlatitude areas close to cold oceans
 Lots of annual plants
 Periodic firestorms necessary to make up
for lost compostation, facilitate
germination
 Animals: grazers, fruit eating birds,
rodents, lizards
Taiga (Coniferous Forest)
Taiga




Cone bearing evergreens
Long cold winters, short wet summers
Most precipitation in form of snow
Large migrating grazing animals like
moose, elk deer
Tundra
Tundra
 Long bitter winter, long 24 hr photoperiod
during growing season, arctic winter
 Moisture good but no trees due to:
 Permafrost preventing root growth
 Animals adapted by thick coats
 Grazing migratory herds