Transcript Succession _ Biomes

Succession
• Succession – the
orderly natural
changes and species
replacements that take
place in the
communities of an
ecosystem
• Takes a long time, not
easily observable
• Occurs in stages
Primary Succession
• From a disturbance, such as
rocks moving to expose new
soil starts Primary
succession.
• Pioneer species set up such
as mosses and lichens
• As these species die, they
create soil for further species
• Shrubs, ferns, grasses come
next
• Pines, beeches and maples
colonize after that
• When the community
stabilizes, a climax
community is established
– How can you tell?
Secondary Succession
• Occurs when interrupted
by natural disasters or
human actions
• Occurs in areas that
previously contained life
and soil.
• Pioneer species maybe
different since the soil is
already present
• Occurs by the same
process as primary
succession.
• Takes less time
– Why?
Biomes
• Ecosystems that have similar kinds of
climax communities are called Biomes.
• Biomes are limited by temperature and
precipitation (terrestrial types)
• There are two major types of biomes
– Aquatic (those in the water, sea) (3/4 of the
Earth)
– Terrestrial (those on land)
Marine Biomes
• Estuary – coastal body of
water, in part surrounded by
land where freshwater and
saltwater mix.
• Scientists separate marine
biomes into two parts:
– Photic Zone : portion of the
biome shallow enough to allow
light through
• Plankton, juvenile marine
organisms
– Aphotic zone : deeper water
where light cannot penetrate
• Adapted to life in the dark.
Terrestrial Biomes - Tundra
• Tundra – Circles the
poles, treeless with long
summer days and short
periods of winter sunlight
• Under the topsoil is a
frozen part called
permafrost.
• Soil is nutrient poor and
can’t hold larger plants &
trees
• Small mammals live
there like owls and
lemmings
Taiga
• Taiga – just south of
the tundra
• Warmer than the
Tundra, land of fir &
spruce trees
• Canada, Northern
Europe & Asia
• Contains larger
species like Caribou,
snowshoe hare
Desert
• Desert – driest biome
with sparse plant life
• Less than 25 cm of
precipitation
• Organisms have
adapted to conserve
water (mice,
scorpions, snakes,
owls, etc)
Grassland
• Grasslands – covered by
grasses and similarly
small plants
• 25 – 75 cm of
precipitation
• Occupies more area than
any other land biome
• Good for growing crops
• Dominated by grazing
animals (bison)
Temperate Forest
• Temperate Forest –
above and below the
equator
• Nutrient rich soil with
Hardwood trees
• 70 to 150 cm of
precipitation
• Home to many forest
animals (bears, squirrels,
salamanders)
Tropical Rain Forest
• Tropical Rain Forest –
located at the equator
• Warm and wet with lush
plant growth
• Average 25C, with 200600 cm of rain
• Home to the most amount
of species on the planet
• Has many niches due to
the layers of the
rainforest (forest floor,
trees, canopy, etc)