Wednesday, Sept. 23rd
Learning Goals
• Distinguish between the processes of primary and
secondary succession.
Agenda
• Biomes Review
• Notes
• Ecological Succession WS
Homework
• Biomes Quiz Monday!
Taiga
(Boreal Coniferous Forest)
• -10°C to 14°C; Cool year round
• 35-75 cm; Adequate Rainfall to
support trees
• Low in nutrients and Acidic
• Coniferous forest with long
winters but mild summers when
ground thaws
• Pines, cedars, spruce, fir trees
• Moose, hares, Geese and
Migratory waterfowl
• Bears, wolves, lynx
Tundra
• -26°C to 12°C; cold year round
• <25 cm; dry
• Thin, nutrient poor soil over
frozen; Permafrost
• Strong, very cold winds with
little precipitation, short &
soggy summers
• Grasses, sedges, moss, lichens
• Lemmings, Caribou, & musk
oxen
• Snowy owls, Arctic foxes,
Migratory birds
Temperate Deciduous Forest
• 6°C to 28°C; Has both cool and
warm seasons
• 75-125 cm; Adequate Rainfall to
support trees
• Moist with moderately thick
topsoil, Rich in nutrients (humus)
• 4 seasons (spring, summer, winter,
fall)
• Oaks, pecan, maples, hickories,
willows
• Squirrels, rabbits, white-tailed deer,
songbirds
• Wild hogs, fox, raccoon, coyotes,
bears
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Temperate Grassland
• 0°C to 25°C; Has both cool and
warm seasons
• 25 – 75 cm; Wet season and dry
season
• Deep layer of nutrient rich
topsoil; Good for farming
• Warm to hot summers and cool
to cold winters
• Lush, perennial grasses, few
scattered trees
• Deer, prairie dogs, buffalo
• Wolves, coyotes, badgers, grizzly
bears, armadillo
Desert
• 7°C to 38°C; May be very cold or
very hot
• < 25cm; Very dry year round
• Dry, often sandy soil, low in
nutrients
• Low precipitation with extreme
temperature changes ( hot in day &
cold at night)
• Cacti, succulents, Creosote bushes,
vegetation that stores water with
waxy cuticles
• Lizards, tortoises, mule deer, camels
• Roadrunners, peccary, rattlesnakes,
kit fox
Chaparral
• 10°C to 18°C; Hot summer & cool
winter
• < 25cm; dry summer & rainy winter
• Rocky, thin topsoil, low in
nutrients
• Mild, rainy winters & hot, dry
summers; Called plains; “western
movies”
• Dense, spiny shrubs like scrub oaks,
scattered clumps of conifers
• Black-tailed deer, jackrabbits,
mountain goats, ground squirrels
• Mountain lions, cougars, bobcats,
coyotes
Tropical Savanna
• 16°C to 34°C; Always warm
• 75-150cm; 6 month rainy
season (monsoon)
• Dry, thin layer of topsoil;
porous; low in nutrients
• Alternating wet and dry seasons
with large number of herbivores
& lots of migratory animals
• Tall grasses, acacia trees
• Giraffe, elephant, zebra,
wildebeest
• Lions, hyenas, vultures, meerkats
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Tropical Rain Forest
• 20°C to 34°C; Always warm and humid
• 200-400cm; Rains almost daily; long,
wet season
• Moist thin topsoil that is low in
nutrients
• Located near the equator;
called jungles or tropics
• Canopy layer of vegetation, vines,
epiphytes like orchids & bromeliads,
tropical ferns
• Parrots, monkeys, chimpanzees,
gorillas, large insects & spiders
• Anaconda, emerald tree boa, jaguars,
giant anteaters
As Biomes Change…
so does the
Biodiversity
Succession
• The predictable orderly
transition from one biotic
community to another.
What is Succession?
– One community of living things
gradually replaces another
• Natural succession occurs
because:
1. The physical environment is
changed by the growth of the
biotic community itself.
2. The area becomes more
favorable to a new species and
less favorable to the present
occupants.
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Two Major Types of Succession
1. Primary succession
Two Major Types of Succession
2. Secondary succession
– An area that has not supported life OR
disturbance eliminated all vegetation
and/or soil
– EX: sand dune, bare rock exposed by
glacial retreat, drying lake, lava flow,
newly created pond
– Disturbance dramatically alters, but does
not destroy, all local organisms
– Once supported life; community is
destroyed but the soil is not
– EX: abandoned field, forest fires, logging,
hurricanes
Succession Occurs in a
Predictable Order
Succession Occurs in a
Predictable Order
• Pioneer species are
the first to colonize
an area
• The area will continually change until a climax
community is reached
– A state of equilibrium, a self-perpetuating forest
until acted upon by another disturbance
– EX: Lichens on bare
rock, moss, grasses
and weeds in a field
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Stages of Succession
1.
2.
3.
4.
5.
6.
7.
8.
Pioneer species: lichens, moss
Grassy meadow
Old field
Sun-loving shrubs
Sun-loving trees
Conifers (pine, cedar)
Shade-tolerant trees (oak, hickory)
Climax Community: shade-loving trees (maples, beeches)
Adaptations of Successional Species
Characteristic
Number of Seeds
Seed size
Dispersal
Seed viability
Growth rate
Mature size
Shade tolerance
Early Successional
Plant
Late Successional
Plant
Many
Small
Wind, water, stuck to
animals
Long, remain
dormant for years
Rapid
Small
Low
Few
Large
Gravity, eaten by
animals
Short
Slow
Large
High
Trends in Succession
• The kinds of plants and animals continuously change.
• Biomass increases with succession.
• Diversity of species increases with succession.
What biodiversity will be found in the forest below?
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