Transcript CH 3 and 4Comm and Biomes 2013

Chapter 3
Communities and Biomes
Part 1
Ecosystem: interactions among
populations in a community
 Consists
A
of:
community of organisms
 The soil, water, and weather
 Energy
Biome - a major ecosystem that shares the
same type of climate and has similar life forms.
1. Salt water
2. Freshwater
3. Estuary (mix
of salt and
fresh water)
4. Terrestrial
(dry land)
Tundra (Alpine and Arctic)
Permafrost - permanently frozen ground
Plants - short roots; fast growing; perennials.
Animals have thick fur / body fat / coloration.
Taiga / Coniferous Forest
Conifers - cone-bearing trees / bending branches / needles
as leaves. Animals also have thick fur / body fat.
Temperate / Deciduous Forest
Broad-leaved trees lose their leaves yearly.
Some birds migrate.
Tropical Rain Forest
Arboreal - tree-dwelling animals
Trees / Plants:
1. Canopy 2. Understory 3. Ground
Desert
Most desert animals are nocturnal.
Estivation - sleeping during hot days.
Plants have waxy leaves / spines.
Grasslands (Savanna and Temperate)
What are Steppes?
Most animals have good vision and speed.
Plants have underground stems / survive fires.
Aquatic Biomes
Freshwater – Ponds, lakes,
streams, rivers, wetlands.
Marine – Oceans, coral reefs,
estuaries.
CLIMATOGRAM Measures two things:

Average Temperature

Average Precipitation
Chapters 3-4
Communities and Biomes /
Population
Part 2
Succession: changes over time

Primary succession – gradual growth of an ecosystem
over a long period of time. Example: Hawaii. Rock ->
Lichen -> moss -> grass -> shrub -> tree -> vines
Succession: changes over time

Pioneer species – first species in an area
Succession: changes over time


Climax community – shows little or no change over time
Secondary succession (previously supported vegetation) –
sequence of life after natural disasters (examples: Forest fires,
glaciers, avalanches, flood, hurricane, tsunami, tornadoes, volcanic
eruption).
1988 forest fire in
Yellowstone Nat’l Park
Population Dynamics
 Exponential
Growth - as a population gets
larger, it also grows faster.
 Carrying capacity - the maximum number
of organisms that an environment can
support.
Limiting factors:
Factors that affect an organism’s ability to survive.
 Density
dependent factors:
 Disease
 Competition
 Parasites
 Food
& water
 Space
Density independent factors
(abiotic factors):
 Temperature
 Storms
 Floods
 Drought
 Habitat
disruption (logging,
burning, draining swamps,
moving in exotic species)
Demography - human population growth
Immigration - moving in
 Emigration - moving out
 Growth rate
 Natality - birth rate
 Fatality - death rate
