98. Sections 3 & 4:

Biogeography – the study of where organisms live and

their methods of dispersal to those places

The Earth’s biogeography has been affected by continental

drift – the slow movement of land masses riding atop the

hot, liquid core of the Earth.

99. Changing Earth:

225 million years ago only one large land mass called

Pangaea existed; over time the continents we know today

separated and took up their present locations

100. Dispersal – the movement of

organisms from one place to another

Large organisms may be able to walk, swim or fly to new

locations

Methods of dispersal for small organisms:

1) Wind – blows bacteria, fungi spores,

seeds and tiny insects or spiders

2) Water – moves floating objects like

coconuts, leaves or branches that serve

as rafts for insects and small animals

3) Animals – eat seeds and carry them elsewhere

4) Humans travel all over the globe and may carry

parasites, insect pests, rodents, etc.

101. Limits to Dispersal

Three things can stop the spread of new species:

1) physical barriers – water, mountains and deserts are hard to cross

2) competition – if one species uses all of the resources, new species will be kept out of the area; especially true among plants

3) climate – each organism requires a certain climate

102. Species Types:

Native Species – those organisms that evolved naturally in

an area; raccoons are native to N. America

Endemic Species – native species that are

different from those found anywhere else

in the world; kangaroos are endemic to

Australia (no other continent has them)

Invasive Species – organisms that have been transported

to new locations where they create problems as they

compete with native species

Let’s see some native species…

This link shows a unique museum that includes many

species native to the Arizona desert:

http://www.youtube.com/watch?v=gGCCfbOPV60

Let’s see some endemic species…

These clips features species found only in the Galapagos Islands (off the coast of S. America):

http://www.youtube.com/watch?v=E7IK_qt0hEw

http://www.youtube.com/watch?v=i6oQQfy3K9c

Let’s look at some invasive species…

America faces a growing problem with thousands of

organisms invading our country:

http://www.youtube.com/watch?v=mUssO68D2eM

Do Not Copy

Biomes – a group of ecosystems with

similar climate & organisms (handout #103)

Six major land biomes:

1) Desert – very hot, dry climate; cacti are specially adapted for low rainfall

2) Grassland - not enough rain for large trees; mostly grass;2 kinds exist a) prairie (hot summers & cold winters); central U.S.

b) savanna (warm all year; some small trees); Africa

3) Deciduous Forest – hot summers; cold winters cause trees to shed their leaves and animals to hibernate; trees include maples, oaks, elms, etc. this is our biome

4) Rain Forests – plentiful rainfall2 kinds exista) Tropical Rain Forest (hot all year); near equator

b) Temperate Rain Forest (cooler climate); Northwest U.S.

5) Boreal Forest (also called Taiga) – winters are long & very cold; trees are coniferous w/ needles to conserve water since snow has no chance to soak down into soil during cold months

6) Tundra – extremely cold & dry; permafrost is soil that stays frozen all year; mostly small plants; north of Arctic Circle

Major Land Biomes: Cold

Hot

Dry Wet

TUNDRA

Boreal

Forest

Prairie

Grassland

Deciduous

Forest

Temperate

Rain Forest

DesertSavanna

GrasslandTropical Rain Forest

104. Miscellaneous Geographic Regions (some areas do not fit any biome description):

1) Mountain Ranges – the conditions

of temperature and moisture change

from the base of a mountain to the

peak so that a single biome doesn’t

apply;

2) Polar Regions – Most of Greenland

(near North Pole) and all of Antarctica

(South Pole) are covered by thick sheets

of ice so there are no plants there

105. Freshwater Biomes

1) Still water: holds less dissolved oxygen;

inhabited by bass, sunfish, carp, catfish, etc.

a) ponds – small, shallow and warmer

b) lakes – larger, deeper and colder

2) Moving water: holds more dissolved

oxygen (due to mixing of air with the

water); inhabited by trout, salmon, etc.

a) streams – small, swift, cold

b) rivers – larger, slower, warmer

Do Not Copy

Marine Biomes (handout #106):

1) Estuary – where a river meets the ocean; lots of nutrients

and sediments are dumped here creating a habitat suitable for

many organisms to live

2) Intertidal Zone – the shallows between the high tide mark

and the low tide mark; only covered by water some of the time

3) Neritic Zone – shallow water from the low tide mark out

to the edge of the continental shelf (where deep water begins)

4) Photic Zone – water near the surface extending down only

a few hundred meters; this is where light is able to penetrate; all

the producers (algae and plankton) here & the most animal life

5) Benthic Zone – all along the ocean floor from shallow

water to the deepest parts; can be total darkness

High Low Shelf

Tide Tide Edge

Photic Zone (Just Beneath the Surface)

107. Succession: changes in the

environment over time

Two types:

1) Primary Succession- These changes occur

in an area that starts with no soil (just bare

rock) and no organisms; example could be a volcanic

island where eventually soil forms and organisms move in.

2) Secondary Succession – These changes occur after a

disturbance in an ecosystem wipes out all the organisms,

but soil remains; examples could be a forest fire or a

hurricane followed by slow recovery during which plants

and animals return.

Animation of Primary Succession:

http://www.youtube.com/watch?v=vNHnwHaSolA

Explanation of Secondary Succession:

http://www.youtube.com/watch?v=O8-

LZdIyUQg&feature=related

Image Credits:

Pangaea: http://www.google.com/imgres?q=Pangaea+illustrations&hl=en&sa=X&biw=1024&bih=600&tb

m=isch&prmd=imvnsb&tbnid=5hrJFjFO1pvJ2M:&imgrefurl=http://www.exploratorium.edu/faul

tline/activezone/slides/pangea-

slide.html&docid=rqFgtIUIIFxqQM&imgurl=http://www.exploratorium.edu/faultline/basics/imag

es/pangea_lrg.gif&w=530&h=661&ei=DV0dT9KnIqPz0gHoh9ylCg&zoom=1&iact=rc&dur=498

&sig=109441506116969674550&page=1&tbnh=143&tbnw=115&start=0&ndsp=11&ved=1t:42

9,r:2,s:0&tx=69&ty=64

Continental Drift: http://www.google.com/imgres?q=continental+drift&hl=en&biw=1024&bih=600&tbm=isch&tb

nid=OBKPYukkvVniDM:&imgrefurl=http://www.enchantedlearning.com/subjects/dinosaurs/glo

ssary/Contdrift.shtml&docid=l2op6CXHs2IpJM&imgurl=http://www.enchantedlearning.com/eg

ifs/Earthscrust.GIF&w=472&h=243&ei=a14dT4jwEebi0QHdr6jmCw&zoom=1&iact=hc&vpx=

381&vpy=187&dur=8096&hovh=161&hovw=313&tx=187&ty=86&sig=1094415061169696745

50&page=1&tbnh=77&tbnw=150&start=0&ndsp=18&ved=1t:429,r:2,s:0

Image Credits:

Galapagos: http://www.google.com/imgres?imgurl=http://www.worldatlas.com/webimage/countrys/sameri

ca/galpsa.gif&imgrefurl=http://www.worldatlas.com/webimage/countrys/samerica/galap.htm&h=

350&w=320&sz=24&tbnid=NNJsiCJU3tml1M:&tbnh=84&tbnw=77&prev=/search%3Fq%3Dma

p%2Bof%2Bgalapagos%26tbm%3Disch%26tbo%3Du&zoom=1&q=map+of+galapagos&docid=P

c5gO_2NI6uC0M&hl=en&sa=X&ei=bWwdT7DNJIW-0QH-

rKXQCw&sqi=2&ved=0CDcQ9QEwAQ&dur=31