Download Human Impact on the Environment:

Human Impact on the Environment:
Fragmentation
What is Fragmentation?
 The on-set of divisions in an organism's
chosen environment, or habitat
Two main types…
 What are they?
Types of Fragmentation
Natural Causes
 Forest Fires
 Volcanoes
 Earthquakes
 Climate change
 Flooding
 Landslides
 Mountain Range
Types of Fragmentation
Human Causes
 Deforestation
 Urbanization
 Building roads
 Agriculture
 Housing
developments
 Damming
Impacts of Fragmentation on the
Environment
 Less interior space for interior species (species that
need large territories, and typically live deep in the
woods: bear, moose, wolves, songbirds). Results in a
population decrease
 Fewer large, long-standing trees and plants
 Decrease in population genetics and variability (meaning
many species’ DNA begins to look similar)
 Many edges are created, resulting in an increase of
edge species (species that live near the edges of
forests/ habitats, thriving in long grasses and smaller
vegetation: cowbirds, bunnies, deer)
 Increase of small weeds and trees. Greater chance of
invasive species (non-natives) moving into an area
The more fragmented a habitat becomes, the less unbroken
interior space is available for larger animals and trees. Edge
species increase as a result of more edges around a habitat while
interior species decrease.
Eastern Cottontail
Paper-Clip Bunny Lab
Number of Roads
Number of Bunnies
0
20
1
?
2
?
.
.
.
.
.
.
10
?
How to Conduct the Study
 Each paper-clip represents a bunny
 Clear your work space, it represents the bunny’s habitat
 To start, drop all bunnies into their habitat. There are no
roads at this point. All bunnies survive.
 Draw a road through the habitat and drop all the
bunnies again.
 Any bunny that touches the road is now dead. Record
this number in the second row of your chart.
 Continue until ten roads are present, or until you run out
of bunnies.
 Graph your results using a bar graph
Should look something like this…
Number of Bunnies
Relationship Between Number of Surviving
Bunnies and Human-made Roads
25
20
15
Number of
Bunnies
10
5
0
0
1
2
3
Number of Roads
4
5
6
What can we say about what the
graph shows?
To Summarize…
 Ticket out the door (ON HANDOUT)
 Please answer the following questions to hand in before
you leave today:
 1) Name one impact of fragmentation on the
environment
 2) What is an interior species?
 3) Increased human development in certain areas will
probably lead most species populations in the area to
_______.