Transcript Fragmentation and landscape changeSC

I. BIODIVERSITY
II. CAUSES OF SPECIES DECLINES
A. Habitat loss and Degradation
(CH4 is Habitat Destruction and
CH5 is Habitat Fragmentation and Landscape
Change)
B. Overexploitation
C. Invasive species
D. Climate change
Fill in the handout for global loss and….
• Think about which forces around the world are
“loss” and which are more habitat “degradation.”
• What might degradation look like?
• Don’t forget marine and freshwater areas!
• Do include regions in US and Globally that you
have personal knowledge of!
• Draw the state of MN on back. What forces are
important for the state of MN and where are
they??
http://www.ucpress.edu/blog/wp-content/uploads/2010/04/4.4_Percent_Habitat_Loss.jpg
Percent of
landscape
change
from
Grass ->
Corn and
Soy
Net
change or
loss
Percent of
landscape
change
from Corn
and Soy ->
Grass
For converted acres what was the
land like in terms of its “class” and
even within that class.
Acres converted and how close they were to wetlands.
I. BIODIVERSITY
II. CAUSES OF SPECIES DECLINES
A. Habitat loss and Degradation
1. Global->MN (CH4)
2. A focus on midwest grasslands/prairies
(article)
3. Introduction to Fragmentation and
Landscape Change (CH5)
B. Overexploitation
C. Invasive species
D. Climate change
3. Introduction to Fragmentation and
Landscape Change (CH5)
Historical Background…
Fragmentation is breaking up of habitat.
When breaks up we are left with islands of habitat
So initial research on fragmentation inspired by
island biogeography.
We saw graphs of a relationship between size of
island and number of species.
Also looked at distance island was from other
islands.
http://en.wikipedia.org/wiki/Insular_b
iogeography#mediaviewer/File:Area_s
pecies_curve_herpetofauna.svg
Mathematical models were constructed to see the
degree to which these natural patterns could be
predicted based on variables such as, not just the
size, but the distance to other islands (real islands or
habitat islands).
So we had this cool quantitative way to look at
numbers of species in fragments of habitat.
Wait….…are typically other interrelated issues
perhaps we are being too simplistic.
• Total area lost (large area lost vs small area)
• What is between the fragments?
Newer field of landscape ecology emphasized this.
Fragments/patches are very interesting but just as
interesting is the “ocean” around them or the
matrix around them-what was that like?
How do species use or not use this intervening
area? How do species use this whole matrix?
Not just simple habitat vs non-habitat.
Today we see landscapes as mosaics of habitats
of variable values to species.
Use term “landscape change”
We emphasize a deeper more realistic continuum
of landscape types.
NOTE!
Fragmentation is also
not random
Some areas are
completely lost (deep
rich soils) and other
areas are left (higher
drier soils)
Patches left are not
representative of
what was there.
Same amount of
cover
(forest)…arranged
differently.
Advantages and
disadvantages of
each?
SLOSS debate
Which is better and why?
http://www.zo.ut
exas.edu/faculty/s
jasper/images/ed
ges2.jpg
http://www.zo.ut
exas.edu/faculty/s
jasper/images/ed
ges2.jpg
Edge effects!
What are abiotic edge effects?
What are biotic edge effects?
Abiotic…Solar radiation, wind, water, humidity,
ground and air temp, fertilizer runoff
Biotic edge effects…other species
May affect ecosystem functioning like decomp rates,
biomass production….How?
Ex Amazon tropical forest changes in….
• Soil moisture changes (extends 50 m)
• Non-deep forest butterfly and beetle species
(extend 200 meters)
• Elevated tree mortality (extends to 200 m)
Metapopulations?
checkerspot butterfly
Gene flow
Sinks
Sources
Corridors?
Banff National Park Canada