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