Transcript WhereIsHere1 - Prairie Ecosystems

Where is Here
Lecture 2
Prairie Ecosystems
The Urban Savannah
• Frontiers of the Prairie
– Frank Lloyd Wright’s
Prairie Skyscraper, Price Tower Arts center
• Chicago is as it was
on the Ecotone
–
–
–
coined from a combination of eco(logy) plus –tone
from the Greek tonos or tension – in other words,
a place where ecologies are in tension
Chicago Architecture Foundation
oikos-olgie,
Ecology
Study of the household, Total relationship .. of organic
and inorganic environment
Ecology is the scientific study of the distribution and
abundance of living organisms and how the distribution
and abundance are affected by interactions between the
organisms and their environment
1866 Ernst Haeckel
“ontogeny recapitulates
phylogeny”
Father of Evo-Devo,
but also faked some data,
like Mendel and Darwin?
ontogeny recapitulates phylogeny
Ecosystem
• 1935, Tansley studying math and systems
theory, quantifying relationships and community
at various interlocking scales
• A biome is a homogeneous ecological formation
that exists over a large region as tundra or
steppes. The biosphere comprises all of the
Earth's biomes -- the entirety of places where life
is possible -- from the highest mountains to the
depths of the oceans.
EcoZones/ Biomes/ Realms
• Australasia | Antarctic |
Afrotropic | Indo-Malayan
Nearctic | Neotropic | Oceania
| Palearctic
Temperate Grasslands, Savannas, & Shrublands
NA0801
NA0802
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NA0812
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NA0814
NA0815
California Central Valley grasslands
Canadian Aspen forests and parklands
Central and Southern mixed grasslands
Central forest-grasslands transition
Central tall grasslands
Edwards Plateau savanna
Flint Hills tall grasslands
Montana Valley and Foothill grasslands
Nebraska Sand Hills mixed grasslands
Northern mixed grasslands
Northern short grasslands
Northern tall grasslands
Palouse grasslands
Texas blackland prairies
Western short grasslands
EcoRegions
• An ecoregion (ecological region), sometimes called a bioregion, is
the next smallest ecologically and geographically defined area
beneath "realm" or "ecozone".
• The WWF has identified 825 terrestrial ecoregions, and
approximately 450 freshwater ecoregions across the Earth.
• "recurring pattern of ecosystems associated with characteristic
combinations of soil and landform that characterise that region"
(Brunckhorst, 2000).
• Others have defined ecoregions as areas of ecological potential
based on combinations of biophysical parameters such as climate
and topography. Biodiversity is also an important aspect of the study
of ecoregions. The biodiversity of flora, fauna and ecosystems that
characterise an ecoregion tend to be distinct from that of other
ecoregions
• Great Plains has 15 EcoRegions,
• Chicago, “Central Tall Grasslands -> Prairie Oak Transition”
Upper Midwest forest-savanna
transition (NA0415)
• One of the three ecotonal units separating the vast Great Plains
grasslands from the forests of the eastern U.S. is the Upper Midwest
Forest/Savanna Transition Zone
• The predominance of trees in a mosaic of forests, savannas, and
woodlands, and by differences in dominance of major tree species.
• oak, maple, basswood woodland, forest, and savanna ecosystem
(Küchler 1985). The boundaries of this ecoregion were heavily
influenced by fire and drought
Central forest-grasslands transition
• extends from northern Illinois, across much
of Missouri, and into eastern Kansas,
Oklahoma, and Texas.
• Is one of the larger savanna-type
ecoregions, covering more than 380,000
km2
• separates the Eastern Deciduous Forests
from the tallgrass and mixed grass prairies.
• higher tree and shrub densities.
• Annual precipitation ranges from 600-1040
mm, with wetter areas supporting a more
closed tree canopy.
• The uniform soil type (mollisols) unites this
wide-ranging ecoregion.
• Unfortunately, virtually no intact habitat
remains because this ecoregion is one of
the most converted of U.S. ecoregions.
• Almost all of this unit is intensively
farmed for corn and soybeans.
Danger Danger
• Tall Grass Prairies.
• 99.9% plowed under
• 464 species declined “long term survival is in
danger
• 328 (71%) are endemic
• Mixed Grassland Diversity
• 13 amphibians, 18 reptiles, 72 mammals, 160
butterflies, 222 birds, 1595 species of grasses,
sedges and wildflowers
• Species Richness index 2095,
– vs California Redwood forest 1710, Everglades 1855
Prairie global distribution
• 1/3 or earths land surface
• Other world prairie ecosystems?
– Could we survive today without prairie grasslands? What are our major
food stuffs?
• For example, a Temperate grassland or shrubland biome is known
commonly as steppe in central Asia, savanna or veld in southern
Africa, prairie in North America, pampa in South America and
outback or scrub in Australia. Sometimes an entire biome may be
targeted for protection, especially under an individual nation's
Biodiversity Action Plan.
• Independent evolutionary origins, similarities on species
compositions, species dependencies?
• Original site of Crop domestication
•
Could we survive today without prairie grasslands? What are our major food
stuffs?
Glaciers give way
• Chicago Encyclopedia
– 11,000 years ago
– Mastodons and woolly mammoths
– Evergreen Forest (still remnant evergreens)
– Before settlement map (browse)
– Humans? Large animals? giant beaver (Castoroides
ohioensis), Harlan's musk ox (Bootherium bombifrons), and stagmoose (Cervalces scotti ) all occurred in the Chicago region
World Grasslands
Hmm, we never knew what we were undoing
Annals of the Missouri Botanical Garden
Grassland evolution in N. America
Bison
• First Europeans observation Coronado in 1540 “hunters
following endless herds.. Impossible to number.”
precontact population estimated 25-125Million
Last free roaming
buffalo killed in
Canada in 1883,
US in 1891.
Hides used for
belts in the
industrial
revolution.
http://en.wikipedia.org/wiki/American_Bison
Badlands
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Badlands are a type of arid terrain with clay-rich soil that has been extensively
eroded by wind and water. Canyons, ravines, gullies, hoodoos and other such
geological forms are common in badlands. They are often difficult to walk upon.
Badlands usually have a spectacular color display that alternates from dark
black/blue coal stria to bright clays to red scoria.
The term "badlands" has dual origins: the Lakota called the topography "mako sica",
literally "bad lands",
Chinle Badlands, Grand Staircase-Escalante National Monument, Utah, US.
Row of hoodoos at Bryce Canyon National Park in Utah
Loess Hills
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The Loess Hills are generally located between 1 and 15 miles east of the
Missouri River channel. These hills are the first rise in land beyond the flood
plain, forming something of a "front range" for Iowa, and parts of Missouri
and Nebraska adjacent to the Missouri River.
During the Ice Age, glaciers advanced into the middle of North America,
grinding underlying rock into dust-like "glacial flour".
Snow geese flying in front of the loess hills at Squaw Creek National Wildlife Refuge in the Missouri River bottoms near Mound City,
Missouri
Making of Lake Michigan
• Whenever a glacier stabilizes for a time at
the same position, the transported material
accumulates into hilly moraines, several of
which occur in the Chicago region
Wisconsin glaciation,
reached its southernmost
extent near Shelbyville in
central Illinois about 24,000
years ago
17,000 years ago is Time 0
for Chicago, 12,000 for
Lake
Sandy springboard
• Lake floor depressed because the heavy
weight of the ice above the land surface
• The land depressed by the glacial ice
gradually uplifted, a process called
isostatic rebound .
• Good for skyscrapers!? 150’ topsoil
Terra forming
• -17,000 -- -11,000.. Evergreen Spruces (white and black)
and Deciduous Popular, Ash, Ironwook.
– Unique on the globe, warm winters cool summers
• -11,000 end of Pleistocene, beginning of Holocene
warming to deciduous forest dominated by black ash,
elm (Ulmus), and oak prevailed , better than today (few
evergreens left)
• About 6,000 years ago, the climate again became drier,
and the modern mosaic of prairie and woodland began
to develop. Elm and other fire-sensitive trees decreased
in abundance, and oak became the predominate tree on
the landscape.
• Open
Savannah Oak
architecture
• Lots of light
near a
grassland
• Native
Americans
provided a
constant
source of
ignition
Westerly wind protection
• Thicker forests were less subject to fire,
and generally were on the protected east
sides of the rivers. Eg Aurora
• Why do grasses withstand fire and
trees/shrubs don’t?