underc habitats (terrestrial & aquatic). change continues evolutionary and geological change...
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CHANGE CONTINUES• EVOLUTIONARY AND GEOLOGICAL CHANGE (inherent)
• ECOLOGY OF AQUATIC HABITATS (inherent)
• ECOLOGY OF TERRESTRIAL HABITATS (inherent)
• HISTORICAL CHANGES WITH HUMANS(Native Americans and Europeans) – environmental history
FORESTSFORESTS(taught by Dr. Walt Carson, U. of Pittsburgh)(taught by Dr. Walt Carson, U. of Pittsburgh)
AQUATICSAQUATICS(taught by Dr. Todd Crowl, Utah State U. & NSF)(taught by Dr. Todd Crowl, Utah State U. & NSF)
StreamsOpen systems, constant input of water and
nutrients
Precipitation flows into streams via 2 routes:– Overland flow through surface runoff– Infiltrating soil surface, then flowing
underground and into streams as groundwater
Types of flow – permanent, intermittent,interrupted
Watershed
The area that a stream drains, a.k.a, drainage basin, or catchment area
UNDERC area is near continental divide between Great Lakes drainage basin and Mississippi River basin
Water flows downhill– Upstream– Downstream
River Continuum Hypothesis
Predictable structure of river (physical features, dominant organisms) from upstream “headwaters” to downstream
LakesMay be created by a variety of geologic and climatic
events:– Movement of tectonic plates– Volcanic eruptions– Landslides– Fluvial processes– Glaciation
Nutrients
Temperature not the only stratified element of a lake– Oxygen: highest concentration near
surface (photosynthesis)
– Nitrogen: NO3- at surface, NH4
+ at benthos
– Sulfur: SO4 at surface, H2S at benthos
– Iron: Fe+3 at surface, Fe+2 at benthos
Aquatic Succession
Marsh(Eutrophic)
Bog(Dystrophic)
OligotrophicLake
Mesotrophic
to Eutrophic
Lake
Terrestrial
Sphagnum
Wetlands: technical definition
Vegetation– presence of “hydrophytic” (water-loving, flood-
tolerant) plants
Soils– presence of “hydric” (flooded, reduced) soils
Hydrology– water table at or near the surface for part of the
growing season
Bogs• Acidic (pH < 4.1)• Nutrient-poor soils• Ombrotrophic:
precipitation-fed system• Dominant vegetation:
Sphagnum moss, Vaccinium (cranberries and blueberries), and other low-lying species
• Slightly less acidic (pH 4.1-6.0)
• Soil more nutrient-rich• Minerotrophic:
groundwater-fed system• Dominant vegetation:
sedges, rushes, and grasses
Fens
Succession in Terrestrial Plant
Communities
After a community reverts from aquatic to terrestrial, succession continues resulting in successive species replacements until a climax community is established. The species composition of the climax community is determined by climate.
TYPES OF SUCCESSIONTYPES OF SUCCESSION
• PRIMARY -- from bedrock (no soil) through a seriesof communities (seres) to climax.
• SECONDARY -- successional progression is pushed backby a disturbance to a point where soil still existsand then proceeds.
• What did the glaciers do at UNDERC?• What does a large windstorm do?• What does aquatic succession represent?
Modeling Forest Dynamics(SimForest, a simplified version of JABOWA, a
model by Dr. Dan Botkin,http://ddc.hampshire.edu/simforest/
you will try to parameterize the model for UNDERC, learn about it to be prepared)
White Pine
Hemlock
Other
2%
10%
88%
0.08 trees/m2