PowerPoint Presentation - Ecological Indicators for Large River-floodplain Landscapes

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The Wisconsin River has played a pivotal role in
Wisconsins history
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The Wisconsin River-Now
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Outline

• How has the Wisconsin River system changed?
• Landscape
• River flow and water quality
• How do physiography, flooding, landscape pattern,
  land cover history and soils influence riparian
  forests in the Wisconsin River floodplain?
• Presence
• Community structure
• Abundance of trees
• Shrubs

Wisconsin River also a good analogue for other
rivers in Wisconsin and upper Midwest.
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The Wisconsin River and its Watershed
Length 690 km Watershed 31,440 km2 Drop 328
m Wide floodplain 26 mainstem dams
0 257 km
(Martin 1965)
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Changes in the Landscape

• Settlement profoundly changed the landscape
• Butthe amount, persistence, and increase in
  forest during 20th C is striking!
• Forest now occupies gt50 of the floodplain and is
  well connected
• Forest even more prevalent along the river
  edge (77-89 in the 1990s)

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Flow Modification and Tree Recruitment

• Seedling recruitment limited by summer pulses
  and spring peak flows
• Flow regulation may have enhanced tree seedling
  recruitment

Overwinter Seedling Survival
(Dixon 2003)
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2. Floodplain Forests
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• What factors explain the occurrence patterns of
  invasive shrubs?

Lonicera spp. (Honeysuckle)
Zanthoxylem americanum (Prickly ash)
Rhamnus cathartica (European buckthorn, exotic)