The Wisconsin River has played a pivotal role in Wisconsin’s history…
The Wisconsin River-Now
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.
The Wisconsin River and its Watershed Length: 690 km Watershed: 31,440 km2 Drop: 328 m Wide floodplain 26 mainstem dams This research is part of a larger study investigating the potential effects of historical land use and spatial patterning on current floodplain ecosystem processes within the 100yr floodplain of the lower Wisconsin River. Read stats on Wisconsin River Watershed (?) Our study region is the Wisconsin River watershed, but we focus on landscape within the 100yr floodplain The two reaches shown are what I’ll use to answer my research questions for this talk 0 257 km (Martin 1965)
Changes in the Landscape Settlement profoundly changed the landscape But…the amount, persistence, and increase in forest during 20th C is striking! Forest now occupies >50% of the floodplain and is well connected Forest even more prevalent along the river edge (77-89% in the 1990s)
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)
2. Floodplain Forests
What factors explain the occurrence patterns of invasive shrubs? Lonicera spp. (Honeysuckle) Zanthoxylem americanum (Prickly ash) Rhamnus cathartica (European buckthorn, exotic)