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Go over exams (~20 minutes) Discuss guest speaker (5 minutes) Prairie/savanna restoration Wednesday – guest speaker, and we will discuss logistics for next two field trips; next week discuss brief article critique assignments. Mean = 85%. Sandy, glacial lake plain soils.
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Go over exams (~20 minutes) • Discuss guest speaker (5 minutes) • Prairie/savanna restoration • Wednesday – guest speaker, and we will discuss logistics for next two field trips; next week discuss brief article critique assignments
Sandy, glacial lake plain soils Eastern prickly pear cactus Opuntia humifusa
Oak Savanna1 4-43 trees ha-1 black/white oak 51% land area 1Brewer, L.G., and J.L. Vankat. 2001. The vegetation of the Oak Openings of northwestern Ohio at the time of Euro-American settlement. Map and text. Ohio Biological Survey, Columbus, Ohio.
Oak Woodland >43 trees ha-1 black/white oak 23% land area
Wet prairie 0-1 trees ha-1 27% land area
Ecosystem Changes 1860s-Present • Fire suppression • Livestock Grazing • Logging of oaks • Drainage alterations • Conversion to pine plantations • Agricultural clearing, urban development
Red maple: 600 trees ha-1 Black cherry: 80 trees ha-1 Oaks: 180 trees ha-1 (41o33'00"N, 83o52'00"W)
Red maple: 480 trees ha-1 Black cherry: 80 trees ha-1 Oaks: 0 trees ha-1 (41o33'00"N, 83o51'15"W)
Karner blue butterfly http://www.wbu.com/chipperwoods/photos/karner.htm
1984-2003 land cover change Purple = residential
0.02% of original oak savanna remains Nuzzo, V.A. 1986. Extent and status of Midwest oak savanna: presettlement and 1985. Natural Areas Journal 6:6-36.
RESTORATION OBJECTIVES • Reverse trend of ecosystem decline by reestablishing historical tree structure and reintroducing approximate historical disturbance regime to the contemporary degraded ecosystems • Specifically, to reestablish oak savanna, oak woodland, and wet prairie ecosystems in areas where they historically occurred but do not presently occur
How to do this? (a) Determine reference conditions – U.S. govt. land surveys, old trees, remnants, fire scars where possible (b) Choose sites – potential for ER; large oaks, block drainage ditches, soil survey (c) Prescribe treatments (fire, thinning)
Pre-treatment September 1998 Post-treatment July 2002 (41o32'45"N, 83o51'15"W)
Pre-treatment September 1998 (41o32'50"N, 83o51'15"W) Post-treatment July 2002
24 restoration plots: 298 total species, 19 Ohio listed
Post-treatment (2002) * Denotes significant difference at P< 0.05 (paired t-test) Error bars represent 1 standard deviation
Meadowsweet Restoration Wet Prairie Wild lupine Restoration Savanna
It’s not all rosy, • Exotic species not always, but often, problems • Fire timing not consistent with reference • Unclear if missing certain species • Small sizes • Success of Karner blue reintroduction • Use of land?
Species richness (mean 1 SD) LawnNative Plant Area 1.3 0.6 9.7 2.1 t = 9.4; P < 0.01