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Terreslriiit Ecosysleins — Oitr Ll\iiig Rtsoificcs 



For further information: 



Richard A. Henderson 



Wisconsin Department of Natural 



Resources 



Bureau of Research 



1350FemriteDr. 

 Monona, Wl 53716 



let alone their current status. Some reliable sta- 

 tus information does exist for savanna 

 Lepidoptera (moths and butterflies), however; 

 of this group, the Karner blue butterfly 

 (Lycaeides melissa sanmclis) is listed as feder- 

 ally endangered while phlox flower moths 

 iScliinia imlkma) and tawny crescent butterflies 

 (Phyciodes batesii) are under consideration for 

 federal listing. The frosted elfin butterfly 

 iliicisalia ini.s) is listed as threatened in 

 Wisconsin, and four savanna skippers (Eiynnl.s 

 persius, Hesperia leonanhis. H. meteci. and 

 Atrytonopsis hianiui) and the buck moth 

 {Hemileitca maia) are considered rare in the 

 state. Other globally rare insects thought to have 

 been part of the oak savanna ecosystem include 

 the federally listed American burying beetle 

 (Nicrophonis amehcamis) and the red-tailed 

 leafliopper [Aflexia ndvauum). which is under 

 consideration for federal listing. 



Threats 



Threats to the future survival of oak savanna 

 throughout its range can be summarized into 

 four categories. The first, loss of recovery 

 opportunities, can be attributed to accelerating 

 succession to tree and shrub species that pro- 

 duce dense shade; a lack of recruitment and 

 eventual death of long-lived plants surviving 

 now only in suboptimal habitat; changes in pas- 

 turing practices through either increasing or 

 decreasing grazing pressure; and an increasing 

 rate of rural home building in key savanna 

 areas. The second threat is lack of understand- 

 ing about the community by the public, profes- 

 sional resource managers, and scientists. 

 Resistance to the use of prescribed fire, espe- 

 cially in wooded areas, and lack of understand- 

 ing about the importance of fire in maintaining 

 biodiversity are the third threat; invasion by 

 aggressive non-natives (i.e., honeysuckle, buck- 

 thorn, and reed canary grass) is the fourth. 



Recovery Potential 



In the absence of active management, the 

 future of oak savanna looks bleak in Wisconsin 

 and throughout its entire range. The increasing 

 abandonment of lightly to moderately grazed 

 wooded pastures and the accelerating succes- 

 sion of oak woodlots toward heavy shade-pro- 

 ducing trees and shrubs are likely to lead to the 

 further decline and possible loss of much of the 

 remaining savanna flora and fauna, including 

 eventual declines of the oaks themselves. 



If oak savanna habitats are actively man- 

 aged, however, their recovery potential in 

 Wisconsin and throughout their range is sub- 

 stantial (Holtz 1985; Bronny 1989; R.A. 

 Henderson, Wisconsin Department of Natural 

 Resources, unpublished data). Many degraded 

 sites in the dry and wet ends of the spectrum can 

 be recovered with relative ease. Mesic, richer 

 soil savannas will take more time and work, but 

 recovery is still feasible. The native species that 

 formerly inhabited oak savannas can be reintro- 

 duced with a reasonable amount of effort 

 (Packard 1988), but the options available are 

 quickly decreasing. 



In Wisconsin alone, hundreds if not thou- 

 sands of hectares of overgrown but still retriev- 

 able oak savanna exist on public lands and thou- 

 sands more on private lands. Although 

 Wisconsin may be above average in potential 

 for savanna recovery, similar situations exist in 

 other states. Much of this land, especially low 

 productivity sites, could be restored within a 

 few decades simply by thinning trees, brushing, 

 and burning. Well-drained, rich soil sites, how- 

 ever, will require more work and time to restore. 

 Some plant reintroductions may be necessary, 

 but much can be accomplished with fire alone. 

 Light grazing may also have potential as a 

 savanna management tool. 



References 



Barry. A.T., and R.A. Spicer. 1987. The evolution and 

 palaeobiology of land plants. Croom Helm. London. 309 

 pp. 



Bronny. C. 1989. One-two punch: grazing history and the 

 recovery potential of oak savanna. Restoration and 

 Management Notes 7(2):73-76. 



Curtis. J.T. 1959. The vegetation of Wisconsin. University 

 of Wisconsin Press, Madison. 657 pp. 



Holtz, S.L. 1985. Cutting and burning a degraded oak bar- 

 rens: management techniques that stimulate natural dis- 

 turbance. M.S. thesis. University of Wisconsin. Madison. 

 80 pp. 



Johnson. F.L. 1986. Oak-hickory savannahs and transition 

 zones: preservation status and management problems. 

 Pages 345-347 in D.L. Kulhavy and R.N. Conner, eds. 

 Wilderness and natural areas in the eastern United States: 

 a management challenge. Stephen F. Austin State 

 University. Nacogdoches, TX. 



Nuzzo, V.A. 1986. Extent and status of Midwest oak savan- 

 na: presetllement and 1985. Natural Areas Journal 

 6(2):6-36. 



Packard, S. 1988. Just a few oddball species: restoration and 

 the rediscovery of the tallgrass savanna. Restoration and 

 Management Notes 6(1): 13-20. 



Smeins. F.E.. and D.D. Diamond. 1986. Grasslands and 

 savannahs of east central Texas: ecology, preservation, 

 and management. Pages 381-394 in D.L. Kulhavy and 

 R.N. Conner, eds. Wilderness and natural areas in the 

 eastern United States: a management challenge. Stephen 

 F. Austin State University, Nacogdoches, TX. 



