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Northern Research Station
One Gifford Pinchot Drive
Madison, WI 53726
(608) 231-9318
(608) 231-9544 TTY/TDD

Sustaining Forests

Plant Diversity in Managed Forests

[photo:] Redring milkweed (Asclepias variegata), growing in an Ohio mixed-oak forest after repeated prescribed fires.Research Issue

The great majority of plant diversity in forests is contained in the herbaceous layer, comprised of both herbaceous and woody species.  We seek a better understanding of how forest management activities affect plant diversity.  NRS-2 scientists are investigating the direct and indirect effects of timber harvesting, prescribed burning, herbicide application, and deer browsing (alone and in combination) on plant composition and diversity in mixed oak, Allegheny, and Northern Hardwood forests. 


Our Research

Ongoing studies include:

  • Effects of operational herbicide treatments on plant diversity, seed banks, and regeneration in Allegheny Hardwood forests. Principal investigator: Todd Ristau
  • Interactive effects of fire, gaps, and deer browsing on herbaceous diversity. Principal investigator: Alejandro Royo
  • Herbaceous plant abundance, diversity, and demography in response to landscape-scale reduction of deer densities. Principal investigator: Alejandro Royo
  • Effects of fire and fire surrogate treatments on plant composition and diversity in mixed-oak forests. Principal investigator: Todd Hutchinson
  • Response of herbaceous communities in forests impacted by Emerald Ash Borer (EAB). Principal investigators: Kathleen Knight, Robert Long, Alejandro Royo, Todd Hutchinson.

Expected Outcomes

These studies will improve the scientific knowledge of how plant diversity is affected by various forest management practices.  Ultimately, this knowledge can be used by managers to develop prescriptions which include the sustaining or enhancing of plant diversity as an objective.

Royo, A.A., Collins, R., Adams, M.B., Kirschbaum, C., and Carson, W.P.  In press. An experimental test of the major causes of herbaceous understory dynamics in eastern deciduous forests.  Ecology. 

Research Results

Selected Publications:  Plant Diversity in Managed Forests

Horsley, S.B., Bailey, S.W., Ristau, T.E., Long, R.P., and Hallett, R.A.  2008.  Linking environmental gradients, species composition, and vegetation indicators of sugar maple health in the northeastern United States.  Canadian Journal of Forest Research 38:1761-1774.

Royo, A.A., and Carson, W.P.  2008.  Direct and indirect effects of a dense understory on tree seedling recruitment in temperate forests:  habitat-mediated predation versus competition.  Canadian Journal of Forest Research 38:1634-1645.

Phillips, R., Hutchinson, T., Brudnak, L., and Waldrop, T.  2007.  Fire and fire surrogate treatments in mixed-oak forests:  effects on herbaceous layer vegetation.  In Butler, B.W. and Cook, W.,compilers. The fire environment - innovations, management, and policy; conferenence proceedings.  USDA Forest Service Proceedings RMRS-P46-CD.  pp. 475-485.

Hutchinson, T.F.  2006.  Fire and the herbaceous layer of eastern oak forestsIn Dickinson, M.B., Editor.  Fire in eastern oak forests: delivering science to land managers.  USDA Forest Service GTR-NRS-P-1.  pp. 136-149.

Royo, A.A., and Carson, W.P.  2006.  On the formation of dense understory layers in forests worldwide:  consequences and implications for forest dynamics, biodiversity, and succession.  Canadian Journal of Forest Research 36:1345-1362.

Comisky, L., Royo, A.A., and Carson, W.P.  2005.  Deer browsing creates rock refugia gardens on large boulders in the Allegheny National Forest, Pennsylvania.  American Midland Naturalist 154:201-206.

Hutchinson, T.F., Boerner, R.E.J., Sutherland, S., Sutherland E.K., Ortt, M., and Iverson, L.R.  2005.  Prescribed fire effects on the herbaceous layer of mixed-oak forests.  Canadian Journal of Forest Research 35:877-890.

Ristau, T.E., and Horsley, S.B.  2001.  Sampling to assess species diversity of herbaceous layer vegetation in Allegheny hardwood forests.  Journal of the Torrey Botanical Society 128:150-164.

Hutchinson, T.F., Boerner, R.E.J., Iverson, L.R. , Sutherland, S., and  Sutherland, E.K.  1999.  Landscape patterns of understory composition and richness across a moisture and nitrogen mineralization gradient in Ohio (U.S.A.) Quercus forests.  Plant Ecology 144:179-189.

Research Participants

Principal Investigators

  • Todd Hutchinson, USDA-Forest Service- Northern Research Station Research Ecologist
  • Todd Ristau, USDA-Forest Service- Northern Research Station Research Ecologist
  • Alejandro Royo, USDA-Forest Service- Northern Research Station Research Ecologist

Research Partners

  • Kathleen Knight, USDA-Forest Service- Northern Research Station Research Ecologist
  • Robert Long, USDA-Forest Service- Northern Research Station Research Plant Pathologist
  • Susan Stout, USDA-Forest Service- Northern Research Station Research Project Leader and Silviculturist
  • Walter Carson, University of Pittsburgh
  • Dave DeCalesta, USDA-Forest Service, retired
  • Tim Pierson, Penn State Cooperative Extension

Last Modified: 01/25/2010