We can't know what silvicultural prescriptions to apply until we know how those activities will affect desired ecosystem services

Small-Scale Structural Complexity

Small-scale structural complexity - SpruceWhat characteristics can be used to predict changes in small-scale structural complexity in managed stands? These projects used long-term monitoring data from southern Finland and Switzerland to explore which structures best explained the SCI in stands managed to create and sustain even- and uneven-size structures.


  • Zenner, E.K. 2016. Differential growth response to increasing growing stock and structural complexity in even- and uneven-sized mixed Picea abies stands in southern Finland. Canadian Journal of Forest Research 46:1195-1204.
  • Peck, J.E., E.K. Zenner, P. Brang, and A. Zingg. 2014. Tree size distribution and abundance explain structural complexity differentially within stands of even- and uneven-aged structure types. European Journal of Forest Research 133:335-346.
  • Zenner, E.K., J.E. Peck, E. Lähde, and O. Laiho. 2012. Decomposing small-scale structural complexity in even- and uneven-sized Norway spruce dominated forests in southern Finland. Forestry 85(1):41-49.

Harvest Impacts

Harvest impactWhat are the immediate impacts of timber harvesting activities on the ground and its flora? One project in the long-term Missouri Ozarks Forest Ecosystem Project (MOFEP) found short-term changes in the ground flora after the first wave of harvest entries. How fast does heavy equipment compact the soil and does it matter? Another project correlated re-vegetation following harvest with the number of times equipment was driven over a given spot (recorded using GPS). Yet others have explored the effects of harvesting traffic in the Carpathian Mountains. Sure enough, it doesn't take too many passes to compact the soil. Suckering species like aspen don't seem to mind, but herbs sure do.


  • Naghdi, R., A. Solgi, E.K. Zenner, and F. Keivan Behjou. 2018. Soil physical properties degrade further on skid trails in the year following the termination of skidding operations. Journal of Forestry Research 29(1):93-101.
  • Masumian, A., R. Naghdi, R., E.K. Zenner, M. Nikooy, and M. Lotfalian. 2017. Comparison of different erosion control techniques in the Hyrcanian forest in northern Iran. Journal of Forest Science 63(12):549-554.
  • Naghdi, R., A. Solgi, E.K. Zenner, A. Najafi, A. Salehi, and M. Nikooy. 2017. Compaction of forest soils with heavy logging machinery. Silva Balcanica 18(1):25-39.
  • Masumian, A., R. Naghdi, and E.K. Zenner. 2017. Effectiveness of water diversion and erosion control structures on skid trails following timber harvesting. Ecological Engineering 105:370-378
  • Masumian, A., Naghdi, R., and E.K. Zenner. 2017. Effectiveness of water diversion and erosion control structures on skid trails following timber harvesting. Ecological Engineering, 105:370-378.
  • Nahgdi, R., A. Solgi, E.R. Labelle, and E.K. Zenner. 2016. Influence of ground-based skidding on physical and chemical properties of forest soils and their effects on maple seedling growth. European Journal of Forest Research, 135:949-962.
  • Jourgholami M, Khoramizadeh A, Zenner EK. 2016. Effects of soil compaction on seedling morphology, growth, and architecture of chestnut-leaved oak (Quercus castaneifolia C.A.M.) in greenhouse situations. iForest - Biogeosciences and Forestry 10(1):145-153.
  • Najafi, A., A. Solgi, and E.K. Zenner. 2015. Soil disturbances caused by different skidding methods in northern mountainous forests of Iran. International Journal of Forest Engineering, 26(3):212-224.
  • Jaafari, A., A. Najafi, and E.K. Zenner. 2014. Ground-based skidder traffic changes chemical soil properties in a mountainous Oriental beech (Fagus orientalis Lipsky) forest in Iran. Journal of Terramechanics 55:39-46.
  • Jourgholami, M., S. Soltanpour, A. Etehadi Abari, and E.K. Zenner. 2014. Influence of slope on physical soil disturbance due to farm tractor forwarding in a Hyrcanian forest of northern Iran. iForest - Biosciences and Forestry 7:342-348.
  • Sattar, E., A. Najafi, M.A. Rab, and E.K. Zenner. 2012. Recovery of bulk density, porosity and rutting from ground skidding over a 20-year period after timber harvesting in Iran. Silva Fennica, 46(4):521-538.
  • Zenner, E.K. and A.L. Berger. 2008. Influence of skidder traffic and canopy removal intensities on the ground flora in a clearcut-with-reserves northern hardwood stand in Minnesota, USA. Forest Ecology and Management 256:1785-1794.
  • Zenner, E.K., J. T. Fauskee, A.L. Berger, and K.J. Puettmann. 2007. Impacts of skidding traffic intensity on soil disturbance, soil recovery, and aspen regeneration in north-central Minnesota. Northern Journal of Applied Forestry 24:177-183.
  • Zenner, E.K., J.M. Kabrick, R.G. Jensen, J.E. Peck, and J.K. Grabner. 2006. Responses of ground flora to a gradient of harvest intensity in the Missouri Ozarks. Forest Ecology and Management 222:326-334.