Date of Award
Master of Science
Integrated Environmental Sciences
Mary E. Lehman, Ph.D.
Alix D. Fink, Ph.D.
Timothy W. Stewart, Ph.D.
I compared clearcutting and shelterwood harvesting effects on all understory vegetation (woody and nonwoody) in Piedmont hardwood forests. Clearcutting and shelterwood harvesting are both even.-aged management practices, put in contrast to clearcutting, the shelterwood method retains selected trees as partial canopy. The retained canopy is reported to be beneficial to desired tree species and restrict competition of undesired tree species, grasses and shrubs.·Research comparing the shelterwood method to clearcutting has been limited , particularly in hardwood forests. We collected data on understory plant communities in clearcut, low-leave shelterwood, and mature forest sites (not harvested in
at least 100 years). Percent coverage values for all plant species found in 10 randomly selected 4-m2 plots per treatment were estimated, and tree stems were counted and categorized by species and height. Environmental measures of canopy coverage, air
temperature, relative humidity , soil pH, and soil organic matter and nutrient content were also recorded . Analysis of data indicated that shelterwood and clearcut treatments were not significantly different regarding species richness, diversity, total vegetation coverage, understory species composition and many environmental measures. Species richness, diversity and total vegetation coverage were significantly greater for both harvesting methods compared to mature forest sites. Understory species composition was also different for harvested treatment s compared to the mature forest treatment. Harvested treatments were also different from the mature forest treatment in terms of greater light transmission to understory vegetation (indicated by lower canopy coverage), greater temperature variation, and greater concentrations of two macronutrient s (Ca and Mg). Number of tree stems was greatest for shelterwood, followed by clearcut, then mature forest treatments. Number of oak stems was greater for the shelterwood method than the clearcut method, but competition from undesirable species, such as Liriodendron tulipifera, was significantly greater for both clearcut and shelterwood methods than for the mature forest treatment (indicating that alternative harvesting methods or additional treatments following harvest may be necessary to limit competition and increase success of oak regeneration).
Hartman, Lorelei J., "A Comparison of Clearcut and Shelterwood Harvesting Effects on Understory Vegetation in Central Virginia Piedmont Forests" (2003). Theses, Dissertations & Honors Papers. 117.