Individual and interactive effects of white-tailed deer and an exotic shrub on artificial and natural regeneration in mixed hardwood forests.
Level 5 - mechanism / opinion, no new human data
Non-human ecological field experiment
PubMed 28721187 · doi:10.1093/aobpla/plx024
What was done
Researchers conducted a field experiment across five forest sites using deer exclosures and removal of the invasive shrub *Lonicera maackii*. They evaluated the individual and interactive impacts of white-tailed deer (*Odocoileus virginianus*) and *L. maackii* on underplanted seedlings of American chestnut (*Castanea dentata*) and northern red oak (*Quercus rubra*), as well as on the composition, species richness, and diversity of naturally regenerating native tree seedlings.
What was found
The abstract does not report numerical values or effect sizes. Qualitatively, both deer browsing and *L. maackii* presence individually reduced underplanted seedling survival, with no interactive effects identified. *Lonicera maackii* or deer presence alone caused similar survival declines in *Q. rubra*, whereas deer presence alone caused lower survival in *C. dentata* than *L. maackii* alone. *Lonicera maackii* reduced light levels, increased moisture stress, and decreased relative basal diameter growth in *Q. rubra*. Deer reduced relative height growth in both species and increased moisture stress in *C. dentata*. Neither factor significantly affected soil/foliar nitrogen or overall seedling abundance, richness, or diversity, but both shifted composition toward shade-tolerant and unpalatable or browse-tolerant species.
Why it matters
This study shows that invasive shrubs and ungulate browsing independently impede hardwood forest restoration through distinct physiological and physical mechanisms, indicating both pressures must be managed simultaneously.
Limits
The study is limited to five sites and the abstract omits exact sample sizes (number of seedlings), numerical data, confidence intervals, and p-values. Long-term recruitment into the overstory canopy was not assessed.
Cited by
- supports High deer population densities cause significant ecological damage to woodlands in the Midwestern United States.