TITLE:
Regeneration Responses in Partially-Harvested Riparian Management Zones in Northern Minnesota
AUTHORS:
Douglas N. Kastendick, Brian J. Palik, Eric K. Zenner, Randy K. Kolka, Charles R. Blinn, Joshua J. Kragthorpe
KEYWORDS:
Riparian Management, Overstory Retention, Regeneration, RMZ, Riparian Forest
JOURNAL NAME:
Journal of Water Resource and Protection,
Vol.6 No.6,
April
28,
2014
ABSTRACT:
Trees
serve important functions in riparian areas. Guidelines often suggest how
riparian forests should be managed to sustain functions, including tree
retention and increasing the component of conifers and later-successional
species. While regeneration of early successional species is not discouraged,
there is uncertainty about the ability to regenerate the latter along with more
desirable species. We investigated the regeneration of species differing in
successional status and growth forms under different amounts of residual basal
area. The study was conducted in riparian sites in northern Minnesota USA. At
each site, one portion of the riparian area was uncut, while a downstream area
was harvested to 16 or 8 m2·ha-1. Woody vegetation was
sampled before and five-years after harvesting and summarized as early, mid-,
and late successional hardwoods, as well as conifers and shrubs. After five
years, the density of early successional trees was lower at 16 m2·ha-1 compared to 8 m2·ha-1; densities in both treatments were
lower than in clearcuts. Densities of mid- and late successional hardwoods and
conifers did not increase in either treatment. The higher basal area treatment
resulted in a lower density of shrubs, which might be important for establishing
more desirable tree species, although this may require additional activities to
promote establishment.