PARENT SESSION
Poster Session # 14: Forest Ecology.

Wednesday, August 6 Presentation from 5:00 PM to 6:30 PM. SITCC Exhibit Hall B.

Age class distribution of a virgin shortleaf pine stand.

Bragg, Don^*,1, Heitzman, Eric², Guldin, James³, ¹ USDA Forest Service, Monticello, AR, USA² University of Arkansas-Monticello, Monticello, AR, USA³ USDA Forest Service, Hot Springs, AR, USA

ABSTRACT- A recently uncovered set of shortleaf pine (Pinus echinata Mill.) increment cores from the Lake Winona Research Natural Area (LWRNA) in the Ouachita National Forest of Arkansas was assessed for age and increment. According to the core sample, this uneven-aged virgin stand contains shortleaf pine that date back to the mid-1700s, although most individual trees are less than 130 years old. Several prominent spikes in decadel representation suggest major recruitment events occurred in the 1870s to 1890s and again in the 1920s, possibly arising from disturbances related to the exploitation and settlement of the Ouachita Mountains. Canopy recruitment declined dramatically from 1930 to 1990 (with very few shortleaf pine originating after 1950), corresponding to the implementation of effective fire control in this region. Since shortleaf pine responds well to frequent burning and most hardwoods do not, the loss of fire from the LWRNA has contributed to the virtual cessation of pine establishment and the development of a prominent oak, hickory, maple, and gum midstory. Additionally, small-scale lightning, wind, insect, and disease events continue to claim old overstory shortleaf without much potential for their replacement. The LWRNA, created to preserve a rare old-growth shortleaf pine remnant, stands to gradually lose its pine component and become a hardwood-dominated forest if major natural disturbances like fire continue to be excluded.

Key words: old-growth, Pinus echinata, Ouachita Mountains, disturbance ecology