The influence of mountain laurel on regeneration in pitch pine canopy gaps of the Coweeta Basin, North Carolina, U.S.A.

Abstract

Because of its dense nature, mountain laurel (Kalmialatifolia L.) understories may be retarding the regeneration of xeric pitch pine (Pinusrigida Mill.) sites in the southern Appalachians and thereby influencing successional dynamics. This study examined the impact of the laurel understory on hardwood successional ecology in living pitch pine stands and pine gaps at their upper and lower elevational distribution. The laurel understory was physically removed from half the plots; the remaining plots served as a control. The plots were inventoried and all seedlings were tagged and measured to determine importance values, recruitment, survivorship, and biomass for 2 years following treatment. The results indicate that the presence or absence of the laurel understory does not affect initial seedling recruitment, survivorship, or their relative competitiveness. However, mountain laurel does suppress growth of smaller seedlings. Given the higher importance value, recruitment, and survivorship of red maple (Acerrubrum L.), the regeneration layer in these pitch pine sites is currently dominated by red maple, with scarlet oak (Quercuscoccinea Muenchh.) and other xeric-site hardwoods as associates. With the adaptive ability of red maple to take advantage of openings, red maple will continue to dominate and ultimately regenerate these communities with other hardwoods as minor associates.