Growth and intraspecific competitive abilities of the dioecious Lindera melissifolia (Lauraceae) in varied flooding regimes

HAWKINS, T. S., N. M. SCHIFF, T. D. LEININGER, E. S. GARDINER, M. S. DEVALL, P. B. HAMEL, A. D. WILSON, AND K. F. CONNOR (USDA Forest Service, Southern Research Station, Stoneville, MS 38776). Growth and intraspecific competitive abilities of the dioecious Lindera melissifolia (Lauraceae) in varied flooding regimes. J. Torrey Bot. Sec. 136: 91-101. 2009.-The contribution of sexual dimorphism to male-biased colony ratios observed in field populations of the federally endangered Lindera melissifolia was investigated. Growth characteristics and intraspecific relative competitive abilities were determined for first-year male and female L. melissifolia plants grown at varied densities and receiving three flooding treatments. In the no-flooding and 30-day-flooding treatments, stem height, stem diameter, and total leaf area for male plants were significantly greater than that of higher density male plantings and of female plants without respect to density. In both male and female plants, stem growth ceased and leaves were abscised in response to flooding. Although density effects in combination with hydrologic regime influenced intersexual competition, male-bias from competitive exclusion was not indicated. Growth characteristics for male plants grown alone suggest potential for greater interspecific competitive abilities than that of female plants. Therefore, male plants may be better adapted for colonizing suitable habitat, thus contributing to male-biased colony ratios observed in naturally occurring populations.