Document: KAO-3-31-22

Effects of ontogeny and shading on carbon allocation to storage in seedlings of Ardisia crenata, a shade tolerant non-native shrub.

KITAJIMA, K.* and M.DOOLEY

University of Florida, FL 32611 ¹

Abstract:
Ardisia crenata (Myrsinaceae), an evergreen shade-tolerant shrub species introduced from Asia, is successfully invading the understories of closed mixed forests in North-Central Florida, often creating a dense monodominant understory. Seedlings of A. crenata can survive under leaf litters and exhibit a high resprouting ability. Ecophysiological basis of seedling shade tolerance of A. crenata was examined in terms of whole-plant carbon allocation patterns for 1-6 months old seedlings in a green house. A. crenata seedlings exhibited a high degree of self shading, which resulted in a low efficiency of light interception and daily photosynthetic income per unit leaf area. Concentration of total non-structural carbohydrates (TNC) was high in roots and stems of 2 months old seedlings raised from seeds under 4 % of full sun (44% and 22 % of dry mass, respectively) and higher than similar-sized seedlings collected in the forest understory. Greenhouse seedlings subsequently transferred to 24 % and 2 % of full sun exhibited typical whole-plant acclimation responses and ontogenetic shifts, and differed in relative growth rates (26 and 18 mg/g/day, respectively) and TNC concentration in tap roots (48% and 30 % of root mass, respectively, at 6 months after germination). High carbon allocation to storage appears important for survival and maintenance of slow growth of A. crenata, while its architecture of shading itself and neighbors enhances its competitive potential in the shaded understory.

Keywords: seedling shade tolerance, plant invasion, carbon balance, seedling growth, ontogeny

This abstract is being presented at: 10:45 AM in session:
Oral Session #1: Plant Carbon Allocation.