Distribution of Dry Mass Between Shoot and Root in Nine Understory Species

Abstract

Relationships between shoot and root masses were examined in nine peren- nial species native to coniferous forest understories in the northwest United States. Seedlings were grown in a greenhouse under either sun or shade (35% of full sun) for 35 days, then were harvested. Plants of Smilacina racemosa and S. stellata were grown from rhizomes in an experimental garden for three years, then harvested, dried and weighed. All species showed significant linear relationships between natural logarithms of shoot and root dry mass, although the relationships were less pronounced,in seedlings of three hypogeous species. Slopes were similar among six of the species; the intercepts ranged from -1.49 to 1.98. Shading affected allometric relationships in Disporum trachycarpum, Rosa gymnocarpa and Smilacina stellata. Slopes were similar between three-year-old Smilacina plants and Smilacina seedlings. In general, the relationships between shoot and root mass in seedlings of the nine species were described by the allometric equation