© 1992 Heron Publishing—Victoria, Canada
Leaf water status and root system water flux of shortleaf pine (Pinus echinata Mill.) seedlings in relation to new root growth after transplanting
John C. Brissette (1) and Jim L. Chambers (2)
1. USDA Forest Service, Southern Forest Experiment Station, 2500 Shreveport Highway, Pineville, LA 71360, USA / 2. School of Forestry, Wildlife, and Fisheries, Louisiana Agricultural Experiment Station, Louisiana State University Agricultural
Center, Baton Rouge, LA 70803, USA / Received August 21, 1991
Summary
Water relations and root growth of shortleaf pine (Pinus echinata Mill.) were studied four weeks after seedlings from a half-sib family had been transplanted to one of three regimes of soil
water availability at a root zone temperature of either 15 or 20 °C. About one-third of the variation in new root growth was
explained by the root zone environment. The interaction between root zone temperature and soil water availability accounted
for 10% of the variation in new root growth. In the most favorable root environment, new roots averaged 620 mm2 of projected surface area. Leaf water potential increased exponentially with new root projected surface area, becoming constant
at about 300 mm2. Leaf conductance and root system water flux increased linearly with new root growth.
