Application. Root deformations, such as j-rooting, have long been considered detrimental to forest seedling growth. Based on the results of this study, j-rooting will not result in water stress or lead to reductions in growth three years after planting. Tree planters need to be concerned with planting seedlings quickly and at the correct depth. Instructing planters to avoid j-roots by pulling back up on the seedlings when they are placed in the bottom of planting hole may do more damage than good since the end result could be shallower root placement.Abstract. The effects of j-rooting on water stress and growth of loblolly (Pinus taeda L.) and eastern white pine (Pinus strobus L.) were examined over three growing seasons in the field. Seedlings were planted in an area with severe herbaceous competition with either their roots planted straight or bent into a j shape. All seedlings were planted with their root collars placed at the soil surface. During the first year j-rooted seedlings consistently had lower water potentials but never statistically significant. Since both treatments were planted with the root collar at the soil surface, this trend was likely due to an initial shallower root system in j-rooted seedlings. In year three no differences in water potential were significant and no trends were evident. Growth did not differ significantly by treatment at any time but, by year three, j-rooted plants were consistently larger for both species.

Loblolly pine (Pinus taeda L.) seedlings were grown in sand culture and exposed to solution A1 concentrations of 0, 5, 10, 20, 40, and 80 mg.I-1 in two separate studies. Root regeneration potential (RRP) of loblolly pine was found to be very sensitive to A1. Both the total number and total length of new white roots produced during a 24-day period declined with as little as 5 mg AI.1-~ in solution.

Soils from red spruce (Picea rubens Sarg.) and loblolly pine (Pinus taeda L.) stands were amended with either 0, 150, 300, 600 or 1200 mg/kg Pb as PbCl2. Six-month-old spruce and six-week-old pine seedlings were planted in their respective native soils and treated for 19 weeks with simulated rain of either pH 4.5 or 3.0. Rain was applied directly to the soil at a rate of 1.5 cm per week. Net photosynthesis, height, and needle, shoot, and root dry weights were measured at the completion of the experiment. In both soils, pH decreased and nitrate concentration increased with the application of a simulated rain solution of pH 3.0. Despite these changes in soil chemistry, simulated rain pH had no significant effect on the growth of either species. Red spruce photosynthesis was 35% higher; however, at a pH of 3.0. Loblolly pine photosynthesis was not affected by solution pH. Growth and photosynthesis of red spruce were inhibited even at the 150 mg/kg Pb level, with additional Pb resulting in increasing inhibition. Growth of loblolly pine seedlings was less sensitive to Pb, and decreased only at the higher concentrations. Loblolly pine photosynthesis exhibited no decline even at the highest Pb level. These results suggest that both red spruce and loblolly pine are more sensitive to soil Pb than to acid precipitation. In addition, loblolly pine appears to be more tolerant of Pb than red spruce, when both species are grown in their respective native soils. For. Sci. 33(3):668-675.

Rehydration characteristics of cut eastern white pine (Pinus strobus L.) and Norway spruce [Picea abies (L.) Karst.] Christmas trees were evaluated over a wide range of xylem water potentials and storage periods. Cut pines failed to rehydrate fully when initial xylem water potential was less than –3.00 MPa. Norway spruce trees completely rehydrated at xylem water potentials as low as –3.50 MPa, with partial rehydration occurring below –4.0 MPa. Twig water content closely paralleled xylem water potential. All sample trees rehydrated fully when outdoor storage periods were < 6 weeks during the months of December and January.