Circular distribution of various root system characteristics in the three discontinuous slope oriented sectors.

(1) For the 2nd order additional fine roots, the sector to which they belonged, with regard to slope orientation, was not recorded. Additional fine root number on the stump averaged 4.4 (80% of the number of larger roots) in the slope treatment and 3.9 (45% of the number of larger roots) in the slope+flexing treatment. These values reached 3, 36%, 4.8 and 67% for the number of 2nd order additional fine roots branching below the stump respectively.
“us” = upslope, “ds” = downslope, “pp” = discontinuous sector perpendicular to slope. For the “pp” sector, when the variable is a root volume, length or number, the value in the table and for the statistical analysis was divided by 2. P values (%) are from the mixed model test of fixed factor “sector;” “tree” is the random factor. Data not shown for control seedlings, or seedlings grown with flexing on a 0° slope, as no significant differences were found, except for root length in the shallow root compartment (P = 2.9%) in control trees. When the sector effect is significant, sectors with the same letter in superscript are not significantly different. Data for the deep root compartment were often not available (NA) because few trees had roots in this compartment.