| No roots of live oak (Qurecus virginiana) or sycamore (Platanus
occidentalis) went through BiobarrierTM during a 3-year period after planting.
Most roots on both species without a barrier were located in the top 30
cm (12 in) of soil, and root number decreased with increasing soil depth.
Roots were located at deeper soil depths beyond the Biobarrier. The roots
15cm (6 in) from the Biobarrier were mostly 30 to 45 cm (12-18 in) below
the soil surface. Eighty percent of oak roots and 72% of sycamore roots
greater than 3 mm in diameter 0.9 m (3 ft) from the trunk without a barrier
were in the top 30 cm (12 in) of soil, whereas, only 42% (oak) and 38% (sycamore)
of roots were in the top 30 cm (12 in) for trees with the root barrier.
Biobarrier forced roots deeper in the soil but in the high water table in
this study, many roots returned to the soil surface by the time they had
grown 1.2 m (4 ft) away from the barrier. |