Article Figures & Data
Figures
- Figure 1.
Five types of water-conducting systems in various conifers as shown by the tracheidal channels that were dyed by trunk injection. The numbers give the height in centimeters of the transverse section above injection. A. Spiral ascent, turning right: Abies, Picea, Larix, and Pinus (Rehder’s section 3: Taeda). B. Spiral ascent turning left: Pinus (Section 2: Cembra). C. Interlocked ascent: Sequoia, Libocedrus and Juniperus. D. Sectorial, winding ascent: Tsuga and Pseudotsuga. E. Sectorial, straight ascent: Thuja and Chamaecyparis. From Rudinski and Vite 1959, Courtesy of Boyce Thompson Institute for Plant Research. Oaks and many ring porous species have a pattern similar to E.
- Figure 2.
Plan view diagram of the horizontal woody root system developed from a single lateral root of red maple about 60 years old. Solid circles show the location of other trees in the stand. Arrows indicate that the root tips were not found and therefore these roots continue somewhat farther than is shown. (From Lyford and Wilson 1964).
- Figure 4.
Drawing, not to scale, of framework system of longleaf pine tree grown in well drained soils with a second layer of roots running in the soil layers where oxygen supplies become limiting.
- Figure 5.
(Upper) Photograph of framework roots of longleaf pine including striker roots. 90% of the surface root system has rotted and washed away (Kerr Lake, Corps of Engineers, North Carolina). (Lower) Roots of loblolly bay tree Persea borbonia L. One of hundreds of trees of various species exposed by beach erosion associated with Hurricane David — Seabrook Island, S.C. All specimens show a two layered root system — see figures 2-4 and 2-5.
- Figure 6.
Mat of roots above the permanent water table exposed by digging a drainage canal. Green Swamp, North Carolina. A few species have specialized tissues containing air passages and specialized metabolisms that permit their roots to penetrate several feet below the permanent water table where there is inherently little or no oxygen. Iron oxide depoits are typically associated with such roots.
- Figure 3.
Schematic diagram showing reoccupation of soil area near the base of a mature tree by the growth of adventitious roots. 1. Root fans growing from the younger portions of the woody roots which have extended to a distance of several meters from tree. 2. Root fans on adventitious roots only recently emerged from the zone of rapid taper or root collar and now occupying the area near the base of the tree. 3. Vertical roots. (From Lyford and Wilson 1964).
- Figure 7.
Schematic diagram showing woody and non-woody root relationships. 1. Stem. 2. Adventitious roots in the zone of rapid taper. 3. Lateral root. 4. Non-woody root fans growing from opposite sides of the rope-like woody root. 5. Tip of woody root and emerging first order non-woody roots. 6. Second and higher order non-woody roots growing from the first order non-woody root. 7. Uninfected tip of second order non-woody root with root hairs. 8. Third order non-woody root with single bead-shaped mycorrhizae. 9. Fourth order non-woody root with single and necklace-beaded mycorrhizae. The horizontal bar beneath each root section represents a distance of about 1 cm. (Lyford and Wilson 1964).
- Figure 8.
Scale diagrams of a horizontal woody third order lateral with particular emphasis on the roots that return to the surface and elaborate into many small diameter non-woody roots in the forest floor. Top view (above), side view (below). The squares are 1 m on a side. Species: rěd oak (Quercus rubra L). From Lyford 1980.
- Figure 9.
Photograph of roots intermingling in the soil. Mixed hardwood stand. Harvard Forest, Petersham, Mass. The roots in front of the trowel have been exposed by careful brushing and pulling away of the litter. Many hours were required. The roots in the background were exposed by digging down and destroying the fine surface roots in the process. The roots have been sprayed with whitewash to make them stand out. Lyford’s work. Photo by Perry.
- Figure 10.
Photograph of root tips growing in the litter of a mixed hardwood forest. The mycorrhizae extend out from the root tips to greatly expand the functional surface area of the roots. Photo by Ted Shear, NCSU. Root diameters about 0.5 mm.
- Figure 11.
Roots growing in crevices of bricks. There was no oxygen below the bricks which overlie a compact clay on the N.C. State University Campus. Tree roots commonly follow cracks and crevices or air passages under pavement.
- Figure 12.
Roots do not grow as this artist’s conception indicates. Inaccurate illustrations like this one have led to harmful practices in the management of trees in both forest and urban situations. Illustration from a brochure of the Society of American Foresters.
- Figure 13.
Scale drawing of Memorial Oak Tree, Schenck Forest, North Carolina State University. The original drawing was made by tracing the projected image of the tree (Figure 14) onto a piece of 8.5″ × 11″ paper. A #2 Rapidograph pen point was used to produce a line 0.4 mm thick. This is the thinest line that can be reasonably reproduced in publications. The original drawing was 24 cm or 9.45″ wide and represents a typical root spread of 212 ft. The Schenck Oak is ±106′ tall and is represented on the vertical axis as 12 cm or 4.72″. The original drawing represented a 274 fold reduction in the actual height of the tree. Further reduction would be required to represent the tree on a normal textbook page. Most branches and tree roots would not be visible if drawn to this scale. The width of a typical white oak leaf would be about the thickness of the lines in the drawing. Ninety percent of the tree roots would not be visible at this scale. Most of the roots of the tree would be located in the soil layer represented by the thickness of the line representing the soil surface. The dash dot line is located 5’ below the surface and very few if any roots would penetrate beyond this depth in a representative soil.
- Figure 14.
This photograph of the Schenck Memorial Oak was projected and traced to produce Figure 13. The Schenck Memorial Oak is 106′ tall and has a crown spread of 94 ft. and a dbh of 42″. The tree is a white oak.
- Figure 15.
Many roots of trees grow closely intermingled with grass roots — right in the surface millimeters of a lawn. Fertilizers and herbicides do not have to move in the soil in order to affect trees.
