Call me Pharaoh, that answers everything.
You want more? Here ya go.
With the original roots deprived of oxygen, water and nutrients, and the adventitious roots competing with turfgrass, the growing trees could not get the resources they needed to live. Across Stroud Street from this site, one pine tree in the middle of a grove of pine trees is turning brown. It is the only one with a noticeably crooked trunk. After removing mulch and soil from the stem we found a large root girdling over 50% of the trunk. No other signs of pests were seen. The disruption in circulation and buttress development from this stem-girdling root may be responsible for both the disfigurement and the death. This root condition also does not meet industry standards for growing or planting trees.
American National Standards Institute (ANSI) Z60.1 Nursery Standard 1.1.1.1: “…the soil line, which should be at or near the top of the root flare.” And 1.6.3: “…Soil above the root flare…should be removed.” And the ANSI A300 (Part 6) Transplanting Standard 63.6.2.3: “The bottom of the trunk flare *shall* be at or above the finished grade.” The original landscape plans that I viewed for the site made no reference to proper growing, inspection or planting practices. Instead, it contained substandard (and biologically irrelevant) “root*ball* to grade” language. It appears that these trees were grown and installed in a substandard manner, due to substandard specification and oversight.
While on site I went near the front door of the RBC center. I saw a planting of about 50 thin-barked hornbeam trees. Some are dead, and many are dying. These trees have bark loss and wood decay, mainly on the south and southwest sides of the stems. These stems have no lower branches, so they are deprived of shade and nourishment. They do not have trunk wrap or other barriers to shade the stems.
DISCUSSION
Misinformation from NCSU Extension about tree planting is common, even in recent publications. The first two that came up in an internet search are:
http://alamance.ces.ncsu.edu/files/library/1/Tree%20Planting%2010-07-09.pdf
http://wayne.ces.ncsu.edu/index.php?page=news&ci=LAWN+157
This next one is substantially compliant, but it does not have the standard “trunk flare shall be planted to grade” specification.
http://www.cals.ncsu.edu/extgardener/tree.pdf
This basic condition for health and survival is visible to the untrained eye on trees that are not grown in nurseries or installed by landscapers. Without it, trees can be buried, original roots will suffocate, stems will be strangled by their own roots, and trees will continue to die from anthropogenic causes. All trees that are planted in the future should comply with ANSI standards, despite any recommendations to the contrary.
Other states such as Florida and California are adopting ANSI-compliant nursery standards that provide for healthier plants, and protect buyers from the expense of dealing with fatal defects: hort.ufl.edu/bmp/BMPbrochure.pdf and
www.urbantree.org/specs.asp. If the industry in North Carolina adopts such standards, this state’s urban forest and urban populations might benefit greatly in the future. These standards also call for retaining lower branches while the tree develops, to thicken and protect the stem.
Should every dead pine tree be replaced with another pine tree? Considering the number of pines at the RBC Center, these eight dead trees may be just the tip of a very large iceberg that is rapidly melting. Considering the number of trees that are being lost, and the abundance of Pinus taeda on this site, it is not clear that every pine tree that dies has to be replaced by a pine tree. The row above the small parking lot could be replanted with small ornamental trees or shrubs, which might deliver more aesthetic, environmental, and sustainable benefits than seven more pines would. There is also the safety issue of planting pines on slopes near people and property. These “edge trees” tend to sprawl into the open and lean over the target area. Those with defects such as stem-girdling roots and fusiform rust are more likely to fail in severe storms, falling into the open, and possibly occupied areas.
Across the entire site, dozens if not hundreds of pines closely planted in rows have fatal (>1/3 circumference without substantial scar tissue) fusiform rust infections. Since pines are sun-demanding trees, they will not flourish under more established trees. In the short term, the loss of these trees will create gaps, but the sooner they are removed, the sooner the healthier trees can close these gaps. Retaining lower branches and expanding natural areas outward as the remaining trees mature will also mask these gaps, and improve tree health. The landscape plans were flawed from the start due to the lack of proper inspection and planting specifications. The impracticality of planting pines in shade, along with other costs, must be considered along with whatever perceived aesthetic benefits are associated with adhering to these plans.
Tissue death on stems exposed to the sun is known as sunscald. Bark tissues that were shaded in the nursery and suddenly exposed to sunlight can dry out and die. Without this protective covering, the inner wood is exposed to cracking and infection, causing a decline in health and stability.
NCSU once taught courses in the Physiology of Woody Plants and Arboriculture,
http://joa.isa-arbor.com/request.asp?JournalID=1&ArticleID=1699&Type=2 but currently does not. Without sufficient education in the care of trees, graduates are not well equipped to manage trees, and this land-grant university fails to meet this essential part of its mission. The result is unhealthy and unsafe trees on large sites such as the RBC Center, and countless smaller sites across North Carolina.
RECOMMENDATIONS
1. Immediately remove all pines that have fatal (>1/3 circumference without substantial scar tissue) fusiform rust infections, before they sporulate this spring. Consult with NCSU Pathology professionals on this.
2. Treat infestations of southern pine beetle located at the margins of smaller infections. Consult with NCSU Entomology professionals on this.
3. Remove mulch and soil from the stems and examine the root crowns of all the other pine trees.
4. Remove stem-girdling roots.
5. Apply 2-4” of mulch under the branches, but not on the stems.
6. Install rattan shields like the below, without the wood and burlap, and painted in a shade of red somewhere between Wolfpack and Hurricane red, around the hornbeams.
7. Restore courses on arboriculture at North Carolina State University in the Forestry and Horticulture Departments.
8. Teach basic arboricultural principles to students in the Landscape Architecture and related departments.
This concludes my report. It is my hope that closer attention to the basic needs of the woody plants at the RBC Center and across the state will allow them to provide greater contributions at less cost, for the benefit of visitors and citizens in the decades to come.
