Select a title from the list below to see an abstract of the article. For information about ordering reprints of complete articles, contact ISA at (217) 355-9411 or isa@isa-arbor.com.
Tree Lilac Cultivars Tested As
Street Trees: Initial Results
by Henry D. Gerhold
Abstract. Three Japanese tree lilac (Syringa reticulata)
cultivars, 2 each in 11 communities, were planted for evaluation as street
trees. Cooperators in the Municipal Tree Restoration Program using standardized
methods measured them annually for 3 years, and periodically afterwards.
'Ivory Silk', 'Regent', and 'Summer Snow' performed well at all locations.
All 3 cultivars grew slowly initially, and their foliage tended to turn
yellow in late summer. Height growth of 'Summer Snow', reputed to be slower
than 'Ivory Silk', was not slower at all locations.
Serviceberry Cultivars Tested
As Street Trees: Initial Results
by Henry D. Gerhold
Abstract. Five serviceberry (Amelanchier) cultivars, 2 each in
11 communities, were planted for evaluation as street trees. They were
measured annually for 3 years, and periodically afterwards, by cooperators
in the Municipal Tree Restoration Program using standardized methods. 'Autumn
Brilliance', 'Cumulus', 'Princess Diana', 'Robin Hill', and 'Tradition'®
all performed well in general, but they suffered somewhat from urban stresses.
'Autumn Brilliance' had healthier foliage, higher survival, and was broader
but not as tall as the others.
Underlying Beliefs and Attitudes
About Topping Trees
by James R. Fazio and Edwin E. Krumpe
Abstract. Topping trees has long been a problem in community
forestry, not only by creating visual blight, but also by endangering the
health of trees and the safety of pedestrians and property. Despite regulations
in some cities and a long history of educational campaigns, the practice
continues. In this study, a survey was conducted in one region of the United
States to determine the reasons behind the continuing practice, in part
by directly interviewing people who had requested or allowed their shade
trees to be topped. The survey investigated attitudes toward topping, knowledge
of basic tree care, how the individuals receive advice related to tree
care, how their topping service was obtained, and related sociodemographic
characteristics. A second survey was conducted among tree care companies
in the same study area to allow comparisons and determine policies toward
topping.
Cyclic Irrigation Improves Irrigation
Application Efficiency and Growth of Sawtooth Oak
by Glenn B. Fain, Ken M. Tilt, Charles H. Gilliam, Harry G. Ponder,
and Jeff L. Sibley
Abstract. Two studies were conducted to evaluate different irrigation
regimes for production of container-grown sawtooth oak. Three irrigation
treatments (single, 3 times daily, and 6 times daily) and 2 substrate treatments
(100% pinebark and 4:1 (v:v) pinebark:coir) were evaluated to determine
their effects on irrigation application efficiency and growth of sawtooth
oak (Quercus acutissima Carruthers) in a pot-in-pot production system.
Irrigation application efficiency increased with cyclic treatments compared
to a single application and was increased with the pinebark:coir substrate
compared to pinebark alone in the single application treatment. Growth
was greater when irrigation was applied in 6 cycles than in 1 single application.
Trees grown in pinebark:coir substrate were larger than those grown in
the pinebark substrate.
Evaluating Trees for Saltwater
Spray Tolerance for Oceanfront Sites
by Bonnie Appleton, Roger R. Huff, and Susan C. French.
Abstract. Trees growing along the major resort area thoroughfare
of the city of Virginia Beach are subjected to saltwater spray from the
Atlantic Ocean. Despite the city's desire to plant trees for shade along
this thoroughfare, none of 8 species that were reported to be salt tolerant
and that met city design requirements were aesthetically acceptable after
1 year in moderate and high wind exposure locations. Species tested were
loquat (Eriobotrya japonica), thornless honeylocust (Gleditsia
triacanthos var. inermis), Chinese flametree (Koelreuteria
bipinnata), goldenraintree (K. paniculata), fruitless sweetgum
(Liquidambar styraciflua 'Rotundiloba'), dwarf southern magnolia
(Magnolia grandiflora 'Little Gem'), sweetbay magnolia (M. virginiana),
and lacebark elm (Ulmus parvifolia 'King's Choice').
Growth of Trees on the Virginia
Tech Campus in Response to Various Factors
by Richard W. Rhoades and R. Jay Stipes
Abstract. Soil stresses allegedly repress tree health, growth,
and longevity. Such stresses commonly occur on college campuses where soil
compaction can result from pedestrian and vehicular traffic. Trees on campuses,
as their forest counterparts, also sustain damage from storms and biotic
stress agents. We monitored an expression of stress on selected trees on
sites judged to be stressful or nonstressful (control) on the Virginia
Tech campus. We measured dbh (diameter at breast height) of 9 species and
crown diameter of 8 species, from 1993 to 1995. Trunk growth rates differed
significantly among species. Five major factors influenced growth of trees:
ice damage, percentage of paved area beneath the crown, heart rot, chlorosis,
and Dutch elm disease. Almost half (49%) of trees were injured physically
or manifested disease or rot. We also compared growth rates of trees in
2 groups classified by percentage of paved area beneath the crown, viz.
low stress versus presumed stressed sites. Annual rates of trunk growth
of campus trees were higher than comparative growth rates of the same species
in forests. This was the combined result of several factors, including
the fact that open-grown trees, lacking competition in a forest, grow faster.
Based on our results, we cannot state conclusively that site stress suppressed
growth of trees on campus. Health and longevity variables were not monitored.