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Measuring Soil Compaction on
Construction Sites: A Review of Surface Nuclear Gauges and Penetrometers
Thomas B. Randrup and John M. Lichter
Abstract. This paper reviews two different techniques of determining
soil compaction on construction sites. The surface nuclear gauge is found
suitable for measuring soil compaction in soils with less than 5% organic
matter by weight and at a depth of no more than 0.15 m (6 in.). Penetrometer
readings are often unreliable on compacted soils, as well as in dry and
stony soil conditions. Therefore, the penetrometer is rarely a valuable
device on construction sites as a definitive measurement instrument, but
it may be useful as an indicator of compacted areas. Recommendations to
measure soil compaction on construction sites are given.
Key Words. Urban soils; quantification of soil compaction; soil compaction;
penetrometer; surface nuclear gauge.
Host Suitability
of Asiatic Elm Species and Hybrids for Larvae and Adults of the Elm Leaf
Beetle (Coleoptera: Chrysomelidae)
Fredric Miller and George Ware
Abstract. Selected elms (Ulmus spp.) and their hybrids growing
at The Morton Arboretum in Lisle, Illinois, U.S., were evaluated in no-choice
larval and adult suitability laboratory bioassays for the elm leaf beetle,
Pyrrhalta luteola Müller. No-choice larval suitability studies revealed
that the elm genotypes of U. davidiana x U. japonica, U. elongata, U. parvifolia,
U. szechuanica, and U. ‘Morton’-Accolade were the least suitable for larval
development and pupation. Ulmus davidiana x U. japonica-wilsoniana-pumila,
U. pumila (reference), U. lamellosa, U. macrocarpa, U. szechuanica x U.
japonica, U. ‘Morton Plainsman’-Vanguard, and U. ‘Morton Red Tip’-Danada
Charm were more suitable for larval development and pupation. Similar low
and high suitability rankings were also observed for adult beetles in no-choice
studies reared from the larval suitability study. Larval development time
and proportion of larvae reaching pupation appear to be a good predictor
of adult emergence. Larvae feeding on less suitable genotypes took longer
to develop with a lesser proportion of adults emerging. The reverse is
also true. Preovipositional period was found, in part, to be a function
of suitability. Female longevity reflected suitability for the elms tested
in this study. Ulmus pumila appears to be a major influence on both larval
and adult host suitability. The least suitable elm genotypes, listed above,
show promise for future elm breeding programs and for use in localities
with acute and chronic elm leaf beetle populations.
Forest Health Monitoring Protocol
Applied to Roadside Trees in Maryland
Anne Buckelew Cumming, Michael F. Galvin, Robert J. Rabaglia, Jonathan
R. Cumming, and Daneil B. Twardus
Abstract. The Maryland Roadside Tree Law places trees in all
public road rights-of-way in the State of Maryland, U.S., under the jurisdiction
of the Maryland Department of Natural Resources-Forest Service. Passed
in 1914, this law is one of the oldest tree conservation laws in the United
States. However, little statistical data have ever been generated related
to Maryland’s roadside trees. This paper provides a methodology for assessing
the condition of roadside trees by combining GIS tools, rights-of-way definitions,
and components of a national forest health monitoring program. The assessment
of roadside trees was carried out in six of Maryland’s most urbanized jurisdictions.
Results indicate that 14% of Maryland’s roadsides are tree lined and that
the trees are in good health based on crown and damage indicators collected.
Shannon-Weaver index and importance values were calculated to describe
species diversity. Views on the efficacy of the law in protecting roadside
trees in light of the findings, and the findings themselves, are discussed.
Using Qualitative Data Collection
Methods When Planning for Community Forests
William E. Elmendorf and A.E. Luloff
Abstract. When gathering information and planning for community forest policies and programs, planners, municipal foresters, and arborists can find it difficult to identify, involve, and listen to all persons important and affected. Accordingly, the concerns, beliefs, attitudes, and behaviors of some people continue to be misstated, unknown, and ignored. Furthermore, some people continue to be excluded in information gathering and planning either by design or lack of effort, which can lead to poor information and planning, increased conflict and cost of conflict, poor collaboration, and increased mistrust and apathy. Use of key informant interviews, focus groups, and visual techniques such as stakeholder mapping, vision galleries, and sacred place mapping can help planners and municipal foresters and arborists to better develop mail and telephone surveys. These methods can also be used to gather information about people's opinions and attitudes, help identify and include both insiders and outsiders in the community forest planning process, and help reduce conflict.
A Survey to Determine the Leaf
Nitrogen Concentrations of 25 Landscape Tree Species
Ed Perry and Gary W. Hickman
Abstract. A survey was conducted to determine the concentrations of leaf nitrogen in 25 landscape tree species. Leaf samples were taken from mature, healthy trees in the landscape and analyzed for percent (total) nitrogen. Concentrations ranged from 1.0% (dry weight basis) for deodar cedar (Cedrus deodara) and Southern magnolia (Magnolia grandiflora) to 3.6% for white mulberry (Morus alba). The leaf nitrogen levels determined by the current study were compared to two other published surveys. From a practical standpoint, the list of tree species and their corresponding minimum leaf nitrogen values from visually healthy trees will allow arborists and landscape maintenance professionals to more effectively use leaf analysis for diagnosing nitrogen deficiency. The information can also be used for designing fertilizer programs, much as critical leaf nutrient level guides are currently used in the fruit and nut tree industries.
Homeowners' Opinions on the
Practice and Effects of Topping Trees
David D. Close, John W. Groninger, Jean C. Mangun, and Paul L. Roth
Abstract. Utility (involuntary) and voluntary tree topping continues
to be a common practice despite the efforts of various anti-topping advertising
campaigns. A survey questionnaire was conducted to gain insight into homeowner
motivations and knowledge of the consequences of topping, whether topping
is consumer or service driven, and whether sociodemographics are related
to levels of satisfaction with topping. Results indicate that topping is
viewed more favorably by less educated homeowners and is consumer driven.
This study also revealed people do not understand the consequences of topping.
Differences also were apparent between voluntary and involuntary topping
with the latter group more likely to recognize the negative effects of
topping on tree health. Future anti-topping, advertising campaign creators
should use information from this study to direct their message toward the
most appropriate audiences.