SLAM Lab - Research

Projects in this section are prior work examples of research projects conducted while an Assistant Professor of Sustainable Landscape Management in the Department of Horticulture at Iowa State University.

Increasing Resiliency through Greater Urban Tree Diversity

Numerous human actors are involved with decisions that narrow naturally occurring tree diversity to the relatively few tree species that are commonly available in the nursery industry for planting in urban spaces. Yet, relying on a small number of species puts urban forest health, and the ecosystem services they provide to people, at great risk due to unforeseen circumstances and threats. We conducted a nation-wide series of focus groups to understand the realities faced by different actor groups that ultimately result in the observed low urban tree diversity to determine where additional research can assist in alleviating some of the constraints to increasing urban tree diversity.

USDA NIFA Increasing Resiliency through Greater Urban Tree Diversity

Photo detail: An ash tree lined streetscape in Ohio before (left) and after (right) an infestation of emerald ash borer shows the potential risk of low tree species diversity to communities. Images used courtesy of Dr. Dan Herms, formerly with The Ohio State University.

Specifying Urban Forest Diversity

Many types of professional consultants can specify trees for landscape projects including public and private trees. We used public-record landscape plans submitted for municipal permitting and review to assess the role of consultant discipline on the diversity of tree selections at site, between sites across a city, and at a landscape scale. Results of this study will identify over and under utilized trees and which consultants would benefit from education and training about tree specification and diversity to promote urban forest resiliency.

Presentation of Research to the Minnesota Shade Tree Advisory Committee

Landscape Plant Establishment

This is a 2-year study assessing the use of controlled-release fertilizers to produce marketable native perennials from the greenhouse with residual fertility to aid in landscape establishment. The paired greenhouse and field study is a collaboration with Drs. Currey and Haynes and was conducted on campus and at the ISU Horticulture Research Farm.

Rootball Manipulation for Container Trees

This is a 3-4 year study assessing methods of rootball manipulation techniques to ameliorate root defects caused by growing or transferring trees into containers. Research is needed to determine if such techniques, shown to be useful in warmer climates, are as effective in the northern USA where planting windows and the growing season is shorter.

Soil Remediation & Health

Post-construction soils are often compacted and low-organic matter subsoils. To improve soil health, greenhouse and growth chamber experiments were conducted with tillage radish cultivars to assess the potential of radish for decompacting soils over a range of bulk densities and to produce root channels for herbaceous perennial plant establishment.