UHI Produces Plan for a Sustainable National Mall Treescape

Barb Neal (left), Bryan Denig, and Nina Bassuk on the National Mall.

In hot and steamy June of 2017, a team of researchers and arborists from Cornell University’s Urban Horticulture Institute (UHI), headed up by UHI Director Nina Bassuk, worked dawn to dusk evaluating the condition of the American elms and soils on the National Mall in Washington DC. This iconic landscape is often referred to as “America’s Front Lawn,” and the National Mall turf grass was fully renovated between 2010 and 2016, involving infrastructure upgrades, at a cost of $40 million dollars. Now, UHI hopes the Mall trees will get the same level of attention.

Bassuk and then-graduate student Yoshiki Harada worked together on soil evaluation, taking 108 soil samples back to Cornell, while ISA Board Certified Master Arborist Barbara Neal and UHI Visiting Fellow Bryan Denig performed an ISA Level 2 evaluation of the National Mall’s 550 trees. Bassuk and team also used ground penetration radar on a sample of 16 of the trees to find out precisely where the roots are.

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SMA Announces 2019 Urban Tree of the Year

American hophornbeam (Ostrya virginiana) coping admirably well with the heat on the student union patio at Virginia Tech. Photo by Eric Wiseman

Each year, members of the Society of Municipal Arborists (SMA) vote for the SMA Urban Tree of the Year. Praise for this year’s winner, American hophornbeam (Ostrya virginiana), came from fans in states as far-flung as Wisconsin, New York, Virginia, and Texas.

Here, we hear from the Council’s Dr. Nina Bassuk at Cornell and from her colleague, Dr. Eric Wiseman at Virginia Tech. You can see the full list of SMA Urban Trees of the Year going back to the program’s inception in 1996 here.  

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Cornell Opens New Sustainable Landscapes Trail

Students in Nina Bassuk and Peter Trowbridge’s Creating the Urban Eden class, planting the bioswale in the Peterson parking lot, the site of the recent Cornell Sustainable Landscapes Trail opening ceremony. Photo from Cornell Horticulture blog (https://blogs.cornell.edu/hort)

With excerpts from Cornell Chronicle and the CU Sustainable Landscapes Trail web page

On October 5th, 2018, Nina Bassuk led a tour of the new Sustainable Landscapes Trail on the Cornell campus after an opening ceremony in which, instead of ribbon-cutting, officials celebrated with a “downpour” of water onto the permeable asphalt of the Peterson parking lot, which is underlain by CU-Structural Soil and also features a large bioswale.

A number of the 20 sites along the Trail are associated with the Urban Horticulture Institute/Nina Bassuk, including chinkapin oaks (Quercus muehlenbergii) in CU Soil outside Stocking Hall, goldenrain trees (Koelreuteria paniculata) and silver lindens (Tilia tomentosa) in CU Soil outside Weill Hall, the Tower Road Bioswale, the Ag Quad Biodetention Basins, and the Mann Library Entrance SITES Accredited Garden. Many of these projects involved Nina Bassuk and Peter Trowbridge “Creating the Urban Eden” students in their implementation. For instance, the creation of the Rice Hall Bioswale involved students using the research-based “Scoop and Dump” technique described here

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Nina Bassuk Reviews New Applied Tree Biology Book

Nina Bassuk Reviews Applied Tree Biology by Andrew Hirons and Peter Thomas

Reprinted from the April 2018 Arborist News (Volume 27, Number 2).

The first thing to notice in this very excellent text is the title, Applied Tree Biology. This is not exactly an arboriculture manual or a tree biology textbook. It very deftly explores tree biology and then links it to the art and practice of arboriculture. Although the “applied” part of the text is not limited to managing trees in difficult environments, there is a definite subtext focusing on the trials of trees growing in managed or urban environments.

Ten comprehensive chapters address tree structure (wood, leaves, and roots), seed growth, water relations, carbon acquisition, nutrition, interactions with other organisms, and finally, environmental challenges. Each chapter is lavishly illustrated with graphics and pictures; it is difficult to find a page that does not have some illustrative feature. Given that this book is up-to-date and rather dense in content, the illustrations are very welcome. 

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Cornell Urban Horticulture Institute Team Evaluates Condition of National Mall Elms

Cornell UHI team Barbara Neal, Bryan Denig, and Nina Bassuk assess the health of one of the iconic elms ringing the National Mall. Photo by Yoshiki Harada

In April 2018, the Cornell Urban Horticulture Institute team of Nina Bassuk, Bryan Denig, Yoshiki Harada, and Barbara Neal released an extensive report on the elms (including American elms) of the National Mall in Washington, D.C. The report details a study conducted at the request of the National Park Service to examine the current conditions of the trees and soils on the tree panels of the National Mall, and it includes a fascinating history of the landscape. Here are some highlights from the report.

The National Mall elm trees are an important planting in the monumental core, yet they face several challenges. The soils of the tree panels are very compacted, most likely due to the constant pedestrian use and the numerous large organized events that take place on the Mall. Unevenness in the size and distribution of the tree canopy has resulted from decades of mortality (often due to Dutch Elm Disease) and the planting of certain elm varieties with growth forms that are seen as incompatible with the planting as a whole.

From June 17–20, 2017, the research team conducted a tree inventory and collected soil data and samples for later analysis. In addition, in November 2017, ground penetrating radar done by Council member Gary Raffel was used to document root growth for seventeen of the trees. This report deals with the current tree and soil conditions, while management recommendations are in a separate report to be released in late 2018 or early 2019. 

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Nina Bassuk on Why the Fall Color is So “Meh” Thus Far

Cover photo for Sept Oct 2010Our own Nina Bassuk was interviewed for this Schenectady Daily Gazette article about the thus-far disappointing fall color in the Capital Region and throughout much of New York State. The article includes an arresting pair of pictures contrasting the fall color at this time in 2016 with the fall color now on the same mountainside in Cobleskill.

Bassuk says, “The two triggers that are important for fall colors are the shortening days and the cool nighttime temperatures. We haven’t had much of the cool nighttime temperatures. In fact, September was inordinately hot. It was also very dry. The drought in September caused some leaves to fall before they could change color, but I think it was the lack of cool nights,” she said. “In some places, you can look at some hills and it could be July.” Read more here.