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.
Funding Will Help Support Tree Planting and Other Urban Forestry Projects Statewide
Read on to find out about the awardees and their projects
Governor Andrew M. Cuomo recently announced grant awards totaling $2.3 million for urban forestry projects in communities across New York. The Urban Forestry grants are funded through the state Environmental Protection Fund and are part of New York’s ongoing initiatives to address invasive species, climate change and environmental justice.
“These investments will help improve the quality of life in New York neighborhoods by supporting the replacement of trees impacted by invasive pests,” Governor Cuomo said. “Every New Yorker deserves access to clean air, and through these urban forestry grants, we are promoting the benefits of planting new trees to support a better, healthier New York for all.”
Grants were made available to municipalities, public benefit corporations, public authorities, school districts, soil and water conservation districts, community colleges, not-for-profit organizations, and Indian Nations. Awards range from $11,000 to $75,000, depending on municipal population. Tree inventories and community forestry management plans have no match. Tree planting and maintenance projects have a 25 percent match.
These abridged versions of 88 of the most popular Tree City USA Bulletins are a free, handy reference for the tree enthusiast or professional arborist. They are provided by the Arbor Day Foundation. Click on the bulletin to access and easily print or download a PDF. View the complete collection of Tree City USA Bulletins in the bulletin archive.
From the Urban Forestry and Urban Greening paper’s Abstract:
On the Cornell University campus a long-term study has measured the impacts of a soil remediation strategy on plant growth and soil quality using the Cornell Soil Health Test. The Scoop & Dump (S&D) process of soil remediation consists of physically fracturing compacted urban soils, incorporating large quantities (33% by volume) of compost with the use of a backhoe, and annually top dressing with mulch. This study was designed to investigate the impact of this remediation technique for the amelioration of compaction and degradation of soils in the urbanized environment.
From the Urban Forestry and Urban Greening paper’s Conclusion:
The authors found that the Scoop & Dump method of soil remediation showed improvement in soil quality indicators – bulk density, resistance, aggregate stability, potentially mineralizable nitrogen, active carbon and organic matter content – compared to unamended sites. Over a period of 12 years, soil quality indicators – bulk density, active carbon and potentially mineralizable nitrogen – improved over time showing long-term beneficial effects of using the Scoop & Dump Technique.
The application of the Scoop & Dump soil remediation strategy is an appropriate method for restoring soils damaged by heavy equipment, building construction and urbanization impacts. With minimal annual maintenance including the addition of shredded bark mulch, these improvements in soil quality are maintained or enhanced over time. This technique offers a practical, research-based tool for green industry professionals, arborists and landscape contractors and has a strong potential for improving soil quality using locally sourced materials and sustainable methods.
Sax, M.S., Bassuk, N., van Es, H., Rakow, D., Long-Term Remediation of Compacted Urban Soils by Physical Fracturing and Incorporation of Compost, Urban Forestry and Urban Greening (2017), http://dx.doi.org/10.1016/j.ufug.2017.03.023
In this post, NYSDEC Division of Lands and Forests-Forest Health Oak Wilt Operations Coordinator Jennifer Kotary shares a simple way to prevent the spread of oak wilt.
The connection between forest health and urban forestry is apparent in the management of oak wilt, a serious disease that kills thousands of trees per year. NYSDEC Forest Health has adopted a rapid response to this disease in order to prevent the establishment of oak wilt. This rapid response seeks to prevent the need to spend millions of dollars a year to control oak wilt and to prevent the loss of millions of dollars in oak wood sales in the state. Management is also critical to protect the intrinsic value of trees in urban forests, as trees improve everyone’s quality of life.
Dr. Ed Gilman is a popular presenter among NY arborists and members of our state’s U&CF community, giving talks based on his decades of applied research at the University of Florida (UFL) and countless field observations and conversations with arborists. Gilman retired from UFL in July but— happily for our industry—he is going to continue doing education in the field, especially with commercial arborists around proper pruning techniques. The resources he created on UFL’s website for pruning and all things related to trees and other landscape plants are phenomenal—more about those later.
How is the transition to semi-retirement going? Ed Gilman: Retirement allowed me to step back and take a break from writing; after 120 scientific publications and 35 years of tearing trees apart, I felt it was someone else’s turn. I’ll have more time now to do education in the field with commercial arborists—sharing the practical fruits of my research and that of my colleagues, which I really enjoy. I stay involved with ISA Florida and with the ANSI Pruning Standards committee. It’s nice to remain plugged in and relevant. What would be particularly gratifying is if I could get more people doing what I’m doing in terms of the education of commercial arborists. Stay tuned for more on that.
Some blog posts resonate long past their original publication date date. Transplanting and a Deeper Look at “Fall Hazards” was one of the top five posts in 2015 and was the second most viewed post in 2016. Former NYC Director of Street Tree Planting Matt Stephens and Taking Root Editor Michelle Sutton coauthored this story questioning commonly held beliefs about “fall hazards,” mostly as it applies to B&B trees, but they also discuss the interaction of the fall season with other production methods, like bare root. Nina Bassuk helped craft the section called “The Five Branches of Transplanting Success,” which should be of interest to anyone planting trees.
Kristy King and NYC Forest Restoration: Dreaming Big for the City’s Natural Areas Many readers wanted to learn about the work of the NYC Natural Resources Group, which manages 5,000 acres of forested natural areas across the five boroughs of NYC, and about Director of Forest Restoration Kristy King. Her dream for NYC: “… that all forested areas are dominated by native species and that invasive species have been managed to the point that natural forest regeneration is occurring and that the public holistically values the natural resources in their area.”
NYSDEC Urban Forestry Intern Jennifer Kotary: Get to Know Her! Many blog readers were keen to know about this dynamic up-and-comer. “My internship research involved in-depth exploration of what communities are doing to protect and build green infrastructure across the state. Via Mary’s [Kramarchyk] assigned projects, I was able to produce tangible evidence that there is quite the statewide collective will to plant and nurture an expanding canopy as well as many career and volunteer opportunities to do so.”
SMA’s 2016 Urban Tree of the Year: Musashino Zelkova generated a lot of buzz. ‘Musashino’ has been a successful and popular street tree for many more years in Japan, proving itself useful as a narrow, upright form of zelkova. It can tolerate drought and heat and is pH adaptable and pollution tolerant. See a list of all the past SMA Urban Trees of the Year here.
Gary Raffel: Get to Know Him! Gary has served the Council in a variety of capacities, including as a board member. “I started Dynamic Tree Systems in 2002, offering general tree care service as well as Plant Health Care and Integrated Pest Management programs. I later wanted to find a niche in the industry and purchased a Tree Radar Unit at a time when there were only three of us in the U.S. and eleven people in the world using the equipment. A few years later I became the company’s international trainer, such that when a new unit was sold I would fly to the particular client and spend a week training them on their new equipment (I still do that, in addition to Dynamic Tree Systems).”
Drs. Susan Day and Nina Bassuk have collaborated on a variety of research projects in the urban forest, with a special focus on soil remediation. Susan Day is an associate professor in the Virginia Tech Departments of Forest Resources & Environmental Conservation and Horticulture, and longtime Council stalwart Nina Bassuk directs the Urban Horticulture Institute at Cornell.
Here, Susan Day summarizes her findings after ten years of researching Soil Profile Rebuilding (SPR), a technique that the urban forestry community will be hearing about! See also this post from 2014 about Nina Bassuk’s related soil amendment research.
Soil Profile Rebuilding: An Alternative to Soil Replacement
by Susan Downing Day
Urban foresters and their allies know poor soils can lead to an endless cycle of dieback and tree replacement. Even if trees do establish, growth can be underwhelming and tree health disappointing. Increasingly, project managers have been turning to soil replacement, where existing soils are excavated and removed and replaced with “recycled” or blended soils. These soils present their own challenges, however. For example, many imported blends rely on high sand contents to improve drainage, resulting in low water-holding capacity and drought stress for unirrigated plantings. Resulting sharp transitions in soil texture introduce the possibility of creating a “bath tub” effect in situations where it is impossible to replace all the soil and new soils are confined to the immediate vicinity of individual trees.
There is an alternative to soil replacement that is especially appropriate where there are extended open soil (unpaved) areas such as in street medians—soil rehabilitation. Soil rehabilitation can help restore important ecosystem functions such as stormwater transmission and vegetation support to existing native soils.
This is THE publication to share with your municipality’s engineers and leadership, to show the why and how of CU-Structural Soil.
CU-Structural Soil®, also known as CU-Soil®, is a two-part system comprised of a rigid stone “lattice” that meets engineering requirements for a load-bearing paving base, and a quantity of uncompacted soil that supports tree root growth.
The first section of the Guide discusses the role of soil volume and how to calculate how much soil volume a tree needs. No matter how well matched your tree species is to its site, limited soil volume is something few trees can abide, much less thrive in.
The Guide goes on to give the case for CU-Structural Soil in particular, and answers FAQs like “How much CU-Soil will I need?”, “How do you plant trees in CU-Soil?”, “Can it be retrofitted for use under existing trees?”, and “How is irrigation and drainage handled?” It also explains how to obtain CU-Soil that meets quality control specifications. (This, by the way, is why CU-Soil is licensed—to ensure quality control. Otherwise, anyone could mix up rocks and soil and claim to be selling “CU-Soil.”)
A repository of more than 30 roundtables from CITY TREES magazine 2005-2017 is freely available on the home page of the Society of Municipal Arborists (SMA) website, www.urban-forestry.com.
The roundtable format was a suggestion from Dr. Nina Bassuk that City Trees took and ran with. Each roundtable contains advice and anecdotes on a theme from 8 to 10 professionals. The information will be of interest to anyone involved in the urban and community forestry (UCF) world!
The topics are: Bees, Bioswales, Building Bridges Between LAs and MAs, Building Bridges with City Depts, Part I and II, Cemeteries, Climate Change, Consulting, Contract Growing Partnerships, Drought, EAB, Fall Planting, Flood Damage, Gas Lines and Trees, Historic Trees, Invasives, Large Tree Relocation, Medians, Memorial Trees, Palms in the Urban Forest, Pruning Cycles, Pyrus Problems, Sewer Lines, Slopes, Social Networking, Teaching, Tree Boards, Tree Lights, Urban Forestry’s Location in City Departments, Urban Fruit Trees, Urban Wood, Zoos.
Sample entries from roundtables follow. Please go to www.urban-forestry.com to take advantage of this resource and learn more about the SMA, which welcomes members from all spheres of the UCF world (paid or volunteer).