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Trees and Arbor Day

April 2013

At the Northern Research Station, every day is Arbor Day. Our scientists investigate every aspect of tree health to produce research that helps make water and air cleaner, ecosystems more resilient, forest industry more competitive and sustainable, and cities more livable.

Additional Information

Featured Scientist

Christopher Woodall

Research Forester, Chris Woodall

From leaves to branches to roots, surveys of standing and fallen trees yield a bounty of information on the health and function of United States forests. Chris Woodall, a research forester with the Northern Research Station’s Forest Inventory and Analysis (FIA) program, is developing new ways to assess that information.

Woodall’s interests include forest carbon inventory science, forest detritus dynamics research, refining the survey and analysis of forest products/biomass, and development of novel forest inventory analytical approaches such as tree range shift indicators.

Woodall is the national coordinator of the forest sector of the U.S. Greenhouse Gas Inventory,  a national advisor for the FIA’s Down Woody Materials Inventory, and supervises the Northern FIA Carbon Accounting and Timber Products Inventory Group.

Find out more on Chris' scientist profile

Featured Product

Oak seedling.

SILVAH - Designed and continually upgraded by Northern Research Station scientists, SILVAH (originally short for Silviculture of Allegheny Hardwoods, now containing guidance for mixed oak forests, too) is a computer tool for making silvicultural decisions in hardwood stands of the upper Appalachian or mid-Atlantic region. It is used by state foresters in 6 states, on several National Forests, as well as for commercial forests.
Introduced in 1985, SILVAH’s Version 6.2 was released in 2011 and is available for download at:

The concept is straightforward: users enter their forest management objectives and inventory information on existing overstory, understory, and other site data.  SILVAH uses that information to recommend a prescription for moving the stand closer to the manager’s objectives. SILVAH contains a forest stand growth simulator, gives users the ability to test alternative cuts, enables development of a forest-wide inventory database, and facilitates other forest management planning functions.

Training on SILVAH is offered annually in several locations. This year, it is scheduled in Maryland and Ohio for mixed-oak forests and Pennsylvania for northern and Allegheny hardwood forests.  Information about these sessions is available at

The silviculture behind the SILVAH system in Allegheny, northern hardwood, and mixed-oak forests is described in two publications titled: Prescribing silvicultural treatments in hardwood stands of the Alleghenies and Prescribing regeneration treatments for mixed-oak forests in the Mid-Atlantic region

Featured Research

Chestnut seedlings planted on strip mine siteA giant of a tree, the American chestnut, was felled by a non-native fungus called Cryphonectria parasitica that arrived in New York City on Asian nursery stock in the early 1900s. Chestnut blight spread quickly and inexorably into its new and defenseless host population, altering ecosystems and the lives of people who relied on the tree for food, shelter, and animal production. Within a few decades, American chestnuts had been reduced to living root systems with a few susceptible branches and fading memories of forest giants.

Today, Northern Research Station scientists are helping American chestnut stage a come-back.
Northern Research Station scientists at the Hardwood Tree Improvement and Regeneration Center (HTIRC) in Indiana are working with The American Chestnut Foundation and others to bring American chestnut back to their native range. Using potentially-blight-resistant American chestnut hybrids developed by TACF, the NRS and TACF have begun two restoration plantings, one on the Wayne National Forest in Ohio and another on the Hoosier National Forest in Indiana. These plantings and the associated research are an important next step in testing blight-resistance in the field to understand the ecological steps necessary to successfully restore the American chestnut.

Trees bred by TACF have been used in a variety of mine reclamation projects in the Appalachians, once a major part of the American chestnut’s natural range. Shivanand Hiremath, an NRS research scientist in Delaware, Ohio, studies hybrids in reclaimed coal mine sites to determine what field conditions are conducive for re-establishing chestnut. Hiremath is testing various species of mycorrhizal fungi – fungi that are symbiotic with tree roots and aid host trees in acquiring soil nutrients – to determine which mycorrhizal species will be most beneficial to chestnut seedlings in the nutrient-poor, hostile environments of coal mine soils.

Featured Partnership

Children helping to plant a tree during event for MillionTreesNYC

In 2007, New York City embarked on a 10-year project to plant and care for 1 million new trees throughout the city’s five boroughs. As part of the MillionTreesNYC Advisory Committee and subcommittees focused on research and stewardship, NRS scientists with the New York City Urban Field Station are working with the New York City Department of Parks & Recreation and the New York Restoration Project to achieve the MillionTreesNYC goal: “make NYC even greener and greater.”

Northern Research Station scientists and leaders contribute to workshops and symposiums aimed at building a scientific foundation for tree planting efforts, and scientists helped develop a research agenda to accompany MillionTreesNYC. As part of that effort, NRS scientists compiled a comprehensive urban forestry bibliography of ecological studies and research sources and edited a special issue of the journal Cities and the Environment presenting results from the MillionTreesNYC research symposium held in 2010.

A partnership between the Northern Research Station and the NYC Department of Parks & Recreation, the New York City Urban Field Station is a physical place to conduct research as well as a network of relationships among scientists, practitioners, university cooperators, and facilities focused on urban ecology. The Field Station is contributing to work by several researchers from organizations including Yale University, The New School’s Tishman Environment and Design Center, and Columbia University whose projects include assessing tree growth and survival on MillionTreesNYC reforestation sites and examining the effect of MillionTreesNYC on ecosystem structure and function as well as species diversity and abundance.