You are here: NRS Home / Featured Research / Forest Flow

Forest Flow


July 2016

More than half of America’s freshwater flows from public and private forest land, and about 60 million Americans rely on drinking water that originates on national forests and grasslands. This month, our web features describe an employee, research, a product and a partnership all pooling forces to enhance water quality for people, crayfish and everything in between.

Environmental Education Link

Canoemobile brings classroom learning outside, engaging youth to improve school performance, cultivating a stewardship ethic, and creating pathways to pursue educational and career opportunities in the outdoors.

Canoemobile events are scheduled throughout the summer of 2016. View schedule and locations.

Featured Employee

Ian Halm

Ian Halm

As a kid growing up in New Hampshire, Ian Halm was interested in how things work, from the forests he hiked to the machines he learned to disassemble and reassemble. Today, Halm’s job as a forester at Hubbard Brook Experimental Forest combines all of those interests.

“Basically, what we do is try to figure out how things work,” Halm said.

As the site manager for Hubbard Brook Experimental Forest, Halm keeps track of the multitude of research projects taking place on the site, helps scientists design experiments, collects weekly data, maintains all the equipment, buildings, trails and roads, conducts training on chainsaw use, tree climbing, snowmobiles, ATVs, firefighting and tower climbing, and helps install Smart Forest technology on other experimental forests. He is also responsible for purchasing research and maintenance items needed at Hubbard Brook Experimental Forest.

Not surprisingly, Halm describes “variety” as one of the best aspects of his job.

Following high school, Halm served with the U.S. Coast Guard for 7 years as a machinery technician. He returned to New Hampshire to study forestry in college, and arrived at Hubbard Brook Experimental Forest as a college intern 26 years ago. His engineering experience continues to serve him well; as part of an experiment looking at the effects of drought, Halm recently designed and built a grid that diverts 50 percent of rainfall from a research plot yet does not interrupt light from reaching the forest floor.
After contributing to the design of a drought experiment, Halm worked with scientists to simulate ice storms on eight 100-foot by 100-foot plots, each of which required a different amount of ice. Designing an ice storm demanded significant logistical coordination. “The challenges are a fun part of my job,” Halm said.

Halm’s spare time is spent much like his work time, helping others. The recipient of the Station’s Felix Ponder Award of Excellence in 2013, which recognizes employees who demonstrate outstanding service to others, Halm is the deputy chief of his local volunteer fire department, serves as an emergency medical technician, and volunteers on the ambulance crew several times a month. “I like to help people as much as I can,” Halm said.

More Information on the Hubbard Brook Experimental Forest >>

Featured Product

Fundamentals of Watershed Hydrology

Drawing illustrates fundamentals of hydrologic cycle.

What is a watershed and why should we care? Understanding the science of water, or hydrology, is important because life on Earth depends on water, and people through their actions and water usage impact water quantity and quality.  Individuals and community groups have tremendous influence on management and policy involving water resource management and use, so the more all of us know about water, the greater our ability to keep water clean and aquatic habitats healthy.   

“Unfortunately, there is a general lack of journal-quality publications that describe the basic principles of watershed science and hydrology in plain language,” according to Research Hydrologist Pam Edwards.  She and her co-authors recognized the need for something more expansive than simple fact sheets and short web pages about water resource issues; many people are keenly interested in water quantity and quality, especially in light of the many drought, flooding, and water contamination stories that are common in contemporary news.  Consequently this publication was developed to provide a comprehensive primer about watershed hydrology. 

”Fundamentals of Watershed Hydrology” gives readers an in-depth understanding of the hydrologic cycle or how water moves within and among watersheds.  The movement of water can be described mathematically using the water budget equation, which allows scientists to understand and predict how streamflow will be affected by different land management actions or land use changes.  Readers will also learn what a watershed is and why watersheds are the foundation for understanding and governing water resources.  Forested watersheds are the focus of the paper since they generate about 80 percent of the Country’s freshwater, but the principles apply to all types of lands.  There are plenty of photographs and drawings to help illustrate the concepts, and educators are encouraged to extract and use the figures in classrooms whenever possible. 

More information >>

Featured Research

Pharmaceutical and Personal Care Products in the Waste Stream

Researchers in Balitmore collect samples to assess aquatic health.Since the 1990s, scientists have documented pharmaceutical and personal care products (PPCPs) as contaminants of emerging concern in streams and lakes of the United States.  These chemicals are known to enter aquatic ecosystems via leaking sewer pipes, wastewater treatment plant effluents and septic tanks. In Baltimore, crayfish are helping research aquatic ecologist Anne Timm determine how PPCP concentrations and bioaccumulation rates vary in streams along the urban to rural land-use gradient.

Timm is working with Lee Blaney, an assistant professor of chemical, biochemical and environmental engineering at the University of Maryland Baltimore County, on research into how growth hormones used in agriculture and chemicals used in sunscreens are showing up in water, sediment, and crayfish tissue. Personal care chemicals are considered a threat to the health of aquatic habitats because the chemicals within the PPCP group are known to affect respiration and productivity of algal and microbial communities (a significant food for aquatic species) and are likely to affect other components of aquatic food webs. Timm’s research with crayfish is showing that concentrations of personal care chemicals increase as they move up the food chain, with less concentration occurring in water and sediment and more in crayfish tissue.

Crayfish are an ideal species group to indicate presence of PPCPs in the environment because they are common aquatic invertebrates functioning in the middle of aquatic ecosystem food webs. However, it can be difficult to assess the effects personal care chemicals on crayfish health and reproduction in the United States because so little is known specifically about the more than 400 crayfish species in North America. “There are very few research papers focused on the biology of crayfish considering North America is home to 77 percent of the 500-plus crayfish species known throughout the world,” Timm said. “The importance of crayfish species within aquatic ecosystems is too often ignored.”

The discovery of chemicals associated with personal care products in water is not exclusively an urban issue, but urban infrastructure may make it a more pervasive problem in cities. “It’s happening all over the country,” Timm said. “What’s unique about urban streams is that here we have both watersheds and sewersheds draining into local aquatic habitats.”

Future research may explore how the structure of PPCP chemicals results in different chemicals being found in different places in aquatic habitats, which may affect different aquatic species in a variety of ways. “That’s what I really like about research,” Timm said. “New areas of research are like being an explorer, you don’t know where it’s going to go.”

More Information >>

Featured Partnership

Urban Waters Federal Partnership - Philadelphia

Photo of Delaware River with bridge and industrial buildings.

As it flows through the Philadelphia metropolitan area, including Camden, N.J., Chester, Pa., Philadelphia, Pa. and Wilmington, Del., the Delaware River is a wonderful resource with potential to be extraordinary.   Erosion, flooding, combined sewer overflows, loss of wildlife habitat, industrial contamination, lack of public access and environmental justice issues are among the challenges facing the river as it makes its way through a highly urbanized landscape. In 2013, the Greater Philadelphia/Delaware River Watershed was selected as a location for efforts by the Urban Waters Federal Partnership Program, opening the door for a renaissance on the river and its riverfront. 

The Urban Waters Federal Partnership Program brings federal agencies together with communities across multiple sectors i.e. city, state, regional, academic and non-profit organizations, and helps increase partners’ access to Federal resources.  The goals of the unfunded partnership are to improve the Nation’s water systems and to reconnect urban populations to local waterways.

The USDA Forest Service, locally represented by the Philadelphia Field Station along with the Department of Interior/National Park Service and the National Oceanic and Atmospheric Administration are leading the new Greater Philadelphia/Delaware River Urban Waters Federal Partnership. The Philadelphia Field Station serves as local ambassador conducting outreach to community groups and local agencies, convening and facilitating an All-Partners meeting every year, and helping communities connect with Federal partners.

One lesson learned over the 4-year existence of the partnership is that partnering around very specific goals or activities is much easier than partnering around large issues. For example, one of the most successful efforts of the partnership has been bringing Canoemobile to the area.  Canoemobile, which has provided watershed education and canoeing experiences to over 5,000 children to date, is a very distinct opportunity that meets a water access need.  The defined nature of the activity makes it easier for Federal agencies to determine whether or not they are able to commit to contributing to the effort.

“As we move forward with the Urban Waters Federal Partnership, we are trying to identify more tangible opportunities that will lead to improving water systems and connecting urban populations with local waterways, so that we can continue to see positive change happen,” said Sarah Low, Team Leader of the Philadelphia Field Station. 

More Information >>