Research Highlights - Urban Natural Resource Stewardship

Air Pollution as a Psychosocial Stressor

Gas emissions at a manufacturing complex in Toronto, Canada. Photo by Kibae Park, United Nations

Exposure to air pollution and its sources is increasingly viewed as a psychosocial stress, but its nature is not well understood. A Forest Service scientist, with partners from Drexel University, University of Pennsylvania and organizations in South Philadelphia, explored the role of the concept of “place” on risk perception and community stress within data collected from eight focus groups in Philadelphia, Penn. Discussions focused on air pollution, a nearby oil refinery, health, and a proposal for air monitoring. The framework of place-based elements of risk perception includes place identity, stigma, and social control. The findings indicate that air pollution contributes to physical and psychosocial conditions that act as community-level social stressors. Findings also suggest that programs that seek to change behaviors and gather or spread information on issues such as pollution and other environmental concerns will be challenged unless they directly address: (1) the public's identification with a place or industry; (2) immediate environmental stressors such as abandonment, waste, and odors; and (3) public perceptions of lack of social control and fear of displacement.

Products & Resources:

• Place-based stressors associated with industry and air pollution

Trees Improve Human Health and Save Lives

Computer modeling shows that trees’ removal of air pollution reduces human mortality by about 850 people per year nationally

Map showing estimated removal per square kilometer of land (tonnes km2) of all pollutants (NO2, O3, PM2.5, SO2) by trees per county in 2010. Map by USDA Forest Service

Air pollution is a serious health concern. Trees remove air pollution by intercepting particulate matter on plant surfaces and absorbing gaseous pollutants through the leaf stomata. Forest Service and Davey Institute scientists developed and ran computer simulations with local environmental data showing that trees and forests in the conterminous United States removed 17.4 million metric tons of air pollution in 2010 with human health effects valued at 6.8 billion dollars. This pollution removal equated to an average air-quality improvement of less than 1 percent. Most of the pollution removal occurred in rural areas, while most of the health impacts and values were within urban areas. Health impacts included the avoidance of more than 850 incidences of human mortality and 670,000 incidences of acute respiratory symptoms.

Products & Resources:

• Tree and forest effects on air quality and human health in the United States

Jamaica Bay Social Assessment

A rapid social assessment of urban parkland: Analyzing park use and meaning to inform adaptive management and resiliency planning in New York City’s Jamaica Bay region

Social assessment crew member interviewing park user on Jamaica Bay. Photo by Joana Chan, USDA Forest Service

New York City’s socially and ecologically diverse Jamaica Bay region, population approximately 900,000, became a focus of resiliency planning and adaptive management efforts following Hurricane Sandy in October 2012. Working in partnership with the Natural Areas Conservancy (NAC) and NYC Department of Parks and Recreation (NYC Parks), Forest Service scientists developed a rapid assessment methodology to understand the public use, social meaning, and stewardship potential of parks in the region. This study assessed the 2,140 acres of public parkland adjacent to the Bay that are managed by NYC Parks. The assessment is spatially explicit, scalable, and replicable so that natural resource managers can use it in adaptive management. The focus on speed and replicability enables managers to examine change in socio-cultural ecosystem services over time in the wake of both acute, large-scale disasters and other chronic forms of disturbance. This study will lead to park profiles, white papers, presentations, and datasets for managers. The pilot has been scaled up to a citywide study exploring the use and meaning of ‘natural areas’ in parks. In the future, social data will be combined with citywide ecological assessment data to inform the conservation and management priorities of the NAC and NYC Parks.

Products & Resources:

• Reading the landscape, a reflection on method

Cold Winter Temperatures Set Emerald Ash Borer Back in Minnesota

Larvae of emerald ash borer in on an ash tree at Ft. Snelling State Park in Minneapolis, MN. The larvae are dead (dark brown instead of cream), killed during the winter of 2013-14. Photo by Rob Venette, USDA Forest Service

Emerald ash borer has devastated urban and natural forests in most states where it occurs, causing 100 percent mortality of susceptible ash species. Although emerald ash borer has been in Minnesota since 2009, little mortality has been observed and spread has been slower than in other states. Forest Service researchers have been evaluating the role cold temperatures might play in regulating populations of this insect. In general, the insect survives exposure to temperatures from 0 to -20°F by producing cryoprotectants, so in many places, cold temperatures may not have an impact on this insect. However, as within-tree temperatures fall below -20°F, mortality rates begin to increase. With the Polar Vortex in January 2014, air temperature in the Twin Cities fell to -23°F, a temperature that could cause up to 80 percent mortality. Samples taken from cut logs and standing trees that had been outdoors during the winter showed that 60 to 70 percent of larvae had been killed in most locations. Winter mortality of emerald ash borer is unlikely to eliminate this insect but may give natural resource managers more time to respond to this insect in areas where extremely cold winter temperatures (less than -30°F) are common.

Products & Resources:

• Cold hardiness of emerald ash borer, Agrilus planipennis: a new perspective

Urban Trees Save Lives

By removing airborne fine particulate matter, urban trees improve human health

Forest Service scientists have shown that trees in cities remove tons of particulate matter annually, leading to lower particulate matter concentrations and consequently improved human health and reduced human mortality.

Urban air pollution is a serious human health issue. Trees can remove fine particles from the atmosphere and consequently improve air quality and human health. A Forest Service scientist modeled the effects of urban trees on fine particulate matter concentrations and human health for 10 U.S. cities. He found that the total amount of these particles removed annually by trees varied from 4.7 metric tons in Syracuse to 64.5 metric tons in Atlanta, with resulting annual values varying from $1.1 million in Syracuse to $60.1 million in New York City, mostly from the effects of reduced human mortality. Mortality reductions were typically around 1 person per year per city but were as high as 7.6 people per year in New York City. Average annual percent improvement of air quality ranged between 0.05% (San Francisco) and 0.24% (Atlanta). Understanding the impact of urban trees on air quality can lead to improved urban forest management strategies to sustain human health in cities.

Understanding and Supporting the Transition from Job Training to Green Jobs

Grads show positive environmental attitudes and behaviors and increased self-confidence after New York City program

MillionTreesNYC training program participants practice tree climbing skills in Bronx Park, New York City. Photo by Andrew Newman Program Manager, MillionTreesNYC, used with permission

In 2009, the Forest Service’s Northern Research Station and Northeastern Area State and Private Forestry partnered in supporting the MillionTreesNYC Training Program, with $2 million to help fund the employment of graduates from the 9-month training program. The training program, run by the New York City Department of Parks and Recreation and New York Restoration Project, targeted 18- to 24-year-olds who were previously disconnected from the workforce. Graduates of the program worked directly in arboriculture, ecological restoration, landscape design, and horticulture. Subsequently, Forest Service scientists convened a workshop on how to improve the transition from green-job training to careers. They reported on lessons learned by experts, practitioners, and trainers, who participated in a panel discussion, followed by roundtable discussions, and a keynote address. They also analyzed the experiences of graduates from the program and found that these urban conservation jobs could be transformational for economically disadvantaged youth.

Products & Resources:

• From job training to green jobs: a case study for a young adult employment program centered on environmental restoration in New York City, USA
• Supporting Success: Making the Transition to Green Collar: Report from the Workshop Jobs, Summer 2010 (PDF)

Urban Waters Partnership for Northwest Indiana: A Unique Collaboration

Federal and local partners work to improve local water quality and people’s access to the great (and wet) outdoors

A view from Lake Michigan of the industrial belt along northwest Indiana. The area is one location selected for the Urban Waters Federal Partnership Initiative, which aims to reconnect urban communities with their waterways. Photo by Northwest Indiana Paddling Association, used with permission.

The Northwest Indiana Urban Waters Partnership focuses on waterways with wide-ranging regional impacts. With leadership from Forest Service scientists, the federal partnership is working with local organizations concerned about waterways such as the Grand Calumet River Area of Concern, the East Branch of the Little Calumet River, Salt Creek, Trail Creek, and Deep River, and of course, Lake Michigan. Early partnership successes include 1) progress on an environmental assessment necessary to expand paddling opportunities at Indiana Dunes National Lakeshore; 2) Army Corps of Engineers modification of a dam along Deep River to facilitate paddling; 3) development of an online mapping tool (by the US Geological Survey) to allow local users to upload and map different regional information; 4) Forest Service grants awarded to three local communities to address water-quality risks caused by the loss of ash trees to the emerald ash borer; 5) restoration of 38 acres of river and upland ecosystems near Chesterton by the Army Corps of Engineers and the Shirley Heinze Land Trust; 6) exploring options for remediating water quality at East Chicago’s Jeorse Park Beach, one of the most polluted beaches in the country; and 7) providing canoe adventures for children through Wilderness Inquiry visits.

Products & Resources:

• Urban Waters Federal Partnership: Northwest Indiana Area

Conserving Biodiversity in Urban Landscapes

Working with citizen scientists to develop guidelines for conserving biodiversity in urban areas

Neighborhood Nestwatch/University of Massachusetts collaborator Susannah Lerman places a band on an American robin in Springfield, MA.​ Researchers are investigating urban forests conditions that allow robins and other songbirds to flourish. Photo used with permission.

Loss of biodiversity as a result of residential development is a national and global issue and conservation of biodiversity in urban areas is important to keeping cities livable. Forest Service scientists developed habitat relationship models to calculate the bird habitat potential of the urban forest by linking habitat relationship models with the U.S. Forest Service urban forest assessment tool, i-Tree. As part of that effort, researchers are investigating songbirds and native pollinators in yards and urban forests to understand the conditions under which they can persist and flourish in urban landscapes. Citizen “scientists” monitor the fates of color-banded birds and nests in their yards to help understand the features of yards that support viable populations. Other homeowners are participating in a project that highlights the value of delayed lawn mowing to support native pollinators and other beneficial insects. Finally, scientists are monitoring the abundance and nesting success of songbirds in forest patches and comparing these values to extensively forested areas. Using this information, we can provide homeowners and municipalities with information to guide their practices and policies to promote biodiversity from the scale of individual yards to forest conservation areas.

Products & Resources:

• Using urban forest assessment tools to model bird habitat potential
• Effects of low-density housing development on shrubland birds in western Massachusetts

From World's Largest Landfill to New York City's Newest Park

City of New York. Used with permission.

Kayakers in Fresh Kills Park, NYC.

The Fresh Kills Salt Marsh, at the southwestern corner of Staten Island in New York City, was once the world's largest landfill. Now the NYC Department of Parks and Recreation is converting the landfill into a park and a citywide cultural and recreation destination through extensive ecological restoration and landscape planning efforts. At 2,200 acres, Fresh Kills Park will be the largest park developed in New York City in more than 100 years. Forest Service researchers at the New York City Urban Field Station and throughout the NRS are working with university cooperators to explore the process of conversion and its impacts on the social and biophysical landscape. Researchers assessed Staten Island residents' attitudes toward the park, developed a communications strategy to address public health concerns about it, and used focus groups to understand residents' memories of the landfill as well as their fears and interests in using the future park. In another study, native poplar and willow plants collected from Staten Island are being propagated at the NRS Institute for Applied Ecosystem Studies in Rhinelander, WI, where they will be grown in the greenhouse and hybridized, and the most successful genotypes will be outplanted at Fresh Kills Park.

U.S. Urban Tree Cover Declining

Image source: Quickbird

Trees in urban areas provide numerous benefits to residents. Tree cover in urban areas is on the decline while the process of urbanization is altering regional tree cover.

Trees in urban areas provide many benefits to city residents. But Northern Research Station scientists have found that urban tree cover has been declining in recent years at a rate of about 20,000 acres per year or about 4.0 million trees per year. Recent analyses by NRS scientists reveal that many forces such as urban development, insects and diseases, natural regeneration, and tree planting are constantly changing the urban tree cover, both positively and negatively. Although tree cover is declining within most urban areas, the development of some urban areas can increase regional tree cover, especially in grassland-dominated states. Understanding these changes is leading to better management plans for sustaining tree cover and its associated benefits for current and future generations.

More Trees Associated with Less Crime in Greater Baltimore

Kim Hairston, Baltimore Sun

Morgan Grove, NRS scientist, speaks with Barbara Rock, a longtime resident of Franklin Square, Baltimore, about the results of his research during a tour with Baltimore Sun.

Northern Research Station scientists found a strong inverse relationship between tree canopy and crimes of robbery, burglary, theft, and shooting when they compared high-resolution tree canopy data and geocoded crime point data in the Baltimore region. These findings add to the literature on the relationship between crime and vegetation in a number of ways. First, the findings show that where there are more trees there is less crime. Second, this result holds for both public and private land, but it is stronger for public land. Third, when spatial autocorrelation is adjusted for, the overall result still holds, but the magnitude is not as great. Finally, it appears there is some slight geographic variability in the relationships between trees and crime and that a few isolated areas see a positive relationship between trees and crime. The modeling results indicated conservatively that a 10 percent increase in tree canopy was associated with a roughly 12 percent decrease in crime.

Understanding Urban Civil Environmental Action Across the U.S.

U.S. Environmental Protection Agency

Gathering prairie seed is an easy, educational, and fun stewardship activity in the Chicago region. Stewards can be any age.

Visualizing where and how hundreds of civic environmental stewardships groups are working in cities across the United States has gotten easier for the public, municipal agencies, and nonprofits, thanks to the continued work of the Stewardship Mapping and Assessment Project (STEW-MAP). STEW-MAP, developed by scientists from the Northern Research Station, supports urban natural resource management, policymaking, and public outreach with databases and interactive maps. This year, the STEW-MAP team continued to expand the project's geographic reach as well as its products and platforms. The team has launched a new multi-city online portal (http://stewmap.net/), which provides information about STEW-MAP projects in New York City, Chicago, Baltimore, and Seattle, including maps, network diagrams, and publications to date.