Methods to Conserve and Enhance the Production of Clean Water from Forests

Stream-side forests are crucial to the protection and enhancement of water resources. They are extremely complex ecosystems that provide useful ecosystem service in mitigating or controlling non-point-source pollution as well as providing optimum food and habitat for stream communities. As a component of an integrated management system including nutrient management and sediment and erosion control practices, stream-side forests have important effects on water quality. They remove excess nutrients and pollutants (that is, fertilizers and some pesticides) and sediments from surface runoff and shallow groundwater and they also shade streams to optimize light and temperature conditions and provide dissolved and particulate organic food for aquatic plants and animals.

Selected Research Studies

Critical Loads Resources for Federal Land Managers
The critical load is scientifically determined based on expected ecosystem response to a given deposition level.  The target load is set by policy makers, land managers, or air regulators to protect sensitive ecosystem components.  The target load may be higher or lower than the critical load, and is based on the economic cost of emissions reductions, timeframe, and other considerations.

This website contains documents and information useful to Federal Land Managers and others for understanding calculations of critical loads for nitrogen and sulfur deposition to forest ecosystems in theory and practice.

Salt Tolerance and Salinity Thresholds of Woody Energy Crops Irrigated with High-salinity Waste Waters
There is a need for environmental practices that merge intensive forestry with waste management. Producing short rotation woody crops for energy, fiber, and environmental benefits requires adequate irrigation and fertilization, which can be supplied via waste waters including landfill leachate. Yet, leachate often contains elevated levels of salts such as chloride and sodium that cause leaf chlorosis and necrosis, decreased biomass accumulation, and increased mortality. Therefore, there is a pressing need to learn about the response of poplar energy crops when salts are taken up into root, leaf, and woody (stem + branch) tissues, as well as identifying thresholds of salt concentrations and salinity that can be recommended for these crops in both field testing and production plantations.

Using Short Rotation Woody Crops to Remediate Soils Heavily Contaminated with Petroleum Hydrocarbons
Organic contaminants such as petroleum hydrocarbons are a major pollution source of surface water, groundwater, soil, and sediments throughout North America and the rest of the world. The rhizosphere is the zone of soil surrounding plant roots. Utilization of plants and their rhizospheric microorganisms to destroy, remove, and stabilize contaminated soils is currently gaining global attention because such systems are efficient and effective from biological and economic standpoints.

Sustainable Production of Woody Energy Crops with Associated Environmental Benefits
Increasing human population levels at regional, national, and global scales have heightened the need for proper management of residential and industrial waste. Contaminants from this waste stream have polluted water, air, and soil much faster than traditional technologies could remediate the problem. Therefore, we are combining intensive forestry and waste management methods to increase the potential for producing woody crops for energy and fiber, along with decreasing the environmental degradation associated with waste disposal and subsequent waste water production.

The Northeast Decision Model
The Northern Station is deeply committed to developing the Northeast Decision Model, a PC-based model designed to aid forest managers in selecting appropriate management practices. The model utilizes knowledge about a variety of ecosystem services, including water, wildlife, and aesthetics. Long-term data and knowledge about water resources obtained from the Hubbard Brook Ecosystem Study (HBES) is critical to the decision model. In addition, these scientists are preparing a stand-alone decision model dedicated to water resources in the 20-state area of Northeastern Area State and Private Forestry. This model enables forest and aquatic managers to choose from a variety of water yield and water quality goals and provide them with management recommendations.

Acid deposition and aquatic ecosystems
Many aquatic ecosystems in the Northeast are affected by acidic deposition from industrial pollution, primarily in the areas with thin soils overlaying granite rock. As base cations become depleted from these soils and they become less alkaline, there is less buffering capacity to counteract the acid deposition and ultimately, increased amounts of aluminum are leached into streams and lakes. Nitrogen saturation of soils will further acidify streamwaters and affect other aspects of the water’s chemical and biological quality and human safety. NRS scientists are studying the linkages between terrestrial and aquatic ecosystems to provide better information on the long-term impacts of acidic deposition.

Clearcutting and watershed flow
Watershed-level evaluations of forest management options (such as clearcutting) and modeling of storm water data show the relation between open or young forest land and increases and decreases in streamflow rates. These data have been translated to harvest-rate and open land guides for various national forest plans, state forest plans, and county forest plans as well as river-basin planning groups in the Lake States.

Mercury and water pollution
NRS scientists are assessing nutrient (nitrogen and phosphorus), carbon, and mercury pools and processes in a variety of ecosystems, including forests, riparian and wetland systems, peatlands, and agricultural watersheds. Ecosystem carbon work extends into characterizing the pools of coarse woody debris in forested riparian areas and streams. This mercury work is focused on two main efforts, one to characterize the mercury cycle under increased sulfate deposition and a second to understand the influence of prescribed fire on mercury cycling.

Groundwater-wells on the Marcell Experimental Forest (MEF)
MEF incorporates an extensive and long-term evaluation of groundwater wells. These data are used in combination with paleo-botanical studies of peat profiles, and soil hydraulic conductivity to illustrate the significance of deep seepage to water and nutrient budgets on experimental watersheds. The MEF along with (now) some 200 sites in the United States has documented the chemistry of precipitation and trends in atmospheric deposition in the United States for the last 25 years. Currently, the MEF has built 8 years of mercury deposition data and has contributed to the evaluation of methane as a greenhouse gas and its potential effects on global warming processes.