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Hydrologic Effects of a Changing Forest Landscape (2008)

Chapter: 5 Recommendations for Forests and Water in the Twenty-First Century

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Suggested Citation:"5 Recommendations for Forests and Water in the Twenty-First Century." National Research Council. 2008. Hydrologic Effects of a Changing Forest Landscape. Washington, DC: The National Academies Press. doi: 10.17226/12223.
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Suggested Citation:"5 Recommendations for Forests and Water in the Twenty-First Century." National Research Council. 2008. Hydrologic Effects of a Changing Forest Landscape. Washington, DC: The National Academies Press. doi: 10.17226/12223.
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Suggested Citation:"5 Recommendations for Forests and Water in the Twenty-First Century." National Research Council. 2008. Hydrologic Effects of a Changing Forest Landscape. Washington, DC: The National Academies Press. doi: 10.17226/12223.
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Suggested Citation:"5 Recommendations for Forests and Water in the Twenty-First Century." National Research Council. 2008. Hydrologic Effects of a Changing Forest Landscape. Washington, DC: The National Academies Press. doi: 10.17226/12223.
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Suggested Citation:"5 Recommendations for Forests and Water in the Twenty-First Century." National Research Council. 2008. Hydrologic Effects of a Changing Forest Landscape. Washington, DC: The National Academies Press. doi: 10.17226/12223.
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Suggested Citation:"5 Recommendations for Forests and Water in the Twenty-First Century." National Research Council. 2008. Hydrologic Effects of a Changing Forest Landscape. Washington, DC: The National Academies Press. doi: 10.17226/12223.
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Suggested Citation:"5 Recommendations for Forests and Water in the Twenty-First Century." National Research Council. 2008. Hydrologic Effects of a Changing Forest Landscape. Washington, DC: The National Academies Press. doi: 10.17226/12223.
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Suggested Citation:"5 Recommendations for Forests and Water in the Twenty-First Century." National Research Council. 2008. Hydrologic Effects of a Changing Forest Landscape. Washington, DC: The National Academies Press. doi: 10.17226/12223.
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Suggested Citation:"5 Recommendations for Forests and Water in the Twenty-First Century." National Research Council. 2008. Hydrologic Effects of a Changing Forest Landscape. Washington, DC: The National Academies Press. doi: 10.17226/12223.
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Suggested Citation:"5 Recommendations for Forests and Water in the Twenty-First Century." National Research Council. 2008. Hydrologic Effects of a Changing Forest Landscape. Washington, DC: The National Academies Press. doi: 10.17226/12223.
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Suggested Citation:"5 Recommendations for Forests and Water in the Twenty-First Century." National Research Council. 2008. Hydrologic Effects of a Changing Forest Landscape. Washington, DC: The National Academies Press. doi: 10.17226/12223.
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Suggested Citation:"5 Recommendations for Forests and Water in the Twenty-First Century." National Research Council. 2008. Hydrologic Effects of a Changing Forest Landscape. Washington, DC: The National Academies Press. doi: 10.17226/12223.
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Suggested Citation:"5 Recommendations for Forests and Water in the Twenty-First Century." National Research Council. 2008. Hydrologic Effects of a Changing Forest Landscape. Washington, DC: The National Academies Press. doi: 10.17226/12223.
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Suggested Citation:"5 Recommendations for Forests and Water in the Twenty-First Century." National Research Council. 2008. Hydrologic Effects of a Changing Forest Landscape. Washington, DC: The National Academies Press. doi: 10.17226/12223.
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Suggested Citation:"5 Recommendations for Forests and Water in the Twenty-First Century." National Research Council. 2008. Hydrologic Effects of a Changing Forest Landscape. Washington, DC: The National Academies Press. doi: 10.17226/12223.
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Suggested Citation:"5 Recommendations for Forests and Water in the Twenty-First Century." National Research Council. 2008. Hydrologic Effects of a Changing Forest Landscape. Washington, DC: The National Academies Press. doi: 10.17226/12223.
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Suggested Citation:"5 Recommendations for Forests and Water in the Twenty-First Century." National Research Council. 2008. Hydrologic Effects of a Changing Forest Landscape. Washington, DC: The National Academies Press. doi: 10.17226/12223.
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Suggested Citation:"5 Recommendations for Forests and Water in the Twenty-First Century." National Research Council. 2008. Hydrologic Effects of a Changing Forest Landscape. Washington, DC: The National Academies Press. doi: 10.17226/12223.
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5 Recommendations for Forests and Water in the Twenty-First Century The preceding chapters have outlined the working understanding of (1) forests, forest management, and emerging issues facing forests (Chapter 2); (2) the state and limits of the body of forest hydrology science (Chapter 3); and (3) research needs to meet management challenges in changing forest landscapes (Chapter 4). Common themes thus far in the report include rapid changes in forests and water systems, science, and management; fragmentation in technology and information transfer across the scientific, management, and citizen communities; and the need to apply scientific principles to larger spatial and longer temporal scales. This chapter builds on previous chapters to recommend actions for scientists, managers, and citizens to better understand connections between forests and clean, plentiful water and to use that understanding to promote sustained water resources from forests. These rec- ommendations are structured to begin to bridge some of the fragmented elements across scientific research, management policies, and community activities. RECOMMENDATIONS FOR FOREST HYDROLOGY SCIENTISTS Managers and citizens will make policy and land use decisions about forests and water based, in part, on scientific knowledge, which elevates the role of scien- tists in those decisions. Forest hydrology plot, process, modeling, and watershed studies provide the foundation for water and forest resources for this and subse- quent generations. Recommendations for scientists to meet water and forest needs fall into three categories: maintaining and enhancing watershed studies, incorporat- ing emerging technologies in research, and developing models for addressing man- agement needs in an uncertain future. Maintaining and Enhancing Small Watershed Studies The combination of small watershed and process studies has built a solid foun- dation of forest hydrology science (Stednick et al., 2004). Over the last half of the twentieth century, small watershed studies collected hydrologic data from forests in many geographic regions, and some of these data span multiple decades. For the oldest records, efforts may be needed to transcribe analogue or hand-written records into digital formats. No matter the form, data records from all small watersheds are of great value for scientists and managers because they provide a foundation for long-term monitoring as well as a collective database that can be used for meta- analyses of the effects of forest change on runoff (e.g., Jones, 2000). 95

96 HYDROLOGIC EFFECTS OF A CHANGING FOREST LANDSCAPE Long-Term Monitoring Data Monitoring involves repeated data measurements that are used to detect changes or trends over time. Two types of monitoring are useful to forest hydrol- ogy: (1) continuous or repeated measurements of streamflow, stream temperature, and stream chemistry; and (2) records obtained over an area, such as by aerial pho- tography or satellite imagery. As these data accumulate over time, they greatly in- crease in value. Long-term monitoring permits observation and contextualization of extreme hydrologic events; detection of trends or cycles in climate or vegetation; and assessment of long-term responses to experimental treatments or disturbance (e.g., Stednick et al., 2004; Jones, 2005). Monitoring records from nested water- sheds (i.e., from headwaters to large watersheds) can reveal cumulative watershed effects. Finally, monitoring data can be used to validate models, including those that predict responses to extreme events. Pieces of the infrastructure for long-term monitoring are already in place. Small watersheds exist on public land, including properties maintained by the U.S. Forest Service, the Agricultural Research Service (ARS), the U.S. Geological Survey (USGS), the Department of Energy (DOE), and the National Park Service. Addi- tional hydrologic data are available from the Environmental Protection Agency. In addition, the U.S. Geological Survey has a national streamgaging system that col- lects hydrologic flow statistics on streams across the country, and many of these gaging stations have multiple decades of streamflow information. Of serious con- cern is that many long-term monitoring efforts have been, or are at the risk of being, suspended due to funding and other constraints. Maintaining existing small watershed studies and reestablishing data collection at abandoned sites could help address key questions about the long-term hydrologic effects of forest change and conversions. Resurrected monitoring and data collec- tion activities could provide information on measurable hydrologic effects at aban- doned experimental watersheds and monitoring stations that have experienced fires or insect infestations since data collection ceased. For example, reestablishing measurements at the historic, experimental Wagon Wheel Gap watersheds in Colo- rado could allow comparisons of earlier data on forest cover change with data rep- resenting the ranching and second-home development that now exists in the water- shed. The Watts Branch watershed in Maryland, where Leopold and colleagues (Leopold et al., 1964) conducted their fundamental studies of channel-forming flows, has subsequently undergone extensive land use change and downcutting of the channel. Recent historical reconstructions (Walter and Merritts, 2008) indicate that downcutting of Watts Branch and many other eastern streams was due to early to mid-nineteenth century breaching of small mill dams that had impounded sedi- ment eroded from forest conversion to agriculture during the 1700s and 1800s. Reestablished streamflow monitoring at sites such as Wagon Wheel Gap and Watts Branch could improve understanding of streamflow responses to complex changes in land use and natural disturbance. In places where data collection has been reestablished on small watersheds, it has produced valuable insights. For example, small instrumented watersheds in the

RECOMMENDATIONS FOR FORESTS AND WATER IN THE 21ST CENTURY 97 ponderosa pine forests of central Arizona were reinstrumented after the Rodeo- Chediski fire of 2002, and these new data allowed comparison of post-fire effects to pre-fire conditions of the 1970s (Ffolliott and Neary, 2003). Also, small instru- mented watersheds in Coyote Creek, Oregon, were reinstrumented 35 years after forest harvest treatments, and these new data allowed detection of long-term forest regeneration and fire suppression effects on streamflows (Perry, 2007). Small Watershed Data as a Meta-Experiment One of the great values of forest hydrology science in small watersheds during the twentieth century lies in the power of the collective dataset, which spans broader spatial scales, research goals, and geographic regions than any individual site. New analyses of the various data in this collective dataset could treat the entire collection of small watershed data as a “meta-experiment.” This meta-experiment would require a new approach to data analysis and could be structured to address some of the research and management questions that span large spatial scales or long time periods. Using the data in this way could extend the familiar individual, small watershed studies to better understand connections between changing forest processes and watershed responses. A meta-experiment of forest hydrology from small watersheds could yield clearer understanding of long-term changes in forested “control” watersheds in re- sponse to fire suppression, climate change, and land use across different sized wa- tersheds (Jones, 2005). Multiple agencies (USFS, ARS, Environmental Protection Agency [EPA], DOE, and USGS) have historical records from early experiments that have not been digitized, as well as long-term records that are available online (e.g., the U.S. Forest Service’s Clim-DB/HydroDB project [http://www.fsl.orst.edu/ climhy/] or the USGS National Water Information System web site [http://water.usgs.gov/data.html}). This next generation of watershed analyses could be undertaken as a multiple agency effort to (1) reestablish monitoring at key sites that have valuable early records, but have been abandoned; (2) digitize histori- cal streamflow and other monitoring records; (3) gather data in centralized locations and make them available online; and (4) develop automated methods for compari- son of long-term records, using computer-based techniques. These data could then be analyzed as a collective set to detect changes across many watersheds and to improve understanding of connections among hydrology, forest systems, land use, management, climate variations, and time. Recommendations for Small Watershed Studies • Scientists should continue small watershed experiments and studies and reestablish monitoring at key sites where data collection and monitoring activities have ceased; • Scientists should centralize historical records from watershed studies in

98 HYDROLOGIC EFFECTS OF A CHANGING FOREST LANDSCAPE digital, well-documented, publicly accessible databases; • Scientists should use the entire collection of small watershed studies as a meta-experiment to increase understanding of forest hydrologic processes; this ef- fort would involve the following elements: — Gathering all data in centralized locations that are available online; — Developing automated methods for comparison of long-term records, using current computer-based techniques; — Examining long-term “control” watershed variability and response to timber harvest, fire suppression, climate change, and disturbances; and — Investigating effects of hydrologic changes on aquatic ecosystems. Emerging Technologies for Quantitative Analysis In addition to continuing and enhancing paired watershed studies, some new and emerging technologies can help advance forest hydrology. Emerging technolo- gies relevant to forest hydrology include (1) satellite imagery and remote sensing, (2) distributed sensor networks, and (3) geographic information systems (GIS) and associated geostatistical and visualization techniques. These emerging technologies make possible data collection over large spatial areas that could be used in combi- nation with plot and process data to better understand how measurements in the experimental sites compare to unmeasured areas in the same watersheds or at the landscape scale (see Box 5-1). Remote Sensing Technologies Airborne and satellite remote sensing techniques can save time and costs asso- ciated with monitoring hydrologic processes over large watersheds and regions, including estimation storage of water in the atmosphere, snow, vegetation, and soil, as well as evapotranspiration (ET). New satellites such as the Terra and Aqua, which both carry the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor, are viewing the entire Earth's surface every one to two days, acquiring data in 36 spectral bands (groups of wavelengths). Currently available MODIS image products provide daily estimates of ET at 1 km resolution. Other satellites operat- ing in both the optical and the microwave parts of the spectrum are useful for map- ping areas of inundation and saturation (Toyra et al., 2001; Sass and Creed, 2007; Clark and Creed, submitted). MODIS, with scaling techniques to reconcile differ- ences in resolution, is being used to provide distributed water balance information at fine spatial and temporal scales (Singh et al., 2004). LiDAR (Light Detection and Ranging) is another emerging technology relevant to forest hydrology. LiDAR imagery has become increasingly available in recent years. Raw LiDAR data can be processed in different ways. In their most common form, LiDAR data are processed into topographic data, and in this form, LiDAR has

RECOMMENDATIONS FOR FORESTS AND WATER IN THE 21ST CENTURY 99 BOX 5-1 Applications of Diffuse Reflectance Spectroscopy and Stable Isotopes to Monitor Landscape Features and Environmental Services Scientists from the World Agroforestry Center, headquartered in Nairobi, Kenya, and col- leagues have developed and applied diffuse reflectance spectroscopy and isotope methodolo- gies to make rapid assessment of the impacts of deforestation and other land use changes on ecosystem properties, soil organic carbon, and soil quality (fertility). Areas of sediment deposi- tion have been linked to source areas of sediment from upland soil erosion. The technology presently requires that reference soil spectral libraries be developed from soil samples ob- tained from the watersheds of interest. “Reflectance fingerprints” are obtained that can quan- tify and simultaneously predict multiple soil and plant properties. These technologies have promise for applying remote sensing to assess the spatial condition of soils and vegetation that control water flow and water quality. SOURCES: Shepherd and Walsh (2002, 2004); Vagen et al. (2005). revolutionized the mapping of topography at fine spatial scales. In a less commonly used form, these data can be processed into forest canopy structure (Lefsky et al., 2002). In this form, the data have an unrealized potential to provide insights as to how canopy structure affects forest hydrologic processes. Through MODIS and LiDAR, essential data that were previously unavailable or difficult to obtain can now be used to model and more accurately predict water storage and flows through large watersheds and regions. Distributed Sensor Networks Multisensor networks connected through wireless technology are under rapid development. These networks are based on nanotechnology and can inexpensively measure key variables such as soil moisture and temperature, at high spatial and temporal resolutions (Szewczyk et al., 2004). At this point in their development, novel sensor networks are limited by basic engineering constraints, such as power sources and technical challenges of processing large amounts of data. Current ef- forts to establish and test sensor networks are focusing on the plot or small water- shed scale, but they are not yet being implemented at larger spatial scales. Still, sensor networks hold promise and possibilities to greatly improve understanding of hydro-ecologic processes at fine scales. Geographic Information Systems and Geovisualization Over the past few decades, developments in geographic information systems, including global positioning systems (GPS), digital elevation models (DEMs), and computer capabilities have greatly advanced the ability to collect and analyze very large spatial and temporal datasets (Guertin et al., 2000). GIS has been shown to be

100 HYDROLOGIC EFFECTS OF A CHANGING FOREST LANDSCAPE a powerful tool, especially when combined with spatial modeling, to predict water and sediment transport in small and large watersheds. For example, the NetMap system (Benda et al., 2007) predicts erosion potential, sediment supply, road den- sity, forest age, fire risk, hillslope failures, and stream habitat indices. Models with watershed terrain analysis features can facilitate planning and management such as targeting “ecological hotspots” for stream restoration. The results can be useful for comparing alternative management scenarios and assessing cumulative watershed effects (CWEs). These technologies are progressing rapidly, allowing new types of predictions at finer resolution and over larger areas than were thought practical even a decade ago. Recommendations for Emerging Technologies • Scientists should refine GIS, remote sensing, and sensor networks to in- crease understanding and prediction accuracy of hydrologic responses at large wa- tershed scales. • Forest hydrologists should be trained to understand and use new GIS, re- mote sensing, and sensor network tools for forest hydrology applications or should develop effective collaborations with specialists. Hydrologic Models Models are important tools for scientists to predict, simulate, and compare the effects of different controlling factors from theory, experiments, and observations across various spatial and temporal scales. In forest hydrology, numerous hydro- logic models have been developed for many different objectives (Singh, 1995; Singh and Frevert, 2006), such as determining the size of culverts for roads or pre- dicting the hydrologic impacts of land use change over different spatial scales and time periods. These models vary in how they represent hydrologic processes, vege- tation, soils, groundwater, and runoff; they also vary in the spatial and temporal scales at which they simulate hydrologic processes. Many hydrologic models have limited capacity to simulate the hydrologic processes and response of natural and altered forested watersheds. One important limitation is due to an implicit assumption that overland flow is the dominant cause of runoff in forested watersheds (Dunne and Leopold, 1978; Hawkins, 1993; Haw- kins and Khojeini, 2000; Eisenbies et al., 2007) and that models of sediment pro- duction are predicated on these overland flow models (Renard et al., 1997; Williams, 1995; Neitsch et al., 2002; Boomer et al., 2008). Another limitation is that most hydrologic models are developed and validated at the spatial scale of small watersheds, and it is difficult to connect forest hydrologic models to models at the large-watershed scale, or to regional or global climate models. Models have great potential to represent and communicate hydrologic effects and CWEs, but scientists differ on how to approach this challenge. Many modelers

RECOMMENDATIONS FOR FORESTS AND WATER IN THE 21ST CENTURY 101 agree that physically based models are more illuminating than models based on empirical relationships (Sidle, 2006). However, advances are needed to develop physically based models at larger spatial and longer temporal scales than the small watershed scale at which models are typically developed and tested. Ideally, physi- cally based models would be based on data and parameters that forest and water managers monitor. Large-scale monitoring using new technologies and long-term monitoring of watersheds can provide some basis for developing scaling rules. The research needs for advancing forest hydrology science include understanding long- term and landscape-scale hydrologic effects of fire and fire suppression, climate change, and cumulative watershed effects (see Chapter 4). Spatially explicit as- sessments and physically based models designed to simulate, predict, or represent these phenomena form the basic needs of forest hydrology-related models for today and the foreseeable future. Recommendations for the Next Generation of Hydrologic Models for Forest Hydrology Applications • Forest hydrologists should extend the capability of models to incorporate the kinds of changes happening in forests, such as fire, cumulative watershed ef- fects, and climate change; • Forest hydrologists should advance models to simulate hydrologic proc- esses across large watersheds; and • Forest hydrologists should use emerging technologies and long-term data- sets to build and test the next generation of forest hydrology models. RECOMMENDATIONS FOR MANAGERS Evolving Best Management Practices Best management practices (BMPs) are widely used to prevent or reduce the negative hydrologic effects of forests and land use activities (see Box 5-2). For- estry BMPs are forest management practices intended to mitigate the negative con- sequences of timber harvest, road construction and maintenance, reforestation, or other forest management practices (Binkley and Brown, 1993; Seyedbagheri, 1998; Aust and Blinn, 2004). BMPs are employed in forests of many different owner- ships across the United States. Although “best” connotes an ideal condition or superior approach, in fact, BMPs are most often negotiated compromises between parties with economic inter- ests in management activities and those with interests in environmental protection. The balance between these two continually evolving sides is a “best” compromise. The environmental side of this negotiation is required by key pieces of legislation, such as the Clean Water Act (CWA) of 1972. A number of studies have assessed compliance with and effectiveness of BMPs with respect to 1970s goals for envi- ronmental protection, such as reducing nonpoint source pollution (Binkley and

102 HYDROLOGIC EFFECTS OF A CHANGING FOREST LANDSCAPE Box 5-2 BEST MANAGEMENT PRACTICES Best management practices (BMPs) are effective, practical, structural or nonstructural methods that prevent or reduce the movement of sediment, nutrients, pesticides, and other pollutants from the land to surface or groundwater, from nonpoint sources such as silvicultural activities (Brown et al., 1993; Brooks et al., 2003; Chang, 2003). The Federal Water Pollution Control Act Amendments of 1972, Public Law 92-500 (and as amended by Section 319, 1986) require the management of nonpoint sources of water pollu- tion from sources including forest-related activities. BMPs have been developed to guide forest landowners, other land managers and timber harvesters toward voluntary compliance with this act. A central objective of this law is to maintain water quality to provide "fishable" and "swim- mable" waters. The Environmental Protection Agency (EPA) recognizes the use of BMPs as the primary method of reducing nonpoint source pollution. Nonpoint sources of pollution are diffuse and may include fertilizers, herbicides, and in- secticides from agricultural lands and residential areas; oil, grease, and toxic chemicals from urban runoff and energy production; sediment from construction sites, crop, and forestlands, and eroding stream banks; salt from irrigation practices and acid drainage from abandoned mines; and bacteria and nutrients from livestock, pet wastes, and septic systems. The amounts of pollutants from single locations often are small and insignificant, but when combined over the landscape, they can create water quality problems. The adoption and use of BMPs help achieve the following water quality goals: 1. To maintain the integrity of stream courses; 2. To reduce the volume of surface runoff originating from an area of forest management disturbance and running directly into surface water; 3. To minimize the movement of pollutants (e.g., pesticides, nutrients, petroleum prod- ucts) and sediment to surface and ground water; and 4. To stabilize exposed mineral soil areas through natural or artificial revegetation. Although it is unrealistic to expect that all nonpoint source pollution can be eliminated, BMPs can be used to minimize the impact of forestry practices on water quality. A thorough understanding of BMPs and flexibility in their application are of vital importance in selecting BMPs. More than one BMP may be effective for a given situation. BMPs usually are designed to be practical and economical while maintaining both water quality and the productivity of forest land. SOURCES: Hawaii Watershed and Management Program (http://www.state.hi.us/dlnr/ do- faw/wmp/bmps.htm) and Environmental Protection Agency (http://www.epa.gov/watertrain/ forestry/ forestry3.htm). Brown, 1993; Aust and Blinn, 2004). In these studies, compliance with BMPs var- ied from 30 to more than 90 percent, with lower levels of compliance associated with road and trail decommissioning and higher levels of compliance with riparian buffer strips (Briggs et al., 1998; Schueler and Briggs, 2000). Studies in the eastern United States have shown that BMPs significantly lowered nonpoint source pollu- tion (sediment, temperature, some nutrients) from clear-cuts and roads (Lynch et al., 1985; Lynch and Corbett, 1990; Kochenderfer et al., 1997; Arthur et al., 1998; Wynn et al., 2000; Vowell, 2001; Aust and Blinn, 2004). Studies indicate that

RECOMMENDATIONS FOR FORESTS AND WATER IN THE 21ST CENTURY 103 BMP effectiveness is site-dependent (Blinn and Kilgore, 2001; Broadmeadow and Nisbet, 2004; Lee et al., 2004), although some general trends emerge. Assessments conducted in the 1980s and 1990s give high marks to BMPs, such as riparian buffer strips for effectiveness in reducing local sediment contributions to streams and other forms of nonpoint source pollution (Ice 2004). However, very little research has investigated whether the current suite of BMPs will be effective in reducing cumu- lative watershed effects, maintaining viable fish populations, or preserving the in- tegrity of forest and stream ecosystems (Swanson and Franklin, 1992; Bisson et al., 1992, Ice 2004). Forest and watershed managers have an important role to play in the evolution of BMPs. As implementers of forest policy and prescriptions, forest and water managers can assess the effectiveness of BMPs relative to the broader goals of con- temporary forest management. Similarly, through their role as implementors of BMPs, managers can assist in BMP evolution to keep BMP design and goals cur- rent with contemporary management practices. Recommendations for Managers to Assist the Evolution of BMPs • Managers should catalogue individual or agency BMP use, design, and goals at the national level and make this information available to the public; • Managers should undertake monitoring to measure effectiveness of indi- vidual BMPs as well as cumulative effects of BMPs; and • Managers should coordinate these monitoring results with regional state, federal, or citizens groups to assist in the evolution of BMPs in an adaptive man- agement framework. Adaptive Management Adaptive management is an approach to natural resources management that promotes carefully designed management actions, assessment of the impact of these actions, and subsequent policy adjustments. An adaptive management strategy ex- plores means of coupling natural and social systems in mutually beneficial ways. Adaptive management recognizes that natural and social systems are not static; they evolve in ways that are often unpredictable over both time and space. In addition to flux in natural systems, adaptive management assumes that human systems change and human interventions induce subsequent ecological adjustments (NRC, 2002). Adaptive management seeks to narrow differences among stakeholders by encour- aging them to implement new approaches that will allow people to live with and profit from natural ecosystem variability at socially acceptable levels of risk (Light et al., 1989). Adaptive management can help managers learn to protect land and water re- sources, using experiments, monitoring, and modeling. In forest watershed man-

104 HYDROLOGIC EFFECTS OF A CHANGING FOREST LANDSCAPE agement, adaptive management means the design of forest management actions based on consensus among stakeholders, monitoring of experiment outcomes, and redesign of forest management practices based on this learning. Monitoring and modeling in the context of adaptive management could permit assessment of cumu- lative watershed effects that encompass complex interactions of water flow, quality, and sediment between headwater catchments and downstream areas (MacDonald and Coe, 2007). There are limitations to the adaptive management approach. Some manage- ment-induced responses may be difficult to detect, particularly at large scales, be- cause they may be small in relation to natural variability or delayed in time after the management action. Adaptive management approaches are also limited in situations where management activities or the resource changes are nearly irreversible. Despite these limitations, adaptive management offers a framework for manag- ers to work effectively with scientists and stakeholders. Managers can participate in adaptive management by (1) engaging in research-manager partnerships to iden- tify properties of watersheds that should be monitored, (2) conducting the monitor- ing of these properties, and (3) interpreting and communicating results of monitor- ing. Modeling is often needed to interpret monitoring results, particularly at larger scales where various land use changes combine to yield an integrated response (see recommendation for modeling by scientists, above) or to incorporate monitoring results into an adaptive management design. Recommendations for Managers in Adaptive Management • Managers should design adaptive management approaches for forested wa- tersheds that coordinate management, research, monitoring, and modeling efforts; • Managers should work with scientists to formulate adaptive management experiments and strategies that assess the effectiveness of current forest manage- ment practices relative to contemporary issues at both the local project scale and the large watershed scale; and • Managers should establish rigorous, consistent monitoring programs, ana- lyze the data collected, and use these data to adapt their management. • Because there are unavoidable lags in ecological, environmental, and so- cial responses to management practices, it is essential that agencies commit to the adaptive management process for multiple decades. RECOMMENDATIONS FOR CITIZENS AND COMMUNITIES Over the past decades, watersheds that were once mostly forested and under single ownership have become fragmented forest patches within a mosaic of land uses and ownership (Chapters 2 and 4). This mosaic obscures the direct effects of forest management and disturbance on hydrology, and makes it difficult to ascribe

RECOMMENDATIONS FOR FORESTS AND WATER IN THE 21ST CENTURY 105 cumulative watershed effects to specific forest management actions (see Chapter 4). CWEs are sometimes most easily understood during extreme events (see Box 5-3) in large watersheds. Such events remind communities that forest management and disturbance effects on hydrologic processes pervade all ecosystems, including hu- man-dominated ones. Water researchers and policy makers have long recognized the benefit of orga- nizing land and water management around hydrologic systems (WWPRAC, 1998; Brooks et al., 2003) and have promoted an integrated approach to watershed man- agement (NRC, 1999). Integrated watershed management is an approach that can help identify water movement from headwaters through various land uses to sus- tainable water supply and quality; it can also provide a means to appraise or manage forest effects on water. The complexity of the water resource and the variety of institutions that govern or oversee it present major challenges. Despite the obvious physical connections, surface water and groundwater are often studied, owned, and regulated as separate resources. Efforts are under way in many states to connect surface and groundwater management, particularly in states facing impending water scarcity, such as Arizona, California, and Colorado (Blomquist et al., 2004). Although the research community and related entities have recognized the benefits of integrated watershed management, this management has been and largely remains fragmented within and across watershed boundaries. Increasing specialization and pressure from local community groups can create an impetus to coordinate watershed efforts and use integrated watershed management in this co- ordination. Watershed Councils Watersheds are natural units fractured by ownership and land use. Cumulative watershed effects, changes in land ownership, changing population and develop- ment patterns, and water supply concerns have spurred local efforts to reconnect watershed hydrology and land use from the community and grass-roots level. New community-level watershed councils and forest groups are proactive in watershed- based and locally driven restoration and management in some areas. Collaborative watershed institutions, such as watershed management partner- ships, councils, or districts, can facilitate the cooperation and collaboration neces- sary to achieve integrated watershed management. Watershed partnerships, coun- cils, and districts have proliferated across the country in recent decades (Kenney et al., 2000; Brooks et al., 2003; Sabatier et al., 2005; Gregersen et al., 2007). These locally led groups share some common attributes in that most (1) use watershed boundaries to define their jurisdictions; (2) involve a wide variety of agencies and stakeholders from all levels of government and society and treat all participants as equals; (3) negotiate face-to-face to solve problems using collaborative methods; (4) seek mutually beneficial and consensus solutions to watershed management

106 HYDROLOGIC EFFECTS OF A CHANGING FOREST LANDSCAPE BOX 5-3 Extreme Storms of December 2007 in Washington and Oregon: Cumulative Water- shed Effects and Monitoring In December 2007, Interstate 5, the major north-south transportation artery for the west coast of the United States was closed for 10 days by flooding that inundated homes and stores and stopped most truck-based transportation (see photo). The flooding was the result of an extreme storm event that produced hurricane force winds along the Oregon coast and deliv- ered more than 35 cm of precipitation in 24 hours to the headwaters of the Chehalis River in central western Washington. In this area, about 30 river gages recorded peak flows that ranked in the top five events, and 10 gages recorded all-time highs. According to the U.S. Geological Survey, this was a 100- to 500-year flood event, based on reconstructed flood mag- nitudes. Flooding around I-5 was exacerbated by debris flows that carried a mixture of sedi- ment, large wood, and water down the south fork of the Chehalis River (see photo). The land- slides that generated the debris flows originated in steep lands owned by the Weyerhauser Corporation along Stillman Creek in the headwaters of the south fork of the Chehalis River. These lands had been clear-cut three and a half years before. Events of this type are rela- tively common in the Pacific Northwest, where timber is an important industry, slopes are steep and prone to landsliding, and intense storms can deliver large amounts of rainfall. The com- plex circumstances in this case illustrate the challenges of identifying and disentangling the direct effects of forest management on hydrologic processes from the indirect and interacting effects of storm size, precipitation, and wind speeds. problems; and (5) build common understanding through extensive, collective fact finding to develop shared understanding of problems and opportunities. Working across a variety of political, technical, social, and economic bounda- ries poses continuing challenges, but a watershed council’s focus on a specific place gives it a context and sense of shared goals that can begin to bridge jurisdictional and disciplinary boundaries. Aplet et al. (1993) recommended community-based institutions to facilitate coordination among various owners to achieve disparate goals within common ecological and social settings. Citizen groups can participate in this community-based coordination by using existing regulations to provide input (public comment) about timber harvest plans and practices affecting land use, water quality, endangered species, fire prevention, wetlands, and forest chemicals, on both private and public lands.

RECOMMENDATIONS FOR FORESTS AND WATER IN THE 21ST CENTURY 107 Photo credit: http://blog.oregonlive.com/breakingnews/2007/12/large_chehalis-flood-01.jpg. Reprinted with permission from Oregon Live LLC. Copyright 2007 by Oregonian Publishing Company. SOURCES: Reiter (2008); Seattle Times (2007). Local collaborations are venues in which the effects of forest management are addressed at the watershed scale with buy-in from owners, providing a highly effec- tive forum for cooperation across ownerships. These new community groups can provide a basis for integrated watershed management that involves a variety of ex- isting institutions responsible for water supply and land management. Community groups would not replace the technical expertise represented by agencies, but they could help initiate and direct management and restoration actions within water- sheds.

108 HYDROLOGIC EFFECTS OF A CHANGING FOREST LANDSCAPE Recommendations to Advance Community Watershed Groups • Citizens should request the USFS, U.S. Bureau of Reclamation, and other federal agencies to provide technical expertise in forest or water resources man- agement to community watershed councils and institutions that focus on local wa- tershed management or restoration. Federal agencies should be authorized and funded to provide such technical assistance. • Citizens should request—and federal and state governments should pro- vide—financial and information resource support for these organizations to ensure continued operation. • Citizens should participate in management and restoration actions within watersheds. Community Engagement with Industry and Federal Agencies “Green certification” for sustainable forest management provides another in- centive for forest managers to address water quantity and quality issues. Certifica- tion is increasingly necessary for large forest landowners to maintain public accep- tance and market access for wood products. For example, the Forest Stewardship Council’s forestry management principles include, “Conserve biological diversity, water resources, soils, and unique and fragile ecosystems and landscapes, maintain- ing the ecological functions and integrity of the forest” (Washburn and Miller, 2003). Some certification systems explicitly require some level of research support to improve forest management as part of their certification requirements, and all require monitoring of forest practices. There is continued controversy about the effects of forest certification on biological diversity (Ghazoul, 2001) and whether forest certification is producing social change (Taylor, 2005). No research has ex- amined how forest certification affects water quantity and quality. Several federal programs now provide opportunities for community groups to influence local watershed management. The 2003 Healthy Forest Restoration Act (HFRA) aims to accelerate hazardous fuel reduction and forest restoration projects on federal lands at risk of fire or insect and disease epidemics. If communities de- velop their own Community Wildfire Protection Plan across public and private ownerships, the community receives funding priority under the National Fire Plan, and the Forest Service and the Bureau of Land Management (BLM) can expedite the fuel treatments through alternative environmental compliance options. HFRA also contains a watershed assistance provision (Title III) allowing the Department of Agriculture to provide technical, financial, and related assistance on non-federal forested land and potentially forested land. In 2003, federal laws were revised to allow so-called stewardship contracting with communities, the private sector, and others. The USFS and BLM may now enter into contracts with local organizations for up to 10 years to improve forest and rangeland health. Stewardship contracts focus on producing desirable results on the

RECOMMENDATIONS FOR FORESTS AND WATER IN THE 21ST CENTURY 109 ground that improve forest and rangeland health and provide benefits to communi- ties. For example, stewardship contracting allows private organizations or busi- nesses to do thinning and remove small trees and undergrowth; as partial payment, they are able to keep part of what they remove (http://www.forestsandrangelands. gov/stewardship/index.shtml#projects). Although many contracts focus on reducing fire risk, example projects also include objectives specifying effects on water from forests, such as “to reduce fuel levels and improve water quality consistent with healthy forest and watershed conditions,” or “to improve wildlife habitat, restore sagebrush-steppe habitat, and improve water flow through drainages,” or “removal of ponderosa pine and juniper, both of which invaded the riparian corridors and related drainages and are currently out-competing native riparian species.” Recommendations for Community Engagement with Industry and Federal Agencies • Communities should use public comment opportunities to provide informa- tion about the effects of forest management plans on local communities. • Communities should develop and promote forest certification programs that consider the effects of forest management on water resources. • Communities should engage in forest stewardship contracting with federal agencies and promote scientifically rigorous monitoring of these forest stewardship contracting projects to determine their effects on water quantity and quality. MOVING FORWARD: FOREST HYDROLOGY SCIENCE AND MANAGEMENT IN THE 21ST CENTURY This review and assessment of the state of forest hydrology knowledge at the beginning of the twenty-first century provides major findings regarding the current understanding of forest hydrology as well as information gaps and research needs to advance forest hydrology from principles to predictions for management. It also offers recommendations to meet those research needs for forest hydrology science and management (Table 5-1). Forest hydrology science has produced a solid understanding of the general principles and basic processes of how water is connected to and moves through forests. The current forest landscape is dynamic due to changing demographics, climate patterns, land use and ownership, and the increased demand for water. For- est science and management are adapting as the land uses and land ownership within forested watersheds become more heterogeneous, changes in climate and its effects are becoming more evident, and it is easier to visualize cumulative water- shed effects over larger spatial scales and longer periods of time. The strong foun- dation of general principles and basic processes in forest hydrology can be applied to meet research needs and fill information gaps over the coming decades.

TABLE 5-1 Current Understanding, Research Needs, and Recommendations for Sustaining Water Supplies from Forests 110 Information Gaps and Research Current Understanding Recommended Actions Needs Science The body of forest hydrology science Hydrologic effects of past Enhance, maintain, and reestablish derives from almost 100 years of management, such as fire abandoned small watershed studies at small spatial and time suppression, clear-cutting, roads studies scales Ways to quantify hydrologic Combine existing data from the large Forest hydrology science has responses at larger spatial and body of small watershed studies established general principles that temporal scales and analyze them for large-scale are understood with a high degree Ways to scale up findings from small trends as a meta-experiment of certainty describing direct spatial and short time scales to Use new technologies, including hydrologic effects of forest larger spatial and longer time sensor networks and remote management and disturbance scales sensing, to improve understanding Effects can be understood through Use general principles to predict of forest hydrology in changing changes in indirect hydrologic responses to landscapes • Forest structure changes in forest landscapes and Engage in adaptive management to • Magnitudes, rates, and flowpaths interacting responses to forest help managers and community • Erosion, nutrient cycling, and soil management and disturbance groups design monitoring chemistry strategies, develop and test models, and conduct studies Reduced forest cover results in relevant to management increased water yield that is • Generally short-lived • Greatest during times of water excess rather than water scarcity • Small or undetectable in water- scarce areas • May be associated with a decline in water quality Management Forests in the United States are Assessment of BMP effectiveness Advance BMP evolution by managed for a wide range of goals Principles and practices of adaptive rigorously assessing and and objectives: timber harvesting, management developing new BMPs and

road networks and road measuring their effectiveness construction, high-severity At the federal level, provide wildfires, and exurban sprawl sustained support for adaptive modify forest hydrology management activities, enabling Forest management practices are managers to partner with scientists evolving in response to to design and implement environmental change, social and monitoring, develop and test economic forces, and technological models, and conduct studies developments relevant to management issues BMPs are used to mitigate impacts Increase role of agency technical on water resources from forest expertise in watershed councils management activities Community Integrated watershed management How watershed councils and their Use watershed councils to meet is a viable vehicle for both stakeholders view and utilize forest multiple goals of integrated community groups and state and hydrology science and scientific watershed management at the federal agencies to help manage expertise from federal agencies community level water and forest resources at the How industry-sponsored green Expand the number and influence of community scale certification and federal forest watershed councils. Citizens groups can influence local stewardship contracts affect water Engage in adaptive management and integrated watershed quantity and quality from forests with scientists and managers management Community watershed groups benefit from state and federal agency technical expertise Existing laws can be used to strengthen the standing and influence of watershed councils New laws offer increased opportunities for community involvement 111

112 HYDROLOGIC EFFECTS OF A CHANGING FOREST LANDSCAPE problems; and (5) build common understanding through extensive, collective fact finding to develop shared understanding of problems and opportunities. Working across a variety of political, technical, social, and economic bounda- ries poses continuing challenges, but a watershed council’s focus on a specific place gives it a context and sense of shared goals that can begin to bridge jurisdictional and disciplinary boundaries. Aplet et al. (1993) recommended community-based institutions to facilitate coordination among various owners to achieve disparate goals within common ecological and social settings. Citizen groups can participate in this community-based coordination by using existing regulations to provide input (public comment) about timber harvest plans and practices affecting land use, water quality, endangered species, fire prevention, wetlands, and forest chemicals, on both private and public lands.

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Of all the outputs of forests, water may be the most important. Streamflow from forests provides two-thirds of the nation's clean water supply. Removing forest cover accelerates the rate that precipitation becomes streamflow; therefore, in some areas, cutting trees causes a temporary increase in the volume of water flowing downstream. This effect has spurred political pressure to cut trees to increase water supply, especially in western states where population is rising. However, cutting trees for water gains is not sustainable: increases in flow rate and volume are typically short-lived, and the practice can ultimately degrade water quality and increase vulnerability to flooding. Forest hydrology, the study of how water flows through forests, can help illuminate the connections between forests and water, but it must advance if it is to deal with today's complexities, including climate change, wildfires, and changing patterns of development and ownership. This book identifies actions that scientists, forest and water managers, and citizens can take to help sustain water resources from forests.

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