8 Restoration
The next topic in the habitat-focused techniques group centers on the idea of restoration. The traditional definition of restoration is returning an ecosystem to its former, undisturbed state with the original functions and structure. We will explore the background of restoration, its track record, and additional details on why this has become a very active management technique. We will end with a case study on the CALFED collaborative restoration program.
BACKGROUND ON RESTORATION
Humans have caused extensive change in landscapes all over the world (Turner 2010). More recently, people have started to recognize the extent of this change and are beginning to view restoration as a way to regain natural settings from derelict lands and waters, and improve degraded habitats and settings (example of restoration in Figure 8.1) (Higgs 2003). Restoration started becoming popular around 1990 as a new way to practice environmental conservation and has been gaining interest in the last few decades. The National Research Council (1992) defined restoration as: returning an ecosystem to its former, undisturbed state with its original functions and structure. This has become a common definition for restoration. The National Research Council recommends conducting an investigation of potential restoration sites by gathering old maps, finding accounts of the area’s history in newspaper articles and elsewhere, and speaking to local residents (National Research Council 1992; Jackson and Hobbs 2009). They also recommend following the practice of integrated resource management, which is management that seeks to restore the structure and function of whole ecosystems by striving to understand and respond holistically to cumulative ecological impacts. A second way is to locate a comparable ecosystem that has not yet experienced degradation and use that as a model environment (Stoddard et al. 2006). A holistic view of the structure and function of the ecosystem is needed for planning restoration activities.
In North America, we often use the Columbian landfall of 1492 as a restoration baseline (Leopold 1963). The pre-1492 landscape is thought of as a near natural environment, where native Americans were considered to be too few in number to have had a significant impact on the landscape. It was also proposed that the European colonization of North America started the major landscape changes and that they, at least in part, caused the extinction of some large animals (Martin 1973). Christopher Columbus ran into people soon after he landed on the shores of San Salvadore (Columbus and Las Casas 1989). There is ongoing debate about the time period in history when humans had the most widespread impact on the environment (Merchant 2005). The further we go back in history, the more we find human impacts on the North American environment (Grayson 2001). Nevertheless, the Columbian baseline is often used to separate landscapes that were transformed by people from those that possessed more natural landscape properties (Bjorkman and Vellend 2010).
Another way to think about restoration is as the practice of some activities that speed up ecosystem change (Hobbs and Cramer 2008). This is not returning an ecosystem to an undisturbed state with its original functions and structure, but rather improving an ecosystem to be more natural, sustainable, and self-regulating. The concept involves restoring the environment to promote more biodiversity and potentially support recovered species (Benayas et al. 2009). The focus is on undoing environmental damage as a way to recover environmental health and function (Figure 8.2). This view is different from natural restoration, which focuses on bringing an ecosystem back to a state of beneficial use, with a high potential for biological recovery. The general goal is to bring back a functioning ecosystem that is able to fit into the current landscape.
THEORETICAL CONCEPTS BEHIND ECOSYSTEM RESTORATION
Recreating nature is often the aim of ecosystem restoration because we want the ecosystem to function naturally and maintain itself (Figure 8.3) (National Research Council 1992). Often, biological restoration is important to maintain species and assemblages of species that were once prominent. A functional biological community is seen as the primary goal of restoration. If the ecosystem restoration site is isolated from colonization and dispersal sources, then human-assisted transport and release is required. The stability of the community and persistence of its member populations signal restoration success. It is important to reestablish key species that can shape the ecosystem (e.g., herbivores) and interact with a wide range of community members. The presence of herbivores will often shape their habitat’s plant cover, which can then affect other functions of the ecosystem. And, carnivores can influence herbivore density and behavior. Also, high species richness can accelerate successful ecosystem restoration (Williams et al. 2017). Increased ecosystem function, like primary and secondary production, is another clear sign of restoration success (Cortina et al. 2006). In addition, natural disturbances (e. g., floods and fires) need to be acceptable because natural disturbances alter the mix of species and foster higher biodiversity through time (Nilsson et al. 2001). Natural disturbances often favor some species while reducing the abundance of others. This process can reset the dominance of competitive species. The emergence of a new biological community, colonization, human-assisted return of species, key species that shape the ecosystem, stability of community, and natural disturbance are all important factors of restoration.
AN ALTERNATIVE VIEW OF RESTORATION
Traditionally, restoration is aimed at returning an ecosystem to its original, undiminished natural state. Another view of restoration embraces rebuilding ecosystems that have been damaged or destroyed thereby creating ecosystems that are sustainable, which can then return benefits to people (Alexander et al. 2016). This is very different from the traditional view of restoration, but this perspective is gaining acceptance because of climate change, the worldwide transport of species, and altered landscapes. This perspective is focused on recreating an ecosystem which has renewed biological function and ecosystem services. The idea is not to restore the ecosystem’s original condition, but to improve it by assisting its recovery (Jones and Schmitz 2009). Ecosystems are highly dynamic and change over time. Thus, the aim is to create a novel ecosystem at the original location, but one which differs from its previous state. The idea is to make the new ecosystem stable and highly resilient. Restoration plans and environmental managers would need to consider what is practical for the site, and develop a realistic plan to improve the ecosystem based on informed conclusions.
Ecosystems are not static, and often change. These changes may be brought about by external factors like climate, and they can also arise internally from different mixes of species. Change is an important ecosystem dynamic because it frequently favors some species over others which can alter the mix of species and promote greater biodiversity. These effects on the mix of present species promotes high biodiversity. Much of restoration planning views the ecosystem as static and is backward looking in that it aims for a fixed, desirable state from the past. The common expectation is a return to a set state. Note, it is not feasible to restore some settings to their original condition, such as mined lands and urban brownfields. In reality, societal interests shape restoration endeavors and ultimately determine the amount of funding and effort expended on the site. Consequently, societal interests must be addressed when planning an ecosystem-scale restoration effort since biocultural and eco-societal interests are an important part of restoration (Cairns 1995). Most restorations are financed through government programs, and the need for public support is essential. Also, public engagement and an image of the desired restoration endpoint help to generate and sustain effective restoration efforts (Palmer et al. 1997; Cairns 2000; Hobbs and Harris 2001; Hobbs 2007; Miller and Hobbs 2007; Hobbs et al. 2010). However, the public often finds it difficult to accept traditional restoration goals like structural properties, biological composition, and functional durability. In public discussions, a healthy environment is often the aim, but the attributes of a healthy environment such as vigor, organization, and resilience can seem arcane and challenging to explain. Some restorations fail because it may take years to determine whether changes are progressing in the intended direction. Many years may be needed to achieve that vision of restoration success, and along the way, deviations from the projected course can occur. At the same time, the public and local leaders are often too impatient to see tangible results from the restoration process. For restoration efforts to be effective, integrative, multi-disciplinary practices are needed and such practices must recognize and account for the social dimensions that inevitably attend such endeavors (Zweig and Kitchens 2010).
THE ROLE OF HABITAT IN RESTORATION
Recreating and diversifying habitat has become a leading strategy for ecosystem restoration. Habitat can be designed to support specific species, have a precise form, and create a visual image (Figure 8.4). Restoration activities create habitats, which are tangible resources. Diversifying habitat is believed to enhance biodiversity (Kremen 2020). Habitat restoration targets biological improvement which can increase biodiversity. However, there has been an inconsistent record of habitat restoration supporting improved biological communities, especially in rivers and streams (Scrimgeour et al. 2013). Maximizing habitat heterogeneity also has a mixed record in enhancing biodiversity (Denslow 1995; Palmer et al. 2010).
A common belief is that the general surroundings of the restoration site limit what can be realized with habitat improvements. Urban restoration is popular and typically includes stream and riparian habitats (Ingram 2008). However, little evidence exists that urban restoration can return an ecosystem to a healthy state. The limitations on biota in these ecosystems come from the surrounding area, like air and water pollution, erosion, quick runoff events, and the restrictions imposed by structural habitat. More emphasis needs to be placed on restoration site selection. The site should not be limited by its surroundings, and should be easily linked to a source of colonists which can respond to the habitat. Creating habitat to restore ecosystems may be alluring but full restoration may ultimately be beyond what can be accomplished. Habitat is required but not entirely sufficient to restore an ecosystem. More planning is required to find holistic solutions to environmental degradation at the site and its surroundings.
THE ESTUARY RESTORATION ACT AND ITS FOCUS ON HABITAT
In 2000, the United States Congress approved the Estuary Restoration Act, which engaged many agencies active in coastal waters (United States Code 2021). The current lead agency is now the National Oceanic and Atmospheric Administration (NOAA). The purposes of Act are to: 1) Promote the restoration of estuary habitat; 2) Develop and implement a National estuary habitat restoration strategy; 3) Provide federal assistance for estuary habitat restoration; and 4) Enhance monitoring and research capabilities. The implementation of the Estuary Restoration Act is an ecosystem-scale restoration effort to improve our estuaries for productive aquatic life and merge agency agendas around a goal.
NOAA promoted an organization called “Restore America’s Estuaries” (Restore America’s Estuaries 2002) and helped pair it with a scientific group called the “Coastal and Estuarine Research Federation” (Coastal and Estuarine Research Federation 2021). The planning process developed by these groups had three main parts (Figure 8.5). First, they planned to evaluate each estuary and its watershed to identify losses in habitat and opportunities for restoring habitats. Second, they planned to establish restoration priorities by identifying habitat needs, linking habitat to species benefits, and incorporating public interests and the economic value of the species. Finally, they sought to develop a plan for restoration which included stakeholder viewpoints, public input, conservation benefits, clear goals, and evaluation. Water quality issues are common challenges in estuaries, and inland dams and diversions can block the spawning of fish and other taxa. A broader view is needed, but promoting restoration is easier with tangible resources ahead of the argument.
NOAA and the United States Congress focused on habitat as a clear path to improvement. For estuaries, restoration is really about habitat. Habitat is generally thought of as the physical conditions needed for a species. It is possible to look at, photograph, and inventory habitat, so it is considered a tangible outcome of restoration activities. Habitat is linked to species and assemblages of species that live in the same region. Thus, it is important to target the needs of species or assemblages of species for restoration. Another common idea is that we can create a set of habitats that are persistent within the estuaries. However, this approach is not holistic and ecosystem based, so it would not return the environmental system to a sustainable condition.
EVALUATING RESTORATION SUCCESS
River and stream restoration has become a world-wide phenomenon as well as a booming enterprise (Palmer et al. 2005). Billions of dollars are being spent in the United States alone. Although there is growing consensus about the importance of river restoration, agreement on what constitutes a successful restoration project continues to be under discussion. Thus, much research on ecosystem restoration has been aimed at evaluating its success or failure (Ruiz-Jaen and Aide 2005; Zedler 2007). It is hard to measure whether restoration reestablishes the state, structure, and functions an ecosystem formerly possessed. Methods are being developed to determine what ecosystem restoration is accomplishing. However, data on the original ecosystem state rarely exist. Therefore, historical investigation processes are being used with paleoecological methods to reconstruct information about past ecosystems and create measures for ecosystem stability (National Research Council 1992). A second path is to find a reference ecosystem that has not been changed (Stoddard et al. 2006) and use that ecosystem as a model for planning the restoration project, and afterward for its evaluation. This option allows the restored ecosystem ‘s structure and function to be measured and characterized against benchmarks from the reference ecosystem. Then, the target ecosystem can be evaluated for needs and a plan developed for restoration activities. The problem with a simple reference is that it represents a single state or expression of ecosystem attributes. Either way, the focus is on emulating past or reference ecosystem conditions. Evaluation to document success at restoration is complicated and research is ongoing to create standardized evaluation criteria for the measurement of success.
Palmer et al. (2005) proposed five criteria for evaluation of ecological success by restoration efforts (Table 8.1). First, a guiding image of an ecological endpoint can be developed by historical reconstruction, reference site emulation, and expert formulation. Second, ecosystems are improved by clear progress toward the guiding image. Improvements can come in a range of levels and affect different ecosystem components, but real progress is linked to restoration activities. Restoration goals have been attained when defined ecological and stakeholder outcomes have been met and future efforts benefit from the understanding gained. Third, resilience is generally increased in order to achieve self-sustainable ecosystems. Measures of resilience are debated in the field of ecology but with time, resilient ecosystems maintain their properties and functions. Restoration measures should show a capacity to remain much like the guiding image despite stress and disturbance. Unless some level of resilience is restored, projects are likely to require on-going management and repair, the very antithesis of self-sustainability. Fourth, no lasting harm is done by restoration activities. Restoration is an intervention that causes impacts to the system, which may be extreme (e.g., changes in soil conditions, invasive plants, alterations of the surface topography). Finally, an ecological assessment is completed and data show improvements to the ecosystem. Well-documented projects that fall short of objectives may contribute to the future health of our landscapes through learning. These five measures are important to judge whether restoration activities have improved the ecological status of the ecosystem.
Table 8.1: Criteria for ecologically successful river restoration. Source: Palmer et al. 2005
The Society for Ecological Restoration International (Science and Policy Working Group 2004) defines restoration as a process of assisting the recovery of an ecosystem that has been degraded, damaged, or destroyed. They proposed nine attributes to use in determining if restoration has been accomplished (Table 8.2). First, the restored ecosystem has a characteristic biological assemblage such as grasslands, antelope, or prominent herbivores. Second, the ecosystem consists of indigenous species to the greatest extent possible. Native species should be easily seen and common. Third, all functional taxon groups for development and stability of the ecosystem are present. Carnivores have been shown to reduce the densities of herbivores which then shifts the plant cover of the ecosystem (Ripple and Beschta 2007). Carnivores are a functional group that has to be maintained to promote the plant cover that is characteristic of the ecosystem. Fourth, the physical environment of the restored ecosystem is capable of sustaining reproducing populations of the species necessary for the species’ continued persistence in the ecosystem. Fifth. the restored ecosystem functions normally and any signs of dysfunction are absent such as non-native dominated plant cover. Sixth, the ecosystem is suitably integrated into the larger landscape and interacts with it through abiotic and biotic flows and exchanges. The general idea is that the restored ecosystem fits into the landscape and exchanges animals, plants, water, and other chemicals with the landscape. Seven, potential threats to the integrity of the restored ecosystem from the surrounding landscape have been eliminated or reduced. Threats include activities like collecting plants and animals, spraying insecticides broadly, groundwater depletion, and others. Eight, the ecosystem is sufficiently resilient to maintain normal properties following periodic stress events like floods, high temperature periods, and droughts. Finally, the restored ecosystem is self-sustaining and has the potential to persist indefinitely under existing environmental conditions. Characterization of the nine attributes can show whether or not restoration progress is being made. If the site is showing clear signs of progress for all criteria, the restoration has accomplished its goal of improved environmental conditions for the ecosystem.
Table 8.2: Criteria for determining when restoration has been accomplished. Source: Science and Policy Working Group 2004
PROGRESS OF RESTORATION EFFORTS
Several reviews of restoration programs provide some insight into the progress of restoration efforts (Bernhardt et al. 2005; Bernhardt and Palmer 2011). A National river restoration synthesis (Bernhardt et al. 2005) was developed which included a database of more than 37,000 restoration projects (Figure 8.6). The United States spent $15 billion to restore streams and rivers during the period from 1990 to 2003, which is over $1 billion a year. The review discovered that funds came from many sources and that substantial societal investment in restoration was occurring. The review only covered rivers and streams though restoration efforts were occurring in other ecosystems. The most common goals for river restoration improvements were for enhanced water quality, management of riparian zones, improved stream habitat, fish passage, and bank stabilization. Approximately 20% of the projects had no goals, and many more projects stated such brief purposes that it was hard to determine whether projects were undertaken to restore stream ecosystems or were merely river manipulation projects (e.g., bank stabilization). Most restoration programs were very small with projects costing less than $45,000, thus many of these projects had narrow interests. Most projects (90%) did not have a plan for evaluation of the effects of restoration activities (e.g., no assessment or monitoring plan). This account gives a picture of what restoration is like in practice because it spans many projects over a decadal time period.
The Natural Heritage programs at the state level often aim to bring back endangered species or rare communities (e. g., marsh birds). Restoration of species is the central target of 25% of the projects; 30% address ecosystems and landscapes (Ehrenfeld 2000). The remaining 45% cover a variety of goals for eliminating limitations on species and the diversity of communities (Ehrenfeld 2000). Thus, the public has to be invested in restoration and the mission has to be broader. The restoration of numerous species at a site requires a diversity of habitats. A broad agenda for restoration supports the idea that the entire ecosystem needs to be healthy to support a diversity of species (Stranko et al. 2012).
Many gaps still exist in terms of restoration progress (Young et al. 2005; Christian-Smith and Merenlender 2010). Ladouceur and Shackelford (2021) issued a call for a global collation of restoration data so that knowledge gaps could be addressed and data synthesized to advance toward a more predictive science that could inform restoration efforts and assist in achieving more consistent restoration success.
CASE STUDY: CALFED COLLABORATIVE RESTORATION PROGRAM
California and the United States Federal government came together to form the CALFED Bay-Delta Program in 1994 (CALFED Bay-Delta Program 2021). CALFED was an ambitious, collaborative, ecosystem restoration program. At the point of its inception, it was the largest and most comprehensive collaborative water management program in the United States. It was centered where the Sacramento and San Joaquin rivers come together at sea level and form a delta that flows into the San Francisco Bay (Figure 8.7). The mission of the CALFED Bay-Delta Program was (CALFED Bay-Delta Program 2021): to develop a long-term comprehensive plan that will restore ecological health and improve water management for beneficial uses of the Bay-Delta system.
The delta is at the hub of the California water system where the northern waters meet the southern waters. Much of the delta’s waters are pumped from the delta and sent south for municipal and agricultural use. The delta has intensive agricultural land uses and a diverse recreational economy, and the area is urbanizing. The plan for CALFED came from an environmental impact statement and report to meet the requirements of the National Environmental Policy Act and the California Environmental Quality Act. The record of decision (CALFED Bay-Delta Program 2000) identified a plan and objectives for managing the bay-delta environment and water together. There were four central objectives for CALFED to pursue (Table 8.3). First, to restore the health of the estuary ecosystem. Second, to improve water supply reliability. Third, to improve water quality in the delta waters. Fourth, to maintain levees. The distinct feature of this ecosystem restoration effort was to balance the water needs of the environment with those of the people.
Many Californians depend on water supplies from the delta. The San Joaquin Delta’s freshwater furnishes municipal water supplies for approximately 22 million Californians (Dutterer and Margerum 2015). The California central valley has some of the most productive farmland in the world, and the area which relies on delta waters is close to 3 million acres (Healey et al. 2008). These numbers were hard to grasp, and California and the federal government prepared to invest billions of dollars in CALFED activities. There are 1,700 km of earthen levees (Figure 8.8) in the delta that control channel dimensions and water flows, and protect land that’s used for agriculture or urban development (Sherman et al. 2004). Most precipitation in California falls north of the delta, while most water use is well south of the delta. Improving levees were an objective for CALFED because they are vulnerable to flooding, earthquakes, and sea level rise. Mean sea level has gone up, and a warming climate is making the high elevation snow melt earlier (Gornitz 1995; Stewart et al. 2004). There are reservoirs well north of the delta to store water and pumps to extract water in the southern part of the delta that discharge into canals to take the water even further south. All these numbers supported the big challenge the CALFED objectives were intended to meet.
Table 8.3: The four objectives of the CALFED assignment and the drivers of change in the Bay-Delta that CALFED was charged with accommodating. Sources: CALFED Bay-Delta Program 2000 and Mount et al. 2006
Geology, climate, and human activity make the delta environment an ever changing place. Mount et al. (2006) characterized the drivers of change in the ecosystem (Table 8.3). The gradual process of subsidence of the land has progressed in some areas as much as 5 m below sea level. Sea level rise aggravates this problem and has been increasing (Gornitz 1995), making the water nearer to levee capacity and altering mixing by changing the tidal processes and channel hydrodynamics. Levees are vulnerable to the slower process of subsidence and sea level rise, and are very vulnerable to instant change from earthquakes as the delta is a high seismic activity area (Service 2007; Burton and Cutter 2008). In addition, the climate has been warming in California, which changes the timing of snow melt in the Sierra Nevada Mountains which in turn affects agricultural schedules (Stewart et al. 2004). Climate warming also has the potential to disrupt current water use (Cloern et al. 2011). People like being connected with area waters and channels. Consequently, the delta has been rapidly urbanizing (Figure 8.9) and this process changes the land cover, runoff rates, and the pollutant concentrations of surface waters (Jordan et al. 2014). The final alarming change is the rise in number of exotic species in the area (Cohen and Carlton 1998). California has relatively newly settled land and waters in comparison to patterns worldwide. Therefore, the state was depauperate in terms of biota, especially in the freshwaters, and new species invaded rapidly. In the delta, non-native species comprised 40-100% of common species, 97% of total animal numbers, and 99% of the biomass (Mount et al. 2006). All these factors indicated a novel ecosystem that needed to be restored to accommodate an estuary where change was anticipated.
CALFED faced many challenges in restoring the delta ecosystem to a better status. Many of the issues were compiled into nine clusters related to: water quality and pollution, flows, water use and storage, levee functionality and sea level rise, habitat restoration, invasive species, pelagic organism decline, migratory birds, and economic development (Table 8.4). Changes in the delta meant that it was hard for CALFED to predict management outcomes. CALFED promoted watershed conservation and best practices for agricultural lands in the area to improve water quality and reduce mercury coming from tributary watersheds. The purpose was to meet standards for drinking water, agricultural use, and ecosystem needs. Issues concerning in-flowing waters to the delta were integrated into the management plans for water across the basins. Fish migrations and spring delta water outflows needed to be higher, and channel and estuary water circulation within the ecosystem needed to be improved. Water management procedures involving storage, conveyance, and pumps posed a threat to aquatic life. The Sacramento-San Joaquin Bay-Delta water system was likely at or near its capacity. Thus, tradeoffs that benefited the environment would end up reducing water volumes for human use, making it hard to decide which outcome to prioritize. Levee vulnerability needed attention as well since breaks in the system protecting farmland and infrastructure could impact the regional economy. The habitat creation plan incorporated space and flow requirements to address the lack of interconnections, as well as accommodate both tidal and floodplain needs. Science provided the knowledge that was needed to plan for these actions, but new areas of uncertainty then emerged. A species of fish using open pelagic waters sharply declined, though the cause was not clear (e.g., contamination, an invading species, entrainment in water pumps). The CALFED agencies needed to integrate the objectives, activities, and anticipated outcomes of the project to manage the whole ecosystem.
An independent review was done by Lund et al. (2007) to see how CALFED was executing the assigned objectives. The delta environment was not serving most stakeholders well, and it was vulnerable to change. The CALFED organization tended to go along with the consensus and not make big changes in operations that would disappoint some stakeholders. The lack of bold decision-making meant that alternative operations which were predicted to accomplish some objectives went overlooked. CALFED was commonly seen as failing to meet all of its objectives. And, its failure to address the challenges introduced an element of risk from imminent changes in this complicated ecosystem. After extensive monitoring, many scientists noted that they still did not understand many of the ecological trends in the San Joaquin Delta (Dutterer and Margerum (2015), and environmental problems remained (Lubell et al. 2013).
Among its successes however, CALFED initiated new communications systems, more integrated management techniques, significant restoration projects, an increase in monitoring and data collection activities, and some significant shifts in conceptualizing water management (Dutterer and Margerum 2015). CALFED components like the Environmental Water Account and Science Program have been deemed relatively successful (Lubell et al. 2013).
In total, the CALFED program spent $3 billion on research, environmental restoration, and administration before dissolving in 2007 (Dutterer and Margerum 2015). A metaanalysis of CALFED sought to determine the reasons for its dissolution (Dutterer and Margerum 2015). Their findings identified limitations related to problem, societal, and policy context; also highlighted were different interpretations about politics, leadership, and governance arrangements (Nawi and Brandt 2008; Dutterer and Margerum 2015). The lessons from CALFED include the limitations of adaptive management, the risk of dependence on political leadership, the challenges of an informal structure, and the flaws in CALFED’s efforts to create a more formal structure (Dutterer and Margerum 2015).
The CALFED case study involved many scientists, from a wide range of disciplines, who were engaged in planning a true ecosystem restoration and other tasks. Their ecosystem project was complex with a lengthy list of issues. Their mandate to balance the water use needs of people with those of the environment proved challenging. Also, this ecosystem is changing gradually and has generated surprises, like a sharp decline in pelagic fishes. The delta restoration was supposed to function naturally and maintain itself as an estuary ecosystem. Some of those goals were met while others were not. Overall, restoration, especially for an entire ecosystem, is complex and time is often needed to accomplish its objectives.
SUMMARY
Humans have caused extensive change and sometimes damage in landscapes all over the world. Restoration helps to return these landscapes to more natural, undisturbed states with their original functions and structure. Many years may be needed to achieve the image of restoration success, and deviations along the way may occur. To be effective, integrative, multi-disciplinary practices are needed along with stakeholder input.
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