Restoring fire-prone Inland Pacific landscapes: seven core principles
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More than a century of forest and fire management of Inland Pacific landscapes has transformed their successional and disturbance dynamics. Regional connectivity of many terrestrial and aquatic habitats is fragmented, flows of some ecological and physical processes have been altered in space and time, and the frequency, size and intensity of many disturbances that configure these habitats have been altered. Current efforts to address these impacts yield a small footprint in comparison to wildfires and insect outbreaks. Moreover, many current projects emphasize thinning and fuels reduction within individual forest stands, while overlooking large-scale habitat connectivity and disturbance flow issues.
We provide a framework for landscape restoration, offering seven principles. We discuss their implication for management, and illustrate their application with examples.
Historical forests were spatially heterogeneous at multiple scales. Heterogeneity was the result of variability and interactions among native ecological patterns and processes, including successional and disturbance processes regulated by climatic and topographic drivers. Native flora and fauna were adapted to these conditions, which conferred a measure of resilience to variability in climate and recurrent contagious disturbances.
To restore key characteristics of this resilience to current landscapes, planning and management are needed at ecoregion, local landscape, successional patch, and tree neighborhood scales. Restoration that works effectively across ownerships and allocations will require active thinking about landscapes as socio-ecological systems that provide services to people within the finite capacities of ecosystems. We focus attention on landscape-level prescriptions as foundational to restoration planning and execution.
KeywordsForest and rangeland restoration Hierarchical organization Large fires Patch size distributions Successional patches Topographic controls
A growing human population that demands contradictory or competing ecosystem services (Krieger 2001);
Impaired ability of some landscapes to provide these services due to past management (Millenium Ecosystem Assessment 2005);
Increased exposure to large and often severe disturbances (Schoennagel et al. 2004; McKenzie et al. 2004; Agee and Skinner 2005; Hessburg et al. 2005; Peterson et al. 2005; Miller and Davis 2009; Miller et al. 2009; cf. Baker 2012; Williams and Baker 2012; Odion et al. 2014);
High uncertainty regarding future effects of climate change (Millar et al. 2007);
To address these challenges, a new collaborative social contract for federal land management in the West is emerging ( Schultz et al. 2012; Butler 2013; Larson et al. 2013; Charnley et al. 2014). Established collaboratives seek to move past once crippling conflicts over natural resource management, forge social consensus around management approaches that can restore or create climate- and fire-resilient landscapes, and improve future options for people (Brown et al. 2004; Cheng and Sturtevant 2012; Charnley et al. 2014; Stephens et al. 2014). To effectively manage landscapes as resilient and adaptable social-ecological systems (Folke et al. 2005; Chapin et al. 2010), collaboratives must work from a solid scientific foundation.
In this review, we present principles from recent landscape science that are relevant to collaborative restoration, to raise the bar for land use planning and management across all ownerships. We emphasize Inland Pacific forests of Washington, Oregon, and California; however, our ideas are useful for landscapes beyond this domain, including the southwestern US and Rocky Mountain regions (Jain et al. 2008; Reynolds et al. 2013). Furthermore, we emphasize management of fire-prone forests, but recognize the importance of other physiognomic types as part of these landscapes, as well as lands intensively used by people.
Recent research has expanded our understanding of multi-scale heterogeneity in historical fire-prone forests. Fire-prone forests are current or historical dry, mesic, or cold interior forest types that depend on wildfires for regeneration and succession. Heterogeneity resulted from interactions among climate, vegetation, topography, and disturbances that created successional patterns and shaped disturbance regimes to which native flora and fauna are adapted at fine-, meso-, and broad-scales. It evolved dynamically and conferred a measure of resilience to shifts in climate and recurrent contagious disturbances.
Historical context–unintended consequences
For most of the twentieth century, federal land management in the Inland Pacific emphasized wildfire suppression, domestic livestock grazing, and wood production to meet the demands of a growing society (White 1991; Langston 1995; Robbins 1999). Grounded in a utilitarian view of forests, silvicultural methods were devised to grow, harvest, and regenerate trees (Smith et al. 1997). Wildfires were viewed as threatening to people, infrastructure, and the timber supply.
Silviculture and forest management have focused on stands as the basic unit of organization (Puettman et al. 2012). Stands are defined as contiguous areas of trees with common structural, compositional, and biophysical conditions ( Helms 1988; Nyland 2002). Delineation of treatment units, ‘operational stands’(sensu O’Hara and Nagel 2013), however, is shaped by added operational considerations including economic viability, road access, property boundaries, logging systems, and harvest scheduling.
These treatment units stood out in marked contrast to historical successional patches, which were variably-sized and shaped by the surrounding topography and prior disturbances. Even-aged management within operational stands promoted uniformity of tree conditions (e.g., size, density, species, spacing), while reducing costs of harvest, yarding, and log transportation. Uneven-aged management promoted variable size and age distributions, and often led to multistory structures dominated by shade tolerant species. Harvests of all types generally targeted high volume stands and removed large and old trees of fire tolerant species. Furthermore, prescriptions focused on tree conditions within stands and overlooked the larger scale patterns that emerged from this stand-based management.
Stand management and dispersed clearcutting necessitated development of extensive road networks to reach high-value stands (Reeves et al. 1995). The new roads altered local hydrology, increased chronic and catastrophic sedimentation, and reduced floodplain functioning via channelization (Luce and Black 1999; Jones et al. 2000). Roads fragmented aquatic habitats, and created fish passage barriers via crossings and culverts (Bisson et al. 2003; Rieman et al. 2003). Roads were effective fuelbreaks during moderate fire weather conditions; they played a role in spreading invasive plants, and provided access for firefighters (Forman 2003). Roads also disturbed wildlife nesting and denning, and interrupted breeding and dispersal habitat connectivity (Raphael et al. 2001; Gaines et al. 2003).
Today, successional patchworks of many forest landscapes no longer reflect a tightly linked relationship with their natural disturbance regime calling for restoration of many watersheds and lands (Keane et al. 2009; Wiens et al. 2012; Moritz et al. 2013). Instead, new fire, insect and pathogen disturbance regimes are driven by past management, a warming climate, and contagious patterns of fuels and hosts (Noss et al. 2006), fostering increased numbers of larger and more severe disturbances than occurred historically (McKenzie et al. 2004; Hessburg et al. 2005, 2013; Miller and Davis 2009). Predicted changes in the climate could exacerbate these trends (Millar et al. 2007; Allen et al. 2010; Stephens et al. 2013).
Moving from stands to landscapes: core principles and management implications
Re-purposing past approaches to forest management will not address the socio-political and ecological challenges that lie ahead (Lertzman and Fall 1998). Many ecologists, managers, and policy-makers are calling for restoration of many watersheds and landscapes (e.g., see Lertzman and Fall 1998; Bosworth 2006; Noss et al. 2006; ISAB 2011; Franklin and Johnson 2012; North 2012; North et al. 2012a; Franklin et al. 2014; Stephens et al. 2014). For example, the federal Forest Landscape Restoration Act of 2009 called for “collaborative, science-based ecosystem restoration of priority forest landscapes.” Proposals for landscape-scale restoration have been developed from the Pacific Northwest to the northern Rockies, Sierra Nevada, and the Southwest. However, to be credible, these efforts will need an operational framework based on multi-scale planning and adaptive management, multi-partner and interdisciplinary collaboration, and core ecological principles that reach across scientific disciplines (Grumbine 1994).
Here, we focus attention on anunderutilized forest management concept: the landscape prescription. Scientifically grounded landscape prescriptions are needed to create habitat and successional patterns at local and regional landscape scales that move landscapes towards conditions that confer climate and disturbance resilience, while creating functional, well-connected habitat networks for a broad array of native aquatic and terrestrial species. A landscape prescription can provide clearly articulated restoration objectives, target ranges for both total area (proportion of landscape) and patch size distributions of successional and habitat types, and specific guidance on how and where to adjust the spatial arrangement of patches (Perry et al. 2011; North et al. 2012b; Hessburg et al. 2013; Perera et al. 2004).
Seven core principles and their planning and management implications
Principle 1: Regional landscapes function as multi-level, cross-connected, patchwork hierarchies.
Implication: Conduct planning and management at appropriate scales to effectively restore multi-level landscape patterns, processes, and dynamics.
Principle 2: Topography provides a natural template for vegetation and disturbance patterns at local landscape, successional patch, and tree neighborhood scales.
Implication: Use topography to guide restoration of successional and habitat patchworks.
Principle 3: Disturbance and succession drive ecosystem change.
Implication: Move toward restoring natural fire regimes and the variation in successional patterns that supported them so that other processes may follow.
Principle 4: Predictable patch size distributions historically emerged from linked climate-disturbance-topography-vegetation interactions.
Implication: Move toward restoring size distributions of historical successional patches and allow changing climate and disturbance regimes to adapt them.
Principle 5: Successional patches are “landscapes within landscapes”.
Implication: In dry pine, and dry to mesic mixed-conifer forests, restore characteristic tree clump and gap variation within patches.
Principle 6: Widely distributed large, old trees provide a critical backbone to dry pine and dry to mesic mixed-conifer forest landscapes.
Implication: Retain and expand on existing relict trees, old forests, and post-disturbance large snags and down logs in these types.
Principle 7: Land ownership, allocation, management and access patterns disrupt landscape and ecosystem patterns.
Implication: Work collaboratively to develop restoration projects that effectively work across ownerships, allocations, and access needs.
Regional landscapes function as multi-level, cross-connected, patchwork hierarchies (O’Neill 1986; Urban et al. 1987; Wu and Loucks 1995), with patterns1 and processes2 that interact across spatial scales(Holling 1992; Wu and David 2002; Peters et al. 2004; Falk et al. 2007).
Over broad scales, historical successional patterns and disturbance dynamics reflected climatic variability and natural disturbance regimes of the ecoregion (Whitlock and Bartlein 1997; Swetnam et al. 1999; Whitlock et al. 2003, 2010 Keane et al. 2009; Wiens et al. 2012). Within successional patches, tree clump and gap patterns, tree sizes (living and dead), and tree, shrub, and herb species compositions reflected fine-scale productivity, environmental, climatic, and disturbance controls (Larson and Churchill 2012; Churchill et al. 2013; Lydersen et al. 2013).
Hierarchical levels are connected through so-called “top-down” and “bottom-up” controls that operate within and across spatial scales (Wu and Loucks 1995; Wu and David 2002). In our suggested four-level hierarchy, spatial patterns and processes at the scale of the local landscape are partially constrained by the top-down control of climate, geology, landforms, and biota (Fig. 2; Urban et al. 1987; Turner 1989). Patchworks of local landscapes and those operating within successional patches and tree neighborhoods provide critical “bottom-up” control of processes and patterns (Wu and Loucks 1995; Wu and David 2002). For example, patterns of tree species, tree sizes, and tree vigor at tree neighborhood, and successional patch levels can affect patterns of bark beetle induced mortality in local landscapes by influencing host contagion and beetle dispersal. However, these bottom-up controls can be overridden by the top-down influence of extreme climatic events that reduce host vigor or favor beetle survivorship (Bentz et al. 2010).
Conduct planning and management at appropriate scales to effectively restore multi-level landscape patterns, processes, and dynamics. A reasonable start is to put forest and woodland landscapes on a path to successional patterns and disturbance dynamics that reflect the natural disturbance regimes of regional and local landscapes (Swetnam et al. 1999; Keane et al. 2009; Wiens et al. 2012), and allow the future climate to adapt them. To place landscapes on this path, pattern modifications across scales will be needed in areas where past management alterations are greatest. Management to modify successional patterns should provide a good match to the disturbance ecology and expected future climatic regime of the landscapes in question.
Local landscape prescriptions are also needed that acknowledge constraints imposed by higher levels in the hierarchy that may limit what is achievable. For example, at the ecoregional level, shifting species ranges in response to warming may preclude the persistence of certain tree species at their trailing edge, while others may expand their ranges (Hampe and Petit 2005; Crookston et al. 2010). Thus, landscape prescriptions need to be compatible with the climate at the ecoregion and local landscape levels.
Topography provides a natural template for vegetation and disturbance patterns at local landscape, successional patch, and tree neighborhood scales. Topography modulates broad- to fine-scale patterns of climate and weather, surface lithologies and soils, geomorphic processes, vegetation productivity, and disturbances (Neilson 1986, 1995; Pearson and Dawson 2003). Thus, topography provides an intuitive and persistent physical template for vegetation patterns within regional and local landscapes.
Use topography to guide restoration of successional and habitat patchworks. Landscape prescriptions can use topography to tailor species composition, vegetation density, canopy layering, and other structural conditions to edaphic and environmental conditions (Lydersen and North 2012; Merschel et al. 2014). Partitioning the landscape into basic topographic settings, such as valley-bottoms, ridgetops, and south- and north-facing slopes, can be an aid in distributing forest treatments to patch boundaries that are more logical than those based largely on proximity to roads (North et al. 2009, 2012b). Spatially mapped climatic water balance metrics (e.g., actual evapotranspiration and deficit) can be used to further refine and quantify topographic conditions into useful ranges for site potential and species composition determinations, and to guide climate adaptation (e.g., see Stephenson 1998; Dobrowski et al. 2011; Churchill et al. 2013; Kane et al. 2015). Below, we provide a general approach for using topography in a landscape prescription using archetypal forest conditions as example landscapes.
Managing low- to mid-elevation south aspects and ridgelines. Southerly aspects and ridges can be managed to support fire-tolerant species in clumped tree distributions by: (1) favoring medium- (e.g., 40–60 cm dbh) to large-sized(e.g., 60–100 cm dbh, note that size ranges will depend on species and site productivity) trees; (2) promoting vegetation density and composition that is resilient to primarily low- and mixed-severity fires; and (3) maintaining relatively low vegetation density via forest thinning, prescribed burning, and/or managed wildfires. Tree size classes, tree clump and gap size distributions, and total canopy cover would vary from place to place and through time, but ranges of conditions could be calibrated from historical reconstructions (see Principle 5, Larson and Churchill 2012) and modified by incorporating expected climatic changes (e.g., see Churchill et al. 2013).
Managing low- to mid-elevation north aspects and valley-bottoms. North aspects and valley-bottoms generally support a mix of fire-tolerant and fire-intolerant tree species in relatively dense, often multi-layered arrangements. Because these fuel types typically support mixed surface and crown fire behavior, restorative prescriptions should allow patches of mixed and high-severity fires (see also Principle 4). These denser forests may also be subject to insect outbreaks. However, the naturally scattered distribution of north aspect and valley-bottom forests across the landscape (Fig. 4) typically constrains the frequency, severity, and duration of defoliator and bark beetle outbreaks by interrupting host contagion. Special attention to riparian zones is needed because such areas provide key structural elements of aquatic habitats such as large wood and undercut stream banks.
By suggesting topography as a natural template, we do not advise any strict correspondence of forest successional patches with topographic edges. Instead, applying feathered edges on the margins, for example, dry pine patches grading into dry or mesic mixed-conifer patches(i.e., transitional zones with adjacent patches) might be more typical of the “soft edges” observed under more natural disturbance conditions (Stamps et al. 1987).
A greatly enlarged role for managed surface and crown fires
Conventional restoration activities take place at the stand-scale, but such activities will not likely scale up to accomplish needed ecoregional and local landscape pattern modification. Furthermore, conventional vegetation management practices alone will not restore fire regimes or mimic fire effects. Most of the work of restoring landscapes will likely need to be done using managed wildfires over large areas and prescribed burning (North et al. 2012a, 2015), with mechanical treatments in key areas that require spatial precision of outcomes and existing road access. This increased tolerance for wildfire, especially during moderate fire years and shoulder seasons, will require continued public education on the ecological role of fire, as well as changes in policies and professional incentives for forest managers. Cutting trees, whether commercially or pre-commercially, can emulate fire effects on tree density and layering, but it cannot reproduce the effects of fire on nutrient cycling, snag creation, surface fuel reduction, mineral seedbed preparation, and regenerating associated shrub and herb vegetation (Johnson 1992, Johnson and Miyanishi 1995). If not designed with clear ecological objectives and constraints, commercial timber harvest can result in removal of scarce large-sized trees to cover harvesting costs, reduced snag densities, excessive soil compaction, simplification of spatial patterns, and residual fine fuel buildup that can promote future fire spread. This is a particular concern adjacent to riverine systems, where retention of large dead wood is critical. In contrast, management ignited or managed wildfires burning under moderate fire weather conditions can often accomplish ecological objectives without timber harvest, as has been observed in some wilderness and road less areas, and in forests where mixed and high-severity fires naturally dominate (Meyer 2015).
The historical range of variability (HRV, Keane et al. 2009; Landres et al. 1999; McGarigal and Romme 2012; Wiens et al. 2012) of regional successional patterns can be used to inform management targets, where these reference conditions are based on climates that are similar to those anticipated in the future (Stephens et al. 2008, 2010). Moreover, the climatic variability during the HRV reference period undoubtedly overlaps with future climates, making them a useful reference. However, where HRV reference conditions are based on climates that highly differ from those anticipated in the future, they will be far less useful.
Several authors have referred to a future range of variation (FRV), which identifies alternative reference conditions that are suited to a predicted future climate (Hessburg et al. 2013; Keane et al. 2009; Moritz et al. 2011, 2013). In ecoregions where the anticipated twenty first century climate is much warmer and drier/wetter than that of the early twentieth century, FRV reference conditions will be most useful to guide restoration efforts (USFS 2012; Hessburg et al. 2013). The FRV in some ecoregions is currently being approximated using either historical or contemporary analogue landscapes with successional patterns that have experienced the predicted future climate (Hessburg et al. 2013) or via succession and disturbance simulation modeling techniques (Keane et al. 2002; Loehman et al. 2011; Miller 2007). Both techniques are useful for exploring alternative vegetation patterns that will be fostered by a changing climate and understanding desirable changes to the existing conditions.
In some cases, the restoration approach will need to recognize current vulnerabilities to uncharacteristic disturbances and landscape inertia associated with other ecological processes (Merschel et al. 2014; Stephens et al. 2008, 2010; Stine et al. 2014). For example, in eastern Oregon, Douglas-fir and grand fir regeneration has become so widespread during the period of fire exclusion that seed rain from these species makes it unlikely that ponderosa pine will re-establish as a dominant species even after fires (Merschel et al. 2014). Re-establishment of pine may necessitate extensive cover type manipulation (Stine et al. 2014).
Restoration of resilient landscapes will not be feasible everywhere and some landscape prescriptions will need to acknowledge that long-term, unavoidable shifts in landscapes toward novel or “hybrid” ecosystems have occurred (Hobbs et al. 2009). In the future, western forests will contain more people, non-native species, an altered climate, and increased demands for carbon storage, food and water, minerals, wood and other forest products. Some long-term shifts will preclude a return to pre-development conditions (Higgs et al. 2014). Planning for sustainability will require the best efforts of resource economists and physical, biological, and social scientists.
“Perfect storm” conditions for large wildfires
Dynamic interactions among the climate, disturbances, successional conditions and patterns of environments were the mechanism by which successional mosaics historically emerged in dry, mesic, and cold forests of the inland Pacific West. Mosaics varied across space and time, but variability was constrained by the dominant climate and disturbance influences. In contrast, today’s successional patterns, fueled by a warming climate, appear to be driving more severe disturbance regimes (generally lower fire frequency and higher severity) in a kind of ‘perfect storm’, with uncertain ecological trajectories associated with some fires (Lydersen et al. 2014). By excluding all but the largest fires via suppression, we enable successional processes to create dense patches of stressed trees on some parts of the landscape, with higher than historical surface fuel loads, high landscape contagion, and dense canopy fuels. This successional landscape is a regional-scale condition in which wildfires are more likely to be large and often severe. Moreover, it is marked by vast areas of shade-tolerant, fire sensitive species (e.g., grand, white fir, Douglas-fir, subalpine fir, Engelmann spruce), that produce abundant seeds, and that can colonize disturbed areas, further reinforcing a broad-scale species compositional shift.
Move toward restoring size distributions of historical successional patches and allow changing climate and disturbance regimes to adapt them. Historical successional patch size distributions were the by product of ongoing disturbances and changes to the climate system, providing a broad landscape resilience mechanism. If successional pattern conditions today were those of pre-management era forests, we would have minimal concern for their capacity to adjust to the climatic changes we are experiencing today.
Successional patches include non-forested “openings”, the largest of which may still be evident today, though their margins have been encroached upon (Arno and Gruell 1986; Coop and Givnish 2007). Smaller openings have disappeared (Skinner 1995), and their historical distribution can be determined from reconstructions of fine-scale forest structure (Principle 5). In the absence of local, historically derived information, landscape prescriptions should focus on increasing the frequency of variably-sized openings and successional patches (Dickinson 2014).
Patch size distributions will fluctuate as they adjust to climate, and to the proportion of the area affected by wild and managed fires and vegetation treatments (Keane et al. 2002). However, as patch size distributions of successional patches become more in sync with current climate and natural disturbance regimes, we expect that these adjustments will become less dramatic and abrupt, and offer less uncertainty to future habitat conditions.
Recommended adaptations to conventional silviculture
Recent landscape reconstructions at meso-and fine-scales (Churchill et al. 2013; Hessburg et al. 1999b; Collins et al. 2011, 2015; Larson and Churchill 2012; North et al. 2009; Lydersen and North 2012; Stephens et al. 2008; 2015; Taylor 2010) suggest that three adaptations are needed to conventional silviculture:
(1) Operational treatment units, whether mechanical or prescribed fire, should (re)create ranges and distributions of vegetation patch sizes that are characteristic of an ecoregion (Collins and Stephens 2010; Perry et al. 2011; Reynolds et al. 2013; Stine et al. 2014).
(3) Within patches, patterns of individual trees, tree clumps and gaps should reflect the fine-scale heterogeneity that would be expected given the natural disturbance regimes and biophysical setting (North et al. 2009; Sánchez Meador et al. 2011; Churchill et al. 2013; Kane et al. 2014; Fig. 10).
Restoring patterns across scales mimics the template that historically maintained species diversity and ecosystem functions thereby preparing the landscape for future disturbances.
The percentage of four sampled ecoregional areas with medium- and large-sized trees in the overstory, in each of three crown cover classes
Percentage area with medium-a and large-sizedb trees by crown cover (CC) class
10–30 % CCc
40–60 % CC
>60 % CC
Total % area
Northern glaciated Mountains
Their long period of landscape service as live trees (e.g., 250–400 year), snags (30–100 year), logs (100–200 year), mulch (0–100 year), and soil carbon or charcoal (100–1000s year, Deluca and Aplet 2008) made large, old trees building blocks of the regional landscape. In addition, they are vital to many wildlife and fish habitats ( Foster et al. 1998; Franklin et al. 2000; Hunter 2005; Agee and Skinner 2005; Reeves and Bisson 2009), and the legacy of large dead wood from wildfires and bark beetle outbreaks is a particularly important driver of habitat condition in the streams of many forested watersheds (Gregory et al. 2003). However, in some forests that experience frequent, low to moderate intensity fires, repeated fires can consume much of the down wood, leaving overall densities of these structural elements relatively low and patchily distributed. For example, this was observed in northwestern Mexico, where spatial variability in dead wood resources was measured in Jeffrey pine-mixed-conifer forests with relatively intact fire regimes (Stephens 2004; Stephens et al. 2007).
Table 1 shows the historical percentage area of four fire-prone provinces in eastern Oregon and Washington with remnant medium- and large-sized old trees. These data show that remnant medium- and large-sized old trees occupied partial overstories of up to 40 % of patches, regardless of their successional condition. Early twentieth century timber inventories show that 68 % of the Warm Springs and Klamath Indian reservations in central Oregon had at least 12 trees per hectare over 53 cm diameter at breast height (Hagmann et al. 2013, 2014). Their widespread presence suggested that remnant old trees were prevalent and important features of fire-prone landscapes.
Protect remaining live old trees and retain large old trees and snags after fires
Restorative management activities in many dry pine and mixed conifer landscapes should maintain existing patches of old forests, and retain remnant medium- and large-sized early seral trees where they occur. To improve the longevity of larger early seral trees, restorative activities would include thinning and removing neighboring shade-tolerant trees to reduce competition for water and nutrients, and removing nearby surface and ladder fuels to reduce fire intensities that would threaten their long-term survival. Furthermore, many south-facing aspects and ridgetops no longer support a characteristic abundance of early seral trees of any size and age. These settings should be evaluated for their ability to support the long term survival of early seral trees as the climate warms and dries. If deemed suitable, such sites could be emphasized for re-establishing thriving new populations, which in turn can be maintained through natural or prescribed fires and/or mechanical fuels reduction. Many existing ponderosa pine plantations can be managed and tended for future old pines as well. Where post-fire fuels are a bonafide reburn concern, salvage treatments should focus on removal of small trees and emphasize retention of large-trees, both living and dead.
Decrease impacts of legacy roads
Landscape restoration requires addressing the ongoing impacts of existing road networks on forest ecosystem processes and functions. The effect of road networks on aquatic and terrestrial ecosystems is well established (Bisson et al. 2003; Forman 2003; Gaines et al. 2003;Reed et al. 1996; Luce and Black 1999; Trombulak and Frissell 2000; Raphael et al. 2001). Past management has left extensive and expensive legacy road networks, which are now declining in condition. These roads deliver chronic sediment to nearby rivers and streams, and disrupt flow regimes. Deferred maintenance on retained roads yields persistent adverse impacts to fish and wildlife habitats. In addition, road systems function as alternative drainage networks, which significantly disrupt the timing and magnitude of flows and subsurface hydrology. However, not all roads are equally damaging or influential. Instead, most of the chronic sediment, channel confinement, barrier, and flow issues are associated with a fraction of the existing network, and these roads are readily identifiable. Landscape restoration projects should prioritize elimination, upgrading, or movement of these most damaging roads. Roads located in valley-bottom settings that restrict normal floodplain functioning are among those most damaging to aquatic habitat. Removal of these roads and floodplain restoration is especially important to recovering native aquatic species, and will require planning and coordination across ownerships and interest groups.
Work collaboratively to develop restoration projects that effectively work across ownerships, allocations, and access needs. Landscape prescriptions must be implemented at a relatively broad scale to be ecologically effective, particularly in the context of restoring disturbance regimes. To be socio-politically effective, restoration plans need cross-boundary collaboration and problem solving (Tabor et al. 2014; Wondolleck and Yaffee 2000). Collaboration on a project from conception through design, implementation, and monitoring can expand options for management in the long run, and create synergies that are otherwise unavailable. Moreover, litigation history shows that restoration planning greatly benefits from involving all stakeholder groups who have a vested interest in the outcomes (Culhane 2013). Partner interactions create the opportunity to daylight concerns before they become litigious, and create landscape-level prescriptions that can accommodate them by design (Larson et al. 2013).
Forest collaboratives are well suited to cross-ownership and multi-stakeholder planning (Cheng and Sturtevant 2012; Charnley et al. 2014), and there are significant opportunities to coordinate activities that exceed the capacities of individual landowners. For example, in the state of Washington, USA, the northern spotted owl is federally listed as an endangered species. Federal land managers and the Washington Department of Fish and Wildlife manage most of the current nesting, roosting, and foraging habitats, while dispersal habitats often occur on intermingled Washington State Department of Natural Resources trust lands (USFWS 2012), which are managed as working forests. Road maintenance, removal, and closures, and restoration of fish and wildlife habitats and connectivity all require a similar high degree of coordination.
Implications emerging from all seven principles
Emerging from all seven principles is the idea that landscape prescriptions are foundational to restoration. Landscape prescriptions are a way for managers to implement the principles outlined above and to move beyond stand-centered forest management.
Large-scale ecoregional prescriptions are important to reconnecting broad habitat networks and re-scaling disturbance processes.
Local landscape prescriptions define objectives for successional patch types, size distributions, and spatial arrangements across the topographic template.
Patch-level prescriptions describe target conditions within successional patches.
Linked evaluations and prescriptions are needed at each level where landscape change has been significant and restoration is warranted.
Ecoregional prescriptions are strategic—they highlight priority areas for reconnecting habitats and conditions under which wildfires may/may not contribute to restoring desirable local landscape patterns (North et al. 2012a). Ecoregional prescriptions should identify areas where post-disturbance silviculture or burning may be appropriate/inappropriate, and where wildfires can contribute to restoration (Allen et al. 2002; Reinhardt et al. 2008; Peterson et al. 2015). Ecoregional prescriptions should provide clear guidance for reestablishing large-scale ecoregional connectivity for wide-ranging and migratory aquatic and terrestrial species.
Local landscape prescriptions are tactical—they identify specific project areas where treatments can begin to restore ecoregional patterns and processes for multiple resources (Box 7). Local landscape prescriptions provide guidance about how to arrange different successional patches across the topographic template (Principle 2), the target patch size distributions (Principle 4), and how to protect and increase abundance of legacy old trees (Principle 6). Articulating how silvicultural treatments, prescribed fire, and wildfire can work together to restore disturbance regimes (Principle 3) will be necessary for a successful local landscape prescription. Terrestrial and aquatic habitat and road system restoration opportunities should be linked in local landscape prescriptions to take advantage of simultaneous problem-solving opportunities (Rieman et al. 2010). For example, local prescriptions can identify harmful road segments and fish passage barriers, opportunities to expand local fish strongholds and rebuild larger, more productive fish and wildlife habitat patches (sensu Rieman et al. 2000, 2010).
A local landscape prescription on the Colville National Forest
We provide here an example landscape prescription from a 9500 ha mixed-conifer watershed in northeast Washington that historically supported a predominantly mixed-severity fire regime, but has been modified by fire suppression, grazing, and logging. The landscape prescription was derived from an equally-weighted HRV and FRV departure analysis that was specific to the watershed (see Hessburg et al. 2013). The basis for the prescription is thus, one part departure from HRV pattern conditions, and one part climate change adaptation, in a bet-hedging strategy to conserve maximal future options. The landscape prescription provides clear, spatially-mapped recommendations to managers on where to modify forest structure, composition, and the overall distribution of patch sizes. The prescription intentionally avoids statements about average stand conditions to facilitate creation of heterogeneity at multiple spatial scales. Improved alignment of cover type and structure conditions with topography and biophysical settings, and more naturally occurring disturbance regimes (Fig. 13), were additional goals. Treatment type for different portions of the watershed (e.g. no-treatment, mechanical, prescribed or wildfire) was also identified based on treatment need, road access, and other factors. For example, the prescription for roadless areas of the watershed was to leave them alone to grow into large tree, closed canopy forest in cool, moist refugial topographic locations, and to allow managed wildfire to create stand initiation and open canopy patches in drier areas, where feasible. An abridged version of the prescription follows:
Objectives for the whole watershed:
• Reduce landscape fragmentation by increasing patch size of most cover-structure types, as well as connectivity in some cases.
• For all forested cover types, consolidate and expand approximately ½ of the small patches (1–50 ha) into 100-400 ha patches, where possible.
In the dry forest area of the watershed:
• Increase the area of the ponderosa pine (Pinus ponderosa Dougl. ex Laws.) cover type with large and old over story trees, from 3 to 12–15 % of the watershed area.
• Increase the area of woodland cover types from less than 1 to 2–3 % of the watershed area. Increase the range of patch sizes to 40–125 ha, where possible.
• Reduce the amount of the Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) cover type from 25 to 8–12 % of the watershed area, especially in young forest multistory and stem exclusion structures.
In the mesic and cold forest area of the watershed:
• Increase the area of the ponderosa pine cover type from 2 to 8–10 % of the watershed area. Promote old forest structure as well as stand initiation using wild and prescribed fires to fullest advantage.
• Increase the area of the Douglas-fir cover type from 8 to 20–30 % of the watershed area. Promote open and close canopy old forest and reduce stem exclusion structure.
• Increase the patch size range of lodgepole pine (Pinus contorta Dougl. ex. Loud.) and western larch (Larix occidentalis Nutt.). Increase area in stand initiation.
• Increase the area of hardwood, shrub, herb, and woodland cover types from less than 1 % of the area to 4–7 % of the watershed area. Increase the range of patch sizes to 10–25 ha.
• Reduce the area of the subalpine fir (Abies lasiocarpa (Hook.) Nutt.) cover type from 12 to 3–4 % of the watershed area, and that of the western redcedar (Thuja plicata Donn ex D. Don) cover type from 6 to 2–3 % of the watershed area.
Outside areas of old multi-story forest in dry, mesic, and cold forest, reduce the total area with high fuel loads (surface, ladder, and crown fuels) and increase the total area and size of patches with low fuel loads, especially on south-facing aspects and on ridgetops.
Managing fire-prone landscapes today to increase their climate- and fire-resilience poses immense challenges to managers, in planning and execution (North et al. 2012a, b). The current management environment is internally and externally polarized by mistrust, and a concern that land managers may never make a paradigm shift to sustainable ecosystem management (sensu Grumbine 1994; Spies et al. 2012, 2014; Dunlap and Mertig 2014). Here we argue that the time for that shift has come, and many partners of federal lands wish to help it along (Brown et al. 2004; Cheng and Sturtevant 2012; Charnley et al. 2014).
Prior to the modern management era, western forest and rangeland landscapes were spatially heterogeneous at several scales.
This heterogeneity resulted from native ecological and physical processes and their interactions with forest habitat and successional patterns.
These processes created habitat and networking conditions to which native flora and fauna are adapted.
Forest and rangeland conditions and their associated species were adaptable and resilient to shifts in climate and recurrent contagious disturbances.
Multi-scale heterogeneity has been altered in many areas over the course of management.
Disturbance processes, particularly wildfires and bark beetle outbreaks, will continue to be primary determinants of patterns in managed and unmanaged landscapes.
Future climatic changes may surpass those experienced in the Inland Pacific region during the last interglacial. In that event, historical insights can inform our understanding of ecosystem responses to climate forcing, but management adaptations will need to be forward-looking.
Collaboration on restorative management among managers, stakeholders, and scientific disciplines is essential because forest landscapes are coupled terrestrial and aquatic, social and ecological systems, and people have a stake in the outcomes. Collaboration and negotiation are imperative precursors to management.
Our principles stress the importance of scale and the interconnectedness of landscapes across scales. The traditional view of managing stands of trees in isolation is a relic of the past.
Landscape restoration will require the integrated use of vegetation treatments, prescribed and managed fires to achieve the necessary changes in landscape patterns, at scales broad enough to be meaningful. Management can be informed by natural landscape patterns that result from interactions between biotic communities, disturbances, and physiographic environments (DeLong and Tanner 1996). Such conditions can be quantified using past vegetation patterns HRV, and where appropriate, climate change analogue conditions, and used to help craft landscape prescriptions (Box 7) that provide guidance on the amount, distribution, and pattern of successional conditions to create through management actions.
Wildfires and insect outbreaks are an inevitable part of future landscapes. Future management should aim to restore more resilient vegetation patterns that can help to realign the severity and patch sizes of these disturbances, promote natural post-disturbance recovery, reduce the need for expensive active management, and drastically reduce the role and need of fire suppression.
For example, successional or habitat conditions, surface and canopy fuels, tree mortality, fire severity patterns.
For example, hydrologic and nutrient cycles, energy flows, and vegetation succession and disturbance dynamics.
The fire regime includes the frequency, severity (effects), intensity (energy release), size distribution, and seasonality of fires. The natural fire regime is that which generally occurs when variation in fire frequency, severity, seasonality, and extent reflects characteristic interactions between the biota, geology, and climate settings of the forest type and ecoregion (Swetnam et al. 1999; Landres et al. 1999).
Low severity fires are those where <20 % of the overstory tree cover or basal area is killed by fire and fires are generally surface fires. Mixed severity fires are those where 20–70 % of the overstory tree cover or basal area is killed by fire, and fires typically display a mix of surface and crown fire. High severity fires are those where >70 % of the overstory tree cover or basal area is killed by fire, and fires are primarily crown fires (Agee 1993).
The authors thank Keith Reynolds, Cameron Thomas, Richy Harrod, Rachel White, and the anonymous reviewers for helpful reviews. We thank James Pass and the staff from the Three Rivers Ranger District on the Colville NF for working with us on the landscape evaluation and prescription for the Orient Watershed. We also thank the PNW, Rocky Mountain, and PSW Research Stations, the Joint Fire Sciences Program, National Science Foundation (Award #1256819), and the National Fire Plan for generous support of the many research studies synthesized in this review.
- Agee JK (1993) Fire ecology of pacific northwest forests. Island Press, CoveloGoogle Scholar
- Agee JK (1998) The landscape ecology of western forest fire regimes. Northwest Sci 72:24–34Google Scholar
- Allen CD, Macalady AK, Chenchouni H, Bachelet D, McDowell N, Vennetier M, Kitzberger T, Rigling A, Breshears DD, Hogg EH, Gonzalez P, Fensham R, Zhang Z, Castro J, Demidova N, Limp J-H, Allard G, Running SW, Semerci A, Cobb N (2010) A global overview of drought and heat-induced tree mortality reveals emerging climate change risks for forests. For Ecol Manag 259:660–684CrossRefGoogle Scholar
- Arnst A (1985) We climbed the highest mountains. Fernhopper Press, PortlandGoogle Scholar
- Baker WL (2012) Implications of spatially extensive historical data from surveys for restoring dry forests of Oregon’s eastern Cascades. Ecosphere, 3(3) art23Google Scholar
- Belote RT, Aplet GH (2014) Land protection and timber harvesting along productivity and diversity gradients in the Northern Rocky Mountains. Ecosphere, 5(2) art17 Google Scholar
- Bisson PA, Dunham JB, Reeves GH (2009) Freshwater ecosystems and resilience of Pacific salmon: habitat management based on natural variability. Ecol Soc 14(1):45Google Scholar
- Bosworth D (2006) Investing in the future: ecological restoration and the US forest service. J For 105:208–211Google Scholar
- Butler WH (2013) Collaboration at arm’s length: navigating agency engagement in landscape-scale ecological restoration collaboratives. J For 111:395–403Google Scholar
- Chapin FS III, Carpenter SR, Kofinas GP, Folke C, Abel N, Clark WC, Olsson P, Stafford Smith DM, Walker BH, Young OR, Berkes F, Biggs R, Grove JM, Naylor RL, Pinkerton E, Steffen W, Swanson FJ (2010) Ecosystem stewardship: sustainability strategies for a rapidly changing planet. Trends Ecol Evol 25:241–249PubMedCrossRefGoogle Scholar
- Charnley S, Sheridan TE, Nabhan GP (eds) (2014) Stitching the west back together: conservation of working landscapes. University of Chicago Press, ChicagoGoogle Scholar
- Collins BM, Lydersen JM, Everett RG, Fry DF, Stephens SL (2015) Novel characterization of landscape-level variabilty in historical vegetation structure. Ecol Appl 16:1267–1276Google Scholar
- Culhane PJ (2013) Public lands politics: interest group influence on the forest service and the bureau of land management. Routledge, New YorkGoogle Scholar
- Dodd NL, Schweinsburg RE, Boe S (2006) Landscape-scale forest habitat relationships to tassel-eared squirrel populations: implications for ponderosa pine forest restoration. Restor Ecol 14(4):537–547Google Scholar
- Dodson EK, Peterson DW, Harrod RJ (2008) Understory vegetation response to thinning and burning restoration treatments in dry conifer forests of the eastern Cascades, USA. For Ecol Manag 255(8):3130–3140Google Scholar
- Duncan SL, McComb BC, Johnson KN (2010) Integrating ecological and social ranges of variability in conservation of biodiversity: past, present, and future. Ecol Soc 15(1):5Google Scholar
- Dunlap RE, Mertig AG (2014) American environmentalism: The US environmental movement, 1970–1990. Taylor & Francis, LondonGoogle Scholar
- Ellison AM, Bank MS, Clinton BD, Colburn EA, Elliot K, Ford CR, Foster DR, Kloeppel BD, Knoepp JD, Lovett GM, Mohan J, Orwig DA, Rodenhouse NL, Sobczak WV, Stinson KA, Stone JK, Swan CM, Thompson J, Von Holle B, Webster JR (2005) Loss of foundation species: consequences for the structure and dynamics of forested ecosystems. Front Ecol Environ 3:479–486CrossRefGoogle Scholar
- Fettig CJ, Klepzig KD, Billings RF, Munson AS, Nebeker TE, Negrón JF, Nowak JT (2007) The effectiveness of vegetation management practices for prevention and control of bark beetle infestations in coniferous forests of the western and southern United States. For Ecol Manag 238(1):24–53Google Scholar
- Forman RT (2003) Road ecology: science and solutions. Island Press, WashingtonGoogle Scholar
- Franklin JF, Johnson KN (2012) A restoration framework for federal forests in the Pacific Northwest. J For 110:429–439Google Scholar
- Franklin JF, Johnson KN, Churchill DJ, Hagmann K, Johnson D, Johnston J (2013) Restoration of dry forests in eastern Oregon: a field guide. Nat Conserv, PortlandGoogle Scholar
- Fulé PZ, Crouse JE, Roccaforte JP, Kalies EL (2012) Do thinning and/or burning treatments in western USA ponderosa or Jeffrey pine-dominated forests help restore natural fire behavior? For Ecol Manag 269:68–81Google Scholar
- Gaines WL, Singleton PH, Ross RC (2003) Assessing the cumulative effects of linear recreation routes on wildlife habitats on the Okanogan and Wenatchee National Forests. USDA Forest Service, Pacific Northwest Research Station, PNW-GTR-586Google Scholar
- Gregory S, Boyer KL, Gurnell AM (2003) The ecology and management of wood in world rivers. Am Fish Soc Symp 37:315–336Google Scholar
- Habeck JR (1994) Using general land office records to assess forest succession in ponderosa pine/Douglas-fir forests in western Montana. Northwest Sci 68:69–78Google Scholar
- Helms JA (1988) Forest vegetation management for conifer production. Wiley, New YorkGoogle Scholar
- Hessburg PF, Mitchell RG, Filip GM (1994) Historical and current roles of insects and pathogens in eastern Oregon and Washington forested landscapes. General Technical Report PNW-GTR-327. Portland: USDA-FS, Pacific Northwest Research StationGoogle Scholar
- Hessburg PF, Smith BG, Kreiter SD et al (1999b) Historical and current forest and range landscapes in the interior Columbia River Basin and portions of the Klamath and Great Basins: Part I: Linking vegetation patterns and landscape vulnerability to potential insect and pathogen disturbances. General Technical Report PNW-GTR-458. Portland: USDA-FS, Pacific Northwest Research Station, p 357Google Scholar
- Hessburg PF, Perry DA, Spies TA, Skinner CN, Stephens SL, Taylor AH, Franklin JF, McComb B, Riegel G (2015) Management of mixed severity forests in Washington, Oregon, and California. For Ecol Manag 262:703–717Google Scholar
- ISAB (2011) Using a comprehensive landscape approach for more effective conservation and restoration. Northwest Power and Conservation Council Report No. ISAB 2011-4. Portland. www.nwcouncil.org/fw/isab/isab2011-4/. Accessed 15 Aug 2013
- Jain TB, Graham RT, Sandquist J, Butler M, Brockus K, Frigard D, Cobb D, Sup-Han H, Halbrook J, Denner R, Evans JS (2008) Restoration of northern Rocky Mountain moist forests: Integrating fuel treatments from the site to the landscape. pp 147–172 in USDA Forest Service, PNW-GTR-733Google Scholar
- Keiter RB (2005) Public lands and law reform: putting theory, policy, and practice in perspective. Utah Law Rev 1127:1173–1180Google Scholar
- Knight RL, Landres PB (1998) Stewardship across boundaries. Island Press, WashingtonGoogle Scholar
- Krieger D (2001) Economic value of forest ecosystem services: areview. The Wilderness Society, WashingtonGoogle Scholar
- Küchler AW(1964) Potential natural vegetation of the conterminous United States. Manual to accompany the map (No. 36). American Geographical SocietyGoogle Scholar
- Landres PB, Morgan P, Swanson FJ (1999) Overview of the use of natural variability concepts in managing ecological systems. Ecol Appl 9:1179–1188Google Scholar
- Langston N (1995) Forest dreams, forest nightmares: the paradox of old growth in the Inland West. University of Washington Press, SeattleGoogle Scholar
- Larson AJ, Belote RT, Williamson MA, Aplet GH (2013) Making monitoring count: project design for active adaptive management. J For 111:348–356Google Scholar
- Lertzman KP, Fall J (1998) From forest stands to landscapes: spatial scales and the roles of disturbances. In: Peterson DL, Parker VT (eds) Ecological scale: theory and applications. Columbia University Press, New York, pp 339–367Google Scholar
- Marshall R (1928) The life history of some western white pine stands on the Kaniksu National Forest. Northwest Sci 2:48–53Google Scholar
- McGarigal K, Romme WH (2012) Modeling historical range of variation at a rangeof scales: example application. In: Wiens J, Regan C, Hayward G, Safford H (eds) Historical environmental variation in conservation and natural resource management. Wiley, HobokenGoogle Scholar
- Meyer MD (2015) Forest fire severity patterns of resource objective wildfires in the southern Sierra Nevada. J For 113:49–56Google Scholar
- Millennium Ecosystem Assessment (2005) Ecosystems and human well-being: synthesis. Island Press, WashingtonGoogle Scholar
- Miller C, Davis B (2009) Quantifying the consequences of fire suppression in two California national parks. George Wright Forum 26:76–88Google Scholar
- Miller JM, Keen FP (1960) Biology and control of the western pine beetle: a summary of the first fifty years of research. USDA Forest Service Miscellaneous Publication 800, WashingtonGoogle Scholar
- Moritz MA, Hessburg PF, Povak NA (2011) Native fire regimes and landscape resilience. In: McKenzie D, Miller CA, Falk DA (eds) The landscape ecology of fire. Springer, New YorkGoogle Scholar
- North M (2012) A desired future condition for Sierra Nevada forests. In: M. North (ed.) Managing Sierra Nevada Forests, General Technical Report PSW-GTR-237: 165-175, USDA-FS, Pacific Southwest Research Station, Albany, pp 165–175Google Scholar
- North M, Stine P, O’Hara K, Zielinski W, Stephens S (2009) An ecosystem management strategy for Sierran mixed-conifer forests. General Technical Report PSW-GTR-220. Albany: USDA-FS, Pacific Southwest Research Station. p 49Google Scholar
- North MP, Collins BM, Stephens SL (2012a) Using fire to increase the scale, benefits and future maintenance of fuels treatments. J For 110:392–401Google Scholar
- North M, Boynton RM, Stine PA, Shipley KF, Underwood EC, Roth NE, Viers JH, Quinn JF (2012b) Geographic information system landscape analysis using GTR 220 concepts. In: M North (ed) Managing Sierra Nevada Forests, General Technical Report PSW-GTR-237:107-115. USDA-FS, Pacific Southwest Research Station, Albany, p 184Google Scholar
- North M, Brough A, Long J, Collins B, Bowden P, Yasuda D, Miller J, Suighara N (2015) Constraints on mechanized treatment significantly limit mechanical fuels reduction extent in the Sierra Nevada. J For 113:40–48Google Scholar
- Noss RF, Cooperrider A (1994) Saving nature’s legacy: protecting and restoring biodiversity. Island Press, WashingtonGoogle Scholar
- Nyland R (2002) Silviculture: concepts and applications. Waveland Press Inc, New YorkGoogle Scholar
- Odion DC, Hanson CT, Arsenault A, Baker WL, DellaSala DA, Hutto RL, Klenner W, Moritz MA, Sheriff RL, Veblen TT, Williams MA (2014) Examining historical and current mixed-severity fire regimes in ponderosa pine and mixed-conifer forests of western North America. PLoS ONE 9(2):e87852PubMedCentralPubMedCrossRefGoogle Scholar
- O’Hara K, Latham P, Hessburg PF, Smith BG (1996) Development of a forest stand structural stage classification for the Interior Columbia River Basin. West J Appl For 11:97–102Google Scholar
- O’Hara KL, Nagel LM (2013) The stand: revisiting a central concept in forestry. J For 111:335–340Google Scholar
- Oliver CD, Larson BC (1996) Forest stand dynamics. McGraw-Hill, New YorkGoogle Scholar
- O’Neill RV (1986) A hierarchical concept of ecosystems. Princeton University Press, PrincetonGoogle Scholar
- Perera A, Bus LJ, Weber MG (2004) Emulating natural forest landscape disturbances: concepts and applications. Columbia University Press, New YorkGoogle Scholar
- Peters DPC, Pielke RA, Bestelmeyer BT, Allen CD, Munson-McGee S, Havstad KM (2004) Cross-scale interactions, nonlinearities, and forecasting catastrophic events. Proceedings of the National Academy of Sciences of the USA, 101:15130–15135Google Scholar
- Peterson DL, Johnson MC, Agee JK, Jain TB, McKenzie D, Reinhardt ED (2005) Forest structure and fire hazard in dry forests of the Western United States. USDA-FS, General Technical Report PNW‐GTR‐628, pp 1–30Google Scholar
- Puettmann KJ, Coates KD, Messier CC (2012) A critique of silviculture: managing for complexity. Island Press, WashingtonGoogle Scholar
- Reeves GH, Bisson PA (2009) Fish and old-growth forests. In: Spies TA, Duncan SL (eds) Old growth in a new world: a Pacific Northwest icon re-examined. Island Press, Washington, pp 70–82Google Scholar
- Reeves GH, Benda LE, Burnett KM, Bisson PA, Sedell JR (1995) A disturbance-based ecosystem approach to maintaining and restoring freshwater habitats of evolutionarily significant units of anadromous salmonids in the Pacific Northwest. Am Fish Soc Symp 17:334–349Google Scholar
- Reynolds RT, Meador AJS, Youtz JA, Nicolet T, Matonis MS, Jackson PL, DeLorenzo DG, Graves AD (2013) Restoring composition and structure in southwestern frequent-fire forests: a science-based framework for improving ecosystem resiliency. USDA Forest Service, RMRS-GTR-310Google Scholar
- Robbins WG (1999) Landscape and environment: ecological change in the Intermontane Northwest. In: Boyd R (ed) Indians, fire, and the land in the pacific northwest. Oregon State University Press, Corvallis, pp 219–237Google Scholar
- Sánchez Meador AJ, Moore MM, Bakker JD, Parysow PF (2009) 108 years of change in spatial pattern following selective harvest of a pinus ponderosa stand in northern Arizona, USA. J Veg Sci 20:79–90Google Scholar
- Schultz CA, Jedd T, Beam RD (2012) The collaborative forest landscape restoration program: a history and overview of the first projects. J For 110:381–391Google Scholar
- Smith DM, Larson BC, Kelty MJ, Ashton PMS (1997) The practice of silviculture: applied forest ecology. Wiley, New YorkGoogle Scholar
- Stephens SL, Fry DL, Franco-Vizcaino E (2008) Wildfire and spatial patterns in forests in northwestern Mexico: the United States wishes it had similar fire problems. Ecol Soc 13(2):10Google Scholar
- Stephens SL, Millar CI, Collins BM (2010) Operational approaches to managing forests of the future in Mediterranean regions within a context of changing climates. Environ Res Lett 5:1–9Google Scholar
- Stephens SL, Bigelow SW, Burnett RD, Collins BM, Gallagher CV, Keane J, Kelt DA, North MP, Roberts LJ, Stine PA, Van Vuren DH (2014) California spotted owl, songbird, and small mammal responses to landscape-scale fuel treatments. Bioscience 64:893–906Google Scholar
- Stephens SL, Lydersen JM, Collins BM, Fry DL, Meyer MD (2015) Historical and current landscape-scale ponderosa pine andmixed-conifer forest structure in the Southern Sierra Nevada. Ecosphere 304:492–504Google Scholar
- Stine P, Hessburg PF, Spies TA, Kramer M, Fettig CJ, Hansen A, Lehmkuhl J, O’Hara K, Polivka K, Singleton P, Charnley S, Merschel A (2014) The ecology and management of mesic mixed-conifer forests in eastern Oregon and Washington: a synthesis of the relevant biophysical science and implications for future land management. General Technical Report PNW-GTR-897. Portland, p 254Google Scholar
- Tabor GM, Carlson A, Belote T (2014) Challenges and opportunities for large landscape-scale management in a shifting climate: The importance of nested adaptation responses across geospatial and temporal scales. Rocky Mountain Research Station Paper P-71:205-227. USDA-FS, Fort CollinsGoogle Scholar
- USFS (2012) The Okanogan-Wenatchee National Forest Restoration Strategy: Adaptive ecosystem management to restore landscape resiliency. http://www.fs.fed.us/r6/wenatchee/forest-restoration
- USFWS (2012) Endangered and threatened wildlife and plants; designation of revised critical habitat for the northern spotted owl. Final rule; 50 CFR, Part 17, FWS–R1–ES–2011–0112; 4500030114, RIN 1018–AX69, Federal Register 77, 233, Tuesday, December 4, 2012, Rules and Regulations; US Gov Printing Office: Washington, pp 71876–2068Google Scholar
- White R (1991) Its your misfortune and none of my own: a new history of the American West. University of Oklahoma Press, Norman p 644Google Scholar
- Wondolleck JM, Yaffee SL (2000) Making collaboration work: lessons from innovation in natural resource managment. Island Press, WashingtonGoogle Scholar
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