Abstract
While “resilience” has become a buzzword in agriculture and land management circles, notably as a framework for the response to climate change, there has not been a clear path as to how to organize and deploy a range of resilience-related ideas, tools, and practices to improve climate change response. Generic statements about the need for improved resilience are common, and programs to help enhance resilience are common as a basis for policy development and implementation. These initiatives include references to a range of “climate-smart practices” that should be encouraged, but because they are national strategies, they seldom go beyond general principles. Land management requires a level of spatiotemporal precision in decision-making, planning, and application that calls for much more than broad principles and generic practice. This paper reviews the concepts that have made resilience an important part of land management goals across policy, programs, and application; demonstrates how those concepts can be organized and applied to decision-making to respond to climate change on rangelands; and finally, proposes some approaches that can help improve the value of a resilience-based approach.
Introduction
Ecological Resilience
Resilience, as a term related to ecosystem behavior, first appeared in C.S. Holling’s Resilience and Stability of Ecological Systems (Holling 1973). In both theory and practical examples, Holling differentiated between ecosystem stability and ecosystem resilience as a basis for management. In the mid-20th century prevailing approach, based on stability, the emphasis was on ecosystem functions and products at equilibrium and emphasized the maintenance of a predictable world. Conversely, a resilience-based approach emphasizes recognizing the inevitability of change, and the importance of flexibility in managing for persistence in nonequilibrium systems. At the time, policy, program, and practice was based on a widespread and longstanding belief that ecosystem behavior was deterministic, and good management was sufficient for recovery, even after substantial degradation. Holling used the example of shrub increase in overgrazed grasslands to support the need for a resilience-based approach that emphasized the importance of understanding ecological dynamics and implementing management based on response to the inherent variability rather than prescriptions.
The remainder of the 20th century saw advances in the field of nonequilibrium ecology, especially as applied to rangeland ecosystems (Archer 1989; Westoby et al. 1989; National Research Council 1994; Gunderson 2000). In this approach, supported both by a century of observation as well as experimental results, rangelands were viewed more as dynamic ecosystems in which year-to-year change was not just a management challenge, but an integral part of their functional sustainability. The perceived lack of stability resulted from high levels of variability in both space (soils and topography) and time (rainfall and temperature patterns) and interactions among those driving variables. These nonequilibrium models explained (and generally predicted) rangeland ecosystem behavior and have become the prevailing basis for ecological experimentation and management theory (Bestelmeyer et al. 2017).
Resilience is a relative term, not an absolute measure (Center for Climate and Energy Solutions 2019). Estimating or determining how to manage for resilience requires context: what part of the rangeland system are we concerned about (production, profitability, species diversity, etc.) and what should the rangeland system be resilient to (drought, flood, etc.)? In the case of climate resilience, particular events can be defined. For instance, ecological drought, like any disturbance, can be described in terms of extent, intensity, and frequency (Crausbay et al. 2020). Likewise, the process, attribute, or component likely to be affected can be defined, and more importantly, measured as a means of evaluating the effect of resilience management.
Even though the early applications of resilience behaviors proposed by Holling (1973) clearly included the functioning of human institutions, there was limited application of those principles in the development of policy and programs for land management (Reid et al. 2014). The inclusion of interlinked social, economic, and ecological systems as objects of study and the idea that similar principles of system behavior can be applied to land, people, and institutions (Walker et al. 2004; Colding and Barthel 2019) have gained credence and provided insight as to how resilience can be enhanced. The emergence of socioecological systems as the framework for the study of resilience management has redefined and advanced rangeland management over the past two decades (Fernandez-Jimenez et al. 2019).
Resilience in Complex Socioecological Systems
Although change has to be accepted in complex adaptive systems and there is ample evidence that ecological systems change even when unoccupied by humans (e.g., the first five global mass extinction events), the goal in socioecological systems is to keep ecological change at a manageable pace (Sediri et al. 2020). So, in a realistic applied sense, resilience is about keeping the pace and direction of change under control, particularly in response to disturbance, whether expected or unexpected (Chambers et al. 2014). It is also about developing structures and systems that can withstand those disturbances.
A socioecological system is a combination of social, economic, and ecological actors and processes that are inextricably linked (Hruska et al. 2017). This conceptual framework allows researchers, advisors, and land managers to account for both the social and ecological components of a complex ecosystem as they seek to effectively communicate change and how change can be better managed in both a passive and active sense. Socioecological systems possess resilience, adaptive capacity, and transformability.
Rangelands should be viewed as socioecological systems, regardless of their ownership, location, or management objectives (Bruno et al. 2020), and sustainability is heavily reliant on the understanding of and ability to direct ecological processes at large scales. Rangeland management infrequently uses the extensive application of cultural inputs (irrigation and fertilizer) and relies heavily on the ability to subtly direct ecological processes over multiyear time scales to achieve objectives. The economics, and human well-being, are linked closely to ecological processes and natural events in a day-to-day fashion. The history of rangeland management is littered with failures that attempted to overcome changes in long-term ecological processes with cultural inputs (for example, native shrub increase, introduction of invasive grass species, and excessive livestock numbers in drought). Understanding how socioecological systems function and converting that understanding to management action is at the heart of sustainable rangeland management (Spiegal et al. 2018).
Resilience, already identified as the ability of a system to tolerate and recover from disturbance, is an important indicator of how likely long-term change is to occur. Resilience is an important ecological property, regardless of whether change is desirable or undesirable. Just because a population, an ecological process, a plant community, or a socioecological system is undesirable, it does not alter the attribute of resilience. Resilience also has a downside and must be considered as a part of management decision-making. In many cases, overcoming resilience of an undesirable condition may be a critical management objective. The understanding, measurement, and communication of the negative connotations of resilience are just as important in managing the speed and direction of change.
Given the outsized role that climate change has and will continue to play in the understanding and management of rangeland ecosystems, an approach that brings all these elements together in a way that provides a framework for testing theoretical underpinnings to improve science, gives policy makers a logical and transparent way to communicate, and most importantly, supports on-the-ground managers with credible and accessible advice, would be a significant contribution. How the components of resilience assessment and management are organized is important to developing and communicating a credible response to climate change effects on rangelands. Accounting for uncertainty in decision-making can benefit from using a risk analysis approach (Center for Climate and Energy Solutions 2019). A credible assessment of risk takes into account the threat, or the likelihood of an event occurring, as well as the ability of managers to cope with it, expressed as vulnerability (figure 1).
Threats are events that are likely to cause damage and, in general, are out of the control of the manager. Although rangeland socioecological systems are under threat from a wide variety of events, such as land conversion, invasive species, political instability, etc., climate change is generally regarded as the overriding event threatening the existence of rangeland ecosystems and their human occupants (Godde et al. 2020). Particularly in the United States, accelerated climate change is the dominant threat. For the purposes of this discussion, I will focus primarily on the impacts of and responses to drought.
In terms of climate change on rangelands, quantifying threats can be expressed in probabilistic terms. See Chambers et al. (2020) for an extensive review of tools and procedures for quantifying climate change threats, such as ecological drought. For instance, “a 30% reduction in annual growing season rainfall at least once in the next five years.” Availability of climate records extending over a century in most locations and the availability of accessible midterm climate predictions (i.e., National Drought Mitigation Center, found at www.drought.unl.edu) make the credible description of threats straightforward, if not simple, and transparent even at relatively small spatial scales. The other side of the equation, vulnerability, is less straightforward and requires a much more manager-oriented approach.
Vulnerability—weaknesses in the ability to respond to threats—can be assessed by examining the combination of exposure, sensitivity and adaptive capacity as a way to gauge the risks a rangeland sociological system faces, at least qualitatively. A realistic vulnerability assessment is a necessary basis for developing response plans with reasonable chances of success. Although these qualitative estimates may lack precision, a realistic examination of the components of vulnerability are much more important than unnecessarily precise estimates of difficult-to-quantify factors.
Exposure is the likelihood of an event occurring: how often and how severe is the drought? Readily available and easy-to-understand tools, especially for historical trends in rainfall patterns are available via the National Oceanic and Atmospheric Agency (climate.gov). Many federal agencies also provide tools that synthesize the information at a local scale (Ecological Site Descriptions, https://edit.jornada.nmsu.edu).
Sensitivity is the degree to which critical species, communities, processes, and operations will be affected: how will the reduction in precipitation affect forage production? Like the availability of easily accessible tools for predicting changes in important climatic events, several new tools are available at the county (or smaller) scale to examine the relationship between rainfall patterns and forage production. GrassCast, a multiagency platform for examining historical trends in climate and forage production can be found at www.grasscast.unl.edu. Rangeland Analysis Platform, an online tool to visualize historic trends in rangeland production can be found at www.rangelands.app. Rangeland Production Monitoring Service (www.fs.usda.gov/tools) is an online platform that can be used to examine historical trends and predict forage production, as well as changes in vegetation. All these tools are free, easily accessible, and provide interpretable information at spatial and temporal scales relevant to management.
Exposure and sensitivity together can be combined to make an estimate of potential impact. For most critical rangeland processes, potential impact can be calculated reasonably well at a regional or landscape scale using readily available tools (Brown et al. 2016).
Far more important to a credible assessment of vulnerability is an individual’s or group’s ability to adjust operations sufficiently to accommodate the changes necessary and maintain the socioecological system in at least a reasonable semblance of predisturbance conditions. The relationship between resilience and vulnerability is complex and requires a case-by-case analysis. There is no support in the literature or in practice for predetermined relationships.
Adaptive capacity is the ability of social, ecological, and economic systems to change in response to the impact. For all practical purposes, adaptive capacity is the same as resilience. Resilience is only relevant within the context of specifics about exposure, sensitivity, and impact. Thus, resilience is the last component of the vulnerability assessment that should be calculated, not the first. It is impossible to estimate resilience without a thorough understanding and documentation of the threat, exposure, sensitivity, potential impact, and finally, adaptive capacity. Only when the vulnerability assessment is completed can priorities be credibly assessed. In this case, vulnerabilities can be qualitatively ranked as low, medium, or high (figure 1). In practice, it may only be necessary to rank the vulnerabilities and address the most pressing need. These vulnerability assessment outcomes can also be placed in the context of other decision frameworks, such as the Resist, Accept, or Direct approach employed by the National Park Service (Schurrman et al. 2020).
Managing Resilience in Rangelands
Resilience—the amount of disturbance (drought, invasive species, and overgrazing) a rangeland socioecological system can absorb and return to predisturbance levels of production, species diversity, economic performance, etc., after the disturbance ceases—is at the core of developing realistic responses to climate change. The vulnerability assessment framework (figure 1) provides a logical and transparent means of organizing information and communicating a location or operation specific response. Although, it can initially seem overwhelming, most of the information necessary is easily accessible, whether landscape-scale climate change attributes or operation-scale financial details. Identification of the most important threats can greatly reduce the amount of effort required, and the results are incorporated into a transparent rule-based system for decision-making. Like most other rangeland management decisions, confidence in the information used in the assessment is more important than statistical certainty (Lynam et al. 2007). In most cases, a lack of precision in climate change impacts estimates should not preclude development of a commensurate management response.
Rangeland socioecological systems function as complex adaptive systems (Janssen et al. 2000) and have been approached as such in management and experimental contexts, but policy has generally lagged (Briske 2017). The central tenant of this approach is that rangeland socioecological systems frequently have multiple possible stable configurations (plant communities, land uses, and production levels) depending on relatively subtle changes in soil, climate, landscape context, and historical disturbance regimes (Bestelmeyer et al. 2017). The elucidation of these concepts and fine-scale applications has been commensurate with, and derived from, the development of ideas about ecological resilience and stability, socioecological systems, and nonequilibrium ecology. Rangeland scientists and practitioners have been global leaders in the development and application of state-and-transition models (STMs) to describe the dynamics of rangelands (Westoby et al. 1989; Bestelmeyer et al. 2022). More than 30 years of this concerted effort has resulted in STMs being applied to a variety of situations including chemistry, financial planning, and medicine (Siebert et al. 2012), but primarily as land management decision support tools (Brown and MacLeod 2018). These graphical models depict how systems (or conditions) change in response to specified actions. They are particularly appropriate for describing rangeland socioecological systems (Spiegal et al. 2018) and have been applied to almost all rangelands of the United States.
Climate change is not included in STMs uniformly across the United States. However, many of the STMs refer to the impacts of drought, fire, invasive species, overgrazing, flooding, and a variety of other disturbances that have been associated with changes in climate and/or weather variability (Bestelmeyer et al. 2017). There are more than ample examples of how changes in weather associated with projected changes in climate could be incorporated into a credible vulnerability assessment for climate change threats. See Brown et al. (2016) for examples from mixed grass prairie and Chihuahuan Desert rangelands of how long-term (100 y) trends and short-term (<10 y) variations in precipitation and forage production can affect livestock carrying capacity. Fortunately, the potential and utility of STMs as models of climate change impacts and adaptive responses goes far beyond the relatively simple relationship of precipitation and forage production (Bestelmeyer et al. 2022). However, there are caveats that must be considered in the application of the principles of complex adaptive systems, STMs, and resilience management.
First, and most important, managing resilience on rangelands must be viewed from perspective of desired outcomes. Although the policy/program perspective has been to promote resilience in an overwhelmingly positive sense, land managers and scientists are more than aware that resilience, as an ecological attribute, is often more a hinderance. As early as the 1980s, researchers (Archer 1989; Westoby et al. 1989) explicitly described changes in rangeland plant communities where “degraded” ecological states were difficult, if not impossible, to manage for a return to more desired conditions. Since, these “irreversible transitions” have been applied to invasive cool-season grasses in Northern Plains grasslands (Toledo et al. 2014): juniper increase in Northern Great Basin sagebrush/grass lands (Miller and Tausch 2001), shrub increase in hot desert grasslands (Bestelmeyer et al. 2003), exotic woody plant invasions in Texas Gulf Coast prairie (Grace et al. 1998), annual grass invasion in California Mediterranean grasslands (George et al. 1992), and many, many more (Eldridge et al. 2011). In all these cases, and numerous others, the resilience of the “degraded” state must be interpreted to be greater than the resilience of the “desirable” state, or else improved management via the application of resilience management practices would have returned those plant communities to a more desirable state. Although most of these examples have focused on plant community composition changes, the implications for other aspects of the rangeland socioecological systems are obvious (livestock operations, wildlife habitat, and ranching as a profession/lifestyle). As recognition of these other ecosystem services and the impact of ecological state change becomes a theme in the rangeland socioecological systems literature (Fernandez-Gimenez et al. 2019; Wilmer et al. 2019), the increasing influence and impacts of climate change on the ability of managers to manage resilience in a positive fashion become obvious.
From the preceding discussion, and more than a century of relevant research and observation, it should be obvious that most US rangelands have very limited resilience once an undesirable state change has occurred. The notable exception seems to be the short, mixed, and tallgrass prairie ecosystems with relatively deep, fertile soils and favorable climate. Although Twidwell et al. (2021a) have described these grasslands as highly resilient, tree and shrub increase remain a persistent and increasingly difficult challenge. If other, less resilient ecosystems are an indication, at some point even these highly resilient systems may change irreversibly. To avoid that realization, the widely agreed upon response involves substantial alterations to land management practice as a necessary condition for maintaining the resilience inherent in the iconic rangelands (Wilcox et al. 2021).
The differing responses of major US rangeland regions may offer a clue into a more realistic examination of the value of resilience as a response to climate change (Adler et al. 2004). The more arid rangelands characterized by highly variable precipitation, poor nutrient status soils, and lack of an evolutionary legacy of large herbivores are generally regarded as having less resilience and, in fact, have experienced more widespread degradation in response to similar settlement patterns (Axelrod 1985; Milchunas et al. 1988; Milchunas 2006; Herrick et al. 2010; Bardgett et al. 2021). Inherent resilience, conveyed by the biophysical properties of an ecosystem, is an indicator of the amount of disturbance these rangeland ecological systems can tolerate and remain intact, as judged by the departure from hypothesized pre-European settlement conditions. As an example, recent reviews project that North American prairies are less likely to undergo changes to structure and function compared to the more arid ecosystems of the western United States (Brown and Thorpe 2008; Polley et al. 2013, 2019).
Conversely, managed resilience is the amount of resilience that can be attributed to management actions. Although there has been an inordinate amount of emphasis on managing for resilience in agricultural systems (e.g., regenerative agriculture), in most rangeland systems the ability of management to substantially enhance ecological resilience is limited, at best. For example, soil carbon (C) (and supporting processes), as an indicator of enhanced resilience, responds much more to fluctuations in weather and to soil texture than to management changes (Augustine et al. 2020; Carey et al. 2020), even over long-term (>30 y) widely different management regimes (Teague et al. 2011; Derner et al. 2019). Similarly, vegetation attributes that might indicate resilience (productivity and species composition) have shown only limited response to changes in management and are also primarily driven by variability in site characteristics and weather (Briske et al. 2008, 2011; Hawkins et al. 2017; McDonald et al. 2019, 2021; Morris 2021; Wang et al. 2020;).
On the other hand, there is an increasing amount of evidence that the social and economic aspects of resilience can be enhanced, regardless of the inherent resilience of the particular rangeland ecosystem (Ritten et al. 2010; MacLeod and Brown 2014; Roche et al. 2015; Torell et al. 2018; Gosnell et al. 2020). As seasonal variability in production is projected to increase in many rangeland-based livestock systems (Polley et al. 2013; Briske et al. 2015), increasing flexibility in livestock numbers, livestock species mixes, nonlivestock enterprises, and off-ranch income can play an important role in enhancing economic resilience (Joyce et al. 2013). Developing larger and more effective networks to help ranching families explore and implement solutions to climate change driven changes offers promise (Reid et al. 2014; Knapp et al. 2019; Wilmer et al. 2019; Dinan et al. 2021).
Socioecological resilience is very much context-dependent (Walker et al. 2002) and cannot be defined independent of a thorough and well-communicated understanding of the location and the people involved. Attempts to build resilience with universal “practices” are likely to fail, and even more importantly, miss opportunities for collaborative learning. As Walker et al. (2002) asked, “Resilience of what?” and “Resilience to what?” A credible assessment of vulnerability requires a well-developed and well-communicated description of current conditions. Throughout the complex adaptive systems literature, “initial conditions” or the starting point are important determinants of system behavior (Holland 2006). Small changes in initial conditions can generate large changes in the system’s outcome. In the case of rangeland socioecological systems, failure to describe the initial conditions not only ignores the importance of current conditions in the mechanics of the complex system, but it misses an important opportunity to connect with participants in the system (Reid et al. 2014). In most cases, the decline of ecological resilience and eventual degradation is a result of, or at least inextricably linked to, the existing social and economic systems. It would be hard to imagine the extensive restoration of a “degraded” ecosystem without substantial changes in the social and economic components (the culture) as well (Bestelmeyer and Briske 2012; Twidwell et al. 2021b; Wilcox et al. 2021).
This is not to say that management doesn’t matter. The same research base has defined rules for supporting ecological, economic, and social decision-making unique to the individual specific rangeland ecosystems in the United States. Bad management (overstocking, inflexibility during drought, taking economic risks, and ignoring technical guidance and local best practice) is bad management. Obviously, poor management of any component of the socioecological system will weaken overall resilience. The challenge is in allocating resources to achieve the greatest amount of resilience.
Based on the extensive and consistent research results, and accumulated observations, it is reasonable to conclude that the three components of rangeland resilience in a climate change context are well understood enough that we can identify some general directions for emphasis. Ecological resilience is largely governed by inherent biophysical properties, while managed resilience has limited potential. Enhancing economic resilience is achievable, but likely requires much more attention, including flexibility and support networks. Social resilience, probably the least studied component of resilience, can be enhanced and shows potential, especially in developing learning networks.
A Transformative Approach
Transformability is the capacity to create a fundamentally new system when ecological, economic, or social structures make the existing system untenable (Walker et al. 2004). From the preceding discussion, it is reasonable to say that many rangeland ecosystems have transformed (assumed a new, less desirable ecological state) or are in the process of transforming to a less desirable state. We must assume that the social and economic systems associated with them have also transformed, perhaps at a pace that was not, at the time, alarming, but is now easily quantifiable. Management objectives, across ownerships, are focused on “restoring” the original, desirable state. We have not been particularly successful and are constantly seeking new technologies to accelerate the restoration.
While the capacity to transform, via management, to a new system can be seen as a desirable trait, transformations are certainly not without and costs and risks (Sediri et al. 2020; Jackson 2021). Because transformations are, by definition, relatively radical changes in the way complex adaptive systems operate, it is not uncommon for entirely new, unexpected, and undesirable systems to emerge. Decisions, on the part of individual land managers (with or without policy encouragement) to transform the socioecological system in which they are operating, are frequently disastrous (e.g., Dust Bowl) and can cascade beyond intended boundaries (Peters et al. 2020).
Transformations, by definition, take time, resources, and continued attention (Joyce et al. 2013; Jackson 2021). Once a state change occurs, regardless of whether it was driven by management or external forces, it is very unlikely to return to the original “reference” condition unless there are extraordinary actions taken. Usually, these actions require both high levels of cultural (fossil fuel) inputs and at least partial abandonment or major revision of previously existing production goals.
For example, the Conservation Reserve Program provides not only financial support for land reshaping (if necessary) and reseeding perennial species, but also medium term (10+ years) leases to ensure that ecosystem services associated with the changes in land use are maintained. Other similar easement programs within the Agricultural Conservation Easement Programs offer opportunities for more flexible, longer-term attention to the inherent nonequilibrium dynamics that characterize rangeland socioecological systems.
The Resist-Accept-Direct (RAD) framework (Crausbay et al. 2020) explicitly addresses transformational ecology and management in response to a changing climate. This approach specifically deals with the changing management and research requirements for nonequilibrium ecosystems acknowledging the complexity of a changing decision space (Clifford et al. 2002). Although the RAD framework has been illustrated primarily with public lands management, the approach offers much for private, working lands management and is complimentary to the vulnerability assessment approach in this paper (figure 1).
These types of programs, which include flexible, long-term financial support with opportunities for combinations of land management, redefinition of ecosystem service goals, and increased technical decision-support that includes more viewpoints and sources of knowledge will be necessary to implement these transformational responses to climate change. These programmatic approaches also assume there will be changes in the economic systems and the social systems that are based on these lands, regardless of ownership. If true resilience really does include the ecological, economic, and social aspects of rangelands, then all the subsystems will have to change as well.
- Received April 1, 2022.
- Revision received September 14, 2022.
- Accepted October 7, 2022.
- © 2023 by the Soil and Water Conservation Society