An introduction to decision science for conservation

Biodiversity conservation decisions are difficult, especially when they involve differing values, complex multidimensional objectives, scarce resources, urgency, and considerable uncertainty. Decision science embodies a theory about how to make difficult decisions and an extensive array of frameworks and tools that make that theory practical. We sought to improve conceptual clarity and practical application of decision science to help decision makers apply decision science to conservation problems. We addressed barriers to the uptake of decision science, including a lack of training and awareness of decision science; confusion over common terminology and which tools and frameworks to apply; and the mistaken impression that applying decision science must be time consuming, expensive, and complex. To aid in navigating the extensive and disparate decision science literature, we clarify meaning of common terms: decision science, decision theory, decision analysis, structured decision-making, and decision-support tools. Applying decision science does not have to be complex or time consuming; rather, it begins with knowing how to think through the components of a decision utilizing decision analysis (i.e., define the problem, elicit objectives, develop alternatives, estimate consequences, and perform trade-offs). This is best achieved by applying a rapid-prototyping approach. At each step, decision-support tools can provide additional insight and clarity, whereas decision-support frameworks (e.g., priority threat management and systematic conservation planning) can aid navigation of multiple steps of a decision analysis for particular contexts. We summarize key decision-support frameworks and tools and describe to which step of a decision analysis, and to which contexts, each is most useful to apply. Our introduction to decision science will aid in contextualizing current approaches and new developments, and help decision makers begin to apply decision science to conservation problems.     

Structuring Decisions for Managing Threatened and Endangered Species in a Changing Climate

The management of endangered species under climate change is a challenging and often controversial task that incorporates input from a variety of different environmental, economic, social, and political interests. Yet many listing and recovery decisions for endangered species unfold on an ad hoc basis without reference to decision‐aiding approaches that can improve the quality of management choices. Unlike many treatments of this issue, which consider endangered species management a science‐based problem, we suggest that a clear decision‐making process is equally necessary. In the face of new threats due to climate change, managers’ choices about endangered species require closely linked analyses and deliberations that identify key objectives and develop measurable attributes, generate and compare management alternatives, estimate expected consequences and key sources of uncertainty, and clarify trade‐offs across different dimensions of value. Several recent cases of endangered species conservation decisions illustrate our proposed decision‐focused approach, including Gulf of Maine Atlantic salmon (Salmo salar) recovery framework development, Cultus Lake sockeye salmon (Oncorhynchus nerka) management, and Upper Columbia River white sturgeon (Acipenser transmontanus) recovery planning. Estructuración de Decisiones para Manejar Especies Amenazadas y en Peligro en un Clima Cambiante     

A classification framework for interspecific trade-offs in aquatic ecology

In some cases, wildlife management objectives directed at multiple species can conflict with one another, creating species trade-offs. For managers to effectively identify trade-offs and avoid their undesirable outcomes, they must understand the agents involved and their corresponding interactions. A literature review of interspecific trade-offs within freshwater and marine ecosystems was conducted to illustrate the scope of potential interspecific trade-offs that may occur. We identified common pitfalls that lead to failed recognition of interspecific trade-offs, including, single-species management and limited consideration of the spatial and temporal scale of ecosystems and their management regimes. We devised a classification framework of common interspecific trade-offs within aquatic systems. The classification can help managers determine whether the conflict is species based through direct relationships (i.e., predator–prey, competition, other antagonistic relationships) or indirect relationships involving intermediate species (i.e., conflict-generating species) or whether the conflict is driven by opposing management objectives for species that would otherwise not interact (i.e., nontarget management effects). Once the nature and scope of trade-offs are understood, existing decision-making tools, such as structured decision-making and real-options analysis, can be incorporated to improve the management of aquatic ecosystems. Article Impact Statement: A synthesis of interspecific trade-offs in aquatic ecosystems supports their identification and resolution.     

Evaluation of potential responses to invasive non-native species with structured decision making

In managing invasions and colonizations of non-native species, eradication or control efforts must proceed quickly. There are 2 challenges in taking such quick action. First, managers frequently have to choose among complex and often competing environmental, social, and economic objectives. Second, the effects are highly uncertain. We applied participatory structured decision making (SDM) to develop a response plan for the recent invasion of non-native myrtle rust (Uredo rangelii) in Australia. Structured decision making breaks a complex decision process into 5 steps: identify problems (i.e., decisions to be made), formulate objectives, develop management alternatives, estimate consequences of implementing those alternatives, and select preferred alternatives by evaluating trade-offs among alternatives. To determine the preferred mid- to long-term alternatives to managing the rust, we conducted 2 participatory workshops and 18 interviews with individuals to elicit stakeholders' key concerns and convert them into 5 objectives (minimize management cost, minimize economic cost to industry, minimize effects on natural ecosystems and landscape amenities, and minimize environmental effects associated with use of fungicide) and to identify the 5 management alternatives (full eradication, partial eradication, slow spread, live with it [i.e., major effort invested in mitigation of effects], and do nothing). We also developed decision trees to graphically represent the essence of the decision by displaying the relations between uncertainties and decision points. In the short term or before local expansion of myrtle rust, the do-nothing alternative was not preferred, but an eradication alternative was only recommended if the probability of eradication exceeded about 40%. After the expansion of myrtle rust, the slow-the-spread alternative was preferred regardless of which of the short-term management alternatives was selected at an earlier stage. The participatory SDM approach effectively resulted in informed and transparent response plans that incorporated multiple objectives in decision-making processes under high uncertainty.     

Setting conservation management thresholds using a novel participatory modeling approach

We devised a participatory modeling approach for setting management thresholds that show when management intervention is required to address undesirable ecosystem changes. This approach was designed to be used when management thresholds: must be set for environmental indicators in the face of multiple competing objectives; need to incorporate scientific understanding and value judgments; and will be set by participants with limited modeling experience. We applied our approach to a case study where management thresholds were set for a mat‐forming brown alga, Hormosira banksii, in a protected area management context. Participants, including management staff and scientists, were involved in a workshop to test the approach, and set management thresholds to address the threat of trampling by visitors to an intertidal rocky reef. The approach involved trading off the environmental objective, to maintain the condition of intertidal reef communities, with social and economic objectives to ensure management intervention was cost‐effective. Ecological scenarios, developed using scenario planning, were a key feature that provided the foundation for where to set management thresholds. The scenarios developed represented declines in percent cover of H. banksii that may occur under increased threatening processes. Participants defined 4 discrete management alternatives to address the threat of trampling and estimated the effect of these alternatives on the objectives under each ecological scenario. A weighted additive model was used to aggregate participants’ consequence estimates. Model outputs (decision scores) clearly expressed uncertainty, which can be considered by decision makers and used to inform where to set management thresholds. This approach encourages a proactive form of conservation, where management thresholds and associated actions are defined a priori for ecological indicators, rather than reacting to unexpected ecosystem changes in the future.     

Use of carrion fly iDNA metabarcoding to monitor invasive and native mammals

Severely fragmented habitats increase the risk of extirpation of native mammal populations through isolation, increased edge effects, and predation. Therefore, monitoring the movement of mammal populations through anthropogenically altered landscapes can inform conservation. We used metabarcoding of invertebrate-derived DNA (iDNA) from carrion flies (Calliphoridae and Sarcophagidae) to track mammal populations in the wheat belt of southwestern Australia, where widespread clearing for agriculture has removed most of the native perennial vegetation and replaced it with an agricultural system. We investigated whether the localization of the iDNA signal reflected the predicted distribution of 4 native species—echidna (Tachyglossus aculeatus), numbat (Myrmecobius fasciatus), woylie (Bettongia penicillata), and chuditch (Dasyurus geoffroii)—and 2 non-native, invasive mammal species—fox (Vulpes vulpes) and feral cat (Felis catus). We collected bulk iDNA samples (n = 150 samples from 3428 carrion flies) at 3 time points from 3 conservation reserves and 35 road edges between them. We detected 14 of the 40 mammal species known from the region, including our target species. Most detections of target taxa were in conservation reserves. There were a few detections from road edges. We detected foxes and feral cats throughout the study area, including all conservation reserves. There was a significant difference between the diversity (F_3, 98 = 5.91, p < 0.001) and composition (F_3, 43 = 1.72, p < 0.01) of taxa detections on road edges and conservation reserves. Conservation reserves hosted more native biodiversity than road edges. Our results suggest that the signals from iDNA reflect the known distribution of target mammals in this region. The development of iDNA methods shows promise for future noninvasive monitoring of mammals. With further development, iDNA metabarcoding could inform decision-making related to conservation of endangered taxa, invasive species management, and impacts of habitat fragmentation.     

Applying a values-based decision process to facilitate comanagement of threatened species in Aotearoa New Zealand

Ko koe ki tēnā, ko ahau ki tēnai kīwai o te kete (you at that, and I at this handle of the basket). This Māori (New Zealanders of indigenous descent) saying conveys the principle of cooperation—we achieve more through working together, rather than separately. Despite decades of calls to rectify cultural imbalance in conservation, threatened species management still relies overwhelmingly on ideas from Western science and on top-down implementation. Values-based approaches to decision making can be used to integrate indigenous peoples’ values into species conservation in a more meaningful way. We used such a values-based method, structured decision making, to develop comanagement of pekapeka (Mystacina tuberculata) (short-tailed bat) and tara iti (Sternula nereis davisae) (Fairy Tern) between Māori and Pākehā (New Zealanders of European descent). We implemented this framework in a series of workshops in which facilitated discussions were used to gather expert knowledge to predict outcomes and make management recommendations. For both species, stakeholders clearly stated their values as fundamental objectives from the start, which allowed alternative strategies to be devised that naturally addressed their diverse values, including mātauranga Māori (Māori knowledge and perspectives). On this shared basis, all partners willingly engaged in the process, and decisions were largely agreed to by all. Most expectations of conflicts between values of Western science and Māori culture were unfounded. Where required, positive compromises were made by jointly developing alternative strategies. The values-based process successfully taha wairua taha tangata (brought both worlds together to achieve the objective) through codeveloped recovery strategies. This approach challenges the traditional model of scientists first preparing management plans focused on biological objectives, then consulting indigenous groups for approval. We recommend values-based approaches, such as structured decision making, as powerful methods for development of comanagement conservation plans between different peoples.     

A Meta‐Analysis of the Effects of Common Management Actions on the Nest Success of North American Birds

Abstract: Management strategies for the recovery of declining bird populations often must be made without sufficient data to predict the outcome of proposed actions or sufficient time and resources necessary to collect these data. We quantitatively reviewed studies of bird management in Canada and the United States to evaluate the relative efficacy of 4 common management interventions and to determine variables associated with their success. We compared how livestock exclusion, prescribed burning, removal of predators, and removal of cowbirds (Molothrus ater) affect bird nest success and used meta‐regression to evaluate the influence of species and study‐specific covariates on management outcomes. On average, all 4 management interventions increased nest success. When common species and threatened, endangered, or declining species (as defined by long‐term trend data from the North American Breeding Bird Survey) were analyzed together, predator removal was the most effective management option. The difference in mean nest success between treatment and control plots in predator‐removal experiments was more than twice that of either livestock exclusion or prescribed burning. However, when we considered management outcomes from only threatened, endangered, or declining species, livestock exclusions resulted in the greatest mean increase in nest success, more than twice that of the 3 other treatments. Our meta‐regression results indicated that between‐species variation accounted for approximately 86%, 40%, 35%, and 7% of the overall variation in the results of livestock‐exclusion, prescribed‐burn, predator‐removal, and cowbird‐removal studies, respectively. However, the covariates we tested explained significant variation only in outcomes among prescribed‐burn studies. The difference in nest success between burned and unburned plots displayed a significant, positive trend in association with time since fire and was significantly larger in grasslands than in woodlands. Our results highlight the importance of comparative studies on management effects in developing efficient and effective conservation strategies.     

The moral residue of conservation

Should conservationists use lethal management to control introduced wildlife populations? Should they kill individual animals to protect endangered species? Are trade-offs that prioritize some values at the expense of others morally appropriate? These sorts of ethical questions are common in conservation. In debating such questions, conservationists often seem to presume 1 of 2 possible answers: the act in question is right or it is wrong. But morality in conservation is considerably more complex than this simple binary suggests. A robust conservation ethic requires a vocabulary that gives voice to the uncertainty and unease that arise when what seems to be the best available course of action also seems to involve a measure of wrongdoing. The philosophical literature on moral residue and moral dilemmas supplies this vocabulary. Moral dilemmas arise when one must neglect certain moral requirements to fulfill others. Under such circumstances, even the best possible decision leaves a moral residue, which is experienced emotionally as some form of grief. Examples of conservation scenarios that leave a moral residue include management of introduced rabbits in Australia, trophy hunting in Africa, and forest management trade-offs in the Pacific Northwest. Moral residue is integral to the moral experience of conservationists today, and grief is an appropriate response to many decisions conservationists must make. Article impact statement: Defensible conservation decisions may neglect moral requirements, leaving a moral residue; conservationists should respond with grief.     

Redesigning harvest strategies for sustainable fishery management in the face of extreme environmental variability

Short-lived, fast-growing species that contribute greatly to global capture fisheries are sensitive to fluctuations in the environment. Uncertainties in exact stock–environment relationships have meant that environmental variability and extremes have been difficult to integrate directly into fisheries management. We applied a management strategy evaluation approach for one of Australia's large prawn stocks to test the robustness of harvest control rules to environmental variability. The model ensemble included coupled environmental-population models and an alternative catchability scenario fitted to historical catch per unit effort data. We compared the efficacy of alternative management actions to conserve marine resources under a variable environment while accounting for fisher livelihoods. Model fits to catch per unit effort were reasonably good and similar across operating models (OMs). For models that were coupled to the environment, environmental parameters for El Niño years were estimated with good associated precision, and OM3 had a lower AIC score (77.61)  than the base model (OM1, 80.39), whereas OM2 (AIC 82.41) had a similar AIC score, suggesting the OMs were all plausible model alternatives. Our model testing resulted in a plausible subset of management options, and stakeholders selected a permanent closure of the first fishing season based on overall performance of this option; ability to reduce the risk of fishery closure and stock collapse; robustness to uncertainties; and ease of implementation. Our simulation approach enabled the selection of an optimal yet pragmatic solution for addressing economic and conservation objectives under a variable environment with extreme events.     

Improving supplementary feeding in species conservation

Supplementary feeding is often a knee‐jerk reaction to population declines, and its application is not critically evaluated, leading to polarized views among managers on its usefulness. Here, we advocate a more strategic approach to supplementary feeding so that the choice to use it is clearly justified over, or in combination with, other management actions and the predicted consequences are then critically assessed following implementation. We propose combining methods from a set of specialist disciplines that will allow critical evaluation of the need, benefit, and risks of food supplementation. Through the use of nutritional ecology, population ecology, and structured decision making, conservation managers can make better choices about what and how to feed by estimating consequences on population recovery across a range of possible actions. This structured approach also informs targeted monitoring and more clearly allows supplementary feeding to be integrated in recovery plans and reduces the risk of inefficient decisions. In New Zealand, managers of the endangered Hihi (Notiomystis cincta) often rely on supplementary feeding to support reintroduced populations. On Kapiti island the reintroduced Hihi population has responded well to food supplementation, but the logistics of providing an increasing demand recently outstretched management capacity. To decide whether and how the feeding regime should be revised, managers used a structured decision making approach informed by population responses to alternative feeding regimes. The decision was made to reduce the spatial distribution of feeders and invest saved time in increasing volume of food delivered into a smaller core area. The approach used allowed a transparent and defendable management decision in regard to supplementary feeding, reflecting the multiple objectives of managers and their priorities.     

Choosing a Management Strategy: Two Structured Decision-Making Methods for Evaluating the Predictions of Stochastic Simulation Models

We describe two structured decision-making methods—one using a hierarchy of goals and a second using ranking on the sum of weighted criteria—that may be useful for many practical conservation problems, particularly when advisory groups evaluate the output of simulation models. We illustrate both methods by applying them to the problem of choosing a management strategy to address the "mobbing" problem in endangered Hawaiian monk seals. Both methods require estimates of the probabilities of various outcomes, such as a population size of more than 400 seals after 20 years under a specific management regime. We used a simulation model of a small monk seal population to generate these probabilities. Both methods provide an explicit, well-documented, and reproducible decision process that helps justify the decision. Furthermore, they are easy for those untrained in decision analysis to understand and use, they focus discussion on management objectives, they facilitate an examination of trade-offs in the light of multiple and sometimes conflicting objectives, they are suitable for use in workshops, and, at least in our example, they lead to management recommendations that are not highly sensitive to minor changes in probability estimates or other factors.     

Evaluating institutional fit for the conservation of threatened species

Recovery and conservation of threatened species require adequate institutional responses. We tested an approach to systematically identify and measure how an institutional framework acknowledges threats and required responses for the recovery of endangered species. We measured institutional functional fit with a drivers-pressure-state-impacts-response (DPSIR) model integrated with a quantitative text mining method and qualitative analysis of statutory instruments to examine regulatory responses that support the recovery of 2 endangered species native to Australia, the bridled nailtail wallaby (Onychogalea fraenata) and the Eastern Bristlebird (Dasyornis brachypterus). The key components of the DPSIR model were present in the institutional framework at statutory and operational levels, but some institutional gaps remained in the protection and recovery of the Eastern Bristlebird, including feral predator control, weed control, and grazing management in some locations. However, regulatory frameworks varied in their geographic scope and the application and implementation of many instruments remained optional. Quantitative text mining can be used to quickly navigate a large volume of regulatory documents, but challenges remain in selection of terms, queries of co-occurrence, and interpretation of word frequency counts. To inform policy, we recommend that quantitative assessments of institutional fit be complemented with qualitative analysis and interpreted in light of the sociopolitical and institutional context.     

Mate retention and male polyterritoriality in the pied flycatcher Ficedula hypoleuca

Summary We studied pair bond maintenance in the pied flycatcher in an experiment on nest predation at the incubation stage. Males defending one or more additional nestboxes (i.e. polyterritorial) on the day of nest predation were significantly more successful in retaining their mate than were the monoterritorial males (54% and 13% succeed, respectively). We manipulated the number of nest sites available for renesting, and found that the females remained preferentially with those males that had access to a new site, regardless of the previous territorial status of the male. Thus, the success of the polyterritorial males in mate retention was related primarily to the resource defended (a new nest site) rather than to some quality of the particular males per se. When the females could choose between alternative nestboxes for renesting, they selected the one located at the greatest distance from the initial site (Fig. 1). Male polyterritorial behaviour has previously been interpreted as a means of achieving polygyny. Our results show that this behaviour may be advantageous even in the absence of polygyny, especially at high levels of nest predation.     

Planning for ex situ conservation in the face of uncertainty

Ex situ conservation strategies for threatened species often require long‐term commitment and financial investment to achieve management objectives. We present a framework that considers the decision to adopt ex situ management for a target species as the end point of several linked decisions. We used a decision tree to intuitively represent the logical sequence of decision making. The first decision is to identify the specific management actions most likely to achieve the fundamental objectives of the recovery plan, with or without the use of ex‐situ populations. Once this decision has been made, one decides whether to establish an ex situ population, accounting for the probability of success in the initial phase of the recovery plan, for example, the probability of successful breeding in captivity. Approaching these decisions in the reverse order (attempting to establish an ex situ population before its purpose is clearly defined) can lead to a poor allocation of resources, because it may restrict the range of available decisions in the second stage. We applied our decision framework to the recovery program for the threatened spotted tree frog (Litoria spenceri) of southeastern Australia. Across a range of possible management actions, only those including ex situ management were expected to provide >50% probability of the species’ persistence, but these actions cost more than use of in situ alternatives only. The expected benefits of ex situ actions were predicted to be offset by additional uncertainty and stochasticity associated with establishing and maintaining ex situ populations. Naïvely implementing ex situ conservation strategies can lead to inefficient management. Our framework may help managers explicitly evaluate objectives, management options, and the probability of success prior to establishing a captive colony of any given species.     

Bayesian Decision Analysis for Evaluating Management Options to Promote Recovery of a Depleted Salmon Population

Abstract:  The endangered population of sockeye salmon (Oncorhynchus nerka) in Cultus Lake, British Columbia, Canada, migrates through commercial fishing areas along with other, much more abundant sockeye salmon populations, but it is not feasible to selectively harvest only the latter, abundant populations. This situation creates controversial trade-offs between recovery actions and economic revenue. We conducted a Bayesian decision analysis to evaluate options for recovery of Cultus Lake sockeye salmon. We used a stochastic population model that included 2 sources of uncertainty that are often omitted from such analyses: structural uncertainty in the magnitude of a potential Allee effect and implementation uncertainty (the deviation between targets and actual outcomes of management actions). Numerous state-dependent, time-independent management actions meet recovery objectives. These actions prescribe limitations on commercial harvest rates as a function of abundance of Cultus Lake sockeye salmon. We also quantified how much reduction in economic value of commercial harvests of the more abundant sockeye salmon populations would be expected for a given increase in the probability of recovery of the Cultus population. Such results illustrate how Bayesian decision analysis can rank options for dealing with conservation risks and can help inform trade-off discussions among decision makers and among groups that have competing objectives.     

Lessons from other disciplines for setting management thresholds for biodiversity conservation

Successful, state-dependent management, in which the goal of management is to maintain a system in a desired state, involves defining the boundaries between different states. Once these boundaries have been defined, managers require a strategic action plan with thresholds that initiate management interventions to either maintain or return the system to a desired state. This approach to management is widely used across diverse industries from agriculture, to medicine, to information technology, but it has only been adopted in conservation management relatively recently. Conservation practitioners have expressed a willingness to integrate this structured approach in their management systems, but they have also voiced concerns, including lack of a robust process for doing so. Given the widespread use of state-dependent management in other fields, we conducted an extensive review of the literature on threshold-based management to gain insight into how and where it is applied and identify potential lessons for conservation management. We identified 22 industries using 75 different methods for setting management thresholds in 843 studies. Methods spanned six broad approaches, including expert driven, statistical, predictive, optimization, experimental, and artificial intelligence methods. The objectives of each of these studies influenced the approaches used, including the methods for setting thresholds and selecting actions, and the number of thresholds set. The role of value judgments in setting thresholds was clear; studies across all industries frequently involved experts in setting thresholds, often accompanied by computational tools to simulate the consequences of proposed thresholds under different conditions. Of the 30 conservation studies examined, two-thirds used expert-driven methods, consistent with prior evidence that experience-based information often drives conservation management decisions. The methods we identified from other disciplines could help conservation decision makers set thresholds for management interventions in different contexts, linking monitoring to management actions and ensuring that conservation interventions are timely and effective.     

Integrated models to support multiobjective ecological restoration decisions

Many objectives motivate ecological restoration, including improving vegetation condition, increasing the range and abundance of threatened species, and improving species richness and diversity. Although models have been used to examine the outcomes of ecological restoration, few researchers have attempted to develop models to account for multiple, potentially competing objectives. We developed a combined state‐and‐transition, species‐distribution model to predict the effects of restoration actions on vegetation condition and extent, bird diversity, and the distribution of several bird species in southeastern Australian woodlands. The actions reflected several management objectives. We then validated the models against an independent data set and investigated how the best management decision might change when objectives were valued differently. We also used model results to identify effective restoration options for vegetation and bird species under a constrained budget. In the examples we evaluated, no one action (improving vegetation condition and extent, increasing bird diversity, or increasing the probability of occurrence for threatened species) provided the best outcome across all objectives. In agricultural lands, the optimal management actions for promoting the occurrence of the Brown Treecreeper (Climacteris picumnus), an iconic threatened species, resulted in little improvement in the extent of the vegetation and a high probability of decreased vegetation condition. This result highlights that the best management action in any situation depends on how much the different objectives are valued. In our example scenario, no management or weed control were most likely to be the best management options to satisfy multiple restoration objectives. Our approach to exploring trade‐offs in management outcomes through integrated modeling and structured decision‐support approaches has wide application for situations in which trade‐offs exist between competing conservation objectives.     

Resolving future fire management conflicts using multicriteria decision making

Management strategies to reduce the risks to human life and property from wildfire commonly involve burning native vegetation. However, planned burning can conflict with other societal objectives such as human health and biodiversity conservation. These conflicts are likely to intensify as fire regimes change under future climates and as growing human populations encroach farther into fire‐prone ecosystems. Decisions about managing fire risks are therefore complex and warrant more sophisticated approaches than are typically used. We applied a multicriteria decision making approach (MCDA) with the potential to improve fire management outcomes to the case of a highly populated, biodiverse, and flammable wildland–urban interface. We considered the effects of 22 planned burning options on 8 objectives: house protection, maximizing water quality, minimizing carbon emissions and impacts on human health, and minimizing declines of 5 distinct species types. The MCDA identified a small number of management options (burning forest adjacent to houses) that performed well for most objectives, but not for one species type (arboreal mammal) or for water quality. Although MCDA made the conflict between objectives explicit, resolution of the problem depended on the weighting assigned to each objective. Additive weighting of criteria traded off the arboreal mammal and water quality objectives for other objectives. Multiplicative weighting identified scenarios that avoided poor outcomes for any objective, which is important for avoiding potentially irreversible biodiversity losses. To distinguish reliably among management options, future work should focus on reducing uncertainty in outcomes across a range of objectives. Considering management actions that have more predictable outcomes than landscape fuel management will be important. We found that, where data were adequate, an MCDA can support decision making in the complex and often conflicted area of fire management.