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Aim: Many tree species may be threatened with declines in range and biomass, or even extinction, if they cannot disperse or adapt quickly enough to keep pace with climate change. One potential, and potentially risky, strategy to mitigate this threat is assisted migration (AM), the intentional movement of species to facilitate population range shifts to more climatically suitable locations under climate change. The ability for AM to minimise risk and maximise conservation and forestry outcomes depends on a multi-faceted decision process for determining, what, where and how much to move. We provide an assessment on how the benefits and risks of AM could affect the decision-making process. Location: Mountainous coastal western United States. Taxon: Trees. Methods: We used a dynamic vegetation model parameterised with 23 tree species. Results: We found that most of the modelled species are likely to experience a substantial decline in biomass, with many potentially facing regional extinction by 2100 under the high-emission SSP5-85 climate-change scenario. Though simulations show AM had little effect on the forestry goal of total biomass across all species, its effects on the conservation goal of promoting individual species' persistence were far more substantial. Among eight AM strategies (differing in the life cycle stage of movement and target destination selection criteria), the approach that conserved the highest biomass for individual species involved relocating target seedlings to areas that recently experienced fire. Although this strategy significantly reduced extinction risk for six at-risk species compared with no action, it also slightly reduced biomass of four species, due to increasing competition. Species with relatively weak tolerance to drought, fire or high temperature were the most likely candidate groups for AM. Main Conclusions: Our simulations indicate that AM can aid conservation by reducing extinction risks for species vulnerable to climate change, but it has limited impact on forestry-specific goals, affecting overall biomass minimally. This model framework could be applied to other forest ecosystems to evaluate the efficacy of AM globally.

Climate change is dramatically altering the environmental context in which marine resources are harvested and managed. A growing field of academic literature has begun to explore the adaptive capacity of fishers and managers to respond to this change, but much of this field is abstract and theory-driven. Therefore, it is unclear whether this literature accurately reflects the adaptation priorities of fishery management practitioners, or whether there are gaps in the literature that these practitioners could fill with on-the-ground knowledge. Second, even if these principles of adaptive capacity are perfectly aligned with management practitioners’ priorities, it is unclear to what extent these principles are actively considered in the decision making process, and if not, why. This study seeks to address these questions by confronting fisheries professionals with academic ideas around adaptive capacity through a series of semi-structured interviews with federal fishery managers and scientists whose work informs decision making in the United States regional fishery management system. The study then uses these interviews to identify three low-cost, high-impact action items that could make concepts from the academic literature more accessible and useful to these practitioners and expand the literature by incorporating practitioners’ expertise. These action items are: 1) distinguish adaptive capacity from adaptive management, 2) use practitioner insights to contextualize the elements of adaptive capacity within the constraints and opportunities of governance systems, and 3) expand academic research to explicitly consider the capacity to adapt on appropriate timelines given the scale and pace of systemic change.

While conservation fish hatchery programs can be a valuable tool providing demographic support, they can also cause domestication, risking unintended fitness consequences to both target and connected populations. When conservation hatcheries are used over a fixed amount of time, the interaction between program duration and species life history might determine the scale of fitness effects and the effectiveness of mitigation measures. We develop a mathematical model to quantify the effectiveness of approaches to mitigate unintended fitness consequences in such temporary conservation hatchery programs. We parameterize our model to represent a conservation aquaculture-based recovery program for white sturgeon (Acipenser transmontatus) in the Nechako River (British Columbia), which might impose genetic risks on the adjacent populations within the Fraser River. We find that, over a period spanning 50-200 years of hatchery operation, the life history characteristics of white sturgeon, particularly late age of maturity and longevity, reduce the genetic risks of conservation hatcheries when compared to shorter-lived species. The genetic impacts of the hatchery accumulate slowly providing increasing the potential for adaptive management in this system.

Dispersal of reproductive propagules determines recruitment patterns and connectivity among populations and can influence how populations respond to major disturbance events. Dispersal distributions can depend on propagule release strategies. For instance, the bull kelp, Nereocystis luetkeana, can release propagules (spores) from two heights in the water column ("bimodal release"): at the water surface, directly from the reproductive tissues (sori) on the kelp's blades, and near the seafloor after the sori abscise and sink through the water column. N. luetkeana is a foundation species that occurs from central California to Alaska and is experiencing unprecedented levels of population declines near its southern range limit. We know little of the kelp's dispersal distributions, which could influence population recovery and restoration. Here, we quantify how bimodal spore release heights affect dispersal outcomes based on a numerical model specifically designed for N. luetkeana. The model incorporates oceanographic conditions typical of the species' coastal range and kelp biological traits. With bimodal release heights, 34% of spores are predicted to settle within 10 m of the parental alga and 60% are predicted to disperse beyond 100 m. As an annual species, bimodal release heights can facilitate the local regeneration of adults within a source kelp forest while also supporting connectivity among multiple forests within broader bull kelp metapopulations. To leverage this pattern of bimodal spore dispersal in bull kelp restoration management, directing resources toward strategically located focal populations that can seed other ones could amplify the scale of recovery.

Human‐caused global change produces biotic and abiotic conditions that increase the uncertainty and risk of failure of restoration efforts. A focus of managing for resiliency, that is, the ability of the system to respond to disturbance, has the potential to reduce this uncertainty and risk. However, identifying what drives resiliency might depend on how one measures it. An example of a system where identifying how the drivers of different aspects of resiliency can inform restoration under climate change is the northern coast of California, where kelp experienced a decline in coverage of over 95% due to the combination of an intense marine heat wave and the functional extinction of the primary predator of the kelp‐grazing purple sea urchin, the sunflower sea star. Although restoration efforts focused on urchin removal and kelp reintroduction in this system are ongoing, the question of how to increase the resiliency of this system to future marine heat waves remains open. In this paper, we introduce a dynamical model that describes a tritrophic food chain of kelp, purple urchins, and a purple urchin predator such as the sunflower sea star. We run a global sensitivity analysis of three different resiliency metrics (recovery likelihood, recovery rate, and resistance to disturbance) of the kelp forest to identify their ecological drivers. We find that each metric depends the most on a unique set of drivers: Recovery likelihood depends the most on live and drift kelp production, recovery rate depends the most on urchin production and feedbacks that determine urchin grazing on live kelp, and resistance depends the most on feedbacks that determine predator consumption of urchins. Therefore, an understanding of the potential role of predator reintroduction or recovery in kelp systems relies on a comprehensive approach to measuring resiliency. [ABSTRACT FROM AUTHOR]

Fisheries face unprecedented environmental change. An important aspect of resilience to this change is the adaptive capacity of managers and stakeholders to respond to new conditions. A growing academic literature has demonstrated the value of fostering this adaptive capacity and highlighted key elements of fisheries social-ecological systems that can promote it. However, it is unclear to what extent these abstract academic ideas around adaptive capacity are relevant and valuable to on-the-ground resource managers, and if so, whether there are aspects of the literature that particularly resonate with their needs. Here, we compare academic concepts of adaptive capacity to the ways that management practitioners conceptualize and implement these ideas in practice, elicited through interviews with key professionals in United States federal fishery management bodies. Practitioners overwhelmingly cited flexibility to respond to change as the most consistently important element of adaptive capacity. Yet, they also detailed how the U.S. fishery management system routinely limits and constrains the flexibility of managers and stakeholders. Seeking out opportunities that enhance flexibility without jeopardizing other key aspects of adaptive capacity could increase management's adaptive capacity to global change in the USA and elsewhere. [ABSTRACT FROM AUTHOR]

The importance of dispersal rates and distances has long been appreciated by ecologists and evolutionary biologists. An emerging field of research is revealing how temporal variation in dispersal can substantially influence ecological and evolutionary outcomes. We review how dispersal rates can temporally vary substantially in many ecosystems, a pattern that is particularly well‐documented for aquatic organisms but is likely pervasive in terrestrial ecosystems as well. We then synthesize the effects of temporal variation in dispersal on five key ecological and evolutionary processes: 1) metapopulation dynamics, 2) local adaptation, 3) range limits and range expansions, 4) species coexistence and 5) metacommunity dynamics. Our review demonstrates that temporal variation in dispersal is more than just statistical 'noise' but can in fact lead to different outcomes than expected were dispersal temporally constant. For example, increasing the magnitude of temporal variation in dispersal can lead to lower metapopulation growth rates, permit greater local adaptation, facilitate and accelerate range expansion, increase regional coexistence, and alter local and regional species diversity. These effects of temporal variation in dispersal can inform conservation and natural resource management decisions such as prioritization in spatial planning, management of spillover from domesticated or captive populations into native populations, and the design of effective control strategies for invasive species. [ABSTRACT FROM AUTHOR]

Climate change is dramatically altering the environmental context in which marine resources are harvested and managed. A growing field of academic literature has begun to explore the adaptive capacity of fishers and managers to respond to this change, but much of this field is abstract and theory-driven. Therefore, it is unclear whether this literature accurately reflects the adaptation priorities of fishery management practitioners, or whether there are gaps in the literature that these practitioners could fill with on-the-ground knowledge. Second, even if these principles of adaptive capacity are perfectly aligned with management practitioners' priorities, it is unclear to what extent these principles are actively considered in the decision making process, and if not, why. This study seeks to address these questions by confronting fisheries professionals with academic ideas around adaptive capacity through a series of semi-structured interviews with federal fishery managers and scientists whose work informs decision making in the United States regional fishery management system. The study then uses these interviews to identify three low-cost, high-impact action items that could make concepts from the academic literature more accessible and useful to these practitioners and expand the literature by incorporating practitioners' expertise. These action items are: 1) distinguish adaptive capacity from adaptive management, 2) use practitioner insights to contextualize the elements of adaptive capacity within the constraints and opportunities of governance systems, and 3) expand academic research to explicitly consider the capacity to adapt on appropriate timelines given the scale and pace of systemic change. [ABSTRACT FROM AUTHOR]