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Under climate change, ecosystems are experiencing novel drought regimes, often in combination with stressors that reduce resilience and amplify drought's impacts. Consequently, drought appears increasingly likely to push systems beyond important physiological and ecological thresholds, resulting in substantial changes in ecosystem characteristics persisting long after drought ends (i.e. ecological transformation). In the present article, we clarify how drought can lead to transformation across a wide variety of ecosystems including forests, woodlands, and grasslands. Specifically, we describe how climate change alters drought regimes and how this translates to impacts on plant population growth, either directly or through drought's interactions with factors such as land management, biotic interactions, and other disturbances. We emphasize how interactions among mechanisms can inhibit postdrought recovery and can shift trajectories toward alternate states. Providing a holistic picture of how drought initiates long-term change supports the development of risk assessments, predictive models, and management strategies, enhancing preparedness for a complex and growing challenge. [ABSTRACT FROM AUTHOR]

Reforestation activities such as tree planting are important management tools to offset carbon emissions and restore forest ecosystem integrity. Severe wildfire activity, a key driver of forest loss, is increasing throughout the western United States (US) and creating an immense backlog of areas needing reforestation. Major financial investments and recent policy changes are expected to accelerate rates of tree planting, yet the broad-scale impact and efficacy of post-fire planting activities remain poorly understood. We quantified the outcomes of recent (1987–2022) post-fire plantings in the US Interior West using remotely sensed estimates of forest cover change and in-situ survival records (69,245 seedlings) spanning 297 unique fire events. Overall, planted areas gained forest cover 25.7 % more rapidly than environmentally similar, unplanted sites in the same fires, and planted seedling survival averaged 79.5 % (SD = 23.2 %) after one growing season. However, the effects of planting were highly variable over time and across environmental gradients. Forest cover gain and planted seedling survival were typically highest in cold, wet areas and when planting was followed by wetter-than-average years. Planting season also shaped outcomes, with late summer or fall plantings performing best on warm, dry sites, and spring plantings performing best in cold, wet areas. Forest cover gain was fastest in planting units that burned at low to moderate severity and had > 20 % post-fire forest cover in the surrounding area. Nearly half of all plantings were completed in such areas, where natural regeneration processes are most likely to promote forest recovery even without intervention. Here, we demonstrate that tree planting can enhance post-fire forest recovery rates at broad scales, though its effects are dependent on a range of environmental and operational factors. Our results help inform realistic expectations of planting outcomes, an issue of global relevance as such projects expand to achieve restoration and climate mitigation goals. • Tree planting is commonly used to achieve restoration and climate mitigation goals • Areas with post-fire tree planting show 25.7 % faster rates of forest regrowth • Survival of planted seedlings averaged 79.5 % after one growing season • Forest regrowth and seedling survival varied widely across the Interior West • Outcomes of post-fire plantings are likely to differ across environmental gradients [ABSTRACT FROM AUTHOR]

Assessing resilience of wildfire-prone social-ecological systems (SES) can provide a baseline for decision makers and inform future management actions. In this study, we measure stakeholder perceptions of how SES resilience was influenced by historic 2020-wildfire events in northern Colorado and what actions they think are needed to enhance future resilience to wildfire. We developed a contextualized set of resilience principles and indicators based on the literature and expert opinion that included ecological, ecosystem service, and social categories. We conducted 15 stakeholder interviews and 37 surveys to characterize subjective measures of SES resilience. Stakeholders perceived that the resilience of ecological indicators pre- and post-wildfires remained mostly unchanged, but that ecosystem service indicators were negatively affected and social indicators positively affected. Related to future resilience, stakeholders underscored a need for more strategic fuel treatments, especially prescribed fire, and more collaboration and engagement across landowner types. Our findings highlight that wildfire events can have negative and positive effects on components of SES resilience, underscoring the need to disaggregate resilience components. Additionally, we find that stakeholder perceptions of resilience are in line with the literature on objective measures of post-wildfire resilience, suggesting that expert opinion can be used as a reliable method to measure resilience indicators in some contexts. [ABSTRACT FROM AUTHOR]