Future Disturbances Research Articles

Role of biochar made from low‐value woody forest residues in ecological sustainability and carbon neutrality

AbstractForest management activities that are intended to improve forest health and reduce the risk of catastrophic fire generate low‐value woody biomass, which is often piled and open‐burned for disposal. This leads to greenhouse gas emissions, long‐lasting burn scars, air pollution, and increased risk of escaped prescribed fire. Converting low‐value biomass into biochar can be a promising avenue for advancing forest sustainability and carbon neutrality. Biochar can be produced either in a centralized facility or by using place‐based techniques that mitigate greenhouse gas emissions and generate a high‐carbon product with diverse applications. This review explores the multifaceted roles of biochar produced from low‐value biomass during forest restoration activities in the context of the United Nations Sustainable Development Goals and carbon sequestration for climate change mitigation. First, the ecological benefits are evaluated, including soil restoration, nutrient cycling, and vegetation enhancement, which are pivotal for restoring post‐disturbance forest health and enhancing resilience to future disturbance. Second, we evaluate the role of biochar in carbon sequestration and carbon neutrality objectives, which also foster sustainable soil practices and sustainable forest management. In addition, we highlight biochar markets, commercialization, and carbon credit interactions as emerging mechanisms to incentivize biomass utilization for biochar. The integration of biochar made from low‐value woody residues from forest restoration can enhance restoration strategies, engage stakeholders in sustainable land management practices, and mitigate environmental problems while enhancing the resilience of forest ecosystems to future disturbances. The findings underscore the importance of leveraging low‐value woody biomass for biochar production as a strategic resource for achieving comprehensive forest restoration goals and fostering sustainable development in forested landscapes.

Where to start with climate-smart forest management? Climatic risk for forest-based mitigation

Abstract. Natural disturbances like windthrows or forest fires alter the provision of forest ecosystem services such as timber production, protection from natural hazards, and carbon sequestration. After a disturbance, forests release large amounts of carbon and therefore change their status from carbon sinks to carbon sources for some time. Climate-smart forest management may decrease forest vulnerability to disturbances and thus reduce carbon emissions as a consequence of future disturbances. But how can we prioritise the stands most in need of climate-smart management? In this study we adopted a risk mapping framework (hazard times vulnerability) to assess the risk to climate-related forest ecosystem services (carbon stock and sink) in forests prone to windthrow (in the Julian Alps, Italy) and forest fires (in the Apennines, Italy). We calculated hazard by using forest fire and windthrow simulation tools and examined the most important drivers of the respective hazards. We then assessed vulnerability by calculating current carbon stocks and sinks in each forest stand. We combined these values together with the calculated hazard to estimate “carbon risk” and prioritised high-risk stands for climate-smart management. Our findings demonstrate that combining disturbance simulation tools and forest carbon measurements may aid in risk-related decision-making in forests and in planning decisions for climate-smart forestry. This approach may be replicated in other mountain forests to enhance our understanding of their actual carbon vulnerability to forest disturbances.

How do global forest pests respond to increasing temperatures? – a meta‐analysis

Biotic disturbances caused by insects and pathogens have a major impact on forests in the Northern Hemisphere. Knowledge of the effects of increasing temperature on the performance of these forest pests will thus be crucial for predicting future disturbance risks. Here, we systematically review the direct effects of increasing temperatures on four functional subgroups of forest pests, including leaf chewers, sap suckers, bark and wood borers, and pathogens. We considered 118 studies (2003–2022) representing 72 pest species feeding on 33 host genera from sub‐tropical, temperate and boreal forests in Asia, Europe and North America. Based on a subset of 89 studies reporting the required data, we conducted a meta‐analysis 1) distinguishing the functional subgroups, and 2) considering the main life‐history traits, i.e. development, fitness and survival. A temperature corresponding to the expected mean temperature during the growing season in the years 2081–2100 had a significant positive effect on the overall performance of leaf chewers (+18%) and bark and wood borers (+10%), while sap suckers and pathogens remained unaffected. In contrast, performance was not or even significantly negatively affected when a more pronounced temperature increase, i.e. corresponding to the temperature maxima in 2081–2100, was considered. This finding reflects the non‐linear temperature–performance relationship beyond currently evolved temperature optima in insects and pathogens. Furthermore, we showed that differential responses of life‐history traits to increased temperatures may counterbalance each other (e.g. development versus survival), highlighting the importance of a multi‐trait approach to assessing the impact of global warming on pest performance. By quantifying the effects of increasing temperatures on forest pest performance, our results facilitate the prediction of biotic disturbance impacts in a future climate. For instance, they could provide a valuable contribution to the parameterization of large‐scale ecosystem models, which often do not explicitly consider the response of biotic disturbances to climate change.

Uncovering hazards and adaptive capacity: A comprehensive risk assessment study in three conservation areas in Spain

The increase in the frequency, duration and severity of disturbances can disrupt forest composition and structure, posing threats to ecosystem services. Adaptive forest management has the potential to adjust forests to future disturbance regimes, by reducing their susceptibility to these threats and, therefore, increasing their adaptation capacity. However, few comprehensive studies have integrated the factors involved in adaptive forest management by comparing the biomass of national parks of the same region, or examined how global change might affect them in the near future. In this study, we integrate data of forest inventories, wildfires, high-resolution climate and pests information in climate model projections to assess climate-sensitive risks associated with key abiotic disturbances (such as fires, droughts and pests) in coniferous Mediterranean mountain forests, considering various forest management approaches and climate scenarios in three Spanish national parks. We employed the conceptual framework introduced by Lecina-Diaz et al. (2021a) to evaluate risks to forests and considered Exposed values (E), Hazard Magnitude (HM), Susceptibility (S) and Lack of Adaptive Capacity (LAC). We applied statistical weights using expert weights and the analytic hierarchy process (AHP) as the basis for determining the global ranking score of each indicator of the risk components. We extracted information about the climatic scenarios from the Coupled Model Intercomparison Project Phase 6. Three forest management scenarios were generated, named “low intervention», «traditional silviculture”, and "reduction of climate vulnerability", and mapped the risks of carbon sequestration for the different scenarios. The importance of each component was estimated using the AHP. HM was most significantly affected by the Aridity Index and the Fire Risk Index, with weights of 27.7 % and 24.2 %, respectively; S was affected by fuel load (29.0 %) and the Suppression Difficulty index (21.0 %), and LAC was influenced by forest management (32.0 %) and resprouting capacity (22.0 %). The three forest management scenarios exhibited different risk values that decreased with increasing intensity of the intervention in the three protected areas. Likewise, when two climate scenarios were considered, risk increased in the protected areas (Teide National Park, 10.69 %; Sierra Nevada National Park, 10.9 %; Sierra de las Nieves National Park, 6.17 %). Patterns of spatial arrangement of risk, which included HM, S and LAC, were consistent with the risk level, with the highest risk values being concentrated in the buffer areas (natural parks), with areas with a greater presence of coniferous plantations. The risk maps allowed us to identify areas that are critical under extreme conditions and where the greatest disturbance events may occur. Our study underscores that risks of disturbances in mountain ecosystems dominated by conifers within protected areas can be mitigated by forest management. The application of forest management adaptation strategies in national parks and buffer areas has proven effective in reducing risks of disturbances and preserving certain ecosystem services, such as carbon sequestration.

Recovery of bacterial network complexity and stability after simulated extreme rainfall is mediated by K−/r-strategy dominance

The complexity and stability of belowground microbial communities are among the core mechanisms that drive ecosystem functions. Disturbances, such as climate extremes, can exert a substantial influence on these microbial attributes. However, the role of the microbial life history strategy in determining the complexity and stability of desert soil microbial communities after extreme rainfall is poorly understood. Here, we explored the response patterns of bacterial network complexity and stability and characterized the bacterial life history strategy on the basis of the oligotroph (K-strategist)-to-copiotroph (r-strategist) ratio after three extreme rainfall treatments (11, 15, and 25 mm). Experimental results demonstrated that the bacterial communities immediately shifted from the K-strategy to the r-strategy one day after extreme rainfall and gradually recovered to the K-strategy over time, as verified by the increase (31.46 %–125.51 %) then decrease (41.51 % – 95.78 %) in the weighted rrn copy number. Meanwhile, bacterial network complexity and stability showed three-phase patterns [dramatic decline (decreased by 211.67 %–388.46 %)–gradual recovery (increased by 45.60 %–103.65 %)–insignificant change] after three extreme rainfall events. The decline/recovery of these bacterial attributes was highly pronounced/slow after the large extreme rainfall treatment. Specifically, the responses of bacterial network complexity and stability to extreme rainfall showed negative correlations with the response of the weighted rrn copy number (R = -0.55 – -0.74, P < 0.01). The mechanisms underlying the response patterns of bacterial network complexity and stability were related to the prevalence of the r-strategy of the bacterial communities (Phase 1) and the shifts from the r-strategy to the K-strategy due to the gradual reduction in soil moisture (Phase 2 and 3). These results emphasize the importance of the microbial life history strategy in maintaining network complexity and stability and help in understanding how belowground communities can withstand future disturbances.

Mediterranean octocoral populations exposed to marine heatwaves are less resilient to disturbances.

The effects of climate change are now more pervasive than ever. Marine ecosystems have been particularly impacted by climate change, with marine heatwaves (MHWs) being a strong driver of mass mortality events. Even in the most optimistic greenhouse gas emission scenarios, MHWs will continue to increase in frequency, intensity and duration. For this reason, understanding the resilience of marine species to the increase of MHWs is crucial to predicting their viability under future climatic conditions. In this study, we explored the consequences of MHWs on the resilience (the ability of a population to resist and recover after a disturbance) of a Mediterranean key octocoral species, Paramuricea clavata, to further disturbances to their population structure. To quantify P. clavata's capacity to resist and recover from future disturbances, we used demographic information collected from 1999 to 2022, from two different sites in the NW Mediterranean Sea to calculate the transient dynamics of their populations. Our results showed that the differences in the dynamics of populations exposed and those not exposed to MHWs were driven mostly by differences in mean survivorship and growth. We also showed that after MHWs P. clavata populations had lower resistance and slower rates of recovery than those not exposed to MHWs. Populations exposed to MHWs had lower resistance elasticity to most demographic processes compared to unexposed populations. In contrast, the only demographic process showing some differences when comparing the speed of recovery elasticity values between populations exposed and unexposed to MHWs was stasis. Finally, under scenarios of increasing frequency of MHWs, the extinction of P. clavata populations will accelerate and their capacity to resist and recover after further disturbances will be hampered. Overall, these findings confirm that future climatic conditions will make octocoral populations even more vulnerable to further disturbances. These results highlight the importance of limiting local impacts on marine ecosystems to dampen the consequences of climate change.

A novel second-order predictive disturbance observer for systems with input and output delays

This paper proposes a novel second-order predictive disturbance observer for systems experiencing external disturbance with both input and output measurement delays. The proposed observer uses the delayed system state and its derivative information to predict and compensate for future disturbance in real time, despite the delayed control input. Compared with the past studies about second-order disturbance observer, this paper analyses the impact of the disturbance derivatives on the estimation accuracy. This observer is designed using the Lyapunov–Razumikhin theorem and its exponential stability is proven. Comparative analysis and simulations demonstrate its advantages over second-order disturbance observers that do not consider delays.

Beyond resilience: Responses to changing climate and disturbance regimes in temperate forest landscapes across the Northern Hemisphere.

Climate change has profound impacts on forest ecosystem dynamics and could lead to the emergence of novel ecosystems via changes in species composition, forest structure, and potentially a complete loss of tree cover. Disturbances fundamentally shape those dynamics: the prevailing disturbance regime of a region determines the inherent variability of a system, and its climate-mediated change could accelerate forest transformation. We used the individual-based forest landscape and disturbance model iLand to investigate the resilience of three protected temperate forest landscapes on three continents-selected to represent a gradient from low to high disturbance activity-to changing climate and disturbance regimes. In scenarios of sustained strong global warming, natural disturbances increased across all landscapes regardless of projected changes in precipitation (up to a sevenfold increase in disturbance rate over the 180-year simulation period). Forests in landscapes with historically high disturbance activity had a higher chance of remaining resilient in the future, retaining their structure and composition within the range of variability inherent to the system. However, the risk of regime shift and forest loss was also highest in these systems, suggesting forests may be vulnerable to abrupt change beyond a threshold of increasing disturbance activity. Resilience generally decreased with increasing severity of climate change. Novelty in tree species composition was more common than novelty in forest structure, especially under dry climate scenarios. Forests close to the upper tree line experienced high novelty in structure across all three study systems. Our results highlight common patterns and processes of forest change, while also underlining the diverse and context-specific responses of temperate forest landscapes to climate change. Understanding past and future disturbance regimes can anticipate the magnitude and direction of forest change. Yet, even across a broad gradient of disturbance activity, we conclude that climate change mitigation is the most effective means of maintaining forest resilience.

The dynamics of deciduous dipterocarp forest in relation to climate variability in the Sakaerat Biosphere Reserve, Northeastern Thailand

Abstract. Yatar C, Thinkampheang S, Sungkaew S, Wachrinrat C, Asanok L, Kamyo T, Hermhuk S, Kachina P, Thongsawi J, Phumphuang W, Yarnvudhi A, Waengsothorn S, Cheysawat S, Marod D. 2024. The dynamics of deciduous dipterocarp forest in relation to climate variability in the Sakaerat Biosphere Reserve, Northeastern Thailand. Biodiversitas 25: 3088-3098. Climate change is a major environmental problem influencing forest dynamics. To clarify tropical seasonal forest dynamics under climate change, we conducted long-term monitoring of all trees with Diameter at Breast Height (DBH) ?4.5 cm within a 1-ha permanent plot established in 2004 in a deciduous dipterocarp forest in the Sakaerat Biosphere Reserve (SBR), Northeastern Thailand. Surveys of all trees within the plot with DBH ?2 cm were conducted in 2008, 2015, and 2019. Climate data were obtained from the SBR climate station during 2004-2019 and used to extract dates with drought and wet conditions. Forest dynamics varied among species and periods, with stem density exhibiting a decreasing trend. Despite prolonged drought conditions from 2004 to 2009, which usually leads to increased mortality rates, the recruitment rate was 7-fold higher than the mortality rate at a site protected from fire during 2004-2008, and most of the recruited species were pioneer species, shrubs, and small trees. A contrasting trend was observed during 2015-2019, with a mortality rate almost 10-fold higher than the recruitment rate, indicating a significant ecological disturbance, likely to have been driven by a severe El Niño event during 2015-2016. Thus, climate induced disturbances (i.e., drought and fire) appear to have inhibited tree regeneration in the deciduous dipterocarp forest, particularly when they occurred in combination and for specific timing and intensity levels. Addressing the challenges posed by drought and fire to tree regeneration requires holistic management approaches that consider both ecological and climatic factors. Monitoring and adaptive management are also essential to mitigate the impact of future disturbances and support the long-term viability of forest ecosystems.

Hundreds Dying Every day in Karachi as Pakistan Battles Brutal Summer

Global health and livelihoods have been severely impacted by climate change, which is expected to worsen in the future and bring more frequent and intense extreme events (Weiskopf et al,2020). Extreme heatwaves are increasingly common during summertime globally, contributing to an excess of mortality. As climate change continues, it is anticipated that heat-related illness and mortality will rise even more, with higher levels of global warming being associated with greater risk (Ebi et al,2021). Pakistan ranks sixth among nations most susceptible to the effects of climate change (Soomro &amp; Shahid,2024).According to the IPCC, surface temperatures have risen by roughly 1.0°C since the middle of the 19th century and could climb by 1.10°C to 6.40°C in the 21st (IPCC,2018). Pakistan is extremely sensitive to the consequences of climate change as a developing nation, including rising temperatures, variable monsoons, melting Himalayan glaciers, and more frequent and severe extreme weather events. Future disturbances to Karachi's local weather are anticipated because of climate change (Babar et al, 2021). According to a recent BBC report, Pakistan's heatwave has claimed the lives of nearly 500 people. There has been a notable rise in mortality in southern Pakistan due to temperatures above 40°C (104°F) and heavy humidity, which makes it feel like 49°C (120°F). With 141 deaths on 25th May alone, the Edhi ambulance service reported transporting 568 bodies, as opposed to the typical 30 to 40 each day to the Karachi municipal mortuary over the course of six days. The number of persons requesting assistance in hospitals is rising. Each case's precise cause of death is still being investigated (BBC, 2024). According to Soomro and Shahid (2024), Karachi recorded the hottest temperature in the region last month, with the province of Sindh clocking close to 52.2°C. The extreme heat is making life difficult for people in other parts of Pakistan as well. Low winds, high temperatures, and high humidity are the factors that cause heatwaves. When combined with malfunctioning water supply networks, frequent power plant outages, and blackouts, the consequences for those in lower socioeconomic categories in Karachi can be catastrophic. Conversely, in wealthy Karachian areas where petrol generators are typically used to break out blackouts, very few casualties were reported (Hanif, 2017). Pakistan is classified as a mediocre performer with a climate performance ranking of 30th overall. It receives high marks for GHG emissions and energy use, but poor marks for climate policy and very low marks for renewable energy. The absence of strong government organizations devoted to climate concerns impedes efforts despite the urgent need for climate action (SDG 13). As a result, not enough progress has been made in combating climate change (CCPI, 2024). Public health in Karachi would be much improved by addressing issues with cheap, clean energy, sustainable cities and communities, clean water and sanitation, responsible consumption and production, and climate action. Focusing on important problems like dirty water, air pollution, brittle infrastructure, and energy scarcity. Controlling infectious disease outbreaks and lowering respiratory and cardiovascular illnesses associated with air pollution would be made possible by proper sewage and water cleanliness. Heat stroke casualties could be saved by using inexpensive, sustainable energy technologies. These upgrades are the need to solve the environmental and climate-related issues in Karachi. Effective measures must be taken by the government of Pakistan.

Functional responses of understory plants to natural disturbance-based management in eastern and western Canada.

Natural disturbance-based management (NDBM) is hypothesized to maintain managed forest ecosystem integrity by reducing differences between natural and managed forests. The effectiveness of this approach often entails local comparisons of species composition or diversity for a variety of biota from managed and unmanaged forests. Understory vegetation is regularly the focus of such comparison because of its importance in nutrient cycling, forest regeneration, and for wildlife. However, larger scale comparisons between regions with distinct species assemblages may require a trait-based approach to better understand understory responses to disturbance. We compared the long-term effects of retention harvesting on understory vegetation in two large experimental study sites located in eastern and western regions of the Canadian boreal forest. These sites included the Sylviculture en Aménagement Forestier Ecosystémique (SAFE) experiment and the Ecosystem Management Emulating Natural Disturbance (EMEND) experiment, located in the eastern and western regions of Canada, respectively. EMEND and SAFE share common boreal understory species but have distinct tree communities, soils, and climate. Both experiments were designed to evaluate how increasing tree retention after harvest affects biodiversity. Here, we examined taxonomic richness, functional diversity, and functional composition (using community trait mean values) of understory plant communities, and also examine intraspecific trait variability (ITV) for five species common and abundant in both experiments. We observed the limited impacts of retention level on richness, functional diversity, and functional composition of understory plants 20 years postharvest. However, ITV of leaf morphological traits varied between retention levels within each experiment, depending on the species identity. Common species had different functional responses to retention level, showing species-specific reactions to environmental variation. Our result suggests that understory plant communities in the boreal forest achieve resilience to disturbance both in terms of interspecific and intraspecific functional trait diversity. Such diversity may be key to maintaining understory biodiversity in the face of future disturbances and environmental change. Our results reveal the significance of ITV in plant communities for understanding responses to forest harvesting and the importance of choosing appropriate traits when studying species responses to the environment.

Reformy instytucjonalne Unii Gospodarczej i Walutowej po 2010 r. – ocena zasadności i efektywności wprowadzonych rozwiązań na gruncie teorii optymalnych obszarów walutowych

INSTITUTIONAL REFORMS OF THE ECONOMIC AND MONETARY UNION IMPLEMENTED AFTER 2010: THE EFFECTIVENESS OF NEW ARRANGEMENTS ON THE GROUNDS OF THE THEORY OF OPTIMUM CURRENCY AREAS The economic shocks over the last 15 years revealed low effectiveness of macroeconomic adjustment mechanisms, as manifested by growing imbalances in the current accounts, public finances, and labour markets of the euro zone economies. The essence of the institutional reforms introduced after 2010 was to improve the mechanisms for stabilizing macroeconomic balances, as well as to increase the resilience of the EMU economies to future disturbances, especially those of a systemic nature. New solutions have a strong basis in the theory of optimum currency areas, as well as in institutional economics. The effects of the new institutional arrangements indicate a substantial improvement in the resilience of credit institutions to economic shocks, however, other macroeconomic risks remain.

Contemporary Wildfires Not More Severe Than Historically: More Fire of All Severities Needed to Sustain and Adapt Western US Dry Forests as Climate Changes

Fire-adapted dry forests and nearby communities both need to be sustained as climate changes. Wildfires have increased in the ~25.5 million ha of dry forests in the western US, but are wildfires already more severe than historical (preindustrial) wildfires, warranting suppression, or is more fire needed? Recent research suggests that a higher percentage are more severe, but is this from more high-severity fire (≥70% mortality) or simply less lower-severity fire? To resolve this question, I compared government fire-severity data from 2000–2020 with corresponding government Landfire historical data, representing the last few centuries. The fire rotation (expected time to burn across an area of interest) for high-severity fire was 477 years recently versus 255 years historically, a deficit, not a surplus. High-severity fire would need to increase 1.9 times to equal historical rates. Thus, reducing high-severity fire through fuel reductions is fire suppression, which has significant well-known adverse ecological impacts. These include reductions in (1) natural burn patches, snags, and non-forest openings, that favor diverse fire-adapted species, and (2) landscape heterogeneity that can limit future disturbances and enhance landscape ecological processes. Even larger deficits were in moderate (4.4 times) and low (5.8 times) fire severities. However, if only these lower severities were restored, the high-severity percentage would correspondingly be reduced to low levels. All fire severities are needed to provide a variety of post-fire settings that favor a broad suite of selection pressures and adaptations to emerging climate. This paper shows that to sustain and adapt dry forests and nearby communities to fire and climate change, the billions spent on fuel reductions to reduce high-severity fire can be redirected to protecting the built environment, fostering both safe and sustainable dry forests and human communities.

Progress with the Learning Health System 2.0: a rapid review of Learning Health Systems’ responses to pandemics and climate change

BackgroundPandemics and climate change each challenge health systems through increasing numbers and new types of patients. To adapt to these challenges, leading health systems have embraced a Learning Health System (LHS) approach, aiming to increase the efficiency with which data is translated into actionable knowledge. This rapid review sought to determine how these health systems have used LHS frameworks to both address the challenges posed by the COVID-19 pandemic and climate change, and to prepare for future disturbances, and thus transition towards the LHS2.0.MethodsThree databases (Embase, Scopus, and PubMed) were searched for peer-reviewed literature published in English in the five years to March 2023. Publications were included if they described a real-world LHS’s response to one or more of the following: the COVID-19 pandemic, future pandemics, current climate events, future climate change events. Data were extracted and thematically analyzed using the five dimensions of the Institute of Medicine/Zurynski-Braithwaite’s LHS framework: Science and Informatics, Patient-Clinician Partnerships, Continuous Learning Culture, Incentives, and Structure and Governance.ResultsThe search yielded 182 unique publications, four of which reported on LHSs and climate change. Backward citation tracking yielded 13 additional pandemic-related publications. None of the climate change-related papers met the inclusion criteria. Thirty-two publications were included after full-text review. Most were case studies (n = 12, 38%), narrative descriptions (n = 9, 28%) or empirical studies (n = 9, 28%). Science and Informatics (n = 31, 97%), Continuous Learning Culture (n = 26, 81%), Structure and Governance (n = 23, 72%) were the most frequently discussed LHS dimensions. Incentives (n = 21, 66%) and Patient-Clinician Partnerships (n = 18, 56%) received less attention. Twenty-nine papers (91%) discussed benefits or opportunities created by pandemics to furthering the development of an LHS, compared to 22 papers (69%) that discussed challenges.ConclusionsAn LHS 2.0 approach appears well-suited to responding to the rapidly changing and uncertain conditions of a pandemic, and, by extension, to preparing health systems for the effects of climate change. LHSs that embrace a continuous learning culture can inform patient care, public policy, and public messaging, and those that wisely use IT systems for decision-making can more readily enact surveillance systems for future pandemics and climate change-related events.Trial registrationPROSPERO pre-registration: CRD42023408896.

Logging response alters trajectories of reorganization after loss of a foundation tree species.

Forest insect outbreaks cause large changes in ecosystem structure, composition, and function. Humans often respond to insect outbreaks by conducting salvage logging, which can amplify the immediate effects, but it is unclear whether logging will result in lasting differences in forest structure and dynamics when compared with forests affected only by insect outbreaks. We used 15 years of data from an experimental removal of Tsuga canadensis (L.) Carr. (Eastern hemlock), a foundation tree species within eastern North American forests, and contrasted the rate, magnitude, and persistence of response trajectories between girdling (emulating mortality from insect outbreak) and timber harvest treatments. Girdling and logging were equally likely to lead to large changes in forest structure and dynamics, but logging resulted in faster rates of change. Understory light increases and community composition changes were larger and more rapid in the logged plots. Tree seedling and understory vegetation abundance increased more in the girdled plots; this likely occurred because seedlings grew rapidly into the sapling- and tree-size classes after logging and quickly shaded out plants on the forest floor. Downed deadwood pools increased more after logging but standing deadwood pools increased dramatically after girdling. Understory light levels remained elevated for a longer time after girdling. Perhaps because the window of opportunity for understory species to establish was longer in the girdled plots, total species richness increased more in the girdled than logged plots. Despite the potential for greater diversity in the girdled plots, Betula lenta L. (black birch) was the most abundant tree species recruited into the sapling- and tree-size classes in both the girdled and logged plots and is poised to dominate the new forest canopy. The largest difference between the girdling and logging treatments-deadwood structure and quantity-will persist and continue to bolster aboveground carbon storage and structural and habitat diversity in the girdled plots. Human responses to insect outbreaks hasten forest reorganization and remove structural resources that may further alter forest response to ongoing climate stress and future disturbances.

The recovery of octocoral populations following periodic disturbance masks their vulnerability to persistent global change

As the major form of coral reef regime shift, stony coral to macroalgal transitions have received considerable attention. In the Caribbean, however, regime shifts in which scleractinian corals are replaced by octocoral assemblages hold potential for maintaining reef associated communities. Accordingly, forecasting the resilience of octocoral assemblages to future disturbance regimes is necessary to understand these assemblages' capacity to maintain reef biodiversity. We parameterised integral projection models quantifying the survival, growth, and recruitment of the octocorals, Antillogorgia americana, Gorgonia ventalina, and Eunicea flexuosa, in St John, US Virgin Islands, before, during, and after severe hurricane disturbance. Using these models, we forecast the density of populations of each species under varying future hurricane regimes. We demonstrate that although hurricanes reduce population growth, A. americana, G. ventalina, and E. flexuosa each display a capacity for quick recovery following storm disturbance. Despite this recovery potential, we illustrate how the population dynamics of each species correspond with a longer-term decline in their population densities. Despite their resilience to periodic physical disturbance events, ongoing global change jeopardises the future viability of octocoral assemblages.

Synchromodal transport re-planning: an agent-based simulation approach

In the rapidly evolving global marketplace, the logistics sector faces a multitude of challenges that demand implementation of more resilient solutions to respond to any future disturbance. Synchromodal transport, which is viewed as an extension of multimodal transport, is known as a key answer to this issue, as it provides more flexible and sustainable freight transport and also focuses on collaboration between different logistics players. We consider synchromodal transport as a collection of agents that not only have their own characteristics and behaviors, but also interact with each other, which impacts the entire system. In this paper, we study the system using an Agent-Based Modeling approach. The network represents the combination of long-haul and drayage transport, where pre-haulage and end-haulage are done only by truck, and the rest can be done by trucks, trains, or barges. A numerical experiment is conducted to evaluate cost savings and emissions reduction under different logistics service providers’ relation and re-routing scenarios. Our findings show that synchromodal scenarios are more economically and environmentally efficient, and that they lead to higher flexibility and reliability compared to business-as-usual scenarios. Additionally, our model verifies that the cost saving is considerable when logistics service providers collaborate with each other. The results of sensitivity analyses show consistent overall trends when comparing the different scenarios. Therefore, the conclusions drawn from the original experiment appear to be applicable, not only for that specific instance, but have broader relevance and applicability.

Can historic natural disturbances enable conservation opportunities? Evidence from the establishment of national parks in Sweden

ABSTRACT This study investigates conservation establishment and management in the context of Sweden's 30 national parks by conceptualising natural disturbances as focus events for conservation opportunities. Since positive effects on the environment manifest a long time after a natural disturbance, it may take time before society sees a need to conserve the natural area. To conceptualise such delayed responses to a focus event, the concept of a ‘delayed window’ is introduced. An analysis of Park Establishment Proposals from the Swedish Parliament for establishing and extending Sweden’s national parks was conducted by sending a survey to county representatives for each national park (response rate 19/30). The results show that historic natural disturbances were mentioned as a motivating factor for establishing many of Sweden’s 30 national parks (37%, i.e. 11 parks). The result suggests that the delayed window opens when biodiversity and Cultural Ecosystem Services (CES) values of historic disturbance(s) become visible. The time span for motivating values is calculated for biodiversity values (18–829 years) and CES values (5–829 years). However, surveyed representatives responded that future disturbances may not be desired or only desired if controlled or limited, highlighting a paradox in terms of the perceived value of past and future disturbances.

Harnessing Natural Disturbances: A Nature-Based Solution for Restoring and Adapting Dry Forests in the Western USA to Climate Change

Natural disturbances (wildfires, droughts, beetle outbreaks) shaped temperate forests for millennia, including dry forests of the western USA. Could they now best restore and adapt dry forests to climate change while protecting nearby communities? Mechanical fuel-reduction treatments (e.g., thinning) reduce landscape heterogeneity and appear ineffective since &lt;1% of the treated area encounters fire each year and fires are still increasing. We propose and analyze a nature-based solution (NbS), using natural disturbances, to see whether it is feasible, how long it might take, and whether it could more effectively restore and adapt dry forests to climate change. We compared 2010–2019 disturbance rates on ~16 million ha of federal dry forests with historical data. We evaluated how much adaptation is achieved by comparing how trees are selected by treatments and disturbances. We found an NbS, which works with natural disturbances and prioritizes community protection, is feasible in western USA dry forests since disturbances are occurring mostly within historical rates. Natural disturbances, unlike mechanical treatments, select survivors that are more likely to be genetically adapted to survive future disturbances and climate change, while perpetuating ecosystem services. Natural disturbances also could ecologically restore forest heterogeneity, better maintain carbon storage, and reduce management needs. A fully developed disturbance-based NbS could more effectively adapt dry forests to climate change within ~30–40 years if active management is reprioritized to protect the built environment and communities near public forests.

Consistently heterogeneous structures observed at multiple spatial scales across fire-intact reference sites

Yellow pine and mixed-conifer (YPMC) forests of California’s Sierra Nevada have experienced widespread fire suppression for over a century, resulting in ingrowth and densification of trees, heavy fuel accumulation, and shifts in species composition. Under warmer and drier climates, these forests are primed for stand-replacing fires and severe drought mortality, requiring management interventions to improve their resilience and mitigate future impacts. Observations from functioning frequent-fire systems (e.g., contemporary reference sites) can provide key insights about pattern-process relationships in fire-intact systems, which can be used to inform regional management efforts. In this study, we used airborne lidar data to quantify and compare forest structure at multiple spatial scales between contemporary reference sites (i.e., forests with a restored frequent, low-intensity fire regime) and control sites (i.e., typical fire-suppressed forests). We evaluated structures at the neighborhood- (∼1 ha), site- (∼100–1,000 ha), and among-site- (∼10,000–100,000 ha) levels. In reference sites, high proportions of individual trees, small clumps of 2–4 trees, and open space formed mostly open canopy structures at the neighborhood-level, and patches of these neighborhood-level structures were arranged in heterogeneous spatial patterns within sites. We observed low variability in site-level structures among reference sites, indicating a stabilizing effect of frequent, low-intensity fire across broad, ecosystem scales. In fire-suppressed control sites, edaphic factors and other non-fire disturbances occasionally produced heterogeneity at the neighborhood- and site-level, but the degree of heterogeneity was not consistent across sites. Structural patterns in contemporary reference sites suggest improved resilience to future disturbances and climate change, and increased provisioning of ecosystem services relative to control sites. We suggest applying these metrics to help inform multi-scale and multi-resource management in Sierra Nevada forests.