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Acoustic logging is an important method used to determine formation velocities near boreholes. However, in practice, determining accurate formation velocities from acoustic logging data is challenging because of the presence of various noise interferences. Accordingly, a method to increase the amplitudes of refracted waves in open boreholes is proposed herein on the basis of the directional radiation technology of pulse compression signal–driven linear phased array acoustic transmitters. The waveforms generated by a Ricker monopole acoustic transmitter, linear frequency modulation monopole acoustic transmitter and pulse compression signal–driven linear phased array acoustic transmitter in a fluid‐filled open borehole are numerically simulated by employing the finite‐difference method. The effects of the pulse compression signal–driven linear phased array parameters on the amplitudes of the refracted compressional and shear waves are studied. Results show that borehole mode waves with the same velocities and dispersion characteristics can be determined using the pulse compression signal–driven linear phased array acoustic and Ricker monopole acoustic transmitters in fluid‐filled open boreholes. Pulse compression signal–driven linear phased array acoustic transmitters leverage the advantages of pulse compression and phased array technologies, ensuring that a single element can radiate more acoustic energy, whereas pulse compression signal–driven linear phased array parameters can be modulated to further increase the amplitudes of the refracted compressional and shear waves. Compared with Ricker and linear frequency modulation monopole acoustic transmitters, pulse compression signal–driven linear phased array acoustic transmitters can provide downhole received waveforms of better quality and improved a signal‐to‐noise ratio of the mode wave dispersion curves obtained using the downhole received waveforms. Because pulse compression signal–driven linear phased array acoustic transmitters use linear frequency modulation drive signals of longer duration, the recording time required for the received waveforms is also longer and the amount of data generated is larger, presenting new challenges for downhole data processing and high‐speed data transmission. [ABSTRACT FROM AUTHOR]

AbstractThis case study contributes to the research on the environmental beliefs of extractive industry workers in an illiberal populist regime. This research is based on semi-structured interviews with logging sector workers of the Russian Northwest—a severely understudied population directly involved in resource extraction. The data shows that these workers understand forestland as two separate localities: the northwestern region of Russia, in which the loggers have expertise and knowledge, and the rest of the country, in which workers don’t have any work or travel experience. This division facilitates a process of hybridization of populist environmental narratives on one hand, and loggers’ science-supported knowledge and experiences on the other. This hybridization of the workers’ beliefs is anchored in, and perpetuated by, Russia’s state-controlled media and its modern authoritarian populist regime. This research offers policy implications and encourages future studies on the politicization of the environment and resources in authoritarian populist states. [ABSTRACT FROM AUTHOR]

Summary Stem respiration constitutes a substantial proportion of autotrophic respiration in forested ecosystems, but its drivers across different spatial scales and land‐use gradients remain poorly understood. This study quantifies and examines the impact of logging disturbance on stem CO2 efflux (EA) in Malaysian Borneo. EA was quantified at tree‐ and stand‐level in nine 1‐ha plots over a logging gradient from heavily logged to old‐growth using the static chamber method. Tree‐level results showed higher EA per unit stem area in logged vs old‐growth plots (37.0 ± 1.1 vs 26.92 ± 1.14 g C m−2 month−1). However, at stand‐level, there was no difference in EA between logged and old‐growth plots (6.7 ± 1.1 vs 6.0 ± 0.7 Mg C ha−1 yr−1) due to greater stem surface area in old‐growth plots. Allocation to growth respiration and carbon use efficiency was significantly higher in logged plots. Variation in EA at both tree‐ and stand‐level was driven by tree size, growth and differences in investment strategies between the forest types. These results reflect different resource allocation strategies and priorities, with a priority for growth in response to increased light availability in logged plots, while old‐growth plots prioritise maintenance and cell structure. [ABSTRACT FROM AUTHOR]

Movements of moose are caused by variations in resource availability such as food, shelter and the energetic cost of foraging. These variables are important in forest and population management. Therefore, the main objective of the present study was to estimate the influence of forest site types on the distribution of the non hunted moose population in February and March 2020 in the Augustów Forest, a 1102.0 km2 forest complex in north-eastern Poland. In the study area, 20 sampling plots were distributed over a total area of 91.4 km2, where six teams, each consisting of 30 people, observed moose to estimate population numbers. The average population density was 1.22 ± 0.19 moose per km2 and ranged from 0.21 to 3.40 animals/km2. The total population number estimated this way amounted to 1344 animals. Non-linear regression demonstrated a positive relationship between the percentage of hygric-wet forest site types in the sampling plot area and the moose population distribution (r = 0.735, n = 20, p = 0.0096). In winter, these habitats are a critical refuge for moose. For this reason, tree harvesting and hunting in hygric-wet forest site types should be limited during this period. [ABSTRACT FROM AUTHOR]

Forest degradation often permits the proliferation of dense understories that inhibit the development of natural regeneration over long periods. In South American temperate rainforests, native Chusquea bamboo species become unusually competitive after logging and invade forest understories, creating dense and continuous thickets under remnant canopy tree species. In this study, we aim to evaluate how natural regeneration of native species develops after removal of the Chusquea bamboo understory and to define which microsite conditions can facilitate species' early development. To achieve this, we removed the Chusquea understory in 45 experimental units, systematically established in a 4 ha experiment located in degraded temperate forests on Chiloé Island, North‐Patagonia, Chile. We evaluated microsite conditions and monitored the natural regeneration response during 5 years. After 5 years, greater than 81% of the remnant canopy tree species were regenerating, mostly from seed, and there was a 55.5% increase in total natural regeneration (p < 0.05; increase >1 individuals/m2 yr−1), with species like Amomyrtus spp. increasing abundance by greater than 121%. Total natural regeneration presented positive significant correlations (p < 0.01) with the depth of the water table (rs: 0.40), soil carbon (rs: 0.44), nitrogen (rs. 0.41), and organic matter (rs: 0.44). We conclude that removing the Chusquea understory assists the natural recovery of degraded temperate rainforests by facilitating additional recruitment of early, mid, and late successional tree species. In this process, early and mid‐successional tree species are more specific in their microsite preferences than successionally late ones. [ABSTRACT FROM AUTHOR]

Forests around the world, and in the case of this study, the coastal Pacific Northwest United States, store large amounts of carbon, both above ground in the trees and below ground in soils. Understanding the effects of forest disturbance, including timber harvesting, is important in order to evaluate the role that forestry plays in the global carbon cycle. Soil carbon can be difficult to assess with enough precision to detect the kinds of changes that are expected, yet a series of small changes over time in the same direction could have important cumulative effects. In this study, eight randomly selected Douglas‐fir forest stands in Oregon and Washington were sampled at 300 points each using a fixed‐depth sampling approach to attempt to detect a 5% or higher change in soil carbon storage to 1 m, longitudinally from pre‐harvest to 10 years post‐harvest. There was moderate variability in results over time at individual sites, with some sites decreasing slightly and others increasing slightly. Only two sites achieved lower than the 5% minimum detectible difference target. The remaining six sites were able to detect 5.7%–10.7% differences. In one case, an unexpectedly large increase in mineral soil carbon 10 years post‐harvest occurred without clear explanation. On average, forest floor carbon stores were 20% larger 10 years post‐harvest than pre‐harvest. Even with the large increases excluded, both the fixed‐depth approach and equivalent soil mass correction showed there was no significant change in mineral soil carbon stores to 1 m at 10 years post‐harvest in the region. [ABSTRACT FROM AUTHOR]

The native forestry industry is being reconsidered, or actively phased out, across most parts of Australia. This kind of transition has happened elsewhere in the world but, in Australia, there is no clarity from governments about what those forestry areas will become, from an ecological or legal perspective. In this research, we investigate the ecological, climatic, and governance contexts for this transition away from native forestry, placing our results in the context of the Global Biodiversity Framework's push to restore 30% of the Earth's land, coasts and oceans. We demonstrate important gaps in government planning for the future of former native forestry coupes, arguing that “after forestry” many of these places will need active intervention to recover these ecosystems and address historic land degradation. This case study combines legal analysis with a review of the restoration literature to illustrate the importance of the governance framework within which restoration science is evolving. We demonstrate the complexity of governing restoration at large scales as the climate changes, as well as potential opportunities to reconcile fragmented governance arrangements, to ensure that this transition results in resilient forest ecosystems in currently degraded areas. [ABSTRACT FROM AUTHOR]

We present a multiproxy analysis of a sediment core from Freshwater Pond, Barbuda, one of just a few inland paleoenvironmental records from the Lesser Antilles. Our results shed light on the relative contributions of climate variability and Pre- and Post-Columbian human activities to vegetation and fire dynamics on Barbuda. The presence of macroscopic charcoal and pollen of ethnobotanically-useful and disturbance-indicator plant taxa in the sediment record suggests that Pre-Columbian subsistence activities occurred within a few kilometers of the pond between ~150 BCE and ~1250 CE. Our record extends anthropogenic fires back into the early Ceramic (500 BCE–1500 CE) and possibly late Archaic Ages (3000–500 BCE) adding evidence to the timing of arrival of the island's earliest inhabitants. The history of island-wide biomass burning inferred from microscopic charcoal fragments showed heightened fire activity between ~540 and ~1610 CE followed by a period of quiescence that reflected the transition from Pre- to Post-Columbian land-use practices associated with European colonization of the region. The British established a permanent settlement on Barbuda in the 1660s, but given Barbuda's unsuitability for large-scale agriculture, timber harvesting, small-scale farming, and livestock rearing, activities that left no detectable charcoal footprints likely dominated post-colonial land use. The lack of any clear correspondence between the reconstructed histories of fire and effective moisture at Freshwater Pond supports the idea that Late-Holocene fire activity on Barbuda was driven primarily by human activity. [ABSTRACT FROM AUTHOR]

Decades of industrial-scale logging have damaged the structure, function, and composition of Australia's forests; increased the threat from severe fires; and generated social distrust – all in a disrupted climate regime. As state agencies withdraw from logging, restoration of forest resilience becomes paramount. We critique two recent proposals for 'commercial timber operations' in two Australian states that have recently 'ceased logging native forests': (1) wind-throw removal via 'community forestry' in Victoria; and (2) 'ecological thinning' in Western Australia. Analysis suggests that ecological restoration will require: (1) scientifically valid and reliable projects; (2) integration across knowledge systems; (3) full cost-benefit accounting; (4) repair of forest legacy damage; (5) restoration of environmental resilience; (6) control of environmental weeds, pests and pathogens; (7) enhanced capacity for early detection of, and rapid response to disturbance; (8) generation of trust to enable a social licence; (9) fostering integrity in media and public relations; and (10) appropriate categorisation in land use. Neither case study demonstrate the application of these forest restoration principles nor provides a way to evaluate the effectiveness of the proposals. These case studies continue the resource-led exploitation of post-production forests, exacerbating damage through the continued depletion of the natural assets essential to generating resilience. Moving beyond resource-led to environment-led management is necessary to restore the ecological integrity of these forests. A shift from the resource-led focus to an environment-led focus guided by scientifically validated principles is likely to also require new administrative and governance arrangements for these forests. Two case studies of 'ecological forestry' ('community forestry' in Victoria, and 'ecological thinning' in Western Australia) demonstrate the urgency to transition from resource-led to environment-led management in the restoration of post-production forests. [ABSTRACT FROM AUTHOR]

A fundamental challenge for ecologists is to evaluate the effects of anthropogenic disturbance on ecosystem processes and functions. Tropical rainforests in Borneo are biologically diverse and provide an array of ecosystem functions and services. However, these forests are being logged and converted to agricultural plantations at a rapid pace. While there are numerous studies on the impacts of these land-use changes on biodiversity, there are far fewer that investigate the consequences of forest disturbance for ecosystem functioning. We investigated the impacts of land-use change in Bornean tropical rainforests on invertebrate-mediated functions using a suite of six easily measurable processes that are linked to nutrient cycling and plant regeneration, and which can be used as indicators of the degree of disturbance and the health of the forest. We explored whether the conversion of primary forest to logged, fragmented forest or agricultural plantations altered the ecosystem processes of dung removal, predation of insect herbivores, functional activity of soil invertebrates, bioturbation, seed removal, and decomposition. Overall, ecosystem processes remained resistant to habitat change except for seed removal, which was lower in heavily logged forests and plantations than in primary forests. This suggests that, despite the loss of many species when forests are logged and converted to agriculture, ecosystem processes provided by invertebrates can remain robust across land-use gradients. [ABSTRACT FROM AUTHOR]

The power of Bayesian multilevel modeling and contrast analysis for food research is illustrated by meta-analysis of weight–diameter relations of apples (first level) at the factors cultivar, orchard site, year of harvest and tree (second level). Contrast analysis compares the effect of factors. Multilevel modeling connects levels, prevents over- and underfitting and accounts for dependencies in measurements/observations. A nonlinear power–law relation of weight-diameter is derived with parameters for spherical approximation and density. Literature data were analyzed in three ways: i) completely pooled (ignoring variation between groups), ii) per factor (no-pooling, ignoring similarities between groups) and iii) partially pooled (acknowledging variation and similarities, i.e. multilevel modelling). The power–law relation was obeyed at tree, orchard, harvest year and cultivar level. Very small differences were found per tree, orchard site and year of harvest, but differences between cultivars were more substantial. Parameter estimates from multilevel modeling differed between complete pooling and no-pooling. Spherical approximation of apples appeared reasonable, whereas apple densities differ considerably per cultivar. Bayesian analysis appears very suitable for model building, validation, predictive capacity and visualisation of parameter uncertainties. The approach can be applied in a much wider context and more complicated relations than considered here for apple characteristics. [ABSTRACT FROM AUTHOR]

Introduction: In eastern Canada, the boreal forest is associated with an important latitudinal shift in forest composition and structure, which occurs in the transition between the mixed southern boreal forest and the coniferous northern boreal forest. Along this transition, upland mixedwood stands with large deciduous trees (important for cavity-dependent vertebrate species) are gradually replaced by forests with smaller conifer trees, primarily black spruce (Picea mariana). Concomitantly, the availability of lowland forests flooded by the American beaver (Castor canadensis), which can provide adequate conditions for tree-cavity users, is also decreasing. Methods: We hypothesized that this latitudinal gradient would bring important changes in the functional diversity and network structure of vertebrate cavity- using communities. Along this latitudinal gradient we used a nest web approach to analyze the structure and robustness of networks of cavity users in upland forests and in lowland forests flooded by beavers. Results: Despite their low availability in the northern forest region, we found that mixedwood stands persisted throughout the boreal forest in being the main drivers of nest webs network structure of upland forests whereas old black spruce stands contribution was low. In lowland forests, beaver ponds harbored nest webs with a rich and complex structure in both forest regions. Species removal simulations revealed that across our latitudinal gradient upland and lowland forest nest webs responded differently. In upland forests, the removal of trembling aspen and the Pileated Woodpecker (Dryocopus pileatus) caused the highest proportions of secondary extinctions, showing low robustness of nest webs given that these two species were highly connected to the other species. Contrastingly, nest webs in beaver ponds were more robust mainly because excavator species used a higher diversity of tree species despite the removal of the Northern Flicker (Colaptes auratus) which induced numerous secondary extinctions. The Pileated Woodpecker remained the pivotal species across the two forest regions in upland forests whereas the Northern Flicker became the main large cavity provider in beaver ponds across the latitudinal gradient. Discussion: We discuss how mixedwood forests and beaver ponds, which are key habitat types for the cavity-using vertebrate community across our latitudinal gradient, should be maintained and protected in landscapes under industrial timber harvesting. [ABSTRACT FROM AUTHOR]

Background: Understanding how free-ranging animals behave can help in the design of optimal management strategies to both conserve species and enable individuals to express natural behaviours, maximising welfare. Animal-borne accelerometers passively collect data on body acceleration which can be interpreted to quantify behaviour. Accelerometers are increasingly used in behavioural research, however validation of accelerometer readouts to enable classification of discrete behaviours is required for each species. Pangolins are a heavily trafficked clade of mammals, all of which are considered vulnerable to extinction. They are also under-researched, with little known about their behaviour in the wild. In this study, we present the first validation of behavioural classification based on accelerometer readouts for a pangolin species; the ground pangolin (Smutsia temminckii). Results: We present a standardised protocol for attaching accelerometers to pangolins to minimise the impact of devices on welfare. We match the readouts from accelerometers to behaviours defined through video observations. Using a random forest classification, we defined five discrete behaviours (walking, digging, feeding, investigating ground, and stationary, accuracy of 85%) and three activity levels (low, medium, and high, accuracy of 94%) from accelerometer readouts. We determine optimal sampling frequency and window length (50 Hz and five seconds for discrete behaviour, 10 Hz and seven seconds for activity level). We then deploy accelerometers and classify the behaviour of three free-ranging pangolins for between two and four days. We find considerable variation in peak daily activity between free-ranging pangolins with different individuals displaying nocturnal and crepuscular behaviour. We also find that pangolins spend the majority of their time (between 62 and 71%) at rest. Conclusion: The methods we present will enable the quantification of ground pangolin behaviour in the wild to improve our understanding of the species' ecology and help inform conservation efforts. This will also help to improve our fundamental understanding of animal behaviour and ecology. [ABSTRACT FROM AUTHOR]

Habitat structural complexity is an emergent property of ecosystems that directly shapes their biodiversity, functioning and resilience to disturbance. Yet despite its importance, we continue to lack consensus on how best to define structural complexity, nor do we have a generalised approach to measure habitat complexity across ecosystems. To bridge this gap, here we adapt a geometric framework developed to quantify the surface complexity of coral reefs and apply it to the canopies of tropical rainforests. Using high‐resolution, repeat‐acquisition airborne laser scanning data collected over 450 km2 of human‐modified tropical landscapes in Borneo, we generated 3D canopy height models of forests at varying stages of recovery from logging. We then tested whether the geometric framework of habitat complexity – which characterises 3D surfaces according to their height range, rugosity and fractal dimension – was able to detect how both human and natural disturbances drive variation in canopy structure through space and time across these landscapes. We found that together, these three metrics of surface complexity captured major differences in canopy 3D structure between highly degraded, selectively logged and old‐growth forests. Moreover, the three metrics were able to track distinct temporal patterns of structural recovery following logging and wind disturbance. However, in the process we also uncovered several important conceptual and methodological limitations with the geometric framework of habitat complexity. We found that fractal dimension was highly sensitive to small variations in data inputs and was ecologically counteractive (e.g. higher fractal dimension in oil palm plantations than old‐growth forests), while rugosity and height range were tightly correlated (r = 0.75) due to their strong dependency on maximum tree height. Our results suggest that forest structural complexity cannot be summarised using these three descriptors alone, as they overlook key features of canopy vertical and horizontal structure that arise from the way trees fill 3D space.Keywords: Forest disturbance, LiDAR, logging, recovery, remote sensing, structural complexity [ABSTRACT FROM AUTHOR]

Intact Forest Landscapes (IFLs) are defined as forested areas of at least 500 km2 that show no signs of remotely sensed human activity. They are considered to be of high conservation value due to their role in maintaining biodiversity and mitigating climate change. In 2014, the members of the Forest Stewardship Council (FSC), one of the major global certification schemes for responsible forest management, took a conservation stand by restricting logging in FSC-certified IFLs. However, this move raised concerns about the economic viability of FSC-certified logging in these areas. To address these challenges, in 2022, FSC proposed an integrated landscape approach, considering local conditions and stakeholders' needs to balance IFL protection, economic sustainability, and community interests. Here, we leverage publicly available management unit (MU) data, to provide a global quantitative overview of IFLs designated for timber production. We use the concept of 'conservation burden' for the extent that MUs overlap with IFLs, representing the impact that IFL protection has on forest management operations if logging is disallowed. Our data indicates that currently FSC-certified MUs affect 0.6% of global IFLs. Too restrictive policies for logging in IFLs may discourage FSC-certification in global IFLs. Considering the environmental and social benefits of FSC certification, it warrants careful examination whether the benefits of protecting a limited subset of FSC-certified IFLs outweighs the cost of potentially reduced growth of the total FSC-certified area. Our data can provide a basis to facilitate stakeholder engagement for landscape-level IFL management. [ABSTRACT FROM AUTHOR]

The effects of timber harvest practices and climate change have altered forest ecosystems in southeast Alaska. However, quantification of patterns and trends in stream habitats associated with these forests is limited owing to a paucity of data available in remote watersheds. Here, we analyzed a 30-year dataset from southeast Alaska's Tongass National Forest to understand how these factors shape stream habitats. First, we examined differences between broad management classes (i.e., harvested and non-harvested) that have been used to guide stream channel restoration goals. Second, we assessed associations between intrinsic landscape characteristics, watershed management, and timber harvest legacies on aquatic habitat metrics. And third, we examined trends in stream habitat metrics over the duration of the dataset to anticipate future management challenges for these systems. Small effect sizes for some harvest-related predictors suggest that some stream habitat metrics, such as pool densities, are less responsive than others, and management practices such as protecting riparian buffers as well as post-harvest restoration may help conserve fish habitats. Large wood densities increased with time since harvest at sites harvested >50 years ago, indicating that multiple decades of post-harvest forest regrowth may contribute large wood to streams (possibly alder), but that it is not enough time for old-growth trees (e.g., spruce, Picea, or hemlock, Tsuga,), classified as key wood, to develop and be delivered to streams. The declining trend in key wood (i.e., the largest size class of wood) regardless of management history may reflect that pre-harvest legacy old-growth trees are declining along streams, with low replacement. The introduction of wood to maintain complex stream habitats may fill this gap until riparian stands again contribute structural key wood to streams. Trend analyses indicate an increasing spatial extent of undercut banks that may also be influenced by shifting hydrologic regimes under climate change. [ABSTRACT FROM AUTHOR]

Summary: The illegal harvest of timber and the subsequent production of charcoal have been contributing to the deforestation of the Brazilian Amazon and its degradation. Analysis of wood anatomy is a well-established tool used to detect illegally harvested wood and is commonly employed in the control of illegal forestry activities. This study aimed to contribute to a database used for the anatomical identification of wood and charcoal from tree species commonly harvested and marketed in the Amazon. The macro- and microscopic characteristics of wood and charcoal for 15 forest species were described. Characteristics that could be described in detail, such as vessel grouping, type of axial parenchyma, and in some cases, perforation plates and uniseriate rays, are fundamental to the identification of wood and charcoal that are illegally, or even legally, marketed. The study aids in the monitoring of the illegal marketing of wood and charcoal and will contribute to the construction of a database and reference collections that will be available for research, training, and use by forest managers, anatomists and anthracologists who study both wood and charcoal. [ABSTRACT FROM AUTHOR]

Active foraging of tree branches for light and space can result in crown asymmetry. By opening canopy gaps, selective logging may increase the prevalence of trees with asymmetrical crowns and the extents of their asymmetries. Crown asymmetry is relevant to forestry insofar as it may stimulate bole curvature, decrease the range of angles over which trees can be directionally felled, increase rates of natural tree fall, and create dangerous conditions for forest workers. In a forest in Guyana that was selectively logged 23 years prior to our study, we evaluated the asymmetries of crowns of trees on the boundaries of mapped felling gaps. For 192 trees ≥ 20 cm diameter, we measured crown radii into and away from 56 canopy gaps. Assuming that tree crowns were symmetrical at the time of gap creation, we estimate the rate of lateral crown expansion into gaps as the difference between crown radii into and away from the canopy opening. We then compared apparent rates of lateral crown expansion into gaps by tree species, gap size, and stem diameter growth rates. We found that 83% of tree crowns were wider on the gap side than into the closed canopy forest, with crowns on average 2.1 m wider towards canopy gaps. Rates of gap-ward crown extension were faster among long-lived light-demanding pioneer species than in more shade tolerant climax species. Among trees ≥ 20 cm diameter at the time of gap creation, stem growth rates are positively but only weakly correlated with crown asymmetry. [ABSTRACT FROM AUTHOR]

Forest resources are renewable, and the rational exploitation and utilization of forest resources are not only conducive to sustainable development on a population scale, they can also lead to higher economic benefits. Based on the actual timber harvest problem, this paper establishes the joint harvest model of timber and non-timber with nonlinear harvest items. In the numerical simulation, by comparing the existing proportional harvest model, it is concluded that the optimal harvest strategy of nonlinear harvest items in this paper can obtain larger ecological benefits and be more conducive to the sustainable development of a population. Firstly, using the qualitative theory of ordinary differential equations, the dynamic behavior of the model is studied, and the existence and stability of the equilibrium point of the model are proven. Secondly, the optimal control solution is obtained by using the optimal control theory. Finally, the optimal harvesting strategy of timber and non-timber products is given based on the numerical simulation results, and a comparison of the effects of different parameters on the optimal harvest strategy, which provides a certain theoretical basis for the sustainable development of the ecological economy of forestry, is carried out. [ABSTRACT FROM AUTHOR]

Gaps are openings within tropical forest canopies created by natural or anthropogenic disturbances. Important aspects of gap dynamics that are not well understood include how gaps close over time and their potential for contagiousness, indicating whether the presence of gaps may or may not induce the creation of new gaps. This is especially important when we consider disturbances from selective logging activities in rainforests, which take away large trees of high commercial value and leave behind a forest full of gaps. The goal of this study was to quantify and understand how gaps open and close over time within tropical rainforests using a time series of airborne LiDAR data, attributing observed processes to gap types and origins. For this purpose, the Jamari National Forest located in the Brazilian Amazon was chosen as the study area because of the unique availability of multi-temporal small-footprint airborne LiDAR data covering the time period of 2011–2017 with five data acquisitions, alongside the geolocation of trees that were felled by selective logging activities. We found an increased likelihood of natural new gaps opening closer to pre-existing gaps associated with felled tree locations (<20 m distance) rather than farther away from them, suggesting that small-scale disturbances caused by logging, even at a low intensity, may cause a legacy effect of increased mortality over six years after logging due to gap contagiousness. Moreover, gaps were closed at similar annual rates by vertical and lateral ingrowth (16.7% yr−1) and about 90% of the original gap area was closed at six years post-disturbance. Therefore, the relative contribution of lateral and vertical growth for gap closure was similar when consolidated over time. We highlight that aboveground biomass or carbon density of logged forests can be overestimated if considering only top of the canopy height metrics due to fast lateral ingrowth of neighboring trees, especially in the first two years of regeneration where 26% of gaps were closed solely by lateral ingrowth, which would not translate to 26% of regeneration of forest biomass. Trees inside gaps grew 2.2 times faster (1.5 m yr−1) than trees at the surrounding non-gap canopy (0.7 m yr−1). Our study brings new insights into the processes of both the opening and closure of forest gaps within tropical forests and the importance of considering gap types and origins in this analysis. Moreover, it demonstrates the capability of airborne LiDAR multi-temporal data in effectively characterizing the impacts of forest degradation and subsequent recovery. [ABSTRACT FROM AUTHOR]

Large tree decline is occurring globally with critical implications for biodiversity and carbon sequestration. Restoration thinning is a potential management action to accelerate tree growth and promote large tree development in forests, yet trials have been limited and results have been mixed.We conducted a large‐scale trial to determine whether restoration thinning could accelerate the development of large trees in river red gum forests in Australia that had experienced widespread woody thickening and a decline of large trees due to long‐term commercial timber harvesting and river regulation.Thinning was conducted on 44 9‐ha plots by removing trees <40 cm diameter from around retained trees at a range of spacings. Initial tree densities ranged from ~260 to ~1860 trees per ha and 8%–86% of trees were removed by thinning. We monitored 1980 trees prior to thinning, and annually for 5 years post‐thinning. We tested the effects of thinning intensity on diameter growth of different sized trees and explored whether long‐ and short‐term water availability affected outcomes.Thinning promoted the growth of small trees <56 cm diameter, especially in drier sites during wet years. Higher thinning intensities reduced the growth rates of large trees (no smaller than 79.5 cm diameter) in wetter sites.For medium‐ and large‐sized trees, long‐ and short‐term water availability were stronger drivers of tree growth than competition due to tree density.Synthesis and applications. Restoration thinning may accelerate tree growth in young river red gum forests where all trees are small. But restoration thinning may be ineffective or detrimental in multi‐aged forests where the goal is to promote the growth rates of trees that are already medium to large in size. [ABSTRACT FROM AUTHOR]

Species recovery following anthropogenic disturbances will depend on adaptations in survivorship and fecundity. Life‐history theory predicts increased environmental stress will result in (1) shifts in resource allocation from fecundity to body growth/maintenance and (2) increased provisioning among offspring at the cost of reproductive output. For remnant populations that persist after forest harvesting, selection mediated through anthropogenic disturbances may affect resilience to additional stressors such as climate change. We tested how rapid changes in environmental conditions affected maternal investment strategies in two ground beetle species, Pterostichus pensylvanicus and Pterostichus coracinus, by comparing fecundity and survivorship in populations from recently clear‐cut and uncut habitats. Using parents drawn from clear‐cut or uncut stands, we reared progeny in both common garden and reciprocal transplant experiments. In P. pensylvanicus, we found that neither lineage nor rearing habitat affected the number of eggs laid per female or survivorship of offspring. However, eggs laid by females from clear‐cuts were more likely to hatch and offspring reached maturity more quickly, suggesting increased provisioning per offspring. In P. coracinus, females from clear‐cuts laid more eggs, and their eggs hatched more rapidly and had greater hatching success, suggesting increased investment in overall reproductive output and increased offspring provisioning. In the reciprocal transplant, we observed significant habitat by lineage interactions on survival in P. coracinus, with survivorship increasing when progeny were reared in novel habitats. In both species, increased maternal investment among offspring was not associated with a reduction in overall reproductive output, as anticipated. However, maternal investment among offspring declined with increasing female size, implying trade‐offs between increased metabolic demand and fecundity. Taken together, our work suggests that females from more stressful, clear‐cut habitats increased investment in fecundity, compared to females from uncut habitats, and may compensate for larval mortality. These changes were driven by smaller individuals, suggesting that increased environmental stress can influence the relationship between female size and maternal investment strategy. Additionally, reciprocal increases in offspring survivorship in habitats other than the parents suggest that adjacent areas between unharvested and clear‐cut habitat may be useful in maintaining biodiversity under future climate stressors. [ABSTRACT FROM AUTHOR]

Large terrestrial mammals increasingly rely on human‐modified landscapes as anthropogenic footprints expand. Land management activities such as timber harvest, agriculture, and roads can influence prey population dynamics by altering forage resources and predation risk via changes in habitat, but these effects are not well understood in regions with diverse and changing predator guilds. In northeastern Washington state, USA, white‐tailed deer (Odocoileus virginianus) are vulnerable to multiple carnivores, including recently returned gray wolves (Canis lupus), within a highly human‐modified landscape. To understand the factors governing predator–prey dynamics in a human context, we radio‐collared 280 white‐tailed deer, 33 bobcats (Lynx rufus), 50 cougars (Puma concolor), 28 coyotes (C. latrans), and 14 wolves between 2016 and 2021. We first estimated deer vital rates and used a stage‐structured matrix model to estimate their population growth rate. During the study, we observed a stable to declining deer population (lambda = 0.97, 95% confidence interval: 0.88, 1.05), with 74% of Monte Carlo simulations indicating population decrease and 26% of simulations indicating population increase. We then fit Cox proportional hazard models to evaluate how predator exposure, use of human‐modified landscapes, and winter severity influenced deer survival and used these relationships to evaluate impacts on overall population growth. We found that the population growth rate was dually influenced by a negative direct effect of apex predators and a positive effect of timber harvest and agricultural areas. Cougars had a stronger effect on deer population dynamics than wolves, and mesopredators had little influence on the deer population growth rate. Areas of recent timber harvest had 55% more forage biomass than older forests, but horizontal visibility did not differ, suggesting that timber harvest did not influence predation risk. Although proximity to roads did not affect the overall population growth rate, vehicle collisions caused a substantial proportion of deer mortalities, and reducing these collisions could be a win–win for deer and humans. The influence of apex predators and forage indicates a dual limitation by top‐down and bottom‐up factors in this highly human‐modified system, suggesting that a reduction in apex predators would intensify density‐dependent regulation of the deer population owing to limited forage availability. [ABSTRACT FROM AUTHOR]

Stream temperature governs many aquatic ecosystem processes and plays a key role in determining the distribution of cold‐water amphibians and cool‐ and cold‐water fish, including salmonids. Decades of research have focused on the effects of forestry and forest disturbance on stream temperature, and new projects are underway or being planned in jurisdictions including the Provinces of Alberta and British Columbia, Canada, and Washington State, USA. The objective of this paper is to provide a critical review of methodologies employed in previous studies. The review initially focuses on the range of metrics used to quantify stream thermal regimes and the factors that control stream temperature variability in time and space, then focuses on sampling and analytical methodologies used to quantify stream temperature response to forestry activity and forest disturbance. Empirical methods include sampling in time, space, or both, and may or may not include pre‐ and post‐harvest data. Process‐based mechanistic and hybrid empirical‐mechanistic models have also been applied. The advantages and disadvantages of these approaches are discussed, and recommendations provided to support the design and execution of future studies. [ABSTRACT FROM AUTHOR]

Laurel (Laurus nobilis L.) is a valuable non-wood forest product (NWFP) in the global export market, with Turkey being the largest supplier. Laurel harvesting is crucial for achieving long-term goals in the NWFP industry. This study assessed the effectiveness of a hybrid framework for prioritizing management strategies for laurel harvesting to boost the forest-based bioeconomy in Turkey. The existing literature highlights the use of multi-criteria decision-making methods when dealing with multiple conflicting criteria. This study proposes a systematic and comprehensive framework to analyze the current situation and develop effective laurel harvesting strategies. An integrated SWOT-fuzzy Pivot Pairwise Relative Criteria Importance Assessment (F-PIPRECIA) and TOWS Matrix approach was used. Data from ten decision makers evaluated four separate SWOT criteria against thirty-two sub-criteria. The most critical strategy identified was Maxi S2 × Maxi O1 (0.0803). Sensitivity analyses validated the results. This study found that the most effective strategies in Turkey include improving environmental and forest planning tools through circular management methods, promoting investment in forest infrastructure, supporting training and entrepreneurship programs in laurel harvesting, and strengthening innovative forest-based value chains. The hybrid framework aims for sustainable laurel resource management while maximizing economic returns. Implementing this methodology will help conserve biodiversity and enhance local communities' well-being. [ABSTRACT FROM AUTHOR]

With this study, our aim was to estimate the nutrient fluxes relevant for assessing nutrient sustainability as accurately as possible and to calculate nutrient balances for alternative forest management scenarios. Furthermore, we tested whether mapping units from existing geologic maps can serve as a basis for forest practitioners to estimate nutrient sustainability or whether more detailed data are needed. Positive fluxes include deposition and weathering, while negative fluxes include losses due to leaching and nutrient removal through timber harvesting in the balance. Weathering and leachate losses were modeled with a geochemical model. The SwissStandSim model was used to simulate the biomass growth under different harvesting and silvicultural strategies, allowing for sustainability to be assessed for each nutrient at a given intensity of use. This assessment was made per rotation period based on two criteria: (i) nutrient supply and (ii) total stocking volume. As a result, it can be noted that the accurate estimation of individual fluxes is essential for assessing the sustainability of forestry practices and that it needs detailed site-specific data. Various influencing factors turned out to be important, particularly the assumed depth of the root zone. [ABSTRACT FROM AUTHOR]

Stand basal area (SBA) is an important variable in the prediction of forest growth and harvest yield. However, achieving the additivity of SBA models for multiple tree species in the complex structure of broad-leaved mixed forests is an urgent scientific issue in the study of accurately predicting the SBA of mixed forests. This study used data from 58 sample plots (30 m × 30 m) for Populus davidiana × Betula platyphylla broad-leaved mixed forests to construct the SBA basic model based on nonlinear least squares regression (NLS). Adjustment in proportion (AP) and nonlinear seemingly unrelated regression (NSUR) were used to construct a multi-species additive basal area prediction model. The results identified the Richards model (M6) and Korf model (M1) as optimal for predicting the SBA of P. davidiana and B. platyphylla, respectively. The SBA models incorporate site quality, stand density index, and age at 1.3 m above ground level, which improves the prediction accuracy of basal area. Compared to AP, NSUR is an effective method for addressing the additivity of basal area in multi-species mixed forests. The results of this study can provide a scientific basis for optimizing stand structure and accurately predicting SBA in multi-species mixed forests. [ABSTRACT FROM AUTHOR]

This study aims to investigate the impact of forest exploitation methods on monthly discharge and hydrological indices of river flow using graphical methods in a forested watershed in North Iran. To achieve this, 10 hydrological index changes related to river flow regime influenced by the Shelterwood/clear cutting, Femel cutting, and the Near Nature approach forest cutting methods were assessed. According to the results, it can be stated that the Shelterwood/clear cutting method influenced monthly flow indices by increasing the coefficient of variations and intensifying runoff production, while the Femel cutting and the Near Nature approach methods contributed to regulating the flow regime and sustaining river flow. The influence of various tree-cutting techniques on river flow values and fluctuations is more evident during the wettest months compared to low-water months. The period of Shelterwood/clear cutting disrupted the natural correlation between precipitation and runoff production. Furthermore, the shift from Shelterwood/clear cutting to Femel cutting and the Near Nature approach progressively diminished the slope of the curve, indicating a reduction in monthly runoff at both measurement stations. In conclusion, opting for an appropriate method, such as the Near Nature approach, is preferable from both ecological and hydrological perspectives when managing forest areas in the study region and similar conditions involving comparable topography, climate, soil, and forest stands. The index-based coupled with graphical methodology employed appropriately demonstrates the influence of logging techniques on monthly flow patterns, which provides valuable insights into evaluating the repercussions of alternative management interventions on river flow dynamics. [ABSTRACT FROM AUTHOR]

Forests are a large carbon sink and could serve as natural climate solutions that help moderate future warming. Thus, establishing forest carbon baselines is essential for tracking climate‐mitigation targets. Western US forests are natural climate solution hotspots but are profoundly threatened by drought and altered disturbance regimes. How these factors shape spatial patterns of carbon storage and carbon change over time is poorly resolved. Here, we estimate live and dead forest carbon density in 19 forested western US ecoregions with national inventory data (2005–2019) to determine: (a) current carbon distributions, (b) underpinning drivers, and (c) recent trends. Potential drivers of current carbon included harvest, wildfire, insect and disease, topography, and climate. Using random forests, we evaluated driver importance and relationships with current live and dead carbon within ecoregions. We assessed trends using linear models. Pacific Northwest (PNW) and Southwest (SW) ecoregions were most and least carbon dense, respectively. Climate was an important carbon driver in the SW and Lower Rockies. Fire reduced live and increased dead carbon, and was most important in the Upper Rockies and California. No ecoregion was unaffected by fire. Harvest and private ownership reduced carbon, particularly in the PNW. Since 2005, live carbon declined across much of the western US, likely from drought and fire. Carbon has increased in PNW ecoregions, likely recovering from past harvest, but recent record fire years may alter trajectories. Our results provide insight into western US forest carbon function and future vulnerabilities, which is vital for effective climate change mitigation strategies. Plain Language Summary: We investigated the role of western US forests as natural climate solutions by analyzing current forest carbon storage and trends from 2005 to 2019 across 19 forested regions. We found that the Pacific Northwest stores the most carbon, while the Southwest stores the least. Climate, wildfires, and human activities determined carbon amounts. For instance, climate is important in the Southwest and Lower Rockies, while wildfires impact the entire western US, but particularly the Upper Rockies and California. Human activities like harvesting and private ownership, decrease carbon, particularly in the Pacific Northwest. Since 2005, live carbon has declined in many western US areas, likely due to drought and fires. The study highlights the vulnerability of western US forests to climate‐related and human threats to carbon, providing crucial insights for effective climate change mitigation strategies. Understanding these dynamics is essential for scientists, policymakers, and educators working toward sustainable forest management and climate solutions in the region. Key Points: Live carbon has declined across much of western United States forests, likely due to drought and fire, resulting in an increase in dead carbonIn the Pacific Northwest (PNW), harvest led to reduced carbon, but recovery from past harvest likely caused carbon to increase since 2005Our results provide a baseline from which to evaluate future changes and inform management strategies [ABSTRACT FROM AUTHOR]

Understanding the effect of the relationship between timber harvesting attributes on loggers' productivity and efficiency is crucial for the feasibility and expansion of sustainable forest management and logging. We applied a stochastic production frontier model to firm-level operational data collected from 202 loggers in Virginia, United States, in 2019. Logging equipment value, physiographic region, tract area, number of workers and crews in the woods, college education level, and harvest type statistically increase harvesting productivity. Harvesting productivity in the Coastal Plain was the greatest of all physiographic regions, and pine clearcut productivity was statistically greater than that of hardwood thinning. On the other hand, manual felling reduces harvesting productivity. We found an average efficiency rate of 67% among firms in our sample, which is similar to that found in the literature. The estimated values can show factors that improve forest harvest productivity through better planning and investments while improving the sustainable use of inputs and resources. Study Implications: We empirically analyzed factors affecting logging productivity and efficiency in the southern US state of Virginia. Increased productivity was associated with working in the Coastal Plain physiographic region, investing in logging equipment, increasing the number of workers and crews in the woods, increasing pine clearcut as opposed to hardwood thinning, choosing optimal harvesting tract size, and having a college education as opposed to no high school degree. Manual felling reduces harvesting productivity, and average BMP implementation time does not affect harvesting productivity. Our results can be used as a guide in planning future decisions to increase logging productivity. [ABSTRACT FROM AUTHOR]

This article, titled "Leaf-Dicing Masters: Jackfruit Leaf Processing by the Indian Giant Squirrel as a Means to Avoid Latex," describes the active food processing behavior of the Indian giant squirrel, Ratufa indica maxima. The study focuses on the removal of the midrib from mature leaves of two Artocarpus species by the squirrel, which prevents the delivery of concentrated latex to the leaf blades. The researchers suggest that the high plant density and co-evolutionary period may have facilitated this processing behavior. The article includes photographs illustrating the squirrel's leaf feeding and the process of midrib removal. [Extracted from the article]

Trees in breeding programmes are often selected at 1/4–1/3 of rotation, called 'early selection', which is typically between 8 and 10 years in radiata pine. However, differences between populations and genotypes selected for either basic density or wood stiffness are already apparent at age 2. We report the application of very early screening techniques for wood properties in the New Zealand Radiata Pine Breeding Programme deployment populations. Approximately 3000 trees representing three populations with 92 families and 10 clones were grown in a common garden trial, leaning for 21 months to separate compression and opposite wood. The trees were harvested and analysis carried out separately by wood type. The trial showed the existence of large variability in wood properties at early age, in some cases similar to variability near rotation age, and moderate to high degree of genetic control ( 0.35 ≤ h 2 ≤ 0.71 ). The genetic association between traits was strong, particularly between wood stiffness and longitudinal shrinkage ( - 0.69 ) and between longitudinal and volumetric shrinkage (0.83), suggesting that improving stiffness would also have a strong effect on improving dimensional stability. Basic density was also associated with stiffness and shrinkage, but with lower predictive capacity. These results can be used for roguing deployment populations-which already contain superior growing trees-and quickly upgrade the wood quality of seeds and clones currently available to New Zealand forest growers. We discuss necessary modifications to turn this research work into operation to screen any new material before commercial release. [ABSTRACT FROM AUTHOR]

According to the strategy for the development of the forestry complex of the Russian Federation until 2030, approved by Order of the Prime Minister of Russia no. 312r dated February 11, 2021, the contribution of the forestry industry to the country’s economy should increase by 2 times, including through deep wood processing. To this end, enterprises for deep processing of wood raw materials will be actively developed. Consequently, there will be a shortage of wood raw materials, which will lead to an urgent need to expand the raw material base of these industries. Despite this, as the analysis of the practical experience of modern logging enterprises has shown, today, during logging operations, only the stem part of the tree is removed from the cutting area, and the rest of the biomass in the form of stumpwood, branches, twigs and tops is burned or buried, although these parts of the tree are valuable raw materials for the production of many types of products of wood processing enterprises. This state of affairs is due to the lack of effective technology for processing potential raw materials in the places of their formation and a complex of mobile machines for its implementation. As a result, a technology for the production of wood and coniferous flour, technological chips and semi-finished wood-fiber products, as well as mobile equipment for its implementation, has been proposed for the processing of logging waste in the form of tops, branches and twigs. The article presents technological solutions and equipment models built in the SolidWorks computer-aided design system. The introduction of the proposed technologies, machines and mechanisms will increase the share of harvested raw materials per unit area, reduce the environmental load from the logging process, and increase the efficiency of the industry.

In order better to evaluate the brittleness of tight reservoir, some studies were conducted to build the new prediction method of brittleness index. First, mechanical properties of tight formation are obtained by triaxial mechanical tests. Subsequently, the correlation analysis between brittleness index and logging parameters was conducted to determine the potential sensitive parameters to brittleness index. Then, based on grey correlation, the initial sequence of sensitive parameters was determined and normalized. On this basis, based on the analytic hierarchy process, the two-two comparison judgment matrix of sensitive parameters was built, the weight vector was determined. Finally, the relationship model between the brittle index and sensitive parameter was established, which meant that a new prediction model of brittleness index was established. Compared with experiment measurement and elastic parameters methods, new method could also have high precision, and reflect the brittleness of reservoir, moreover not depending on the shear wave logging. Therefore, new method provides a new idea for predicting brittleness index and guidance for reservoir fracturing. [ABSTRACT FROM AUTHOR]

Deforestation, forests diminution, and scarcity of natural food are widely regarded as the primary factors contributing to the presence of brown bears in urban areas of Romania, and human-bear conflicts. Public misunderstanding regarding forest and bear management practices often leads to skepticism of expert information, worsened by misinformation in the media and social networks. This article aims to offer insight into deforestation and human-bear conflicts in Romania. It analyzes national and international official data, to assess the percentage of forested areas, primary causes of deforestation, brown bear population and density, and the number of human-bear conflicts. It also compares Romanian data with other European countries to explore the potential correlation between forested area percentage and human-bear conflicts. Between 2000 and 2020, Romania's forest area comprised 29.02% of its land, while Poland, France, and Italy had percentages of 29.89%, 30.04%, and 30.65%, respectively. Interestingly, the proportion of forest cover did not consistently correlate with the frequency of conflicts. Countries with similar forest percentages to Romania experienced fewer conflicts, whereas countries with higher percentages, like Slovenia (61.65%) and Slovakia (39.86%), faced numerous human-bear conflicts due to the dense brown bear population. The management of bears served as a valuable indicator of the extent of damage caused by these animals. In Croatia, Sweden, Slovakia, and Slovenia, where 10-16% of the bear population was harvested annually, lower levels of damage were reported. In contrast, Romania, with an annual harvest of only 2-3% of the bear population, experienced higher levels of damage.

The efficiency of using logging machines on a steep slope depends on many factors, including the working area of the manipulator, which can be implemented in various technological modes of operation. The geometric parameters of the implemented working area are determined by the working position of the machine in the appropriate technological mode, that is, the place of installation of the machine relative to the tree or group of trees to be harvested. Optimization of the manipulator’s working area, formed during the operation of a logging machine, is one of the most effective ways to increase its productivity. In this article, based on a previously developed mathematical model for optimizing the structural dimensions of the links of a four-link articulated hydraulic manipulator designed for spatial manipulation of the harvester head when cutting and stacking trees for further transportation to the loading area, an analysis of the influence of the main geometric and power characteristics of the harvester on the optimal size of the working area is performed.

In the Russian Federation, a significant part of the forest fund territory is located on permafrost. Many regions of the country have large reserves of mature and overmature commercial forests, and a significant part of these reserves are located in hard-to-reach places, not only due to the underdeveloped road network, but also due to the difficult terrain. Currently, the vast majority of timber harvesting in Russia is carried out using modern machine complexes, mainly including wheeled forestry machines of various layouts and purposes (harvesters, forwarders, skidders, etc.). At the same time, the problem of the negative impact on the soil of forestry machines and skidding systems based on them not only remains relevant, but becomes even more acute, since the ecosystems of mountain forests, forests on the slopes of hills, etc. are among the most vulnerable, subject to water and wind erosion. As is known, the track in the soil is formed under the influence of normal load transmitted through the contact spot of the mover, as well as under the influence of the tangential force realized by the mover when moving the machine. When lifting a machine onto a slope, the tangential tractive effort of the propulsion is required than when moving across the plain. Consequently, the intensity of track formation on the slope is higher, all other things being equal. Machine systems are known where, when working on slopes, winches are used to help machines go down and up the slope. Winches can be either separate units or units integrated into the transmission of machines. The research has shown that using winches when lifting the machine onto a slope significantly reduces fuel consumption and transmission loads, which is a consequence of a decrease in the tangential tractive effort required to move the machine, realized by the engine. Then the intensity of track formation on the slope when the machine is working with a winch is less compared to working without a winch.

Extended Abstract Background: Forest harvesting operations, especially logging, are activities that cause interference and tampering with nature. Tractor-operated systems are the most common type of small-scale equipment used in the north of Iran. Due to the direct contact of wood with the forest soil, land logging has always been associated with a wide range of destructive effects on the forest ecosystem, including changes in the soil's physicochemical properties and damage to the natural regeneration and remaining trees. After logging, deep grooves are visible in the remaining logging roads, which can cause soil erosion, landslides, and soil fall due to the high longitudinal slope of these roads. Changes in the soil's physicochemical properties are among of the most important effects caused by the exploitation and removal of wood from the forest mass. Numerous studies report the long-term recovery of the soil's physicochemical properties. A major management goal in forest exploitation is the need to minimize the effects of vehicle traffic on the forest soil because these negative effects can be significant in the long run. The soil characteristics (appearance, compactness, and texture) and chemical properties in terms of soil elements, organic matter, and pH in two control and forest exploitation areas were studied to provide solutions to reduce these effects. Methods: The Kohmian forestry project is located in the 89th watershed of the northern forests of Iran in the area of Natural Resources of Golestan-Gorgan province. This research was conducted in Parcel 27 of the Kohmian Azadshahr Forestry Project located in Golestan, Iran. To investigate the soil's physicochemical changes due to logging with agricultural tractors, soil was sampled in two control areas and on the crossing paths by metal cylinders at three depths (0-10, 10-20, and 20-30 cm) of the soil in a completely randomized design with three replications. These samples were dried in the laboratory in an oven at 105 °C for 24 h and then weighed using a digital scale (EK4000, Japan) with an accuracy of 0.1 g. After recording the soil dry weight, the physical properties (compaction, apparent specific gravity, moisture, and texture) and chemical properties (organic matter, cation exchange capacity, nitrogen, potassium, phosphorus, calcium, magnesium, iron, zinc, manganese, copper, and acidity) were studied using standard methods. Results: Logging with an agricultural tractor significantly impacted both the soil's physical and chemical properties. The most notable effect was observed in the soil depths sampled from 0-10 cm and 20-30 cm. The alterations predominantly pertained to physical changes in the soil, with no significant modifications detected in the chemical properties. Notably, soil compaction in the trafficked areas at depths of 0-10, 10-20, and 20-30 cm was respectively 46.2, 3.04, and 1.73 times higher than that of the control area. Furthermore, the increase in soil specific gravity at these depths ranged from 20% to 36% compared to the control area. Chemical properties such as cation exchange capacity and the concentrations of elements (e.g., phosphorus, nitrogen, and iron) exhibited reductions of 37.62%, 63.91%, 10.2%, and 73.05%, respectively, in the top 0-10 cm depth. At a depth of 10-20 cm, only organic matter was significantly impacted by tractor traffic, with a reduction of approximately 64% compared to the control area. Chemical properties at a depth of 20-30 cm remained unaffected by tractor traffic. Conclusion: The study highlights the detrimental effects of using an agricultural tractor for primary forest plot transportation. The uneven contact surface of its tires, particularly the lower contact surface in the front tire, along with the absence of a winch, leads to soil disturbance along the logging path. This disturbance includes soil compaction, increased specific gravity, and alterations in soil texture, nitrogen, phosphorus, and iron content, reduced organic matter, and decreased soil exchange capacity. To mitigate these adverse effects, it is recommended to employ specialized logging machinery, such as skidders with rakes, instead of agricultural tractors. Other measures include implementing surface protections on logging paths, restricting logging activities to periods when the forest soil is dry and less prone to damage, and proper disposal of excess logs along the logging route.

A 60‐year precipitation and streamflow record from the Caspar Creek Experimental Watersheds in northern California was used to explore the propagation of meteorological drought to hydrological drought. Standardized precipitation and runoff indices were calculated for the two forested catchments using integration periods of 12, 24, and 36 months. The resulting time series were used to define three severe drought events (1976–1977, 2013–2014, and 2020–2022). The earliest drought followed the 1971–1973 harvest of the 417 ha South Fork (SF) watershed, a second followed the 1989–1992 harvest of the 479 ha North Fork watershed, and a third followed the 2017–2019 reentry harvest of the SF. From these time series, we calculated drought metrics and anomalies to model differences in catchment responses in the context of climate and management. The meteorological drought in the 1977 event was more severe and extreme than the streamflow response. Both of the 21st Century droughts were hydrologically more severe than the 1977 drought. Timber harvest initially shortened and reduced streamflow drought (1977 and 2021) but prolonged and intensified the 2014 streamflow drought. Declining fall precipitation has reduced streamflows, thereby impeding salmonid migration and exacerbating impacts on native fish. Our results provide new insights into the role of climate variation, particularly long‐term and seasonal drought dynamics, in managed forests along the North American Pacific coast. [ABSTRACT FROM AUTHOR]

The issues associated with long‐screened wells (LSWs) (and open boreholes) at contaminated sites are well documented in the groundwater literature but are still not fully appreciated in practice. As established in seminal and review papers going back over three decades, the interpretation of sampling results from LSWs is challenging in the presence of vertical hydraulic gradients and borehole flow; furthermore, LSWs allow for vertical redistribution of contamination between aquifer layers. Acknowledgment of these issues has led to the development of new technologies and well designs to enable discrete‐zone monitoring (DZM), yet LSWs remain common for many reasons, for example, as multipurpose wells, for geophysical logging, and (or) as legacy installations. Despite the literature on LSWs and despite the adoption of DZM at many sites, the use of LSWs persists and the challenges of interpreting sampling results from LSWs remain. In this issue paper, we provide a conceptual overview of the problems posed by LSWs and review existing literature and past work to improve the interpretation of sampling in LSWs. We draw on experience from previous studies at the Hanford Site in eastern WA, USA, and use synthetic examples to illustrate key concepts and challenges for interpretation. A recently published analytical modeling framework is used to develop illustrative synthetic examples and demonstrate a workflow for building scientific intuition to understand issues around interpreting samples from LSWs, which is critical to effective characterization and groundwater remediation at sites with LSWs. [ABSTRACT FROM AUTHOR]

Fire suppression has negatively impacted thousands of acres of private and public lands in the United States. As a case study, the New Jersey Pine Barrens (NJPB) are a disturbance driven ecosystem that is experiencing serious ecological implications due to a loss of traditional forest thinning activities such as harvesting for forest products or thinning for wildfire fuel-load reduction measures coupled with a long-standing philosophy of fire suppression and dormant-season prescribed burning. Dense closed-canopy forest conditions, dissimilar to historic open-canopy forests of the NJPB, have reduced abundance and diversity of certain flora and fauna, including regionally imperiled breeding birds. In recent years, active forest stewardship (e.g., thinning, clear-cutting, and burning) has occurred on private and some public lands within the NJPB; however, the impact of such management on breeding birds is unclear due to a paucity of research on this subject within the NJPB. During 2012, 2013, 2016, and 2017, we conducted repeat-visit point counts (n = 1,800) for breeding songbirds across 75 control and 75 treatment sites within the NJPB to assess the influence of forest structure at three strata levels (groundcover, midstory profile, and canopy) on breeding bird communities. Specifically, we constructed a hierarchical community abundance model within a Bayesian framework for Bird Conservation Region (BCR) 30 priority upland birds (n = 12) within three species suites: Forested Upland, Scrub-Shrub (or Young Forest), and Grassland. At the community level, we found a negative relationship between bird abundance and live tree basal area. At the BCR 30 suite level, we found no relationship between Forested Upland suite-level abundance and any of the measured covariates; however, we found a negative relationship between percentage of woody groundcover and Scrub-Shrub suite-level abundance, and negative relationship between horizontal visual obstruction at 2 m above ground level and Grassland suite-level abundance. Furthermore, the two latter species suites exhibited a strong negative relationship with basal area. We recommend active forest stewardship that specifically targets opening the canopy to achieve basal areas between ~0–15 m2/ha via selective thinning, shelter cutting, and small-scale clear cutting. Mechanical treatment and prescribed burning would produce such conditions and have the added benefit of reducing fuel loads across this ~4,500 km2 landscape as well as assisting in carbon defense strategies for the region. [ABSTRACT FROM AUTHOR]

Understanding the biophysical limitations on forest carbon across diverse ecological regions is crucial for accurately assessing and managing forest carbon stocks. This study investigates the role of climate and disturbance on the spatial variation of two key forest carbon pools: aboveground carbon (AGC) and soil organic carbon (SOC). Using plot‐level carbon pool estimates from Nepal's national forest inventory and structural equation modelling, we explore the relationship of forest carbon stocks to broad‐scale climatic water and energy availability and fine‐scale terrain and disturbance. The forest AGC and SOC models explained 25% and 59% of the observed spatial variation in forest AGC and SOC, respectively. Among the evaluated variables, disturbance exhibited the strongest negative correlation with AGC, while the availability of climatic energy demonstrated the strongest negative correlation with SOC. Disturbances such as selective logging and firewood collection result in immediate forest carbon loss, while soil carbon changes take longer to respond. The lower decomposition rates in the high‐elevation region, due to lower temperatures, preserve organic matter and contribute to the high SOC stocks observed there. These results highlight the critical role of climate and disturbance regimes in shaping landscape patterns of forest carbon stocks. Understanding the underlying drivers of these patterns is crucial for forest carbon management and conservation across diverse ecological zones including the Central Himalayas. [ABSTRACT FROM AUTHOR]