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Across western North America, current ecosystem structure has been determined by historical interactions between climate, fire, livestock grazing, and logging. Climate change could substantially alter species abundance and composition, but the relative weight of the legacy of historical factors and projected future conditions in informing management objectives remains unresolved. We integrated land use histories with broad scale climatic factors to better understand how inland Pacific Northwest ecosystems may develop under projected climates. We measured vegetation structure and age distributions in five vegetation types (shrub steppe to subalpine forest) along an elevation gradient in the eastern Cascades of Washington. We quantitatively assessed compositional changes, and qualitatively summarized the environmental history (climate, fire and fire suppression, grazing, and logging) of each site. Little change was evident in woody species composition at the shrub steppe site. At the shrub steppe/forest ecotone, densities of drought-tolerant Artemisia tripartita and Pinus ponderosa increased. In the dry conifer, montane, and subalpine forest sites, increases in Pseudotsuga menziesii, Abies grandis, and Abies lasiocarpa, respectively, and decreases in Pinus ponderosa, Larix occidentalis, and Pinus contorta, respectively, have shifted species composition from fire and drought-tolerant species to shade-tolerant species. Fire suppression, grazing, and logging explain changes in species composition more clearly than climate variation does, although the relative influence of these factors varies with elevation. Furthermore, some of the observed changes in composition are opposite what we expect would be most suited to projected future climates. Natural resource managers need to recognize that the current state of an ecosystem reflects historical land uses, and that contemporary management actions can have long-term effects on ecosystem structure. Understanding the processes that generated an ecosystem's current structure will lead to more informed management decisions to effectively respond to projected climate changes.

European forests are threatened by increasing numbers of invasive pests and pathogens. Over the past century, Lecanosticta acicola, a foliar pathogen predominantly of Pinus spp., has expanded its range globally, and is increasing in impact. Lecanosticta acicola causes brown spot needle blight, resulting in premature defoliation, reduced growth, and mortality in some hosts. Originating from southern regions of North American, it devastated forests in the USA's southern states in the early twentieth century, and in 1942 was discovered in Spain. Derived from Euphresco project 'Brownspotrisk,' this study aimed to establish the current distribution of Lecanosticta species, and assess the risks of L. acicola to European forests. Pathogen reports from the literature, and new/ unpublished survey data were combined into an open-access geo-database (http://www.portalofforestpathology.com), and used to visualise the pathogen's range, infer its climatic tolerance, and update its host range. Lecanosticta species have now been recorded in 44 countries, mostly in the northern hemisphere. The type species, L. acicola , has increased its range in recent years, and is present in 24 out of the 26 European countries where data were available. Other species of Lecanosticta are largely restricted to Mexico and Central America, and recently Colombia. The geo-database records demonstrate that L. acicola tolerates a wide range of climates across the northern hemisphere, and indicate its potential to colonise Pinus spp. forests across large swathes of the Europe. Preliminary analyses suggest L. acicola could affect 62% of global Pinus species area by the end of this century, under climate change predictions. Although its host range appears slightly narrower than the similar Dothistroma species, Lecanosticta species were recorded on 70 host taxa, mostly Pinus spp., but including, Cedrus and Picea spp. Twenty-three, including species of critical ecological, environmental and economic significance in Europe, are highly susceptible to L. acicola , suffering heavy defoliation and sometimes mortality. Variation in apparent susceptibility between reports could reflect variation between regions in the hosts' genetic make-up, but could also reflect the significant variation in L. acicola populations and lineages found across Europe. This study served to highlight significant gaps in our understanding of the pathogen's behaviour. Lecanosticta acicola has recently been downgraded from an A1 quarantine pest to a regulated non quarantine pathogen, and is now widely distributed across Europe. With a need to consider disease management, this study also explored global BSNB strategies, and used Case Studies to summarise the tactics employed to date in Europe., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors.)

Forests and their ecosystem services are subjected to uncertain factors, causing drastic changes in forest production and/or market conditions, the impacts of which cannot be precisely estimated beforehand. We introduce a theoretical framework, based on control theory, for robust optimization of forest management under uncertainty. Forest owners herein regard their decision support system only as an approximation to an unknown, true, model. Concerns about model misspecification incite them to seek the single harvesting rule that works well over a set of models statistically similar to their approximation. Accounting for mistrust of decision support systems in modelling harvesting behavior is particularly relevant in view of uncertainty induced by climate change. We use a stylized forest model to explore the effects of uncertainty on harvesting decisions, also considering the role of information aimed at reducing, or making forest owners aware of, such uncertainty. The simulation results demonstrate that model uncertainty affects harvesting intensity and thus forest development. Harvest levels are lower for forest managers concerned with model uncertainty, favoring stand volume over harvest revenues. Further, information release affects the level of perceived uncertainty and thus harvesting behavior and forest development, reaffirming the importance of information as a forest policy instrument., (© 2020 The Authors.)

Prescribed fire is commonly used as a tool to meet a range of forest management goals. Owing to their limited movement abilities, terrestrial turtles are likely to be at high risk of injury and mortality, and to experience other fitness consequences with population-level implications from fire. Using radiotelemetry, we studied the responses of Eastern Box Turtles, Terrapene carolina carolina , to prescribed fire management in a sandhills Longleaf Pine forest system over a five-year period and compared our results to a nearby population in an unburned coastal plain location. Individual variation in turtle survival was strongly dependent on how frequently and extensively the areas were burned, with annual survival rates of 94.5% in unburned areas decreasing to 45.9 % in the most extensively burned areas. Turtles at the fire-maintained sandhills site had annual survival rates 4.9 % less than at the unburned coastal plain site, and females had annual survival rates 6.8 % less than males. Survival varied seasonally, with greatest mortality rates in winter and spring, especially among females. Growth rates and body condition did not differ between sites, nor did they vary according to fire extent and frequency at the fire-maintained site. Although mortality was greater and spatially variable at the fire-maintained site, annual survival rates across the site (86 - 90 % for females and males, respectively) were comparable to other stable populations of T. carolina . The lesser than expected mortality rate at the fire-maintained site was likely the result of turtles' strong selection of mesic hardwood forests near bottomlands and streams - habitats that may serve as refugia from fire. In areas where T. carolina conservation is a priority, land managers should integrate maintenance of fire refuge habitats into burn planning to minimize unintended negative impacts to this imperiled species.

Forest carbon (C) density varies tremendously across space due to the inherent heterogeneity of forest ecosystems. Variation of forest C density is especially pronounced in mountainous terrain, where environmental gradients are compressed and vary at multiple spatial scales. Additionally, the influence of environmental gradients may vary with forest age and developmental stage, an important consideration as forest landscapes often have a diversity of stand ages from past management and other disturbance agents. Quantifying forest C density and its underlying environmental determinants in mountain terrain has remained challenging because many available data sources lack the spatial grain and ecological resolution needed at both stand and landscape scales. The objective of this study was to determine if environmental factors influencing aboveground live carbon (ALC) density differed between young versus old forests. We integrated aerial light detection and ranging (lidar) data with 702 field plots to map forest ALC density at a grain of 25 m across the H.J. Andrews Experimental Forest, a 6369 ha watershed in the Cascade Mountains of Oregon, USA. We used linear regressions, random forest ensemble learning (RF) and sequential autoregressive modeling (SAR) to reveal how mapped forest ALC density was related to climate, topography, soils, and past disturbance history (timber harvesting and wildfires). ALC increased with stand age in young managed forests, with much greater variation of ALC in relation to years since wildfire in old unmanaged forests. Timber harvesting was the most important driver of ALC across the entire watershed, despite occurring on only 23% of the landscape. More variation in forest ALC density was explained in models of young managed forests than in models of old unmanaged forests. Besides stand age, ALC density in young managed forests was driven by factors influencing site productivity, whereas variation in ALC density in old unmanaged forests was also affected by finer scale topographic conditions associated with sheltered sites. Past wildfires only had a small influence on current ALC density, which may be a result of long times since fire and/or prevalence of non-stand replacing fire. Our results indicate that forest ALC density depends on a suite of multi-scale environmental drivers mediated by complex mountain topography, and that these relationships are dependent on stand age. The high and context-dependent spatial variability of forest ALC density has implications for quantifying forest carbon stores, establishing upper bounds of potential carbon sequestration, and scaling field data to landscape and regional scales.

Coppicing, once a common type of management in European broadleaved forests, was abandoned in many places after WWII. This form of management provided a variety of structural and microclimatic conditions for tree and understorey vegetation. After the abandonment of this intensive management, succession towards mature close forests ensued, and suitable habitats for species ecologically connected to coppicing were reduced. In our study, we chose a region in central Europe where coppicing was the dominant type of forest management until the first half of the 20 th century but was abandoned after WWII. We investigated long-term changes in both woody and herbaceous species composition in the Lower Morava UNESCO Biosphere Reserve using historical sources and vegetation plot resurveys from the 17 th to the 21 st century. The impact of coppice abandonment on vegetation composition and on the conservation value of forests was evaluated. Dominant tree species appeared to be very stable throughout the past four centuries, but changes occurred in their proportions. A shift from species rich oak-hornbeam woodland towards species poorer communities with increasing proportions of lime, ash and maple was observed after the abandonment of coppicing. The observed tendencies partly differed according to site and data source. The conservation value of forests was measured as the occurrence of red-list species, which were considerably reduced after coppice abandonment. To stop the process of biodiversity loss and support the goals of nature conservation, the re-establishment of coppice management is proposed.

European broadleaved forests have been influenced by humans for centuries. Historical management practices are related to environmental conditions but the role of socio-economic factors is also important. For the successful restoration of traditional management for conservation purposes, detailed knowledge on management history and on the driving forces of historical forest changes is necessary. In order to reconstruct long-term spatio-temporal dynamics in forest management, we chose the Pálava Protected Landscape Area, Czech Republic and analyzed archival sources spanning the past seven centuries. Forests in the study area comprise two relatively large woods (Děvín and Milovice) with different environmental conditions. Historical forest management in both woods was coppicing. The coppice cycle was lengthened from 7 years (14 th century) to more than 30 years (19 th century) with a fluctuating density of standards. After WWII, coppicing was completely abandoned. This led to pronounced changes in forest age structure accompanied by stand unification indicated by a sharp decrease in the Shannon index of age diversity. To study local attributes responsible for spatial patterns in coppice abandonment, we constructed a regression model with the date of abandonment as a dependent variable and three groups of explanatory variables: i) remoteness of forest parcels, (ii) morphometric environmental factors and iii) site productivity. In Děvín Wood, coppicing was abandoned gradually with the pattern of abandonment related significantly to slope steepness and forest productivity. Poorly accessible upper slopes and low productive forest sites were abandoned earlier. By contrast, in Milovice Wood, where no clear topographic gradient is present, the abandonment of coppicing was not related to any of the variables we studied. Our study brings insights into the history and consequences of past management practices, and can be used in current attempts to re-establish coppice management for conservation purposes and as a source of sustainable energy.