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Loss of natural forests by forest clearcutting has been identified as a critical conservation challenge worldwide. This study addressed forest fragmentation and loss in the context of the establishment of a functional green infrastructure as a spatiotemporally connected landscape-scale network of habitats enhancing biodiversity, favorable conservation status, and ecosystem services. Through retrospective analysis of satellite images, we assessed a 50- to 60-year spatiotemporal clearcutting impact trajectory on natural and near-natural boreal forests across a sizable and representative region from the Gulf of Bothnia to the Scandinavian Mountain Range in northern Fennoscandia. This period broadly covers the whole forest clearcutting period; thus, our approach and results can be applied to comprehensive impact assessment of industrial forest management. The entire study region covers close to 46,000 km² of forest-dominated landscape in a late phase of transition from a natural or near-natural to a land-use modified state. We found a substantial loss of intact forest, in particular of large, contiguous areas, a spatial polarization of remaining forest on regional scale where the inland has been more severely affected than the mountain and coastal zones, and a pronounced impact on interior forest core areas. Salient results were a decrease in area of the largest intact forest patch from 225,853 to 68,714 ha in the mountain zone and from 257,715 to 38,668 ha in the foothills zone, a decrease from 75% to 38% intact forest in the inland zones, a decrease in largest patch core area (assessed by considering 100-m patch edge disturbance) from 6114 to 351 ha in the coastal zone, and a geographic imbalance in protected forest with an evident predominance in the mountain zone. These results demonstrate profound disturbance of configuration of the natural forest landscape and disrupted connectivity, which challenges the establishment of functional green infrastructure. Our approach supports the identification of forests for expanded protection and conservation-oriented forest landscape restoration. La pérdida de bosques naturales por causa de la tala uniforme de árboles en los mismos ha sido identificada como unreto muyimportantepara la conservación global. Esteestudioabordó la fragmentación y pérdida de bosques en el contexto del establecimiento de una infraestructura verde funcional como una red de hábitats a escala de paisaje conectados espacio-temporalmente que mejoren la biodiversidad, los estados favorables de conservación y los servicios ambientales. Por medio de un análisis retrospectivo de imágenes satelitales evaluamos una trayectoria de impacto espacio-temporal de 50 a 60 años de tala uniforme sobre bosques boreales naturales y casi naturales en una región considerable y representativa desde el Golfo de Botnia hasta la Cordillera Escandinava en el norte de Fenoescandia. Este rango cubre todo el periodo de tala uniforme en el bosque en términos generales; por lo tanto, nuestra metodología y resultados pueden aplicarse a la evaluación completa del impacto del manejo industrial de bosques. Toda la región de estudio cubría hasta 46,000 km² de paisaje dominado por bosque en una etapa tardía de la transición entre el estado natural o casi natural y el estado de uso de suelo modificado. Encontramos una pérdida sustancial de bosque intacto, particularmente para áreas grandes y contiguas, una polarización espacial del bosque restantea una escala regional en la que tierra adentro hay mayores afectaciones que en las zonas montañosas y costeras, y un impacto pronunciado sobre las áreas nucleares de los bosques interiores. Los resultados salientes fueron una disminución en el área del fragmento más grande de bosque intacto de 225, 853 a 68, 714 ha en la zona montañosa y de 257, 715 a 38, 668 ha en la zona de pie de monte, una disminución del 75% al 38% de bosque intacto en las zonas tierra adentro, una disminución en el área nuclear del fragmento más grande (valorada al considerar 100-m de perturbación al borde del fragmento) de 6, 114 a 351 ha en la zona costera, y un desbalance geográfico en los bosques protegidos con una evidente mayoría en la zona montañosa. Estos resultados demuestran una perturbación profunda de la configuración del paisaje de bosque natural y una conectividad interrumpida, lo que presenta un reto para el establecimiento de una infraestructura verde funcional. Nuestro enfoque sustenta la identificación de bosques para su protección expandida y la restauración del paisaje de bosque orientada hacia la conservación. 森林皆伐造成的自然森林丧失被认为是全世界面胳的重要保护挑战。功能性绿色基础设施是提高生物多 样性、保护状况和生态系统服务的时空上连接的景观尺度生境网络 本研究关注其建设中的森林破碎化和森林 丧失同题。通过分析卫星图像, 我们评估7\"芬诺斯坎通亚 (Fennoscancdia) 北部波的尼亚湾 (Gulf of Bothnia) 到 斯堪的纳维亚山脉(Scandinavian Mountain Range)大面积有代表性的自然和接近自然的北方森林受到 50-60 年森林皆伐的影响轨迹。这一时间段大致包括了整个森林皆伐期，因此我们的方法和结果可以应用于工业森林 管理的综合影响评估。整个研究区域覆盖了近紙000平方公里以森林为主的景風处于自然或接近自然的景 观向人为改造的土地利用类型过渡的后期。我们发现原始森林严重丧失，特别是大面积的连续区域，_ 余的森林 在区域尺度上发生空间的两极分化，其中内陆比山区和沿海地区受到更为严重的影响，内部森林核心区也受到明 显影响。突出的结果包括:山区最大的原始森林斑块面积从225,853公顷减少到 68,714 公埂而在山麓地区 从 257,715 公現滅少到38,668 公埂, 内陆地区从 75% 减少到 38%, 最大的斑块核心区域面积减少(根据 6,114 公顷到 351 公顷的沿海地区 100 米斑块边缘干扰的评估结果X 以及受保护森林的地理分布不平衡(主要在山 区) 。这些结果表明，自然森林景观配置受到严重干抵连接度受到破坏，这对建设功能性绿色基础设施提出了 挑战。我们的方法有助于确定扩大保护及进行保护导向的森林景观恢复的森林范围。

Climate change can impact forest ecosystem processes via individual tree and community responses. While the importance of land-use legacies in modulating these processes have been increasingly recognised, evidence of former land-use mediated climate-growth relationships remain rare. We analysed how differences in former land-use (i.e. forest continuity) affect the growth response of European beech to climate extremes. Here, using dendrochronological and fine root data, we show that ancient forests (forests with a long forest continuity) and recent forests (forests afforested on former farmland) clearly differ with regard to climate–growth relationships. We found that sensitivity to climatic extremes was lower for trees growing in ancient forests, as reflected by significantly lower growth reductions during adverse climatic conditions. Fine root morphology also differed significantly between the former land-use types: on average, trees with high specific root length (SRL) and specific root area (SRA) and low root tissue density (RTD) were associated with recent forests, whereas the opposite traits were characteristic of ancient forests. Moreover, we found that trees of ancient forests hold a larger fine root system than trees of recent forests. Our results demonstrate that land-use legacy-mediated modifications in the size and morphology of the fine root system act as a mechanism in regulating drought resistance of beech, emphasising the need to consider the ‘ecological memory’ of forests when assessing or predicting the sensitivity of forest ecosystems to global environmental change.

ContextAs forest harvesting remains high, there is a crucial need to assess the remaining large, contiguous and intact forests, regionally, nationally and globally.ObjectivesOur objective was to analyze the spatial patterns and structural connectivity of intact and primary forests in northern Sweden with focus on the Scandinavian Mountain region; one of the few remaining large European intact forest landscapes.MethodsOver 22 million ha with 14.5 million ha boreal and subalpine forest and with data consisting of a 60-70 year retrospective sequence, we analyzed distribution, density and connectivity of forests that have not been clear cut, using moving window and landscape analyzes derived from Circuitscape.ResultsWe revealed a contiguous, connected and semi-connected intact forest landscape forming a distinct Green Belt south to north along the mountain range. Almost 60% of the forestland remains intact, including contiguous clusters 10,000 ha and larger. The connectivity is particularly high in protected areas with primary forests outside contributing substantially to overall connectivity. We found gaps in connectivity in the southern parts, and furthermore low or absent connectivity across the whole inland and coastal areas of northern Sweden.ConclusionsGiven its ecological values, the Scandinavian Mountains Green Belt is a key entity supporting ecological legacies, boreal biodiversity and ecosystem services, resilience and adaptive capacity, which needs to be safeguarded for the future. On the very large areas outside the mountain region, forestlands are severely fragmented, connectivity values are lost, and forest landscape restoration is needed for conservation and functional green infrastructure.

Passive rewilding is increasingly seen as a promising tool to counterbalance biodiversity losses and recover native forest ecosystems. One key question, crucial to understanding assembly processes and conservation issues underlying land-use change, is the extent to which functional and phylogenetic diversity may recover in spontaneous recent woodlands. Here, we compared understorey plant communities of recent woodlands (which result from afforestation on agricultural lands during the 20th century) with those of ancient forests (uninterrupted for several centuries) in a hotspot of farmland abandonment in western Europe. We combined taxonomic, functional, and phylogenetic diversity metrics to detect potential differences in community composition, structure (richness, divergence), conservation importance (functional originality and specialization, evolutionary distinctiveness) and resilience (functional redundancy, response diversity). The recent and ancient forests harbored clearly distinct compositions, especially regarding the taxonomic and phylogenetic facets. Recent woodlands had higher taxonomic, functional and phylogenetic richness and a higher evolutionary distinctiveness, whereas functional divergence and phylogenetic divergence were higher in ancient forests. On another hand, we did not find any significant differences in functional specialization, originality, redundancy, or response diversity between recent and ancient forests. Our study constitutes one of the first empirical pieces of evidence that recent woodlands may spontaneously regain plant communities phylogenetically rich and functionally resilient, at least as much as those of ancient relict forests. As passive rewilding is the cheapest restoration method, we suggest that it should be a very useful tool to restore and conserve native forest biodiversity and functions, especially when forest areas are restricted and fragmented.

The EU Biodiversity Strategy 2030 aims to better protect natural ecosystems with high biodiversity and climate change mitigation potential. To achieve this goal, it is crucial to identify forests worth protecting, such as those characterized by long continuity and old age. Here, we propose a robust approach that combines historical maps from the mid‐19th century with remote sensing data to identify areas that have been forested for over 150 years, aiming to reduce the need for detailed and time‐consuming field investigations in potential conservation areas. We tested this approach in a 20,000 km2 region in the Polish Carpathians, an area likely containing many unprotected forests of high conservation value, where historical maps from the mid‐19th century are representative of much of Central Europe. Our results showed that an area of approximately 4200 km2 has been continuously forested since at least the mid‐19th century. Currently, 50% of these forests are outside protected areas, representing an important conservation opportunity. More generally, our approach can support the identification of valuable forests worth protecting before they are lost and provide useful insights for policymakers and stakeholders in the ongoing debate on the challenges of improving forest conservation in the Carpathians, and Europe more widely.

Understanding the processes that shape biodiversity patterns is essential for ecosystem management and conservation. Local environmental conditions are often good predictors of species distribution and variations in habitat quality usually positively correlate to species richness. However, beside habitat limitation, species presence-absence may be constrained by dispersal limitation. We tested the relative importance of both limitations on saproxylic beetle diversity, using forest continuity as a surrogate for dispersal limitation and stand maturity as a surrogate for habitat limitation. Forest continuity relies on the maintenance of a forest cover over time, while stand maturity results in the presence of old-growth habitat features. Forty montane beech-fir forests in the French pre-Alps were sampled, under a balanced sampling design in which forest continuity and stand maturity were crossed. A total of 307 saproxylic beetle species were captured using flight-interception traps and Winkler–Berlese extractors. We explored the response of low- versus high-dispersal species groups to forest continuity and stand maturity. Saproxylic beetle diversity increased significantly with stand maturity and was mostly influenced by variables related to deadwood diversity at the stand scale and suitable habitat availability at the landscape scale. Surprisingly, no evidence of dispersal limitation was found, as diversity patterns were not influenced by forest continuity and associated variables, even for low-dispersal species. Our study demonstrates that in an unfragmented forest landscape, saproxylic beetles are able to colonize recent forests, as long as local deadwood resources are sufficiently diversified (e.g. tree species, position, diameter and/or decay stage).

Long forest continuity has often been linked with high conservation value in western European Quercus and Fagus woodlands, but this assumption of long continuity has rarely been tested. Birks discussed the antiquity of bryophyte-rich Quercus woodland in western United Kingdom, presenting evidence that the modern plant communities developed during the late Holocene influenced by human activities. We use pollen data from forest hollows to show that the modern communities within ancient woodlands are all significantly influenced by recent human disturbance. A short period of deforestation in Johnny’s Wood, Cumbria, UK dates from the late 19th century and is not of Viking age as previously thought. The brief opening of the forest is associated with the local loss of Tilia cordata and Taxus baccata, but a rich bryophyte community exists today. Rich lichen floras of high conservation interest growing on Fagus sylvatica in south-western Sweden occur despite a recent history of human disturbance and local immigration of Fagus as recently as the 9th century ad. Wistman’s Wood, Cornwall, UK had a diverse tree flora until the 11th century ad and then experienced heavy browsing and grazing until ad 1850, after which time the present Quercus woodland developed with its associated flora of high conservation value. Most western European forests today have long and diverse histories of anthropogenic disturbance and current conservation values incorporate both natural and cultural features. Pollen studies with high spatial resolution demonstrate that simple temporal concepts like ‘natural baselines’ and the continuity of forest cover underestimate the complexity of the past. Long forest continuity may be of importance for the local survival of higher plants, but for the insects, fungi, lichens and bryophytes that are so valued in contemporary European temperate and boreal forests, habitat diversity maintained by dynamic processes would appear to be of greater significance.

QUESIONS: What were the long‐term disturbance rates (including variability) and agents in pristine Norway spruce‐dominated (Picea abies (L.) Karst.) forests? Have soil moisture conditions influenced disturbance rates across this boreal spruce‐dominated forest? Were the temporal recruitment patterns of canopy dominants associated with past disturbance periods? LOCATION: Interfluvial region of Northern Dvina and Pinega rivers, Arkhangelsk, northwest Russia. METHODS: We linked dendrochronological data with tree spatial data (n trees = 1659) to reconstruct the temporal and spatial patterns of canopy gaps in a 1.8‐ha area from 1831–2008, and to develop a growth‐release chronology from 1775–2008. RESULTS: No evidence of stand‐replacing disturbances was found within selected forest stands over the studied period. Forest dynamics were driven by small‐ to moderate‐scale canopy disturbances, which maintained a multi‐cohort age structure. Disturbance peaks were observed in the 1820s, 1920s, 1970s and 2000s, with decadal rates reaching 32% of the stand area disturbed. CONCLUSIONS: The overall mean decadal rate was 8.3% canopy area disturbed, which suggests a canopy turnover time of 122 yr, with a 95% confidence envelop of 91–186 yr. Bark beetle outbreaks (possibly exacerbated by droughts) and wind‐storms emerged as the principal disturbance agents. Recruitment of both Norway spruce and downy birch was associated with periods of increased canopy disturbance. Moisture conditions (moist vs mesic stands) were not significantly related to long‐term disturbance rates. The studied spruce‐dominated boreal forests of this region apparently exhibited long‐term forest continuity under this mixed‐severity disturbance regime. These disturbances caused considerable structural alterations to forest canopies, but apparently did not result in a pronounced successional shifts in tree species composition, rather occasional minor enrichments of birch in these heavily spruce‐dominated stands.

Habitat loss and fragmentation can negatively impact the persistence of dispersal-limited lichen species with narrow niches. Rapid change in microclimate due to canopy dieback exposes species to additional stressors that may limit their capacity to survive and colonize. We studied the importance of old trees as micro-refuges and microclimate stability in maintaining lichen survival and diversity. The study was situated in mountain Norway spruce ( Picea abies ) forests of the Gorgany Mountains of the Ukrainian Carpathian mountain belt. Lichens were collected on 13 circular study plots (1000 m 2 ). Dendrochronological methods were used to reconstruct age structure and maximum disturbance event history. A linear mixed effects model and general additive models were used to explain patterns and variability of lichens based on stand age and disturbance history for each plot. Tree age was the strongest variable influencing lichen diversity and composition. Recent (<80 years ago) severely disturbed plots were colonized only by the most common species, however, old trees (>200 years old) that survived the disturbances served as microrefuges for the habitat-specialized and/or dispersal limited species, thus epiphytic lichen biodiversity was markedly higher on those plots in comparison to plots without any old trees. Most species were able to survive microclimatic change after disturbances, or recolonize disturbed patches from surrounding old-growth forests. We concluded that the survival of old trees after disturbances could maintain and/or recover large portions of epiphytic lichen biodiversity even in altered microclimates.

Questions: What is the relative importance of landscape variables compared to habitat quality variables in determining species composition in floodplain forests across different physiographic areas? How do species composition and species traits relate to effects of particular landscape variables? Do lowland and mountain areas differ in effects of landscape variables on species composition? Location: Southern Czech Republic. Methods: A total of 240 vegetation relevés of floodplain forests with measured site conditions were recorded across six physiographic areas. I tested how physiographic area, habitat quality variables and landscape variables such as current land-cover categories, forest continuity, forest size and urbanization influenced plant species composition. I also compared how mountain and lowland areas differ in terms of the relative importance of these variables. To determine how landscape configuration affects the distribution of species traits, relationships of traits and species affinity with landscape variables were tested. Results: Among landscape variables, forest continuity, landscape forest cover and distance to nearest settlement altered the vegetation. These variables also influenced the distributions of species traits, i.e. life forms, life strategies, affinity to forest, dispersal modes, seed characteristics, flooding tolerance and Ellenberg indicator values for nitrogen, light, moisture and soil reaction. Nevertheless, physiographic area and habitat quality variables explained more variation in species composition. Landscape variables were more important in lowland areas. Forest continuity affected species composition only in lowlands. Conclusions: Although habitat quality and physiographic area explained more vegetation variability, landscape configuration was also a key factor influencing species composition and distribution of species traits. However, the results are dependent on forest geographical location, with lowland forests being more influenced by landscape variables compared to mountain forests.