Abstract Boreal forests cover nearly one‐third of global forest area. Glacial cycles have shaped the distribution and connectivity of modern Pinaceae genera, yet species‐level refugia, postglacial migrations, and hybridization patterns remain unclear due to limited high‐resolution taxonomic and temporal data. We applied a hybridization capture approach targeting complete chloroplast genomes of Abies, Larix, Picea, and Pinus to sedimentary ancient DNA (sedaDNA) from 238 samples across 19 sediment records spanning the last 40,000 years from Europe, Asia, and Alaska. Methodological improvements enhanced sequencing depth and genome coverage, enabling detection of low‐abundance taxa and the establishment of semiquantitative conifer time series. Population dynamics were inferred from single‐nucleotide‐polymorphism (SNP)‐based species identification, admixture analysis, and haplotype network reconstruction. Previously undocumented glacial refugial Pinaceae populations were identified in western Taymyr, southern Yakutia, and Far East Siberia. Postglacial recolonization began with Larix as a pioneer during the Late Glacial, followed by Picea and Pinus in subsequent warming phases. On the eastern Tibetan Plateau, Picea asperata and Picea purpurea were dominant. Postglacial Pinaceae dynamics across Europe showed early dominance of Pinus sylvestris in high latitude (Kola Peninsula) and Pinus cembra and Pinus mugo in alpine regions (Swiss and Dinaric Alps) from the Late Glacial, later replaced primarily by Picea abies, which dominated in Czechia, southwestern Russia, and possibly southern Sweden, while Pin. sylvestris remained dominant in northern Germany. We also identified undocumented populations, including a potential hybrid spruce, possibly Picea fennica, expanding in the Kola Peninsula during the Early Holocene, and scattered Larix decidua populations across Europe in the Early and Middle Holocene. In the Dinaric Alps, Picea populations shifted from eastern to western lineages during the Younger Dryas–Holocene transition. In south‐central Alaska, Picea glauca colonized early and expanded in the Late Holocene. Additionally, we documented potential hybridization zones across Europe between Pic. abies and Picea obovata, Abies sibirica and Abies alba, and L. decidua and Larix sibirica, as well as admixture among Larix species and between Pinus sibirica and Pinus pumila in Siberia. In conclusion, hybridization capture of sedaDNA provided high‐resolution insights into past Pinaceae dynamics in Eurasia, supporting future paleogenomic research and forest restoration management.

ABSTRACT Aim Theories on ecological stability lack the long‐term observational data necessary to comprehend the dynamics of durable and complex ecosystems like forests; consequently, the influence of biodiversity on ecosystem stability remains predominantly unexplained. This study examines the mechanisms of forest community and tree population change using long‐term palaeoecological data, evaluates responses to diverse effects, assesses stability and identifies the conditions that compelled these ecosystems to transition into alternative states. Furthermore, we aim to test whether higher diversity and larger populations promote stability. Location Central Europe. Taxon Tracheophytes (spore and pollen‐producing vascular plants). Methods We analyse a 12,000‐year lacustrine sedimentary record from a mountain lake Černé jezero, located in a spruce‐dominated temperate mountain ecosystem in the Bohemian Forest of Central Europe, utilizing various proxies such as pollen, charcoal and geochemical data. We examined accumulation rates, ecological indices, and climatic and regression models to evaluate biodiversity, disturbances, rates of change, population stability and climate dynamics to identify the drivers of these changes. Results Our findings indicate that species richness is negatively correlated with tree population stability. Furthermore, we discovered that tree population growth does not always facilitate stability as theorized. Main Conclusions As mountain forests encounter escalating pressures from climate change and anthropogenic influences, our findings suggest that competition and turnover among species can undermine tree population‐level resilience. Our results also emphasize the necessity of preserving species diversity while acknowledging the potential emerging threats to forest population stability.

The growing uncertainty about the impacts of climate change and increasing disturbances on terrestrial ecosystems highlights the need to evaluate their resilience. Old-growth forests are particularly vulnerable to these changes. This study explores the dynamics and ecological resilience over the last 2700 years in an old-growth beech forest in the Eastern Carpathians, employing a multiproxy approach integrating pollen analysis, macro charcoal influx, fungal spores, and biomarkers. The research focuses on how vegetation reacted to disturbances (fire, fungal outbreaks, and human-related activities) and its response to these changes. The sedimentary record from Lake Morské oko reveals a stable forest community dominated by beech under low disturbance regimes, characterised by fires and fungal outbreaks. However, an increase in human impact around 1150 cal yr BP, shown by macro-charcoal influx and coprophilous fungi spores, introduced grazing and fire practices that shifted forest composition towards stress-tolerant and light-demanding species like birch and hazel. Despite the forest's resilience and partial recovery following reduced disturbances, modern pressures, such as climate change, fires, and prolonged anthropogenic impact, have further shifted the species composition of this community. The findings highlight the high ecological resilience of old-growth forests under low to moderate disturbances while also emphasising their susceptibility to intensified human activity, fires and climate change. This research highlights the importance of conservation strategies that mitigate human pressure and prioritise the regeneration of late-successional species such as beech. Findings from this long-term ecological analysis provide direction for the management and protection of these ecosystems against global environmental change.

Tropical peatlands are one of the most carbon-dense ecosystems on Earth. However, their long-term resilience to climate and environmental changes, including fire events, remains poorly understood and is understudied compared to boreal and temperate peatlands. This study represents the first palaeoenvironmental research conducted on the peatlands of Guyana, addressing a critical knowledge gap in understanding the long-term dynamics of tropical peatland ecosystems in this region. Further knowledge of these dynamics is essential for understanding the vulnerability of these ecosystems in the face of climate change and increasing anthropogenic disturbances.This study investigates the fire history of peatlands in Guyana by analysing charcoal and radiocarbon data from two peat cores. Fieldwork involved the collection of cores from various sites in Guyana, representing different hydrological and vegetation conditions. Charcoal analysis is being conducted to quantify fire events, identifying both their frequency and intensity over time. Radiocarbon dating has been used to establish basal dates of peat accumulation in the two cores, of 970 and 6450 years. Higher resolution radiocarbon dating is being used to establish a chronological framework for fire episodes, enabling the reconstruction of long-term fire history. Complementary analyses, including organic matter characterisation through thermogravimetric analysis, provide additional context on how fire events may have influenced peat composition and carbon storage. Preliminary observations suggest the presence of charcoal-rich layers within the peat cores, indicating continued fire activity over time with varying intensity. These layers vary between the two sites, suggesting localised differences in fire history. These are potentially driven by differing vegetation types, hydrological conditions, or human influence. By the time of conference, we anticipate presenting a timeline of fire episodes, linked to rates of peat accumulation and potential environmental drivers such as shifts in climate or human land use.This research provides critical insights into the role of fire in tropical peatland development, offering a unique perspective on the interactions between fire, carbon accumulation, and ecosystem dynamics in this under-researched region. The findings have significant implications for the conservation and management of tropical peatlands, emphasising the need to consider historical fire regimes when predicting future ecosystem resilience/vulnerability. Overall, this study contributes to the broader understanding of tropical peatlands as dynamic carbon reservoirs that are increasingly threatened by global environmental change.

Norway spruce is one of Europe’s most significant trees, with a millennia-long role crucial for maintaining values of forests. Yet its migration, especially at its current range limits, is not fully understood. The paper presents the results of palynological research on the temporal spread of spruce in NE Poland between ca. 5500–2300 cal BP. The significance of our study lies in the fact that we used pollen records to reconstruct the vegetation using both pollen percentages and a quantitative vegetation reconstruction (REVEALS) model for the first time in this region of Poland. Based on percentage pollen data, we have shown that due to the specificity of the studied sites and local conditions, the migration process may not have been synchronous. However, using the REVEALS model allowed us to determine time intervals for the entire study region where the spruce spread and retreated, along with the correlation of these changes with climate change and human impact on vegetation. Spruce increased its importance ca. 5500 cal BP, and at ca. 5300–5100 cal BP it has been a part of the local stands, which may have been related to the 5.2 ka cooling. The next impulse for the spread of spruce was the 4.8 ka cold event. Another increase in the spruce area begins at ca. 4300–4100 cal BP and was probably associated with 4.2 ka event. Conditions promoting the spread of spruce also occurred at ca. 3500–3300 cal BP and were synchronous with the climate oscillation dated at ca. 3400 cal BP. The role of spruce decreased at 2900–2700 cal BP. It may have been caused by anthropogenic factors despite the climate event of 2.8 ka. Then, spruce was more common, about 2700–2500 cal BP, during periods of stronger anthropogenic pressure associated with intensified colonization at the end of the Bronze Age.

Palaeoecological reconstructions in the Carpathians have primarily focused on the western and south-eastern mountain ranges, leaving a significant gap in our understanding of the central region along the SlovakUkrainian borders. This study investigated Lake Morske oko (Vihorlat Mts., Eastern Slovakia), whose origin has been debated. Using a multiproxy approach that combines hydro-acoustic surveys, sedimentological analysis, biomarker-based organic geochemistry, and pollen analysis, we confirm that the lake formed when a landslide from the eastern slopes of Motrogon and Jedlinka hills dammed the Okna valley shortly before 2780 cal a BP, coinciding with a documented wet period across Europe. Our record reveals a remarkably stable lake system that evolved from being dominated by terrestrial organic input to enhanced in-lake production after 1850 cal a BP. Our quantitative temperature and humidity reconstructions, the first in the region, capture major climatic episodes, including the end of the "2.8 ka event", Roman Warm Period, and Mediaeval Climate Anomaly, during which there was likely increased lake water thermal stratification or reduced connectivity with the catchment. The Little Ice Age period is marked by temperature fluctuations corresponding to the Maunder and Dalton minima. Human influence becomes evident from 1100 and 700 cal a BP through increased Cerealia-type pollen and atmospheric lead deposition from regional mining activities. This study provides a continuous, well-dated Late Holocene palaeoenvironmental record spanning nearly 3000 years from this region of the Carpathians, bridging a crucial gap between western and eastern records while definitively confirming the lake's origin from a landslide.

Central European mountains, including the Sumava Mountains located along the Czechia/Germany border, have a long and rich anthropogenic history. Yet, documenting prehistoric human impact in Central European mountain environments remains a challenge because of the need to disentangle climate and human-caused responses in terrestrial systems. Here, we present the first reconstructed water table depths (WTDs) from two sites, Pekna and Blatenska slat, located in the Sumava Mountains. We compare these local WTD records with new and published pollen, non-pollen palynomorphs (NPPs), plant macrofossils, geochemistry and archeological records to investigate how changes in local hydrology and human activities impacted forest succession and fire activity throughout the Holocene across an elevational gradient. Using a generalized additive model, our results suggest that changes in forest succession and fire activity have been primarily caused by climate throughout the Holocene. However, humans have been utilizing mountain environments and their resources continuously since similar to 4600 cal yr BP, thus playing a secondary role in modifying forest succession to increase resources beneficial to both humans and grazers. Over the last 1000 years, we provide evidence of directly observed human-caused modifications to the landscape. These results contribute to a growing body of literature illustrating human activities and landscape modifications in Central European mountains.

The projected rise in fire activity due to climate change challenges forest conservation efforts worldwide. Current non-intervention approaches, which rely on natural processes for ecosystem conservation, often overlook palaeoecological data depicting long-term, local interactions between fire regime components, forest structure and composition, soil, aquatic environment and anthropogenic disturbance. To explore whether palaeoecological information supports non-intervention strategies in the Picea abies - Fagus sylvatica - Abies alba closed temperate mountain forest under future fire risks, we conducted a multi-proxy, retrospective analysis (charcoal morphology, pollen, plant macro-remains, sedimentology, palaeoclimate models) on a Holocene lacustrine archive located in the Bavarian Forest National Park, Germany. Results show that climate shifts directly induced vegetation reorganizations and fire regime changes around 11.1, 9.3 and 7-6 ka BP, and gradually allowed the expansion of closed mixed forests dominated by the late successional Picea abies - Fagus sylvatica - Abies alba under a remarkably stable, low-fire environment. We emphasize the possible role of shade-related traits of these species as key bottom-up drivers of biomass burning over the past 6000 years likely due to their effects on microclimate, offsetting the species-specific fire traits. Although these forests tolerate low-severity surface fire, more subtle impacts were identified at the level of soil cover and lacustrine environment. First, our data demonstrate that lake browning processes developed naturally since the Early Holocene with the progression of chemical weathering and podzol formation, but an ecological threshold due to browning intensification was crossed ca. 6000 years ago, under maximum forest density and in the absence of fire disturbance. Second, fire likely reduced lake water browning and soil podzolisation processes by mineral erosion and the decrease in litter and soil organic matter due to direct burning or indirect aeration. Soil and aquatic ecosystem components appeared highly interconnected and responded even to low disturbance severities. Consequently, these components may react more sensitively to the predicted increase in fire frequency and severity, with yet unknown ripple effects on the forest ecosystem resilience. Given the critical role of the Picea abies - Fagus sylvatica - Abies alba closed-canopy forests in shaping the microclimate and catchment-lake interactions, our study suggests that non-intervention strategies are suitable for preserving ecosystem stability in these types of forests. By promoting natural recovery of shade-tolerant tree species and minimizing direct anthropogenic impacts, this approach would protect the soil, regulate erosion and delivery of soil organic substances, and potentially mitigate the effects of climate change on fire hazard and on individual forest tree species.

Multi-proxy temperature reconstructions can provide robust insights into past environmental conditions. By combining different proxies we can disentangle the temperature signal from the indirect climate effects on the environment. This study uses a multi-proxy approach to reconstruct temperature and palaeoenvironmental conditions during the Late Glacial and Early Holocene (13.5-8 cal. ka BP) in the Bohemian Forest, Central Europe. We assessed the similarity of the temperature signal based on chironomids, isoprenoid glycerol dialkyl glycerol tetraether lipids (isoGDGTs), and pollen within a comparison with locally modeled temperature data generated by the CHELSA_Trace21k dataset. Pollen, macroscopic charcoal remains, and geochemistry were further used to reconstruct past environmental conditions such as vegetation dynamics, fire activity, the input of lithogenic material (Titanium), nutrient content (Total Nitrogen) and the sources of organic matter (C/N and delta 13Corg). All temperature reconstructions based on independent proxies were positively correlated and followed the same long-term trend. However, results also showed that chironomids-inferred July temperature had lower amplitude variations compared to the other temperature curves. IsoGDGTs showed the most pronounced decrease in temperature values at the onset of the Younger Dryas (YD), corroborating that this cooling event was more marked during winter than summer. However, a decrease of less than 1 degrees C during summer and two shortterm warm events at 12.6 and 12.2 cal ka BP provoked a modest and asynchronous response of the vegetation to the onset of the YD. Nevertheless, isoGDGTs appeared to react to changes in both temperature and organic carbon sources, particularly between 11.2 and 10.6 cal yr BP. These environmental changes, characterized by high values of the GDGT-0/crenarchaeol ratio, recorded an increase in methanogenic activity in the lake sediments, which likely altered the recorded climatic signal. The corresponding anoxic episodes in the lake sediments might be caused by an increasing input of organic carbon from the catchment, related to the development of the vegetation and catchment soils at the beginning of the Holocene. Finally, pollen-based temperature reconstruction showed a lag in the response to major climatic events, such as the onset of YD and Holocene. Our study increases the understanding of the climate-vegetation-environmental feedback during the Late Glacial and Early Holocene in the Bohemian Forest, Central Europe.

The shift towards cultivating domesticated crops was a pivotal development in ecological, economic, and human behavioural systems. As agriculture expanded beyond its origins, it faced diverse environments, often unsuitable for the originally cultivated domesticates. Farmers in Central Europe had to adjust and transform their farming systems, typically cultivating only five domesticated crop species. Here, we present new archaeobotanical data comprising 7955 determined charred remains and 22 radiocarbon dates from South Bohemia. This region, with higher altitudes, colder climates, and less fertile soils, lies on the periphery of Early Neolithic settlement. Our results reveal increased crop diversity as a form of adaptation to the harsher environment that bolstered resilience against crop failure. The earliest 14C-based evidence of deliberate cultivation of barley and Timopheev's wheat in the region also provides new insights into the interplay between crop diffusion, landscapes, and food choices in the Neolithic Central Europe.

Remote islands harbour many endemic species and unique ecosystems. They are also some of the world's most human-impacted systems. It is essential to understand how island species and ecosystems behaved prior to major anthropogenic disruption as a basis for their conservation. This research aims to reconstruct the original, precolonial biodiversity of a remote oceanic island to understand the scale of past extinctions, vegetation changes and biodiversity knowledge gaps. We studied fossil remains from the North Atlantic island of Corvo (Azores), including pollen, charcoal, plant macrofossils, diatoms and geochemistry of wetland sediments from the central crater of the island, Caldeira similar to o. A comprehensive list of current vascular plant species was compiled, along with a translation table comparing fossilized pollen to plant species and a framework for identifying extinctions and misclassifications. Pollen and macrofossils provide evidence for eight local extinctions from the island's flora and show that four species listed as 'introduced' are native. Up to 23 % of the pollen taxa represent extinct/misclassified species. Corvo's past environment was dynamic, shifting from glacial -era open vegetation to various Holocene forest communities, then almost completely deforested by fires, erosion and grazing following Portuguese colonisation. Historical human impacts explain high ecological turnover, several unrecorded extinctions and the present-day abundance of vegetation types like Sphagnum blanket mire. We use Corvo as a case study on how fossil inventories can address the Wallacean and Hookerian biodiversity knowledge gaps on remote islands. Accurate baselines allow stakeholders to make informed conservation decisions using limited financial and human resources, particularly on islands where profound anthropogenic disruption occurred before comprehensive ecological research.

Temperate forests in the Northern Hemisphere are strongly affected by increasing annual temperatures and natural disturbances such as droughts, fires, and pest outbreaks. In many regions, alternatives are explored by the forestry industry for previously commercialized tree species which are rapidly declining in areas outside their optimal climatic niches. However, as the current ranges of tree species have been mainly constrained by human activity, their true climatic and ecological niches are likely different from our observations. For example, little is known about environmental niches and population dynamics of tree species with limited dispersal ability, such as silver fir (Abies alba). Long-term (paleo) records of past landscape composition, past climate, and past disturbances can help to reveal the natural environmental niches of tree species. This study focuses on the Bohemian Forest (Sumava) in Czechia, where the human alteration of forests in higher elevations (>1000 m asl) has only been demonstrated from Medieval times onward. We present an interdisciplinary approach of geochemistry, pollen, charcoal, botanical and insect macro remains from a high-elevation peat record for the last seven millennia. Our multi-proxy study aimed to identify episodes of increased fire and other disturbances such as insect outbreaks, which could have influenced forest dynamics and vegetation succession in this montane region. However, the charcoal and macro-fossil records do not indicate any large local fires, insect outbreaks, browsing, or other disturbances (e.g., anthropogenic) for a major part of the record, suggesting that changes in the vegetation after 6500 cal yr BP were mainly caused by climatic fluctuations. Silver fir (Abies alba) expanded from 4300 cal yr BP, and likely became the dominant tree species at this locality for the next 2000 years, with extremely high pollen values up to 60%. During the establishment of silver fir around the peat bog around 5600 cal yr BP and its expansion around 4300 cal yr BP, the geochemical record and low counts of the testate amoeba Archerella flavum indicate drier conditions on the peat bog. Comparison with climatic simulations on a 1 x 1-km scale from the CHELSA database suggests that the local expansion of silver fir possibly coincided with a decrease in precipitation during both the wettest and warmest quarter of the year, related to a decreasing trend in seasonality of annual precipitation; this might confirm the species' higher tolerance to drought. Although silver fir is currently extremely rare in the Bohemian Forest, it has the potential for local expansion if logging, fire, and game browsing are kept to a minimum.

Rhododendron tomentosum is a vascular plant common in northern regions of Europe, Asia and North America. In central Europe, this species is considered a glacial relict. In recent years, systematic floristic mapping of the distribution of this species in the Bohemian Switzerland National Park has revealed that this rare and highly sensitive species is strongly associated with a specific type of habitat. Rhododendron tomentosum adapted to environmental changes throughout the Holocene: soil acidification, repeated fires and negative effect of forestry on species composition. To identify the survival mechanisms of R. tomentosum, suitable sites in well-preserved parts of a sandstone landscape with assumed minimal human influence were selected. Based on data from intensive field sampling and a set of environmental variables for the whole area of the National Park, habitat suitability maps for R. tomentosum were developed. These maps were then combined with the palaeoecological data and used to identify sources of pollen with greater precision and extend the knowledge of the potential distribution of R. tomentosum outside the intensively sampled areas. Palaeoecological data was particularly useful for reconstructing the past population dynamics of R. tomentosum. The results indicate the long-term stability of sites suitable for this species, supported by locally diversified vegetation development in sandstone areas. This research could therefore provide the first direct evidence of the persistence of R. tomentosum micropopulations throughout a large part of the Holocene.

Aim: In recent decades, a surge in the number of significant and uncontrolled wildfires has occurred worldwide. Global warming may amplify this trend and threaten most ecosystems worldwide. Deciduous forests are characterized by high plant diversity, and understanding their long term dynamics is crucial to anticipate changes in these ecosystems during ongoing global warming. The aim of this study is to understand how European beech forests have colonized the inner Eastern Carpathians and how changes in fire regime and human activities have affected their biodiversity.Location: Inner Eastern Carpathian Mountains, Slovakia.Taxon: Plantae, gymnosperms, angiosperms.Methods: Peat core was extracted from the centre of Durova mlaka mire in 2018. A multi proxy approach has been applied to investigate the development of beech forest. Charcoal analysis has been done each centimetre to reconstruct the fire signal. Pollen analysis has been done at 2 cm resolution to reconstruct the vegetation composition and dynamics, and the variation in palynological richness (PRI), evenness and turnover has been analysed. Macro-remains analysis has been performed at 10 cm resolution to add more information about the local vegetation.Results: Low diversity spruce forest was dominant until 5200 cal. BP during a fire prone period due to specific climatic conditions (drier climate than the following period). The higher fire frequency and intensity following this period is simultaneous with the first expansion of Fagus which indicate that Fagus could occupy post fire habitats, at least at the local scale. However, its dominance coincided with major gaps in fire events from 3900 cal. BP. The PRI has increased during the transition from spruce to beech forest highlighting the importance of beech forests in maintaining plant biodiversity. However, the stronger increase in the richness is synchronous with the increase in human activities around 2000 cal. BP, and then 350 cal. BP.Main Conclusions: Climate-driven fire frequency has been a natural driver of vegetation changes in the Carpathians by promoting the emergence of high diversified beech forest. These changes were significantly modified by later increase in human activities.

Analysis of phytoliths (plant silica bodies) still may have an unrevealed potential in paleoenvironmental reconstruction studies. This can provide novel findings in research on environmental change as phytoliths play an important role in the silicon biogeochemical cycle. In favorable environmental conditions, Picea abies [L.] H. Karst (Norway spruce) needles develop a phytolith layer consisting of more or less cubical or cuboid (blocky) phytoliths in their transfusion tissue that becomes continuous toward the apex of the needle. This can be studied in situ in fossil (subfossil) needles under a stereomicroscope. This study reports the blocky-type phytolith preservation in fossil spruce needles in sediment sections of the lake Černé jezero (Bohemian Forest, Czech Republic). The oldest needle containing phytoliths was 7.8 cal ka BP. Despite differences in the Energy Dispersive X-ray (EDX) spectra of different age phytoliths, the studied subfossil phytoliths did not lose their globular ultrastructure in the needle tissue, proving the stability of this phytolith morphotype. As the tissue of the needle fossils can preserve phytoliths in situ, further micro-analytical measurements will make these needles promising tools for paleoenvironmental reconstructions. The most favorable period for spruce phytolith formation for the studied region appears to be the period 6.0–4.5 cal ka BP, within the Holocene Climate Optimum period. In order to use these phytoliths as a terrestrial climate proxy, the next step is to refine their sensitivity to environmental changes.

The extent of vegetation openness in past European landscapes is widely debated. In particular, the temperate forest biome has traditionally been defined as dense, closed-canopy forest; however, some argue that large herbivores maintained greater openness or even wood-pasture conditions. Here, we address this question for the Last Interglacial period (129,000-116,000 years ago), before Homo sapiens-linked megafauna declines and anthropogenic landscape transformation. We applied the vegetation reconstruction method REVEALS to 96 Last Interglacial pollen records. We found that light woodland and open vegetation represented, on average, more than 50% cover during this period. The degree of openness was highly variable and only partially linked to climatic factors, indicating the importance of natural disturbance regimes. Our results show that the temperate forest biome was historically heterogeneous rather than uniformly dense, which is consistent with the dependency of much of contemporary European biodiversity on open vegetation and light woodland.

Mitigating the effects of global change on biodiversity requires its understanding in the past. The main proxy of plant diversity, fossil pollen record, has a complex relationship to surrounding vegetation and unknown spatial scale. We explored both using modern pollen spectra in species-rich and species-poor regions in temperate Central Europe. We also considered the biasing effects of the trees by using sites in forests and open habitats in each region. Pollen samples were collected from moss polsters at 60 sites and plant species were recorded along two 1 km-transects at each site. We found a significant positive correlation between pollen and plant richness (alpha diversity) in both complete datasets and for both subsets from open habitats. Pollen richness in forest datasets is not significantly related to floristic data due to canopy interception of pollen rather than to pollen productivity. Variances (beta diversity) of the six pollen and floristic datasets are strongly correlated. The source area of pollen richness is determined by the number of species appearing with increasing distance, which aggregates information on diversity of individual patches within the landscape mosaic and on their compositional similarity. Our results validate pollen as a reconstruction tool for plant diversity in the past.

Water brownification has long altered freshwater ecosystems across the northern hemisphere. The intensive surface water brownification of the last 30 years was however preceded by previous long-lasting more humic browning episodes in many catchments. To disentangle a cascade of browning-induced environmental stressors this longer temporal perspective is essential and can be reconstructed using paleolimnological investigations. Here we present a Holocene duration multi-proxy paleolimnological record from a small forest mountain lake in the Bohemian Forest (Czechia) and show that climate-related soil saturation and peatland development has driven surface water brownification for millennia there. A long core retrieved from the central part of the lake was dated using 14C and 210Pb, subsampled and analyzed for diatoms and zoological indicator (chironomids, planktonic cladocerans) remains. X-ray fluorescence (XRF) provided a record of elements sensitive to biogeochemical processes connected to browning and catchment development (P, Ti, Al/Rb, Fe/Ti, Mn/Ti, Si/Ti). Three threshold shifts related to the processes of water browning were detected in both diatom and chironomid successions at ~10.7, ~5.5 and ~4.2 cal. ky BP. Since, postglacial afforestation of the catchment ~10.7 cal. ky BP the lake experienced strong thermal stratification of the waters, but after ~6.8 cal. ky BP soil saturation and expansion of peatlands led to effective shading and probable nutrient limitation within the lake ecosystem. The more intensive in-wash of dissolved organic matter appears to decline after ~4.2 cal. ky BP, when the paludified catchment soils became permanently anoxic. Two temporary negative and positive anomalies of browning progress occur at the same time and may be connected with the "8.2 ka event" and the "4.2 ka event", respectively. The key role of peatlands presence in the catchment was manifested in millennial-scaled browning process and a climatic forcing of long-lasting browning is evidenced by coincidence with the moistening of climate across the northern hemisphere after ~6 cal. ky BP.

Temperate mountain forests have experienced an increase in frequency and severity of natural disturbances (e.g., droughts, fires, windstorms and insect outbreaks) in recent decades due to climate and environmental change. Outbreaks of bark beetles have caused significant dieback of conifer forests in Central Europe and it is essential to model and predict the potential severity of future bark beetle outbreaks. However, to predict future bark beetle activity, historical baseline information is required to contextualize the magnitude of current and potential future outbreaks. A fossil beetle record from a forest hollow in the Tatra Mountains, Slovakia; one of the best-preserved national parks in Central Europe, was produced to identify insect outbreaks during the last millennia. Sub-fossil bark beetle remains were compared with parallel pollen and charcoal to assess whether peaks in conifer bark beetle remains correspond with indications of disturbance documented in historical or sedimentary fossil records. Three peaks in bark beetle remains were detected (1) post-2004, (2) AD 1140-1440, and (3) AD 930-1030. The abundance of species Pityogenes chalcographus and Pityophthorus pityographus in the two top samples can be linked directly to large bark beetle outbreaks in the High Tatra Mountains after 2004. P. chalcographus and P. pityographus are also the abundant species in the second peak (AD 1140-1440) while the third peak (AD 930-1030) consists of the species Polygraphus poligraphus. The most prominent conifer bark beetle in Central Europe, Ips typographus, was found to be present in most of the samples but always at very low numbers. It is plausible that P. chalcographus and P. pityographus fossils might be useful proxies for past conifer bark beetle outbreaks in Central Europe, as they occur together with fossils of I. typographus but appear to be well-preserved. A significant correlation was found between primary bark beetles and macroscopic charcoal densities in the sediment, highlighting the complex interactions between disturbance agents, bark beetles and fire, in this long-term regime of natural disturbances. Our 1400-year disturbance record shows how bark beetle outbreaks have been an important component of the regional natural disturbance regime for over a millennium and have intensified with increasing anthropogenic activity. Bark beetle outbreaks are likely one of the drivers promoting the future ecological stability of the temperate conifer ecosystem over decades to centuries. (C) 2021 Elsevier Ltd. All rights reserved.

Recent catastrophic fires in Australia and North America have raised broad‐scale questions about how the cessation of Indigenous burning practices has impacted fuel accumulation and structure. For sustainable coexistence with fire, a better understanding of the ancient nexus between humans and flammable landscapes is needed. We used novel palaeoecological modeling and charcoal compilations to reassess evidence for changes in land cover and fire activity, focusing on southeast Australia before and after British colonization. Here, we provide what we believe is the first quantitative evidence that the region’s forests and woodlands contained fewer shrubs and more grass before colonization. Changes in vegetation, fuel structures, and connectivity followed different trajectories in different vegetation types. The pattern is best explained by the disruption of Indigenous vegetation management caused by European settlement. Combined with climate‐change impacts on fire weather and drought, the widespread absence of Indigenous fire management practices likely preconditioned fire‐prone regions for wildfires of unprecedented extent.