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For assessment of the potential of the Beppu Bay sediments as a Global boundary Stratotype Section and Point (GSSP) candidate for the Anthropocene, we have integrated datasets of 99 proxies. The datasets for the sequences date back 100 years for most proxy records and 1300 years for several records. The cumulative number of occurrences of the anthropogenic fingerprint reveal unprecedented increases above the base of the 1953 flood layer at 64.6 cm (1953 CE), which coincides with an initial increase in global fallout of 239Pu+240Pu. The onset of the proliferation of anthropogenic fingerprints was followed by diverse human-associated events, including a rapid increase in percent modern 14C in anchovy scales, changes in nitrogen and carbon cycling as recorded by anchovy δ15N and δ13C, elevated pollution of heavy metals, increased deposition of novel materials (spheroidal carbonaceous particles, microplastics, polychlorinated biphenyls), the occurrence of hypoxia (Re/Mo ratio) and eutrophication (biogenic opal, TOC, TN, diatoms, chlorophyll a), unprecedented microplankton community changes (compositions of carotenoids, diatoms, dinoflagellates), abnormally high spring air temperatures as inferred from diatom fossils, and lithological changes. These lines of evidence indicate that the base of the 1953 layer is the best GSSP level candidate in the stratigraphy at this site.

This research has been supported by the Leverhulme Trust (grant no. RC-2018-023), the European Research Council (grant no. 694481), the German Research Foundation (grant no. FE-1096/6-1), the Swiss Government Excellence Postdoctoral Scholarships (grant no. FIRECO 2016.0310), the National Science Centre of Poland (grant no. 2015/17/B/ST10/01656), the SCIEX Scholarship Fund (grant no. PSPB-013/2010), and the Estonian Research Council (grant no. MOBJD313)., Sedimentary charcoal records are widely used to reconstruct regional changes in fire regimes through time in the geological past. Existing global compilations are not geographically comprehensive and do not provide consistent metadata for all sites. Furthermore, the age models provided for these records are not harmonised and many are based on older calibrations of the radiocarbon ages. These issues limit the use of existing compilations for research into past fire regimes. Here, we present an expanded database of charcoal records, accompanied by new age models based on recalibration of radiocarbon ages using IntCal20 and Bayesian age-modelling software. We document the structure and contents of the database, the construction of the age models, and the quality control measures applied. We also record the expansion of geographical coverage relative to previous charcoal compilations and the expansion of metadata that can be used to inform analyses. This first version of the Reading Palaeofire Database contains 1676 records (entities) from 1480 sites worldwide. The database (RPDv1b – Harrison et al., 2021) is available at https://doi.org/10.17864/1947.000345., Leverhulme Trust RC-2018-023, European Research Council (ERC) European Commission 694481, German Research Foundation (DFG) FE-1096/6-1, Swiss Government Excellence Postdoctoral Scholarships FIRECO 2016.0310, SCIEX Scholarship Fund PSPB-013/2010, Estonian Research Council MOBJD313

Sedimentary charcoal records are widely used to reconstruct regional changes in fire regimes through time in the geological past. Existing global compilations are not geographically comprehensive and do not provide consistent metadata for all sites. Furthermore, the age models provided for these records are not harmonised and many are based on older calibrations of the radiocarbon ages. These issues limit the use of existing compilations for research into past fire regimes. Here, we present an expanded database of charcoal records, accompanied by new age models based on recalibration of radiocarbon ages using INTCAL2020 and Bayesian age-modelling software. We document the structure and contents of the database, the construction of the age models, and the quality control measures applied. We also record the expansion of geographical coverage relative to previous charcoal compilations and the expansion of metadata that can be used to inform analyses. This first version of the Reading Palaeofire Database contains 1681 records (entities) from 1477 sites worldwide. The database (DOI: 10.17864/1947.319) is available from https://researchdata.reading.ac.uk/id/eprint/319.

Aeolian dust coming from arid regions of inland China supplies mineral resources to Japanese Islands. While annual deposition rate is as small as 5~10 g m-2 yr-1, total amount of deposition since the last glacial period can form soil layers with several meters depths. We focused on the mineral fertilization effect of aeolian dust on terrestrial ecosystems in Japan. The deposition and incorporation of dust-derived micaceous mineral into soil through time is our special interest because this mineral has an exceptionally higher ability to retain radiocesium than the others, thereby contributing to reduce soil-to-plant transfer of radiocesium after the Fukushima-Daiichi nuclear power Plant accident. However, little study has focused on aeolian dust as a controlling factor of radiocesium dynamics in soils. In this study, peat-core samples collected from the Kamiyoshi (KMY) basin in Kyoto, Japan was used to obtain the aeolian dust that had been deposited on land during the last glacial period. The KMY core with depth from 9.40 to 8.20 m (corresponding to 75 ka to 68 ka) was horizontally divided into 21 portions. The subdivided samples were treated with H2O2 to decompose organic matters and then size-fractionated to obtain 18O value. We found that the 18O values of 16.8±0.3‰, quite similar to those of loess or aeolian dust previously reported. All these properties strongly indicate the origin of the -2 yr-1 to 15.7 g m-2 yr-1 and highly associated with paleoclimate estimated by the pollen record. Namely, the higher aeolian dust flux was observed at colder and drier paleoclimate as indicated by the higher proportion of pinaceous conifer pollen. We conclude that associative analysis of mineral and pollen record in the peat-core can be a promising method to trace the long term deposition pattern of aeolian dust in terrestrial ecosystems in Japan.

This study examined the orbital-scale vegetation response to seasonal climate changes related to the East Asian monsoon and ocean currents during the last glacial–interglacial cycle based on a new continuous pollen record from Lake Biwa, western Japan. During MIS 6, 4, and 2, pinaceous conifer forests were present in both inland and Japan Sea coastal areas around Lake Biwa, influenced by cold and dry conditions in both summer and winter. In contrast, deciduous broadleaved forests and evergreen forests grew during interglacial periods in MIS 5e and 1 under relatively warm and humid conditions in summer, as well as in winter. Fagus crenata , a tree endemic to the Japanese archipelago, was especially widely distributed during MIS 5e due in part to winter snowfall caused by warm current inflows in the Sea of Japan. During MIS 5 and 3, temperate conifer trees were dominant. During periods of low summer insolation in MIS 5, the endemic tree Cryptomeria japonica became dominant in both inland and coastal areas of the region, likely as a result of high precipitation in early summer related to southward shifts of the summer monsoon front and moderate winter climate conditions. In contrast, Sciadopitys verticillata , which is also an endemic tree, had own habitat around inland areas of western Japan during the periods of high summer insolation in MIS 5. Climate fluctuations during the glacial–interglacial cycles created several ecological niches in time and space for each endemic tree in the Japanese archipelago.

Grassland ecosystems worldwide have been extensively converted to other land uses and are globally imperiled. Because many grasslands have been maintained by human activities, understanding their origin and history is fundamentally important to better contemporary management. However, existing methods to reconstruct past vegetation can produce contrasting views on grassland history. Here, we inferred demographic histories of 40 populations of four grassland forb species throughout Japan using high-resolution genome sequences and model-flexible demographic simulation based on the site frequency spectrum. Although two species showed a slight decline in population size between 100 000-10 000 years ago, our results suggest that population sizes of studied species have been maintained within the range of 0.5-2.0 times the most recent estimates for at least 100 000 years across Japan. Our results suggest that greater than 90% declines in Japanese grasslands and subsequent losses of grassland species in the last 100 years are geologically and biologically important and will have substantial consequences for Japanese biota and culture. People have had critical roles in maintaining disturbance-dependent grassland ecosystems and biota in this warm and wet forested country. In these contexts, disturbances associated with forest harvesting and traditional extensive farming have the potential to maintain grassland ecosystems and can provide important opportunities to reconcile resource production and conservation of grassland biodiversity., 日本で草地が10万年以上維持されてきたことを実証 --近年の草地の激減は地質学的時間スケールで大きな出来事--. 京都大学プレスリリース. 2019-05-30.

Concern is growing that global climate change will have widespread impact on the world’s terrestrial ecosystems, but future impacts are imperfectly constrained by ecosystem models and direct observations. All available data, including records of past ecological change, need to be utilized to assess the range of potential future outcomes. Here we show that pervasive ecosystem transformations occurred in response to warming and associated climatic changes during the last glacial-to-interglacial transition, which was of comparable magnitude to climatic change projected to occur in the next 100 to 150 years under high-emission scenarios. We used data from 596 published paleoecological records to examine compositional and structural changes in global terrestrial vegetation since the last glacial period, and to project the magnitude of ecosystem transformations under different emission scenarios in the future. Our results indicate that terrestrial ecosystems are highly sensitive to temperature change, and suggest that without major reductions in greenhouse-gas emissions to the atmosphere (i.e., in line with those targeted in the 2015 Paris Agreement), most terrestrial ecosystems worldwide are at risk of major transformation, with accompanying disruption of ecosystem services and impacts on biodiversity.

We reconstructed vegetation changes and fire events in the southern Lake Baikal region over the past 33 cal kyr using a sediment core from the Buguldeika Saddle, southern Lake Baikal, to examine vegetation response to past short-term climate variations. Herbs, such as Artemisia and Asteraceae, were dominant just before the Last Glacial Maximum (LGM). Low pollen accumulation rates (PARs) with little herb pollen indicate sparse herbaceous vegetation cover during the LGM. Picea expanded after the Bolling interval, suggesting expansion of riparian areas, and shrub Alnus rapidly increased during the following Allerod interval. Abies and Pinus subgen. Haploxylon began to increase at the beginning of the Holocene and Pinus subgen. Diploxylon has been highly dominant since the middle Holocene. The vegetation change after the LGM is similar to that from other sites in the Lake Baikal region, but the responses to short-term climate events are pronounced. Fluctuations in herb elements and vegetation cover as indicated by the PAR correspond to the Younger Dryas (YD) cooling event. The decline in the PAR and increase in herb taxa were remarkable at the beginning of the YD, but Larix and Picea trees were distributed in river valleys near Lake Baikal in the latter half. The rapid expansion of Betula and Artemisia following frequent fires in the early Holocene may have been in response to the 8.2 cal ka BP cooling event. From these findings, the southern Lake Baikal region, including the Selenga River basin, may possibly have been more sensitive than other parts of the region to abrupt climate changes.

To better understand the response of forest vegetation to climate and fire regimes with reference to human activities over the last deglacial period in the Aso Caldera, central Kyushu, southwestern Japan, a 33.9 m long sediment core was examined in order to reconstruct the vegetational and fire history using pollen and charcoal analyses. The results show that a cool temperate broad-leaved deciduous forest, dominated by Quercus (deciduous oaks) with Carpinus and Fagus, prevailed in the Aso Valley from ca. 14.6 ka cal. b.p., indicating warming since the last glacial period. The landscape was presumably covered by a mosaic of deciduous Quercus forests and terrestrial Artemisia communities. Around 12.8–11.7 ka cal. b.p., Quercus dominated the forest and fires occurred frequently. Co-expansion of distinctive Ulmus–Zelkova and Celtis–Aphananthe forests coupled with a progressive retreat of Quercus in the early Holocene could reflect a strengthening of the East Asian summer monsoon under mild and humid climate conditions. Around 8 ka cal. b.p., significant increases in Cyclobalanopsis (evergreen oaks), Castanopsis/Castanea and Podocarpus indicate a further warming, in particular an increased winter temperature. Warm temperate lucidophyllous forests, dominated by Cyclobalanopsis, flourished after 7.3 ka cal. b.p., probably corresponding to the “Holocene Climatic Optimum” interval. Progressive expansion of Quercus at the expense of Cyclobalanopsis began around 6.4 ka cal. b.p. and paralleled an increase in charcoal until ca. 4.8 ka cal. b.p.; this could be evidence of fire disturbance induced by the early-middle Jomon people. The disturbed evergreen forest experienced a temporary recovery but then opened again from 3.6 ka cal. b.p. due to extensive fire deforestation, as suggested by the high charcoal levels during this time. Human exploitation and buckwheat (Fagopyrum) agriculture may have contributed to the opening of the forest, which allowed secondary forests (primarily Pinus and Quercus) and herbaceous communities (mainly Poaceae) to spread. These results are discussed in comparison with other high-resolution pollen data from western Japan to better elucidate the vegetation and fire history over the last deglacial in the Aso Caldera.

The paper presents the first paleontological data (pollen, plant macrofossil, diatom and ostracod) on the sediments of Lake Beloye, which is situated in the forest-steppe zone of Western Siberia. Our study contributes to better understanding of the Middle–Late Holocene regional to local environmental changes. Regionally, we recognized a cold stage of 3.4–2.3 calibrated ka BP and a dry stage of 2.8–1.7 ka BP. The dry stage coincides with the climate-driven lowered level of the lake at 2.6–1.5 ka BP. Later, the climate changed to warmer and wetter, which resulted in a highest stand of the lake at 1.3–0.2 ka BP and was followed by the lowering of the lake. Forest-steppe persisted in this area during the whole period under consideration, but probably shifted southward. Such a shift is reflected in the environment around Lake Beloye similar to that of modern taiga, which existed at 3.2–1.3 ka BP, however, compared to the colder and wetter climate of taiga, the conditions were colder and drier. The local plant associations and the lake ecosystem were affected by those events of climate and lake level changes. The initial eutrophic sedge-reed swamp evolved to the oligo-mesotrophic sphagnum bog, which existed around the lake at 3.2–1.3 ka BP. Later, the bogging process was interrupted by the lake transgression, after which the dried bog around the lake was occupied by the birch forest. The lake ecosystem was strongly affected by the 3.4 ka BP climate change: the low-alkaline eutrophic lake with abundant water higher plants and diatoms changed to the alkaline oligotrophic lake with calcium-fixing macrophytic algae and angiosperms. This resulted in total change of lake's bio-geochemical and sedimentation patterns.

Sediment structure, rock-magnetic and bio-geochemical records obtained from sapropel core samples in Lake Beloye, southern Western Siberia, indicate an abrupt ecosystem change at 3.4 calibrated ka BP. The lake changed from eutrophic to oligotrophic, its vegetation — from carbon-fixing macrophytic angiosperms to calcium-fixing macrophytic algae and angiosperms, and, as a result, the type of sedimentation shifted from peaty sapropel to carbonate-rich sapropel. Those changes could be induced by climate, which was warmer and wetter before 3.4 ka BP and cooler and drier after this. Nevertheless, our data show that those ecosystem changes occurred when the lake became shallower to get about 1 m depth and started to freeze to the bottom in winter time. The full freezing of the lake led to the deposition of carbonates, which resulted in: i) death of carbon-utilizing macrophytic angiosperms; and ii) winter precipitation of calcium carbonate. In summer, additional portions of Ca 2+ and HCO 3 − ions come into the lake from the surrounding CaCO 3 rich loess sediments with ground water. The Beloye Lake thus represents an example of interrelated regional climatic and local ecological factors, which combination resulted in the 3.4 cal. ka BP dramatic change of its ecosystem.

A pollen record of Sonenuma Swamp provides vegetation history for the last 17,000 years around the eastern shore area of Lake Biwa, western Japan. Identification of Quercus subgenus Lepidobalanus pollen by using scanning electron microscope shows composition changes of deciduous oaks at the species level. During 17,000 to 15,000 cal BP, deciduous broadleaved forest mainly consisted of Q. sect. Prinus developed around Sonenuma Swamp associated with pinaceous conifers and birch trees. Q. sect. Prinus and Q. dentata became dominant in the forests from 15,000 to 10,000 cal BP. The increase of Q. dentata in this period was possibly related to fire events around Sonenuma Swamp, as indicated by the charcoal record. From 10,000 to 6000 cal BP, Celtis/Aphananthe trees became dominant in forests around Sonenuma Swamp. Temperate evergreen broadleaved forest composed of Q. subgenus Cyclobalanopsis trees along with Q. sect. Cerris trees developed during the period 6000 to 2500 cal BP. After 2500 cal BP, pine forests and grassland increased, with charcoal abundance likely affected by human activity around Sonenuma Swamp.

In the areas adjacent to Kyoto, an ancient capital of Japan, the regional vegetation is mostly secondary forest. In order to reconstruct the fire and vegetation history of the area and to estimate when and how the secondary forest was established, peat cores were obtained from a small basin in the western Tamba Highlands, 35-km northwest of Kyoto city. Pollen, plant macrofossil and charcoal records from the site indicate that the cool-temperate forest characterized by beech (Fagus crenata) with Japanese cedar (Cryptomeria japonica) developed in the middle Holocene (c. 4700–2400 cal BP). Forest fires were rare during this period. In the late Holocene, charcoal data indicate that at least two major fire events occurred. Following a fire c. 2500 cal BP, the vegetation changed from beech-dominated cool-temperate forest with Japanese cedar to a forest with less beech and increased pine. The next conspicuous fire took place at c. 900 cal BP, after which the vegetation shifted to a deciduous oak and pine-dominated forest, similar to the present vegetation around the site. The Gramineae pollen percentage was continuously high since the second fire event, suggesting that grassland was maintained. In the western Tamba Highlands, secondary forests were established during the eleventh century, but resource depletion was less serious and open secondary forest has been maintained by human activities.

Macroscopic charcoal and pollen in mire sediments from the Soni Plateau, Central Japan, were evaluated to clarify intentional fire history and relationship between vegetation transition and anthropogenic fire or climate change. The sediments deposited in recent centuries, when fire probably occurred every year, include a number density of macroscopic charcoal fragments exceeding 100 fragments/cm3. High charcoal abundances (>100 fragments/cm3) were also recognized in sediments deposited at ∼7000 cal BP and from 1500 cal BP to the present. Sediments deposited between 7000 and 1500 cal BP have a low abundance of charcoal fragments (

Phytoliths and charcoal preserved in two soil sections in northern part of Aso Caldera, central Kyusyu, Japan revealed grassland and fire history since the late-glacial. The phytolith assemblages were divided into two significant zones, respectively. Phytolith assemblages show that the grassland vegetation, composed mainly of Sasa species, has continued since the late-glacial. The grassland compositions changed from Sasa type to Pleioblastus type around 7.5 cal ka. Charcoal records indicate that fire occurred at least in the early Holocene and continued to the present. Judging from the phytolith and charcoal records, the establishment of grassland may have been affected by not only climate changes and volcanic activities, but also fire since the early Holocene. Around the Aso Caldera, numerous prehistoric archaeological sites since the late-glacial have been discovered. Therefore, the occurrence of fire during the Holocene was possibly caused by human activities, and fire influenced the establishment of grassland. The results are important for understanding the relation between the fire and grassland vegetation in the regions where human activity has continued.

To investigate the pollen–tree relationship of surface pollen sample from under canopy sites, surface pollen samples were analysed from 56 sites collected in the montane zone to the subalpine zone of the Hakkoda Mountains, northeastern Japan. The characteristic pollen assemblage was observed in each vegetation type. High percentages of Pinus Haploxylon type pollen were recognized in the Pinus pumila thicket. Abies pollen was characterized in the Abies mariesii forests and the Fagus-Abies mixed forests although it was strongly under-represented. Betula pollen increased in the upper part of Fagus-Abies mixed forest and reached the highest values in the Betula ermanii stands, which corresponded to the vegetation composition. Fagus pollen was abundant not only in the Fagus crenata forests and the Fagus-Abies mixed forests but also in the P. pumila thickets and the A. mariesii forests. Cryptomeria pollen, derived from Cryptomeria japonica plantations in the lower montane area, varied from 4 to 126% (average 52%) in all vegetation types. The scatter plot of pollen percentages and coverages indicated taxa-specific representation. Pinus Haploxylon type and Abies pollen were under-represented because of low plant height, low plant density and small dispersal ability of pollen, respectively. Fagus and Betula showed relatively good linearity. Quercus was over-represented although its coefficient of correlation was the worst, which may be caused by different distributions pattern of two Quercus species, Quercus crispula in the montane zone and dwarf oak Q. crispula var. horikawae in the subalpine zone. The pollen assemblage of the P. pumila thicket , the A. mariesii forest, the Fagus-Abies mixed forest and the F. crenata forest can be distinguished by Canonical Variate Analysis (CVA). CVA results allow clear assessment of former vegetation changes by objective interpretation of fossil pollen data from two forest hollow sites (KS-3 and KS-4 sites) in the Hakkoda Mountains. The vegetation at KS-3 prior to the To-a tephra layer (A.D.915) was a F. crenata forest, shifting to Fagus-Abies mixed forest after A.D.915. The low elevation site of KS-4 was continuously dominated by F. crenata forest, although a temporal change to Fagus-Abies mixed forest was observed.

Pollen and macroscopic charcoal analyses of AMS radiocarbon-dated sediment from Mizorogaike Pond, located near Japan’s ancient capital established in AD 794, were used along with archaeological and historical data to reconstruct vegetation change in the northern Kyoto Basin since 7300 cal yr B.P. Between ca. 7300 and 3400 cal yr B.P. (Early to Late Jomon period), the site was surrounded by warm-temperate forest composed of Quercus subgenus Lepidobalanus and Q. subgenus Cyclobalanopsis with Celtis / Aphananthe trees. With the occurrence of fire disturbance, Q. subgenus Lepidobalanus increased from ca. 3400 to 1400 cal yr B.P. (Late Jomon to Kofun periods). In the early seventh century (Asuka period), Pinus started to increase, coinciding with a significant charcoal peak, probably related to the operation of roof tile kilns near the site. Pinus continued to increase and Q. subgenus Cyclobalanopsis decreased through the seventh to tenth centuries (Asuka to Heian periods). Further increase of Pinus occurred in the eleventh century, possibly reflecting the establishment of the manor of Kamigamo Shrine. From the eleventh to seventeenth centuries (Heian to medieval periods), no significant vegetational change or fire disturbance took place. In the eighteenth century, the landscape became totally open, with poor vegetation and sparse Pinus woodland. The medieval and early modern landscapes reconstructed from the palaeoecological record are rather similar to those described from studies of ancient artwork and historical documents. This study demonstrates that late Holocene vegetation change in the northern Kyoto Basin was closely tied to anthropogenic activities, such as the pottery industry and fuel wood collection.

京都市近郊二次林では遷移が進行し, コジイの優占する森林が広がってきている。本研究は, このような遷移の進行に伴う種構成や種多様性の変化を明らかにするため, アベマキ・コナラが優占する遷移段階中期にあたる落葉広葉樹林と遷移段階後期のコジイ優占林に調査プロットを設けて木本種の種構成と種多様性を調べ, サイズクラスごとに比較した。幹長100 cm以上のサイズクラスでは, 両プロット間で種多様度の差はほとんどみられなかったものの, 種構成が異なっていた。落葉広葉樹林ではコジイ優占林に比べ, 低木, 落葉性, 風散布型樹種の出現率が高くなっていた。これに対し, 小さなサイズクラス (幹長

A new 2.6-m long archaeological sedimentary profile from Kuahuqiao, Zhejiang Province, was examined for pollen-phytolith-charcoal microfossil content. The results bring a new and improved insight into the previously established vegetation sequence, contributing to better understanding the interaction between vegetation, fire and human activity in the early Neolithic Lower Yangtze, discussed in the context of archaeological record and published available data. Three distinctive phases were well represented: the nature-dominated phase (c. 8250–7950 cal. BP), the human-affected phase (c. 7950–7400 cal. BP) and the marine-controlled phase (post-7400 cal. BP), considering vegetation changes, human impact, and environment dynamics. Around 8300 cal. BP, the mixed broadleaved evergreen and deciduous forest, mainly consisting of Quercus , Pinus , Cyclobalanopsis , Liquidambar, and Ulmus/Zelkova , developed at Kuahuqiao. It was initially opened by the early local Neolithic hunters and foragers by means of fire since c.7950 cal. BP, indicated by abundant microfossil charcoal in cultural layers. The disturbed forest in the lowlands progressively retreated and was predominately replaced by a Poaceae-dominated vegetation pattern, suggesting increasingly intensified human interference including rice cultivation since 7760 cal. BP. Quercus and Pinus were the main components among the woods targeted by humans in the local small basin, strongly supported by archaeological records as well. However, the short period of Alnus flourishing reported elsewhere is not documented in the pollen sequence. In addition, the combined pollen and archaeological evidence shows that the well recorded local spread of Typha around 7400 cal. BP could mainly be a natural response to the expansion of water regime in addition to the result of human management of the environment. The increasing water level was presumably induced by the local blocked hydrological ecosystem as a result of its retrogression prompted by rising sea level, before the Kuahuqiao Culture ended in the subsequent marine transgression.

High-resolution pollen records from Taiwan, Japan and Sakhalin document regional vegetation changes during Dansgaard-Oeschger (D-O) cycles during the last glacial. During the period from the cold phase (GS 18/19) to warm phase (D-O 19), the biome shift from temperate conifer forest to cold/cool conifer forest in Japan and from subtropical forest to temperate deciduous/conifer forest in Taiwan. The vegetation in D-O 17, cool mixed forest in central Japan, temperate deciduous broadleaf forest in western Japan and subtropical forest in Taiwan, indicates warm condition but not wet in all area. These vegetation changes lead to biome shift from MIS (Marine Isotope Stage) 4 to MIS 3. The abundance of Cryptomeria japonica and Fagus crenata in D-O 12 and D-O 8 indicates wet conditions brought by the strong summer monsoon through the Islands and high snowfall brought by the inflow of the Tsushima Warm Current into the Sea of Japan. The registration of other D-O warming events in MIS 3, although reflected by shifts in the abundance of key species, is not sufficient to produce changes in biomes. Development of cold deciduous forest in HS (Heinrich events) 1 in Sakhalin, Hokkaido and central Japan was conspicuous and was much larger than that in YD. Vegetation response in YD was small scale and within the same biome in the East Asian Islands. In D-O 1 at the termination of the last glacial, the same taxa that developed in the early Holocene, cold evergreen needleleaf trees in northern region, temperate deciduous broadleaf trees in central and western Japan, and warm-temperate evergreen trees in Taiwan, increased.

A high-resolution pollen record covering the last 40,000 yr (BIW95-4) from Lake Biwa, western Japan, shows regional vegetation responses to millennial-scale climate changes. From 40 to 30 ka,Cryptomeria japonicawas dominant around the lake among pinaceous conifers and deciduous broad-leaved trees. During this period, fluctuations ofC. japonicaare correlated with Dansgaard–Oeschger (D–O) cycles recognized from the anhysteretic remanent magnetization (ARM) record. Increases in the abundance of this taxon may have been caused by wetter summer conditions influenced by the East Asian monsoon or increased snowfall on the Sea of Japan side of the Japanese archipelago. Between 29 and 14 ka, pinaceous conifer forests mainly composed ofPinussubgenusHaploxylon,Tsuga, andPiceatrees developed. At approximately 23 ka,Piceatrees increased in abundance as ARM values decreased. This expansion ofPiceatrees has been correlated with Heinrich event (HE) 2 in the North Atlantic. At about 14 ka, the distribution of broad-leaved forest (mainly composed of deciduous oaks) began to expand after D–O 1. Evidence of significant vegetation change related to the abrupt Younger Dryas cooling event has not been found.

生態系の変化にはさまざまな現象があり，それらに特有な空間スケールと，それらが起こる頻度に関連した時間スケールがある．古生態学的研究を進めるには，目的に応じて，それに適した両スケールを考える必要がある．時間スケールについては，最終氷期において，千年スケールで起こったDansgaad-Oeschgerサイクルのような急激な気候変動に対する植生の応答関係を，時間分解能の高い研究によって解明することができる例を示した．空間スケールについては，琵琶湖のような大規模な堆積盆は広域のスケールでの植生復元を，森林内凹地（forest hollow）のように小規模な堆積盆では林分規模での植生復元に適していることを示した．さらに，複数地点の堆積盆における堆積物の分析によって，古植生の空間的な配置パターンを解明できることを紹介した．

A sediment core (VER99G12; core length, 4.66 m) was taken from the Buguldeika Saddle of Lake Baikal in 1999. Radiocarbon measurements of total organic carbon (TOC) and pollen concentrate fractions from the VER99G12 core were performed by a Tandetron accelerator mass spectrometry (AMS) system (Model-4130, HVEE) at Nagoya University. The AMS 14C ages showed that the VER99G12 core spans the past ∼30 cal ka BP (from the MIS 3 to present), and the average sedimentation rate of this core was calculated to be 13.6 cm/kyr based on the calibrated ages. This means that the time resolution of VER99G12 sediment samples in this study is better than ∼70–80 yr/cm. Stable carbon isotope ratios of TOC (δ13CTOC) in the VER99G12 core varied widely from about 26.6‰ to 31.3‰ during the last glacial/post-glacial transition period (about 17–12 cal ka BP). Therefore, a rapid change in the carbon sources in Lake Baikal occurred in the last glacial/post-glacial transition period is concluded.

走査電子顕微鏡(SEM)を用いて, コナラ属14種(アカガシ亜属7種コナラ亜属7種)について, 合計で113個体938粒の花粉について表面構造を観察した。その結果, アカガシ亜属花粉の表面微細構造には「微小刺」と「顆粒」が認められ, その形状は7種全てにおいて類似した形態を示した。また, コナラ亜属花粉の表面微細構造には, 線状の「突起」が全面に認められる形態(ウバメガシ), 「顆粒」が大きく盛り上がり, それが丸い形状を示す形態(ミズナラ, コナラ, ナラガシワ), 「顆粒」が大きく盛り上がり, それが尖った形状を示す形態(カシワ)および「顆粒」がやや盛り上がり, 花粉表面全体がしわ状になっている形態(アベマキ, クヌギ)が認められた。, Exine sculpture of 938 pollen grains from 113 specimens representing 14 Quercus species (7 species of subgenus Cyclobalanopsis and 7 species of subgenus Lepidobalanus) of Japan were examined by using SEM. On the exine sculpture of Quercus subgenus Cyclobalanopsis pollen, "microspine" and "granula" were recognized and those morphologies were similar among the 7 species. On the exine sculpture of Quercus subgenus Lepidobalanus pollen, the striae type (Q. phillyraeoides), the round granula type (Q. mongolica var. grosseserrata, Q. serrata, and Q. aliena), the sharp-pointed granula type (Q. dentate), and the cockled granula type (Q. variabilis, and Q. acutissima) were recognized.

The pollen record from Kamiyoshi Basin, inland area of western Japan, provides a continuous vegetational history from the penultimate to last glacial period. By comparing it with the coastal area of the Sea of Japan, regional vegetation patterns affected by East Asian monsoon changes are clarified. During the last interglacial, evergreen broad-leaved forests mainly composed of evergreen oaks developed around Kamiyoshi Basin. In MIS 5e/5d, 5c/5b, 5a/4 transitions, Cryptomeria japonica became dominant, both in the inland area and in the coastal area of the Sea of Japan, under the influence of a strong summer monsoon. In MIS 4, pinaceous conifer forests composed of Pinus subgenus Haploxylon, Tsuga, and Picea developed around Kamiyoshi Basin under a cold and dry climate affected by a strong East Asian winter monsoon and a weak summer monsoon. Mixed forests composed of deciduous broad-leaved trees, temperate conifers, and pinaceous conifers expanded during MIS 3. Meanwhile, C. japonica was dominant in the coastal areas of the Sea of Japan during this period, and Cupressaceae trees were the dominant species in the inland area due to the gradient in winter snowfall caused by the East Asian winter monsoon.

Climatically driven Late Pleistocene and Holocene vegetation changes were reconstructed based on pollen records from the sediments of Lake Kotokel and Cheremushka Bog, located on the eastern shore of Lake Baikal. The described paleoenvironmental record has higher resolution than records collected from Lake Baikal and unites individual events identified in prior studies of bottom and onshore cores. Remarkable shifts in landscapes and expansions of index plants are as follows. Forest tundra and/or forest steppe landscape with birch, spruce, Artemisia, and Poaceae prevailed at ca. 50–25 14 C kyr BP. Tundra and/or steppe vegetation dominated by Artemisia and Poaceae was typical for the Last Glacial Maximum. The expansion of shrub birch and willow occurred at ca. 15.5 14 C kyr BP. Two peaks of spruce expansion at ca. 47.5–42.4 14 C kyr BP (Karginian time) and at ca. 14.5–13 ka (Bolling-Allerod warm intervals) suggest that the condition were more humid than today. A slight increase in Artemisia at ca. 11–10.5 14 C kyr BP (13–12 ka) was indicative of the Younger Dryas event. An expansion of birch forests with fir at ca. 12–6.4 ka suggests higher humidity. The currently dominant Scots and Siberian pine forests with birch expanded since 6.4 ka.

We characterized the compositions of organic compounds in a Cheremushka bog sediment core (deposited over the last 35 kyr), located at the eastern coast of Lake Baikal, to obtain basic information about the terrestrial organic matter (OM) which contributed to Lake Baikal sediments. The bog sediment was analyzed for the molecular composition of n -alkanes, lignin phenols and n -C 24 to C 30 alkanoic acids, as well as the carbon isotopic composition of plant wax derived n -C 27 to C 33 alkanes. Concentrations of lignin phenols [vanillyl (V) plus syringyl (S) phenols] normalized to total organic carbon (TOC) in the Holocene are twice those for the last glacial maximum (LGM), while concentrations of TOC-normalized n -C 24 to C 30 alkanoic acids do not change markedly in this period. Thus, the ratio of lignin phenols to n -C 24 to C 30 alkanoic acids increases from the LGM to the Holocene. This result is essentially consistent with pollen analysis indicating an expansion of woody plants in the Holocene and a prevailing herb-abundant environment for the LGM. The δ 13 C values of n -C 27 to C 33 alkanes (e.g. −29‰ to −33‰ for C 31 ) indicate the presence of C 3 -dominant plants throughout the core. The contribution of terrestrial OM to Lake Baikal sediments was estimated using the biomarkers, on the assumption that the OM in the bog sediments is a representative of the terrestrial OM around the lake. Hence, the estimation using lignin phenol or n -C 24 to C 30 alkanoic acid parameters indicates that 11–24% of the TOC in the Academician Ridge sediments is land-derived for both the Holocene and the LGM, which is similar to the estimates from C/N values of bulk OM. However, the estimates for terrestrial OM using the n -C 27 to C 33 alkane parameter are generally higher than those using lignin phenol or n -C 24 to C 30 alkanoic acid parameters. The difference is thought to be associated with the difference in source and behavior of these biomarkers.

大阪湾夢洲沖コアを用いた花粉分析に基づいて，完新世の大阪湾集水域における植生変遷を復元した．このコアからは多数の放射性炭素年代が得られており，11,100～9,800 cal BPではコナラ亜属やクマシデ属から構成される冷温帯性落葉広葉樹林が発達していた．9,800～9,000 cal BPでは，エノキ-ムクノキ林が拡大し，冷温帯性落葉広葉樹林はやや衰退した．9,000～5,400 cal BPでは，エノキ-ムクノキ林と冷温帯性落葉広葉樹林がアカガシ亜属やシイ属から構成される照葉樹林と交代した．5,400～2,900 cal BPでは，照葉樹林が最も発達した．2,900～1,200 cal BPでは，温帯性針葉樹林が増加し，照葉樹林がやや衰退した．1,200～300 cal BPでは，二次林であるアカマツ林が拡大し，自然林である温帯性針葉樹林や照葉樹林が徐々に減少した．また，緩やかな森林の減少が推測された．300 cal BP～現在では，自然林が急速に減少し，アカマツの疎林やはげ山が拡大した．

We conducted particle size and pollen analyses on two cores extracted from Lake Baikal to investigate the response of vegetation to climate change and to assess the differences in vegetation changes between the northern and southern regions of Lake Baikal over the last 350 kyr. Vegetation changes in the Lake Baikal region corresponded well to the fluctuations in median particle size, which are indicators of the climate changes in this region. Forest, which was mainly composed of Pinus and Picea, spread widely during the interglacials/interstadials of MIS 9, 7, 5, and 1, and open forest or desert covered most areas during the glacial/stadial substages. However, the responses of vegetation to climate changes differed between the northern and southern regions. Generally, vegetation expansion was restricted around the northern region. During the interglacial substages equivalent to MIS 9.3, 7.5, and 5.5, forest spread widely around both the northern and southern regions. However, sparsely vegetated (poor) desert/open forest covered the northern region during MIS 5.3 and 5.1, while forest extended around the southern region in these substages. Moreover, during glacial periods, open forest, composed mainly of Artemisia, Chenopodiaceae/Amarantaceae, Betula, and Alnus, covered the southern region, while poor desert/open forest covered the northern region. These different vegetation responses are considered to have been caused by the geographical characteristics of the regions, i.e., the mountains around the northern region and the plains around the Selenga River in the southern region.

Phytolith analysis was applied to clarify a vegetation history at Picea glehnii stands on the Dorokawa Mire, northern Hokkaido. Phytolith assemblages from surface samples and Holocene deposits from the mire are used to clarify the stand-scale vegetation history, with special focus on the dynamics of Gramineae, which includes dwarf bamboo, and the establishment of P. glehnii stands on the mire. The phytolith records during the early-Holocene (ca. 12,000 to 10,000 cal BP) indicate the distribution of Pooideae-dominated vegetation, which reflects the cool climate. Phragmites (reed) dominated vegetation from the early to mid-Holocene (ca. 10,000 to 5,000 cal BP) suggests wet conditions like low-moor. The reed was replaced by dwarf bamboo at ca. 5,000 cal BP, although the distribution of dwarf bamboo was scattered. At ca. 1,500 cal BP, dwarf bamboo increased abruptly and has been sustained to the present. Also, Pinaceae type phytoliths began to occur continuously at ca. 1,000 cal BP. Taking into account the relationship between modern vegetation and modern phytolith assemblages on the mire, the occurrence of the Pinaceae type phytoliths from the sediment samples indicates the existence of P. glehnii in the study sites. On the basis of these results, P. glehnii stands with dense undergrowth of dwarf bamboo would have been established in the study sites on the mire by ca. 1,000 cal BP at least.

New radiocarbon dates obtained from Late Pleistocene and Holocene deposits of the southern, eastern, and northern shores of Lake Baikal in 1995-2001 are presented, and the most important results of paleoenvironmental studies based on (super 14) C data are discussed. The following paleogeographic events were verified with the help of (super 14) C dating: 1) first Late Pleistocene glaciation (Early Zyryan); 2) Middle Zyryan interstadial; 3) loess formation during the Late Zyryan (Sartan) deglaciation; 4) warm and cold events in the Late Glacial; and 5) vegetation changes and forest successions during the Late Glacial and Holocene.

The Neotoma Paleoecology Database is a community-curated data resource that supports interdisciplinary global change research by enabling broad-scale studies of taxon and community diversity, distributions, and dynamics during the large environmental changes of the past. By consolidating many kinds of data into a common repository, Neotoma lowers costs of paleodata management, makes paleoecological data openly available, and offers a high-quality, curated resource. Neotoma’s distributed scientific governance model is flexible and scalable, with many open pathways for participation by new members, data contributors, stewards, and research communities. The Neotoma data model supports, or can be extended to support, any kind of paleoecological or paleoenvironmental data from sedimentary archives. Data additions to Neotoma are growing and now include >3.8 million observations, >17,000 datasets, and >9200 sites. Dataset types currently include fossil pollen, vertebrates, diatoms, ostracodes, macroinvertebrates, plant macrofossils, insects, testate amoebae, geochronological data, and the recently added organic biomarkers, stable isotopes, and specimen-level data. Multiple avenues exist to obtain Neotoma data, including the Explorer map-based interface, an application programming interface, theneotomaR package, and digital object identifiers. As the volume and variety of scientific data grow, community-curated data resources such as Neotoma have become foundational infrastructure for big data science.

バイカル湖の湖底から得られた5.1Maをカバーする全長200mコア(BDP96-1)のうち,第四紀に相当する上部の深度80m以浅についての花粉分析を行い,植生変遷について考察した.産出した化石花粉・胞子のうち51種類を同定したが,マツ科針葉樹が70～80%を占め,その産出状況に特色がみられた.すなわち,大量の化石花粉・胞子の産出する多産層(間氷期,湿潤期)と,草本花粉・胞子がごくわずかに産出するだけの稀産層(氷期,乾燥期)が交互に現れている.上部80mの2Maに32回のサイクルが認められ,δ18O曲線とほぼ調和的な環境変動を記録している.また,マツ科のツガ属と落葉広葉樹のクマシデ属,コナラ亜属,クリ属,ニレ科,ハシバミ属,カエデ属は第四紀前半に絶滅してしまい,後半以降のバイカル湖周辺のタイガはマツ科針葉樹とカバノキ属を中心とした比較的単純な植生からなる森林が継続した.

微粒炭は,植物の燃焼によって生成された微細な炭化植物片である.微粒炭は,しばしば堆積物中に含まれており,森林火災などの植物燃焼の歴史を復元する上で重要な試料である.本研究では,集水域が広く,しかも湖盆が長期にわたって安定している琵琶湖の湖底堆積物を用いて,過去約13万年間の微粒炭の連続的な定量分析を行った.その結果,約13万年前～約1万年前は森林火災が少ない時期で,寒暖・乾湿などの気候変化は植物燃焼量(おもに森林火災)増減の主要因ではないと考えられた.また,約1万年前以降から琵琶湖周辺における植物燃焼量は多くなり,火入れなどの人間活動が活発になったことが明らかになった.さらにA.D.1920年頃以降には,微粒炭の増加が認められた.こうした近年の微粒炭の増加は,石炭などの植物質燃料の人為的な燃焼に起因すると考えられる.

A biomization method, which objectively assigns individual pollen assemblages to biomes ( Prentice et al., 1996 ), was tested using modern pollen data from Japan and applied to fossil pollen data to reconstruct palaeovegetation patterns 6000 and 18,000 14C yr bp Biomization started with the assignment of 135 pollen taxa to plant functional types (PFTs), and nine possible biomes were defined by specific combinations of PFTs. Biomes were correctly assigned to 54% of the 94 modern sites. Incorrect assignments occur near the altitudinal limits of individual biomes, where pollen transport from lower altitudes blurs the local pollen signals or continuous changes in species composition characterizes the range limits of biomes. As a result, the reconstructed changes in the altitudinal limits of biomes at 6000 and 18,000 14C yr bp are likely to be conservative estimates of the actual changes. The biome distribution at 6000 14C yr bp was rather similar to today, suggesting that changes in the bioclimate of Japan have been small since the mid-Holocene. At 18,000 14C yr bp the Japanese lowlands were covered by taiga and cool mixed forests. The southward expansion of these forests and the absence of broadleaved evergreen/warm mixed forests reflect a pronounced year-round cooling.

The pollen record of a long core from the Kurota Lowland of central Honshu in western Japan provides a continuous vegetation and climate history from beyond 120,000 to 25,000 yr BP. The chronology is based on widely dispersed tephra and six conventional 14C dates. Prior to 120,000 yr BP, forests were composed predominantly of Abies, Tsuga, Picea and Pinus (Haploxylon) which indicate a cold climate probably corresponding to oxygen isotope stage 6. During the last interglacial around 120,000 yr BP, Cryptomeria japonica was dominant in forests with a small amount of evergreen oaks. The early stage of the last glacial period is characterised by dominance of C. japonica with two increases (at 105,000 and 90,000–80,000 yr BP) of pinaceous conifers and cool-temperate deciduous broad-leaved trees. Between 70,000 and 60,000 yr BP, pinaceous conifer vegetation developed indicating a dry and cold climate and this was succeeded by a cool-temperate deciduous broad-leaved forest composed mainly of Fagus crenata and deciduous oaks indicating a wet and cool/cold climate. From 55,000 to 40,000 yr BP, temperate coniferous forests composed of C. japonica and Cupressaceae, associated mainly with Tsuga and deciduous oaks, occurred. After 40,000 yr BP, mixed forests of C. japonica, Tsuga and cool-temperate deciduous broad-leaved trees such as Fagus crenata and deciduous oaks prevailed in a wet and cool climate. At 28,000 yr BP, an abrupt decrease of C. japonica and development of forests composed of Tsuga, Pinus (Haploxylon) and Betula with some deciduous broad-leaved trees imply climatic deterioration to the LGM. The vegetation history since the LGM has been revealed previously at Iwaya site in Kurota Lowland. Time series of these pollen records can be correlated with the marine oxygen isotope stages 1 through 6.

兵庫県の氷ノ山地域で,厚層多腐植質A層を持つ土壌を対象に,土壌母材の累積性と土壌の生成環境を調べた.その結果,土壌中の細砂の一次鉱物組成は,どの試料でもおおむねテフラ起源粒子と基岩の岩片とが混在するものであった.粘土・シルト画分の鉱物組成は,すべての試料で,基岩に由来する鉱物と風成塵などの外来物質とが混在するものであった.また,チシマザサ起源と考えられる植物珪酸体が多量に集積し,下層ほど風化が進んでいた.これらの結果から,この地域の厚層多腐植質A層を持つ土壌は,無機母材と有機物とが平衡して供給され,上方に発達した累積的な土壌であることが明らかになった.また土壌中の花粉分析の結果から,ササ植生は土壌生成開始期から長く維持され,現在ブナ林が成立している箇所でも,草原や疎林などの植生から次第に閉鎖した森林へと移り変わってきたと推定された.以上の諸点から,この地域の累積的な土壌の生成には,地形的安定性や冷涼な気候,母材としてのテフラ物質の存在のほかに,長期間にわたるササ植生の存在が強く影響していることが推察された.

DNA was amplified from individual fossil pollen grains of Abies spp. (Pinaceae), which have been detected from Pleistocene peaty deposits (at least 150,000 years old). To identify the species of the fossil pollen by DNA analysis, the region indicating the species-specific sequence was searched among extant Abies species and the spacer region between rrn5 and trnR in chloroplast DNA was sequenced for four grains of the fossil pollen. Three pollen samples produced the same sequence as extant Abies species. The sequence for the remaining sample differed from that of extant Abies by one substitution. This study showed not only a successful DNA analysis from a single grain of fossil pollen but also a new method to identify the species of fossil pollen for the pollen analysis field.

During the past 20 years, several pollen database cooperatives have been established. These databases are now constituent databases of the Neotoma Paleoecology Database, a public domain, multiproxy, relational database designed for Quaternary-Pliocene fossil data and modern surface samples. The pollen database cooperatives have set standards for data quality control and for taxonomic nomenclature and synonymy. The Neotoma database is a secure archive for palynological data, and it is essential cyberinfrastructure for paleoenvironmental research. Applications range in scale from local studies to global-scale biome mapping and paleoclimatic reconstructions.

Local and regional vegetation since the last glacial period was reconstructed on the basis of a palynological study of sediment at Iwaya, in the Sea of Japan area, western Japan. During the interstade (before about 30 000 years BP), forests were composed predominantly ofCryptomeria japonica withTsuga sieboldii and cool-temperate deciduous broad-leaved trees. In the pre-full-glacial, the full-glacial and the early late-glacial (30 000-12 000 years BP), forests were dominated by temperate (montane) and boreal (subalpine) Pinaceae andBetula. During the early full-glacial, the pinaceous forests were mixed with cool-temperate trees such asFagus crenata. In the late full-glacial (18 000-16 000 years BP), the maximum development of pinaceous conifer forests was recognized. Cool-temperate broad-leaved forests composed mainly ofF. crenata andQuercus (Lepidobalanus) replaced the pinaceous forests at about 12 000 years BP and were maintained to the early postglacial.Cryptomeria japonica was distributed around the Mikata lowland during the last glacial.Cryptomeria japonica, which began to increase at 16 000 years BP, increased abruptly in the early postglacial and spread throughout the postglacial in the lowlands. After 6300 years BP, lucidophyllous forests composed mainly ofQuercus (Cyclobalanopsis) andCastanopsis were established in the Mikata district; this was later than in the inland and the Pacific Ocean areas in the Kinki region, western Japan. In historic times (afterca 2000 years BP), secondary forest ofPinus densiflora, which can grow as a pioneer in disturbed habitats, spread.

A pollen analytical study of a core sample from the Torihama site in the Sea of Japan area of the Kinki region was carried out. This core, dated by three types of tephra, corresponded to the period between the early and the middle postglacial periods. In the early postglacial period, the cool-temperate deciduous forest was accompanied byCryptomeria japonica. In the middle postglacial period,C. japonica forests formed on the lowlands. Lucidophyllous forests developed after the deposition of K-Ah ash (6300 years BP) in the Sea of Japan area of the Kinki region, which was later than the development of those in the inland and Pacific Ocean areas.

Recently, populations of Castanopsis cuspidata have often expanded into secondary forests in western Japan. To determine the establishment processes of this species, we analyzed its spatial distribution in a secondary forest dominated by Quercus variabilis and Quercus serrata that is located adjacent to a stand dominated by C. cuspidata. Saplings, defined as ≥30 cm stem length (SL) and