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Erlitou (Henan province, China) is a Bronze Age site which occupies a prominent position in the study of early state and civilization of China. 359 charcoal fragments >4 mm and 40 charred fruit stones unearthed during the 2010 and 2011 excavation seasons at Erlitou have been analysed. Wood charcoals belong to 18 taxa: Platycladus, Pinus, Picea, Prunus armeniaca, Prunus persica, Quercus (deciduous oaks), Celtis, Zelkova, Broussonetia, Ziziphus, Salix, Toona, Koelreuteria, Sophora, Melia, Bambusoideae and 2 unidentified broadleaved species. In addition, 39 Prunus persica stones and 1 Ziziphus stone have been identified. The anthracological results indicate that the main types of woodland vegetation were Quercus broadleaved forest, and coniferous and broadleaved forest during the Erlitou Culture period (1750-1520 BC) including Platycladus orientalis coniferous forest and deciduous vegetation composed of oak, Zelkova, Salix, Toona and some fruit trees such as apricot, peach and Chinese date. Our study indicates a vegetation adapted to a warmer and more humid climate in phases 2 and 3 of the Erlitou Culture period (1680-1560 BC) becoming drier in phase 4 (1560-1520 BC). By the late Erligang period (1400-1300 BC) climate becomes again warmer and more humid. It also suggests that oak played an important role as firewood and possibly for wooden artefacts and as a food source. The appearance of charcoals of apricot, peach and Chinese date also suggests that fruits were consumed, while Chinese hackberries could have been used either as food or fodder.

The relict tree species Zelkova abelicea and Z. sicula (Ulmaceae) occur in Crete and Sicily, respectively. Zelkova abelicea grows in approximately 40 localities in the mountains of Crete, while Z. sicula has been found in only two stands in Sicily. We compared 25 morphological characters of the leaves of both species and used statistical methods (Tukey’stest, discrimination analysis, principal component analysis, agglomeration) to reveal the differences between these two species, their relation to Z. carpinifolia (the third Zelkova south-west Eurasian species), and between the leaves from different shoot types. Our study represents the first comparative biometric analysis of the three Zelkova species localized in the western edge of the current geographic range of the genus. We found that the species differed from each other both, in terms of leaf form characters and level of leaf variation. Zelkova carpinifolia was clearly different from Z. abelicea, while the two populations of Z. sicula, SIB and SIA, were more similar to Z. carpinifolia and Z. abelicea, respectively. The latter finding supports the results of recent molecular studies suggestingt he hybrid origin of Z. sicula. Zelkova abelicea, Z. sicula and Z. carpinifolia differ each other in the leaf characteristics and level of phenotypic variation.

The dynamic tree stability assessment technique allows trees to be measured efficiently, under realistic weather conditions. In this study, the stability of four trees, including two conifers and two broad-leaved species was assessed in the Botanical Gardens of the University of Sopron, Hungary. The examined trees included Horse chestnut, Japanese zelkova, Douglas fir and Giant sequoia. Each tree was measured in various weather and seasonal conditions. Results show that the seasons affected the stability of broadleaved trees significantly, due to considerable changes in the crown surface area, while this difference was much lower in softwoods. Rainy weather loosens the topsoil, which adversely affects the stability of trees with relatively shallow roots. Lower layers take longer to saturate, and therefore trees with very deep roots are usually unaffected by the looser topsoil, while the increased weight of the top layer compacts the lower layers and improves stability, as evidenced by results measured on Sequoia. Snow accumulation on the branches increases the inertia of the tree, which imposes higher torque on the root collar, decreasing stability. In the meantime, the increased resistance offered by frozen ground stabilizes the tree, which more-or-less counterbalances this effect. A more extensive database of tree stability under different conditions is being built to allow for more comprehensive analysis of various factors, like wind direction, tree health and morphology, shading, etc.

Zelkova schneideriana Hand.-Mazz. of the Ulmaceae family is a Tertiary relict and economically deciduous tree species endemic to Central and Southern China. In this study, we performed a transcriptome sequencing of Z. schneideriana using high-throughput sequencing approach to detect polymorphic expressed sequence tag-simple sequence repeats (EST-SSR) markers. A total of 3,235 microsatellite loci were detected from 53,517 unigenes. A set of 30 microsatellite markers were randomly selected to validate in 41 individuals from three populations, of which 10 were polymorphic. The number of alleles per locus ranged from 3 to 11. The observed heterozygosity and expected heterozygosity ranged from 0.366 to 0.829 and 0.439 to 0.848, respectively. These polymorphic SSR primers showed good transferability across different Zelkova species, and are valuable for future studies on genetic diversity, conservation, phylogeography, and species delimitation in Z. schneideriana, as well as other Zelkova species. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-021-02968-5.

PREMISE The hydraulic architecture in the leaves, stems and roots of plants constrains water transport and carbon gain through stomatal limitation to CO2 absorption. Because roots are the main bottleneck in water transport for a range of plant species, we assessed the ecophysiological mechanism and importance of a high fraction of root hydraulic resistance in woody and herbaceous species. METHODS Biomass partitioning and hydraulic conductance of leaves, stems, and roots of Japanese knotweed (Fallopia japonica, a perennial herb) and Japanese zelkova (Zelkova serrata, a deciduous tall tree) were measured. Theoretical analyses were used to examine whether the measured hydraulic architecture and biomass partitioning maximized the plant photosynthetic rate (the product of leaf area and photosynthetic rate per leaf area). RESULTS Root hydraulic resistance accounted for 83% and 68% of the total plant resistance for Japanese knotweed and Japanese zelkova, respectively. Comparisons of hydraulic and biomass partitioning revealed that high root-resistance fractions were attributable to low biomass partitioning to root organs rather than high mass-specific root conductance. The measured partitioning of hydraulic resistance closely corresponded to the predicted optimal partitioning, maximizing the plant photosynthetic rate for the two species. The high fraction of root resistance was predicted to be optimal with variations in air humidity and soil water potential. CONCLUSIONS These results suggest that the hydraulic architecture of plants growing in mesic and fertile habitats not only results in high root resistance due to small biomass partitioning to root organs, but contributes to efficient carbon gain.

1. We clarified the effects of early leaf abscission on the survivorship of the leaf‐mining beetle Trachys yanoi Y. Kurosawa (Coleoptera: Buprestidae) and the underlying mechanism in relation to weather conditions in Japan. Trachys yanoi is an insect pest of zelkova trees [Zelkova serrata (Thunb.) Makino (Rosales: Ulmaceae)]. Larvae burrow into zelkova leaves and feed on leaf tissue, causing early leaf abscission. 2. This study investigated the relationship between the beetle population and weather conditions over 10 years in a zelkova forest. The effects of moisture and temperature on adult emergence from early abscised leaves were examined in the laboratory and in the field. 3. The beetle population in the studied forest was negatively affected by high precipitation levels when the beetles still inhabited early abscised leaves. Fewer adults emerged from early abscised leaves under wet conditions than under dry conditions, in both laboratory and field tests. 4. These results demonstrate that early leaf abscission plays an important role in leaf‐mining beetle survivorship and population dynamics, and that the amount of precipitation when leaf‐mining beetles still inhabit early abscised leaves modulates this effect. 5. Because precipitation when leaf‐mining beetles still inhabit early abscised leaves was mainly driven by an East Asian rainy season front, the beetle population dynamics were affected by the activity of the front.

A comprehensive understanding of the tectonic uplift history of the Tibetan Plateau (TP), a 2000 km wide region with a mean altitude of 4000–5000 m above sea level (asl), is crucial for interpreting global Cenozoic climate change, collisional tectonics and the evolution of the Asian climatic system. However, the timing, degree and extent of the uplift of the TP remain controversial. Here we report new palynological data from Early to Mid-Miocene lacustrine-swamp sediments in the Zeku Basin, northeastern TP. The palynoflora includes 68 palynotaxa at a family or genus level, comprising gymnosperms (16.2%), angiosperms (77.9%), pteridophytes (2.9%) and others (2.9%), and is suggestive of a mixed warm temperate forests of coniferous (e.g., Picea, Abies and Tsuga) and deciduous broadleaved trees (e.g., Ulmus/Zelkova, Betula and Quercus), with some subtropical elements (e.g., Carya and Liquidambar). Three periods of vegetation succession can be recognized from the Caergen Section, indicating a stepwise warming and drying trend from bottom to top. The local palaeoclimatic parameters obtained by applying the Coexistence Approach (CoA) to palynologic assemblages rendered mean annual temperature (MAT) values of 14.2–16.1 °C and mean annual precipitation (MAP) values of 797–1113 mm. This study departs from the traditional application of the CoA, relying on published determination of plant-climate relationships, rather than on data derived from the Paleoflora Database, which is currently not fully open-access. Based on the difference in temperatures between the Early to Mid-Miocene and the present day, and the temperature lapse rate, corrected to take account of Miocene global temperature differences, the estimated palaeoaltitude of the Zeku Basin during the Early to Mid-Miocene was 1200–1400 m asl. This palaeoaltitude estimate suggests that this basin has experienced about 2200–2500 m of uplift since the Early to Mid-Miocene. Findings therefore do not support previous hypotheses that the northeastern TP attained its present altitude before the Miocene.

The Pliocene fluvio-lacustrine sediments of the Yuanmou Basin, Yunnan, near the southeastern part of Qinghai-Tibet Plateau, China, have yielded diverse and abundant assemblages of fossilized mammals and woods. The Yuanmou fossil woods reveal a wood flora with the highest diversity in the Cenozoic wood in China. The woods can play an important role in understanding palaeofloristics and in reconstructing palaeoclimate of southeastern China. In this study, we describe ten angiosperm taxa and three gymnosperm taxa namely: Castanopsis makinoi (Ogura) Suzuki & Terada (Fagaceae), Cedreloxylon cristalliferum Selmeier (Meliaceae), Dalbergioxylon biseriatensis sp. nov. (Fabaceae), Lagerstroemioxylon yuanmouensis Cheng, Li, Jiang & Wang (Lythraceae), Lithocarpoxylon microporosum sp. nov., Lithocarpoxylon sp. (Fagaceae), Paraalbizioxylon sinica sp. nov., P. yunnanensis sp. nov. (Fabaceae), Pterocaryoxylon huxii sp. nov. (Juglandaceae), Zelkova wakimizui (Watari) Watari (Ulmaceae), Abies sp. (Pinaceae), Cephalotaxus sp. (Cephalotaxaceae), and Picea sp. (Pinaceae). Nearest living relative (NLR) comparisons of these taxa, coupled with previously identified taxa, suggest that altitudinal vegetation zones were present in the Yuanmou region during the Pliocene: (i) subtropical evergreen and deciduous mixed broad-leaved forest dominated by Pterocarya/Juglans, Albizia/Acacia, Bischofia and allied taxa at lower elevations, (ii) subtropical evergreen broad-leaved forest dominated by Quercus/Lithocarpus and Castanopsis at middle altitudes of mountains around the basin, and (iii) evergreen coniferous forest of Abies, Picea and other genera at the higher elevations of the mountains. Based on the habits of the NLRs, the prevailing climate was probably humid subtropical and thus differed from the present-day hot and dry climate supporting savanna. It is suggested that subtropical forest was predominant in Yunnan, while tropical rainforest occurred in southwest Asia and India during the same period. The uplift of the mountains near the Qinghai-Tibet plateau in western Yunnan presumably acted as a barrier to block warm and humid air from the Indian Ocean, which influenced the dispersal and distribution of plants.

Airborne pollens cause pollinosis and have the potential to affect microphysics in clouds; however, the number of monitored species has been very limited due to technical difficulties for the morphotype identification. In this study, we applied an eDNA approach to the airborne pollen communities in the suburbs of the Tokyo metropolitan area in Japan, within a mixed urban, rural, and mountain landscape, revealing pollen seasonality of various taxa (a total of 78 families across the period) in the spring season (February to May). Those taxa distinctly shifted in the season, especially in the beginning of February and the middle of April. Air temperature shift was an obvious key factor to affect the airborne pollen community, while the influence of other meteorological factors, such as wind speed, humidity, and precipitation, was not clear. Taxonomic classification of major Amplicon Sequence Variants (ASVs) indicates multiple pollen sources, including natural forest, planted forest, roadside, park lands, and horticultural activities. Most major ASV belongs to Japanese cedar (Cryptomeria japonica), which is the most notable allergen that causes pollinosis in Japan, peaking in mid-February to March. Backward trajectory analysis of air masses suggests that the Japanese cedar and other Cupressaceae plantation forests in the western mountains were a significant source of airborne pollen communities detected at our sampling site. Other major plant pollen sources, including Japanese zelkova (Zelkova serrata) and ginkgo (Ginkgo biloba), emanated from the nearby parks or roadside regions. This study's approach enables us to visualize the phenology of multiple pollen, including timing and duration. Long-term monitoring of this type would provide additional insight into understanding the role of climate change on pollen transmission and links to flowering events.

The earliest planting of trees in urban areas took place in Egypt and the Middle East as early as the twenty-sixth century BC. Early tree planting enhanced private gardens and marked processional routes leading to temples and tombs. The Renaissance ushered in innovations in urban design along with new ideas for the incorporation of trees into cities. These innovations resulted in the creation of tree-lined boulevards, large urban parks, and wooded suburbs that were developed in the eighteenth and nineteenth centuries. Examples of these are the tree-lined boulevards designed by Haussmann in Paris, Central Park designed by Olmsted and Vaux in New York City, and various English suburbs influenced by Ebenezer Howard’s Garden City Concept. At the beginning of World War II cities in Europe and Asia contained to various degrees city parks, public and private gardens, cemeteries supporting trees, and tree-lined boulevards and waterways. Their suburbs were characterized by tree-lined streets and small wooded parks. Commonly used species in temperate zone cities included London plane, common lime, rowan, English elm, field maple common lime, Norway maple, Silver birch, Carolina poplar, horse chestnut, ginkgo, zelkova, camphor tree, and black locust.

В Армении встречаются представители трех родов семейства Ulmaceae: род Ulmus L., представлен 4 видами, род Celtis L. – 3, а род Zelkova Spach – 1. В статье приводятся сведения об условиях произрастания и роспространении, а также ключи для определения видов данных родов., In Armenia are grown represent of three genera of family Ulmaceae: the genera Ulmus L. represented by 4 species, the genera Celtis L. – 3, and the genera Zelkova Spach – 1. Data on habitats and distribution, and keys for definition of species of these genera are given.

International audience; High-resolution pollen analyses were performed on two cores from the western Black Sea and one core from the Marmara Sea, covering the Late Glacial-Holocene transition using 14C chronology. Particular effort was invested in the botanical identification of pollen grains thereby significantly improving our knowledge of regional flora. When interpreted with respect to modern vegetation, pollen records revealed all the major changes caused by climatic fluctuations over the last 20,000 years. The results of this study provide evidence for the occurrence of relict thermophilous-hygrophilous trees (papillate Cupressaceae, Carya, Liquidambar, Zelkova) in certain refugia up to the Holocene. Vegetation dynamics is specified for some taxa (e.g. Cupressus–Juniperus, Fagus, Cedrus) and some ecosystems (e.g. mesophilous forests, Mediterranean sclerophyllous populations, steppes). Pollen data enabled palaeoclimatic reconstructions which were compared with available estimates in the region. The use of a powerful pollen ratio between ‘thermophilous and steppe taxa’ led to fruitful climatostratigraphic relationships with the oxygen isotope curve from the NGRIP core. The Younger Dryas and cooling at 8.2 ka are among the most obvious climatic phases identified in the three cores studied here.

PREMISE: Seed dispersal is extremely important for the recovery and restoration of forest communities. Relict tree genus Zelkova possesses a unique dispersal mechanism: mature fruits fall with the entire twig, and the dried leaves that are still attached function as a drag-enhancing appendage, carrying the fruits away from the parent tree. This singular adaptation has never been investigated in Z. abelicea. METHODS: Drop tests with dispersal units and individual fruits of Z. abelicea were performed in controlled conditions to measure their dispersal velocity and to define their flight mode.RESULTS: Zelkova abelicea utilizes both slowly falling dispersal units with chaotic motion, as well as fast falling individual fruits using the straight path. The falling velocity of Z. abelicea dispersal units is 1.53 m s-1, which is virtually identical to that of the East-Asiatic Z. serrata (1.51 m s-1). In contrast, the falling velocity of individual fruits was m s-1 (Z. serrata:5.36 m s-1).CONCLUSIONS: Members of the genus Zelkova, growing today in distant regions, show remarkable evolutionary conservation of the velocity and flight mechanics of their dispersal units. This is surprising since the Mediterranean and East Asiatic Zelkova species have been separated at least 15-20 Mya. Zelkova abelicea, although growing in the Mediterranean with completely different forest structure and composition, still uses the same dispersal mechanism. The dispersal capacity of the genus Zelkova is less efficient than that of other wind dispersed trees, and it presumably evolved for short-distance ecological spread and not for long-distance biogeographical dispersal.

New Pliocene macrofloras and microfloras perfectly preserved from the Mont-Dore (Puy-de-Dome, Massif central, France) have been reinvestigated. Samples come from different stratigraphical levels collected from three localities, Lac Chambon, La Gratade and Pont de Chocol. The 40Ar/39Ar radiometric datings bracketing the Chambon Lake and La Gratade fossil-bearing horizons give 4.46 ± 0.05 Ma and 3.94 ± 0.04 Ma, respectively, representative of the Zanclean Stage (= Brunssumian B and C), a period of the early Pliocene (5.32 to 3.6 Ma), much older than previously thought (i.e., Piacenzian). Pont de Chocol is considered to be close biostratigraphically, or even identical in age to La Gratade. Detailed morphological evaluation of leaf morphotypes completed with pollen analysis contributed to the better taxonomic knowledge of these palaeofloras. The overview focuses on floristic and phytostratigraphical characteristics of the defined stratigraphical units and their dating and correlation with previously defined palaeofloristic units of the Massif central. The study provides detailed identifications of plants representing 11 gymnosperms among which Pinaceae (pollen and winged seeds), Cupressaceae including “Taxodioid” pollen grains and Sciadopitaceae families (only pollen). Besides, different angiosperm trees and shrubs have been determined from both micro- and macro-remains. Fagaceae is the most diversified with several foliage of beech and deciduous oaks, while diversified Juglandaceae contribute mainly as abundant leaf remains of Carya, Pterocarya and Juglans; Ulmaceae with numerous leave of two Zelkova species, and also Ulmus. Various other deciduous dicotyledonous such as Alnus, Betula, Carpinus, Populus, Acer laetum and A. interrigenum are well documented. Leguminosae are recorded by a small number of leaflet imprints. Evergreen shrubs of Buxaceae (Buxus pliocenica) are scarce. All these taxa contribute to a rich biodiversity of these Pliocene assemblages. All three sites point towards riverine forest habitats dominated by hygrophilic diversified woody plants while in the surrounding plains and slopes the thermophilic elements were scarce and mesophilic taxa abundant as temperate elements. This vegetation can be compared with mixed mesophytic forests depicting a climate cooling during the two considered periods (ca. 4.46 and 3.95 Ma).

A new marine pollen record from SE Sicily is presented. The pollen study was done at a sub-decadal resolution to assess the role and extent of human impact in driving regional environmental and land cover changes over the last four hundred years. The combination of palaeoecological evidence and historical documents provides a detailed report of the main ecological dynamics in relation to socio-economic events, past land use, and land management regulations in Sicily. Our palaeovegetational reconstruction reveals a remarkably stable landscape, preserved by traditional land use practices that have persisted through the long-lasting feudal history of Sicily. After centuries of human-induced environmental stability, an abrupt change in vegetation structure occurred around 1950 AD, reflecting the modern land use policies and agricultural reforms following the Second World War. This vegetational breakpoint in SE Sicily corresponds to a suggested date for the onset of the Anthropocene. (C) 2021 Elsevier B.V. All rights reserved.

A circular bark with a 30 cm width was artificially removed from the trunk of a 250-year-old zelkova tree (Zelkova serrata) heavily damaged by artificial girdling in Sunchang, Jeonbuk Province in March of 2005. The debarked area was cleaned approximately 10 days after artificial girdling and bark margins with 2 cm width above and below the girdled portion were cut off to promote wound callus formation. Nine pieces of fresh bark (width 8 cm, length 35 cm, thickness 0.5 cm) were then prepared from branches of neighbor zelkova trees broken by heavy snowfalls and pasted onto the girdled portion of the tree, after which a Vaseline dressing was applied to water-proof the area and rubber bars were used to hold the implants to the trunk. Two pieces of the implanted fresh barks were successfully grafted onto the girdled area and the damaged tree has been vigorously growing over 13 years. To our knowledge, this is the first case of successful bark implantation to cure a 250-year-old zelkova tree heavily damaged by artificial girdling. This bark implantation technique will be utilized for the conversation and management of heavily damaged big and old trees in the future.

Effects on seed germination characteristics of 17 tree species were investigated under elevated temperature and CO2. Seeds of 5 needle-leaf and 12 broad-leaf species were germinated under four conditions: 24°C + 400 μmol CO2 mol air–1, 24°C + 750 μmol CO2 mol air–1, 27°C + 400 μmol CO2 mol air–1, and 27°C + 750 μmol CO2 mol air–1. The elevated temperature and CO2 affected germination percent (GP) of 7 tree species seeds.GPs of Pinus densiflora, P. thunbergii, Betula ermanii, and Maackia amurensisseeds were affected by the elevated temperature, while only that of P.jezoensis seed was influenced by the elevated CO2. GPs of Malus baccata and Zelkova serrataseeds were influenced by both the elevated temperature and CO2. In addition, the elevated temperature and CO2also affected mean germination time (MGT) of 12 tree species seeds. Particularly, MGTs of P. thunbergii and Rhododendron tschonoskii seeds were influenced by both factors. In conclusion, elevated temperature and CO2 affected seed germination characteristics, which were reflected by significant differences among tree species. Specifically, these two factors exerted stronger influence on germination pattern such as MGT rather than seed germination percent.

Hikobe House is an important cultural property located in Gunma prefecture. It is one of the oldest manor houses in the Kanto region of Japan. The age of the Hikobe House has up to now been uncertain. There are no architectural records or memorandum tags that indicate when the Hikobe House was built. The living room of the Hikobe House has a style of the latter half of the 17th century, while the guest rooms exhibit a style more typical of the 16th century. So, architectural historians did not agree when the house was built. The wooden materials of the Hikobe House (zelkova, cherry tree, and Japanese red pine) are species that are not well suited to dendrochronology. Thus we investigated the materials of the Hikobe House using the radiocarbon (14C) dating method. Using both the 14C wiggle-match dating method on short tree-ring sequences and observations of remodeling traces of the materials, we were able to establish a credible age of Hikobe House as dating from the late 17th century.

A hundred pollen and plant macrofossil records from the Iberian Peninsula, Southern France, the Italian Peninsula, Greece and the Aegean, and the southwestern Black Sea area formed the basis for a review of the Quaternary distribution and extirpation of tree populations from Southern Europe. Following a discussion of the caveats/challenges about using pollen data, the Quaternary history of tree taxa has been reconstructed with attention to Taxodium/Glyptostrobus , Sciadopitys , Cathaya , Cedrus , Tsuga , Eucommia , Engelhardia , Carya , Pterocarya , Parrotia , Liquidambar , and Zelkova. The timing of extinction, distributed over the whole Quaternary, appears very diverse from one region to the other, in agreement with current biodiversity in Southern Europe. The geographical patterns of persistence/disappearance of taxa show unexpected trends and rule out a simple North to South and/or West to East trend in extirpations. In particular, it is possible to detect disjunct populations ( Engelhardia ), long-term persistence of taxa in restricted regions ( Sciadopitys ), distinct populations/species/genera in different geographical areas ( Taxodium type). Some taxa that are still widespread in Europe have undergone extirpation in Mediterranean areas in the lateglacial period and Holocene ( Buxus , Carpinus betulus , Picea ); they provide an indication of the modes of disappearance of tree populations that may be useful to evaluate correctly the vulnerability of modern fragmented plant populations. The demographic histories of tree taxa obtained by combined palaeobotanical and genetic studies is a most challenging field of research needed not only to assess species/population differentiation, but also to reach a better understanding of extinction processes, an essential task in the current global change scenario.

The complete chloroplast genome sequence of the Tertiary relict tree Zelkova serrata was reported in this study. The chloroplast genome is 158,875 bp in length with a typical angiosperm quantitative structure consisting of a large single copy (87,412 bp) and a small single copy (18,683 bp) separated by a pair of inverted repeat (26,390 bp). Genome annotation revealed a total of 129 genes comprising 84 protein-coding genes, 37 tRNA genes, and eight rRNA genes. Phylogenomic analysis based on the whole plastomes indicated that Z. serrata and Z. schneideriana formed a well-supported monophyletic clade sister to genus Ulmus in Ulmaceae.

Xylem and phloem sap flows in an intact, young Japanese zelkova tree (Zelkova serrata (Thunb.) Makino) growing outdoors were measured using magnetic resonance imaging (MRI). Two propagator-based sequences were developed for q-space imaging: pulse field gradient (PFG) with spin echo (PFG-SE) and stimulated echo (PFG-STE), which were used for xylem and phloem flow measurements, respectively. The data evaluation methods were improved to image fast xylem flow and slow phloem flow. Measurements were taken every 2–3 h for several consecutive days in August 2016, and diurnal changes in xylem and phloem sap flows in a cross-section of the trunk were quantified at a resolution of 1 mm2. During the day, apparent xylem flow volume exhibited a typical diurnal pattern following a vapor pressure deficit. The velocity mapping of xylem sap flow across the trunk cross section revealed that the greatest flow volume was found in current-year earlywood that had differentiated in April–May. The combined xylem flow in the 1- and 2-year-old annual rings also contributed to one-third of total sap flow. In the phloem, downward sap flow did not exhibit diurnal changes. This novel application of MRI in visualization of xylem and phloem sap flow by MRI is a promising tool for in vivo study of water transport in mature trees.

Street trees are integral components of urban green infrastructure. The importance of benefits provided by street trees has motivated the development of various tools to quantify the value of ecosystem services. The i-Tree Eco is a widely applied method for quantifying urban forest structure, ecosystem services, and values. Since its first release in 2006, i-Tree Eco has been successfully utilized in over 100 countries around the world. This study described one of the first applications of the i-Tree Eco international project in Kyoto, Japan, by customizing the models and parameters to enhance the accuracy of analysis results. Kyoto’s street trees are prominently dominated by Ginkgo (Ginkgo biloba L.), Trident Maple (Acer buergerianum Miq.), Japanese Zelkova (Zelkova serrata (Thunb.) Makino.), Tuliptree (Liriodendron tulipifera L.), Flowering dogwood (Cornus florida L.), London Planetree (Platanus × acerifolia), Plum/cherry (Prunus spp.), and Weeping willow (Salix babylonica), which account for 92% of the 1230 sample trees and deliver ecosystem service benefits at US$71,434.21 annually or US$58.07/tree/year. The annual value of each function was estimated at US$41.34/tree for carbon storage and sequestration, US$3.26/tree for stormwater runoff reduction, US$11.80/tree for adverse health mitigation effects, and US$1.67/tree for energy savings. The street tree species of Kyoto city that produce the highest average annual benefits are among the largest trees currently in the population, including P. × yedoensis (US$225.32/tree), Z. serrata (US$123.21/tree), S. babylonica (US$80.10/tree), and P. × acerifolia (US$65.88/tree). Our results demonstrated a comprehensive understanding of street trees benefits for Kyoto city, providing baseline information for decision-makers and managers to make effective urban trees management decisions, developing policy, and setting priorities.

A new fossil species of Zelkova is described from the Oligocene Ningming Formation of Guangxi, South China. Zelkova ningmingensis sp. nov. is characterized by leaves with craspedodromous venation pattern and drupaceous fruit type. The new species possesses elliptical to ovate leaves, bearing 7–12 pairs of secondary and simple toothed margin, as well as epidermal cells with straight or rounded anticlinal walls. The species is compared with extant and other fossil species hitherto reported of the genus. It is most similar to the living Zelkova schneideriana in the leaf gross morphology and epidermal characters, which may be suggested to be the ancestral type of Zelkova schneideriana. The discovery of Zelkova ningmingensis sp. nov. in Guangxi indicates that Zelkova has already existed in southern China as early as the Oligocene. In combination with Zelkova material from the Oligocene of Europe, it can be inferred that Eurasian Zelkova had begun to diversify by at least the Oligocene. Because China is the bio...

We determined a suitable amount of fertilizer for konara oak (Quercus serrata) and Japanese zelkova (Zelkova serrata) planted in a harvested pitch pine (Pinus rigida) plantation. Two-year-old bare-root seedlings of konara oak and one-year-old containerized seedlings of Japanese zelkova were planted in April 2011. Three plots were established for each tree species to evaluate each of three fertilization applications. Solid compound fertilizer (N:P:K = 3:4:1) was applied yearly in three amounts (control: no fertilization, F1: 180 kg ha−1, and F2: 360 kg ha−1), every May from 2011 to 2013. We measured the root collar diameter and height, and analyzed the compartmental N and P concentrations. Compartmental N concentrations of konara oak and Japanese zelkova were not consistent based on amount of fertilization. However, the compartmental P concentrations of konara oak and Japanese zelkova were significantly different in the order of F2, F1, and control. Although the differences in growth of konara oak appeared after 3 years of fertilization, Japanese zelkova showed differences after only 2 years of fertilization owing to differences in seedling type. Growth of konara oak was affected by fertilization at F1 and F2 in 2013. However, growth of Japanese zelkova was affected only at F2. Nutrient demand of Japanese zelkova appeard to be higher than that of konara oak, at least during the early growing period. Results from this study could be practically used in harvested pitch pine plantations to determine appropriate fertilization regimes.

Using vein density to study the relationship between plants and environment is an important topic for paleoclimate and paleoenvironment studies. In this paper, the vein density of fossil plants Zelkova ungeri Kovats, Machilus tiantaiensis Ding et Sun and their NLRs was analyzed using the one-dimensional analysis and two-dimensional analysis approaches. The mechanism of vein density responses to the environment variation was also discussed. Further, the differences of the vein density between the fossil and extant leaves were compared. The results indicated that the vein density of Z. schneideriana Hand.-Mazz. and M. pingii Cheng ex Yang increased closely with the increase of precipitation but not closely related with the variation of temperature. The vein density of Z. ungeri and M. tiantaiensis was respectively higher than that of their NLRs. Thus we deduced that the precipitation in eastern Zhejiang Province during the late Miocene was higher than that of nowadays and the paleoclimate was more humid at that time.

Today, NE China is highly affected by cold and dry winter monsoon winds, causing long and severe winters with monthly mean temperatures below − 10 °C. Yet, the Neogene paleoclimatic history of this region is not well understood due to the lack of precisely dated paleontological localities. Herein, we present several Ar–Ar basalt ages round a plant-bearing diatomite sequence of Badaogou, Changbai Mountains (Jilin Province; NE China — border to N-Korea), which allow us to revise its age from Miocene to ~ 2.5 Ma. A paleoenvironmental reconstruction based on fossil leaves, pollen and diatoms suggests deciduous forests rich in Acer , Quercus , Tilia , Ulmus and Zelkova mixed with conifers such as Tsuga , Picea and Abies within an already established mountain region close by. These forests were growing around a nutrient rich freshwater system with a pH > 7 in a presumably deep basin indicated by the strong dominance of planktonic diatoms Stephanodiscus minutulus and Pliocaenicus changbaiensis . The presence of tree taxa known from southern China today, such as Sassafras , Nyssa , Liquidambar , Podocarpus and Cedrus , leads to significantly warmer temperature estimates by the Coexistence Approach (mean annual temperature 11.5–15.7 °C, coldest month mean temperature − 0.3–9.6 °C, warmest month mean temperature 23.0–27.8 °C). Rainfall values aren't as precise, but suggest a mean annual precipitation of 843–1577 mm with monthly extremes of 109–220 mm (wettest), 17–41 mm (driest) and 73–175 mm (warmest). Although records in Eastern and Northern Asia as well as Central China report a cooling and drying after the onset of the Northern Hemisphere glaciation, the paleovegetation in NE China was not yet or hardly affected by the intensification of the winter monsoon. This emphasizes the importance of accurately dated records to improve large-scale paleoclimatic reconstruction as well as our understanding of the complexity of climate change.

The objective of this study is to investigate and evaluate that a roadside tree root intrudes sewer network systems. Two approaches were performed to assess the characteristics of tree root intrusion. First, the characteristics of tree roots that had invaded sewers were directly observed by means of closed-circuit television inspection robot. Second, the intrusion proportions of tree root into rain gutters in the sampling area were investigated. As tree species of low intrusion proportions, the results indicated that Ginkgo biloba Linn. and Acer buergerianum Miq. were 1.7% and 4.3%. On the other hand, tree species of high intrusion proportions were Metasequoia glyptostroboides Hu et Cheng, Ulmus davidiana var. japonica Nakai and Zelkova serrata Makino as 22.2%, 20.4%, and 17.6% respectively. In particular, sewers and gutters around Zelkova species should be the focus of maintenance work because of the high proportion of these trees on roadsides.

Foresters use diameter at breast height (DBH) to estimate timber volumes, quantify ecosystem services, and predict other biometrics that would be difficult to directly measure. But DBH has numerous problems, including a range of “breast heights” and challenges with applying this standard to divergent tree forms. Our study focuses on street trees that fork between 30 and 137 cm of height (hereafter “multi-stemmed trees”), which researchers have identified as particularly challenging in the ongoing development of urban allometric models, as well as consistency in measurements across space and time. Using a mixed methods approach, we surveyed 25 urban forestry practitioners in twelve cities in the northeastern United States (US) about the measurement and management of multi-stemmed street trees, and intensively measured 569 trees of three frequently planted and commonly multi-stemmed genera (Malus, Prunus, and Zelkova) in Philadelphia, PA, US. Specifically, we measured stem diameter at several distances above the ground: at the root collar, at 30 cm, just below the fork (which occurred between 30 and 137 cm), and at 137 cm (up to six stems following established protocols). Survey responses indicated that current mensuration practices are burdensome, that practitioners employ alternatives to the current protocols for measuring at 137 cm, and that small-statured, frequently multi-stemmed trees are an increasing proportion of street tree populations. Analysis of field data did not find substantial differences between methods of measurement with regard to predictive power for total height and average crown width. Alternatives to the current protocols for measuring at 137 cm have other advantages, including time required, ease of measurement, simplicity, and capacity to compare measurements between trees and over time. For trees that fork between 30 and 137 cm, we recommend taking a single diameter measurement at a lower height—either just below the fork or at 30 cm. Diameter measurements at 30 cm better serve researchers seeking to consistently measure radial growth over time, whereas diameter below the fork may suit practitioners who do not need fine resolution in trunk measurements.

We describe the Late Pliocene paleoenvironment and paleoclimate of the Pula fossil site of the western Pannonian Basin, Hungary, which occurs within a lacustrine succession deposited in a volcanic crater (maar). Radiometric dating of adjacent volcanic bodies hosting the fossil-bearing sedimentary assemblages gives an age of 4.25 ± 0.17 Ma (K–Ar). To date, five, articulated rhinoceros skeletons (Dihoplus sp.) have been recovered, and a few fragmentary remains of artiodactyls and freshwater fishes (Perca sp., Leuciscus sp. and Gobius sp.) are also present. An insect taphocoenosis comprises terrestrial groups that inhabited the former lake margins (Syrphidae, Heteroptera, Chalcidoidea, Tenebrionidae) as well as aquatic insects (Dytiscidae, Baetidae, and Chironomidae). Deciduous broad-leaved, woody plants prevailed in and around the Pula locality (Quercus, Ulmus, Zelkova, Acer, Salicaceae) and are associated with some rare floral elements (Ginkgo, Sassafras) and Buxus. Deposition at the lake bottom seems to have taken place in oxygen-depleted layers, and taphonomic evidence indicates that fossil material underwent minimal (if any) weathering. δ13C values of one rhinoceros tooth suggest that this mammal consumed mixed C3 plants in a wooded environment. The climatic conditions inferred from the reconstructed vegetation and stable oxygen isotope data from the tooth enamel support a Cf-type climate (Koppen classification) with a mean annual temperature of 10–13 °C with some dry periods during the year. Pula is comparable to other maar fossil sites of Pliocene age such as Camp dels Ninots, Spain, and Hajnacka I, Slovakia.

Zelkova species, trees of the elm family (Ulmaceae), are part of the Cenozoic relict flora. In western Eurasia, the genus comprises three species that are restricted to disjunct areas (Z. sicula on Sicily, Z. abelicea on Crete and Z. carpinifolia in Transcaucasia). The situation is different in East Asia, where three species (Z. serrata, Z. schneideriana and Z. sinica) have at least partly overlapping distributions. The phylogenetic and phylogeographic status of these East Asian species is still not well understood, mainly since all previous studies used almost exclusively plant material collected in botanical gardens and were based on very small numbers of individuals. Our study is the first based on 33 natural populations covering all important areas with Zelkova species in the Sino-Japanese Floristic Region. Chloroplast and microsatellite markers were used, and Bayesian analyses were run for both types of markers. East Asian Zelkova species cluster into two groups that partially overlap when comparing the two types of markers. For chloroplast markers, the two groups coincide with all Japanese, some Korean and northern Chinese Z. serrata in one group and all other individuals in the other group, regardless of whether they are attributed to Z. serrata, Z. sinica or Z. schneideriana from Korea, mainland China and Taiwan. At the nuclear level, however, the clustering clearly groups all the Z. serrata individuals together, regardless of whether they are from Japan, Korea or China, and the two other species in a second group. This complex genetic pattern in East Asian Zelkova species is most likely due to a combination of ancient diversification and speciation events and more recent hybridization during the last glacial/interglacial retractions and recolonizations. One of the surprising results of our study concerns the populations from Taiwan, which are genetically similar to Z. schneideriana. Thus, their assignation to a separate taxon (Z. tarokoensis) or to a variety of Z. serrata (Z. serrata var. tarokoensis), as currently reported in all local and national floras, might be in need of revision. Furthermore, our results indicate that the East Asian species are more closely related to Z. carpinifolia than to any other Western European species. Haplotypes of Z. sicula and Z. abelicea (Mediterranean region) as well as those of Z. sinica and Z. schneideriana (East Asia) seem to have diversified more recently. The most ancient haplotypes are found among the western Eurasian Z. carpinifolia and the East Asian Z. serrata. This result is in agreement with the carpinifolia and serrata-like morphotypes commonly found in the fossil record.