Metasequoia

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Fitzpatrick-cooper Julia - One of the best experts on this subject based on the ideXlab platform.

Richard Jagels - One of the best experts on this subject based on the ideXlab platform.

  • Why Did Metasequoia Disappear from North America but Not from China
    Bulletin of the Peabody Museum of Natural History, 2007
    Co-Authors: Richard Jagels, Maria A. Equiza
    Abstract:

    Abstract Fossils of Metasequoia, beginning in the Cretaceous Period, have been found throughout the Northern Hemisphere. In North America this genus survived at least through the Pliocene, and in Asia through the early Pleistocene. Fossils from the Holocene are missing on both continents, yet Metasequoia survived, presumably in wet-site refugia along the Yangtze River, and survives today as relic populations in central China. Metasequoia has completely disappeared in North America. We present the case that the ecological requirement of moist bare soil for seedling establishment constrains Metasequoia to regularly disturbed riparian zones. The river systems of the western United States could have provided migratory routes for Metasequoia to the Southeast as climate cooled and land masses rose. However, Taxodium, a genus not found in Asia, has the same specialized seedling establishment requirements as Metasequoia. We previously showed that Metasequoia has the superior photosynthetic system for adapting to ...

  • Differential Carbon Allocation in Metasequoia glyptostroboides, Taxodium distichum and Sequoia sempervirens Growing under Continuous Light
    Bulletin of the Peabody Museum of Natural History, 2007
    Co-Authors: Maria A. Equiza, Richard Jagels, Damián Cirelli
    Abstract:

    Abstract During the early Tertiary, the genus Metasequoia was widely distributed and abundant in the high Arctic, suggestive of an adaptive fit between the Arctic paleoenvironment and the physiology of this relic genus. While present day temperature is clearly restrictive for growth in the Arctic, evidence suggests that the paleotemperature was much more benign. In contrast, the light regime can be assumed unchanged, with annual periods of several months of continuous light and continuous darkness at the high latitudes influencing the plants that populated its paleolandscape. Previously, we have shown that the continuous-light environment is stressful for plant photosynthesis and related metabolic pathways. Here we explore the photosynthetic response along with carbon and nutrient allocation of Metasequoia glyptostroboides, Taxodium distichum and Sequoia sempervirens when exposed to a continuous-light treatment. Our findings indicate that Metasequoia has the unique combination of indeterminate growth and ...

  • physiological responses of three deciduous conifers Metasequoia glyptostroboides taxodium distichum and larix laricina to continuous light adaptive implications for the early tertiary polar summer
    Tree Physiology, 2006
    Co-Authors: Alejandra Equizam M A Equiza, Michael E. Day, Richard Jagels
    Abstract:

    Polar regions were covered with extensive forests during the Cretaceous and early Tertiary, and supported trees comparable in size and productivity to those of present-day temperate forests. With a winter of total or near darkness and a summer of continuous, low-angle illumination, these temperate, high-latitude forests were characterized by a light regime without a contemporary counterpart. Although maximum irradiances were much lower than at mid-latitudes, the 24-h photoperiod provided similar integrated light flux. Taxodium, Larix and Metasequoia, three genera of deciduous conifers that occurred in paleoarctic wet forests, have extant, closely related descendents. However, the contemporary relative abundance of these genera differs greatly from that in the paleoarctic. To provide insight into attributes that favor competitive success in a continuous-light environment, we subjected saplings of these genera to a natural photoperiod or a 24-h photoperiod and measured gas exchange, chlorophyll fluorescence, non-structural carbohydrate concentrations, biomass production and carbon allocation. Exposure to continuous light significantly decreased photosynthetic capacity and quantum efficiency of photosystem II in Taxodium and Larix, but had minimal influence in Metasequoia. In midsummer, foliar starch concentration substantially increased in both Taxodium and Larix saplings grown in continuous light, which may have contributed to end-product down-regulation of photosynthetic capacity. In contrast, Metasequoia allocated photosynthate to continuous production of new foliar biomass. This difference in carbon allocation may have provided Metasequoia with a two fold advantage in the paleoarctic by minimizing depression of photosynthetic capacity and increasing photosynthetic surface.

  • The adaptive physiology of Metasequoia to eocene high-latitude environments
    The Evolution of Plant Physiology, 2004
    Co-Authors: Richard Jagels, Michael E. Day
    Abstract:

    Publisher Summary This chapter explores the physiological basis for Metasequoia's success in the Eocene high-Arctic and the ecophysiological attributes that imparted adaptive value to trees inhabiting this unique environment (Eocene high-Arctic). The environment that has been advanced for Eocene high-latitude forests provided a unique combination of light, temperature, and water regimes that offers an unparalleled set of adaptive challenges to plant species. The temperate continuous light (CL) regime offered both substantial physiological challenges and the potential benefit of high growth rates for species able to overcome those physiological hurdles. Among the unusual aspects of Metasequoia is a collection of characteristics that do not fit contemporary models of shade-adaptation or sun-adaptation. Metasequoia possesses an aggregation of characteristics not generally associated with either adaptive strategy, but competitively adaptive at high latitudes. While the photosynthetic rates of Metasequoia under light intensities typical of the growing season at middle latitudes are clearly much lower than those of sun-adapted conifers, its resource allocation to photosynthetic systems (leaf-level) is close to optimum for the moderate light intensities of the Arctic lowland forests, or cloudier lower palaeolatitudes. Metasequoia could rapidly produce canopies with extensive leaf area, not only efficiently capturing incident light for photosynthesis, but minimizing the transmitted light that would be available for competitors. Production of low-density stem wood permitted Metasequoia rapidly to overtop potential competitors that were establishing concurrently. The importance of photorespiration and alternate pathways for photoenergetics in Metasequoia and other species growing under CL regimes are yet to be explored.

  • Competitive Advantages of Metasequoia in Warm High Latitudes
    Topics in Geobiology, 1
    Co-Authors: Richard Jagels, Maria A. Equiza
    Abstract:

    Although the fossil remains of several conifer species have been found from numerous lowland Eocene sites throughout the very high latitudes (above 75° N), many were rarities, and only Metasequoia Miki appeared to have thrived under the warm and unique lighting conditions of the High Arctic regions of the Northern Hemisphere. To estimate the relative competitiveness of the fossil conifers, mechanical/hydraulic stem attributes, photosynthetic water-use-efficiency and photobiology were compared among extant nearest-living-relatives: Metasequoia glyptostroboides Hu et Cheng, Sequoia sempervirens (D. Don) Endlicher, Taxodium distichum (L.) Richard, Glyptostrobus pensilis (Staunton ex D. Don) K. Koch and Larix laricina (Du Roi) K. Koch. Based on these physiological comparisons we conclude that Taxodium Richard would have been limited primarily by a significant decrease in photosynthetic efficiency when growing under continuous light. Sequoia Endlicher should have been highly competitive, but was likely limited by its evergreen habit. Glyptostrobus Endlicher would have been restricted to minor component status by its slow growth rate and short stature. Finally, although Larix Miller demonstrated improved water-use-efficiency under continuous light, it had a less-competitive photobiology than Metasequoia, and sequestered more resources into stem biomass.

Li Wang - One of the best experts on this subject based on the ideXlab platform.

  • Spring drought as a possible cause for disappearance of native Metasequoia in Yunnan Province, China: Evidence from seed germination and seedling growth
    Global Ecology and Conservation, 2020
    Co-Authors: Yukun Fan, Li Wang, Qinying Lan
    Abstract:

    Abstract Metasequoia glyptostroboides is a well-known relict conifer species that was widely distributed in the Northern Hemisphere from the Mesozoic (Cretaceous) to early Cenozoic, after which its distributional range was contracted significantly. To explore the possible reasons for the disappearance of Metasequoia in southwest China, controlled experiments were conducted on seed germination and seedling growth and survival over a range of temperatures and at different levels of water stress. Germination was 76%–83.2% at temperatures ranging from 10 °C to 30 °C and did not differ significantly. However, germination decreased significantly at 5 °C and 35 °C. Low water stress (−0.2 MPa to −0.4 MPa) promoted germination of Metasequoia seeds, but at −1.5 MPa to −2 MPa normal seedling emergence was only 1.4–2.4%. Seed germination decreased with an increase in storage temperature, and seeds stored at room temperature (23–25 °C) for 6 and 12 months germinated to 0–24.3%. As the concentration of polyethylene glycol 6000 increased, elongation of the roots and stems first increased and then decreased, while the number of leaves and percentage of seedling survival decreased. At −0.6 MPa to −0.7 MPa, seedling survival was only 12%–15%. Thus, moisture conditions were the main factor affecting seed germination and seedling growth and survival of Metasequoia. Our results suggest that the intensification of drought in winter and spring due to development of the monsoon climate in Asia was an important factor for the disappearance of Metasequoia in southwest China.

  • The disappearance of Metasequoia (Cupressaceae) after the middle Miocene in Yunnan, Southwest China: Evidences for evolutionary stasis and intensification of the Asian monsoon
    Review of Palaeobotany and Palynology, 2019
    Co-Authors: Li Wang, Lutz Kunzmann, Yao-wu Xing, Shi-tao Zhang, Yuqing Wang, Zhe-kun Zhou
    Abstract:

    Metasequoia glyptostroboides Hu et W.C.Cheng (Cupressaceae) is a relic plant with a narrow natural distribution in central China. Historically, the genus Metasequoia Hu et W.C.Cheng has rich fossil records from the Cretaceous to the Pleistocene in the Northern Hemisphere, but fossil records of Metasequoia in China are still rare, which limits our knowledge of its biogeographic history under paleoenvironmental changes. Here, we describe leaves including cuticles and ovuliferous cones from the middle Miocene of Zhenyuan, Yunnan, Southwest China, comprising the southernmost fossil record of the genus worldwide. Judging by the great morphological similarity between these fossils and extant M. glyptostroboides, we identify them as Metasequoia sp. (cf. Metasequoia glyptostroboides). The material documents obviously a long lasting morphological stasis within the genus. Meta sequoia sp. (cf. M. glyptostroboides) considerably expands the spatial distribution range of Metasequoia in the geological past. Furthermore, possible reasons for its disappearance in Southwest China are discussed. Together with other evidence, it is concluded that the disappearance of Metasequoia from Southwest China might be related to the evolutionary stasis of Metasequoia, most likely preventing necessary adaptations of the plants to increasing winter and spring aridity induced by the intensification of the Asian monsoon in this region during the Neogene. (C) 2018 Published by Elsevier B.V.

  • Fossilized Metasequoia from Tokamachi and Kumagaya sites.
    2015
    Co-Authors: Yuqing Wang, Arata Momohara, Li Wang, Julie Lebreton-anberrée, Zhe-kun Zhou
    Abstract:

    Fossilized Metasequoia branchlet and needles from Tokamachi (a) and Kumagaya (b) as examples to show the megafossils of Metasequoia used in this research, compare with a modern Metasequoia branchlet (c). White arrows in (a) indicate the branchlet.

  • Fossilized Metasequoia stomatal index and paleo-[CO2]atm concentration estimates during Cenozoic.
    2015
    Co-Authors: Yuqing Wang, Arata Momohara, Li Wang, Julie Lebreton-anberrée, Zhe-kun Zhou
    Abstract:

    Fossilized Metasequoia stomatal index and paleo-[CO2]atm concentration estimates during Cenozoic.

  • Metasequoia samples used for reconstructing paleo-CO2 including fossil sites, ages, latitude, and longitude.
    2015
    Co-Authors: Yuqing Wang, Arata Momohara, Li Wang, Julie Lebreton-anberrée, Zhe-kun Zhou
    Abstract:

    Metasequoia samples used for reconstructing paleo-CO2 including fossil sites, ages, latitude, and longitude.

Maria A. Equiza - One of the best experts on this subject based on the ideXlab platform.

  • Why Did Metasequoia Disappear from North America but Not from China
    Bulletin of the Peabody Museum of Natural History, 2007
    Co-Authors: Richard Jagels, Maria A. Equiza
    Abstract:

    Abstract Fossils of Metasequoia, beginning in the Cretaceous Period, have been found throughout the Northern Hemisphere. In North America this genus survived at least through the Pliocene, and in Asia through the early Pleistocene. Fossils from the Holocene are missing on both continents, yet Metasequoia survived, presumably in wet-site refugia along the Yangtze River, and survives today as relic populations in central China. Metasequoia has completely disappeared in North America. We present the case that the ecological requirement of moist bare soil for seedling establishment constrains Metasequoia to regularly disturbed riparian zones. The river systems of the western United States could have provided migratory routes for Metasequoia to the Southeast as climate cooled and land masses rose. However, Taxodium, a genus not found in Asia, has the same specialized seedling establishment requirements as Metasequoia. We previously showed that Metasequoia has the superior photosynthetic system for adapting to ...

  • Differential Carbon Allocation in Metasequoia glyptostroboides, Taxodium distichum and Sequoia sempervirens Growing under Continuous Light
    Bulletin of the Peabody Museum of Natural History, 2007
    Co-Authors: Maria A. Equiza, Richard Jagels, Damián Cirelli
    Abstract:

    Abstract During the early Tertiary, the genus Metasequoia was widely distributed and abundant in the high Arctic, suggestive of an adaptive fit between the Arctic paleoenvironment and the physiology of this relic genus. While present day temperature is clearly restrictive for growth in the Arctic, evidence suggests that the paleotemperature was much more benign. In contrast, the light regime can be assumed unchanged, with annual periods of several months of continuous light and continuous darkness at the high latitudes influencing the plants that populated its paleolandscape. Previously, we have shown that the continuous-light environment is stressful for plant photosynthesis and related metabolic pathways. Here we explore the photosynthetic response along with carbon and nutrient allocation of Metasequoia glyptostroboides, Taxodium distichum and Sequoia sempervirens when exposed to a continuous-light treatment. Our findings indicate that Metasequoia has the unique combination of indeterminate growth and ...

  • Competitive Advantages of Metasequoia in Warm High Latitudes
    Topics in Geobiology, 1
    Co-Authors: Richard Jagels, Maria A. Equiza
    Abstract:

    Although the fossil remains of several conifer species have been found from numerous lowland Eocene sites throughout the very high latitudes (above 75° N), many were rarities, and only Metasequoia Miki appeared to have thrived under the warm and unique lighting conditions of the High Arctic regions of the Northern Hemisphere. To estimate the relative competitiveness of the fossil conifers, mechanical/hydraulic stem attributes, photosynthetic water-use-efficiency and photobiology were compared among extant nearest-living-relatives: Metasequoia glyptostroboides Hu et Cheng, Sequoia sempervirens (D. Don) Endlicher, Taxodium distichum (L.) Richard, Glyptostrobus pensilis (Staunton ex D. Don) K. Koch and Larix laricina (Du Roi) K. Koch. Based on these physiological comparisons we conclude that Taxodium Richard would have been limited primarily by a significant decrease in photosynthetic efficiency when growing under continuous light. Sequoia Endlicher should have been highly competitive, but was likely limited by its evergreen habit. Glyptostrobus Endlicher would have been restricted to minor component status by its slow growth rate and short stature. Finally, although Larix Miller demonstrated improved water-use-efficiency under continuous light, it had a less-competitive photobiology than Metasequoia, and sequestered more resources into stem biomass.

Qin Leng - One of the best experts on this subject based on the ideXlab platform.

  • Research Advance on Metasequoia: Applications of New Technology
    Science Foundation in China, 2010
    Co-Authors: Qin Leng, Hong Yang, Li Wang
    Abstract:

    The plant genus Metasequoia Miki, 1941 and its sole living relict species Metasequoia glyptostroboides Hu et Cheng, 1948 have been of special interest for both the public and scientists since 1941 when the genus was established. Due to its unique discovery history (fossils discovered earlier than the living species) and incomparable scientific value in the research of plant evolution and its relationship with environmental and climatic changes, Metasequoia becomes arguably the most comprehensively studied higher plant in both fossil and living forms. This paper summarized recent advance in Metasequoia research by reviewing the research history of Metasequoia and the scientific value of this genus, while paid special attention to the application of new methods and techniques in the research field of Metasequoia in the recent decades. The application of biogeochemical (organic geochemistry and stable isotope) analysis as well as the new and innovated methods of preparing large-sized cuticular membrane from leaves with originally thin and fragile cuticles further secure Metasequoia's super star status for the research of palaeoclimatic reconstruction.

  • Diagenesis of plant biopolymers: Decay and macromolecular preservation of Metasequoia
    Organic Geochemistry, 2009
    Co-Authors: Neal S. Gupta, Qin Leng, Hong Yang, Derek E. G. Briggs, George D. Cody, Roger E. Summons
    Abstract:

    Abstract Analysis of modern Metasequoia leaves revealed the presence of the structural polyester cutin, guaiacyl lignin units and polysaccharides. Analysis of environmentally decayed Metasequoia leaves revealed that guaiacyl lignin units and cellulose were degraded more than vinyl phenol (the last being the primary pyrolysis product of cutin and plant cuticles) suggesting that cutin is more stable than lignin and cellulose during degradation, contrary to some previous studies. This observation is supported by electron microscopy showing changes in the cellular structure and cuticle of modern, decayed and fossil Metasequoia leaves. Metasequoia fossils from the Eocene of Republic (Washington State) showed a significant aliphatic component, but biopolymeric lignin and polysaccharides were not detected. Fossils from the Eocene of Axel Heiberg revealed the presence of lignin and an aliphatic polymer up to C29 with cellulose, and fossils from the Miocene Clarkia deposit (Idaho) revealed lignin and an aliphatic polymer up to C27 without any polysaccharides. Modern Metasequoia needles heated experimentally in confined conditions generated a macromolecular composition with an aliphatic polymer up to C32 and additional phenolic compounds similar to those present in the fossils. Experimental heating of cutin is known to generate an aliphatic polymer with carbon chain length units C20 in the heated Metasequoia needles is a product of incorporation of longer chain plant waxes, indicated by the odd/even predominance of the >C27 n-alkanes. The resistant nature of cutin compared to lignin and polysaccharides explains the presence of an n-alkyl component (

  • Labile Biomolecules in Three-dimensionally Preserved Early Tertiary Metasequoia Leaves from Ellesmere Island, Canada
    Bulletin of the Peabody Museum of Natural History, 2007
    Co-Authors: Hong Yang, Qin Leng, Ben A. Lepage
    Abstract:

    Abstract Labile biomolecules, such as carbohydrates and fatty acids, are rarely preserved in the pre-Quaternary geological record and were traditionally thought to play a nonsupportive role in the preservation of morphological structures during the process of fossilization. We document the in situ preservation of polysaccharides and cutin acids in late Paleocene–early Eocene (approximately 60 Ma) three-dimensionally preserved Metasequoia leaves from Ellesmere Island, Nunavut, in the Canadian Arctic Archipelago. In addition to abundant polysaccharides, cutin-derived fatty acids are effectively detected with a modified version of the online pyrolysis–gas chromatography/mass spectrometry technique that uses tetramethylammonium hyroxide. These biomolecules are the oldest of these types of biomolecules so far documented in the fossil record. Scanning electron microscopy observations of transverse sections of the fossil Metasequoia leaf tissues indicate a layered cuticle overlaying the epidermal cells and amorp...

  • Variation of cuticle micromorphology of Metasequoia glyptostroboides (Taxodiaceae)
    Botanical Journal of the Linnean Society, 2001
    Co-Authors: Qin Leng, Hong Yang, Qun Yang, Jianping Zhou
    Abstract:

    Leaf cuticle micromorphology of Metasequoia glyptostroboides Hu & W. C. Cheng was studied with SEM using samples collected from its natural population in south-central China and cultivated trees in Nanjing City. The cuticle characters from both natural and cultivated trees living in different environments allowed us to re-evaluate taxonomic values of certain cuticular characters and to assess their relationships with environmental factors and the degree of tree maturity. External and internal cuticular features of both adaxial (upper) and abaxial (lower) leaf surfaces revealed the following: (1) Cuticle micromorphology of M. glyptostroboides is distinct among Taxodiaceae, but that variation does not exceed the range of this family. (2) Except for an isolated tree outside the Metasequoia valley, the cuticular features displayed by individual trees from the main Metasequoia groves demonstrate a high degree of uniformity, which is in congruence with previous observations on the low population variability at the gross morphology level. (3) Cuticular characters of graftedMetasequoia trees living in different environments are identical to those of their original trees, indicating that no cuticular character of this species could be regarded as an environmental indicator. (4) Recognition of some unique cuticular features in a Metasequoia tree in an isolated location may lead to a rare source for increasing the variation of this endangered species.

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