scholarly journals Searching for a nearest living equivalent for Bennettitales: a promising extinct plant group for stomatal proxy reconstructions of Mesozoic pCO2

GFF ◽  
2021 ◽  
pp. 1-12
Author(s):  
Margret Steinthorsdottir ◽  
Caroline Elliott-Kingston ◽  
Mario Coiro ◽  
Jennifer C. McElwain
Keyword(s):  
Plant Group ◽  
Proxy Reconstructions

scholarly journals Comparative analysis and phylogenetic investigation of Hong Kong Ilex chloroplast genomes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bobby Lim-Ho Kong ◽  
Hyun-Seung Park ◽  
Tai-Wai David Lau ◽  
Zhixiu Lin ◽  
Tae-Jin Yang ◽  
...  
Keyword(s):  
Hong Kong ◽  
Comparative Analysis ◽  
Phylogenetic Relationships ◽  
Species Level ◽  
The Other ◽  
Trna Genes ◽  
Protein Coding ◽  
Chloroplast Genomes ◽  
Plant Group ◽  
Ilex Rotunda

AbstractIlex is a monogeneric plant group (containing approximately 600 species) in the Aquifoliaceae family and one of the most commonly used medicinal herbs. However, its taxonomy and phylogenetic relationships at the species level are debatable. Herein, we obtained the complete chloroplast genomes of all 19 Ilex types that are native to Hong Kong. The genomes are conserved in structure, gene content and arrangement. The chloroplast genomes range in size from 157,119 bp in Ilex graciliflora to 158,020 bp in Ilex kwangtungensis. All these genomes contain 125 genes, of which 88 are protein-coding and 37 are tRNA genes. Four highly varied sequences (rps16-trnQ, rpl32-trnL, ndhD-psaC and ycf1) were found. The number of repeats in the Ilex genomes is mostly conserved, but the number of repeating motifs varies. The phylogenetic relationship among the 19 Ilex genomes, together with eight other available genomes in other studies, was investigated. Most of the species could be correctly assigned to the section or even series level, consistent with previous taxonomy, except Ilex rotunda var. microcarpa, Ilex asprella var. tapuensis and Ilex chapaensis. These species were reclassified; I. rotunda was placed in the section Micrococca, while the other two were grouped with the section Pseudoaquifolium. These studies provide a better understanding of Ilex phylogeny and refine its classification.

The Currently Earliest Angiosperm Fruit from the Jurassic of North America

2021 ◽  
Vol 2 (4) ◽  
Author(s):  
Xin Wang
Keyword(s):  
North America ◽  
Early Cretaceous ◽  
Middle Jurassic ◽  
Early Evolution ◽  
The North ◽  
Plant Group ◽  
Ecological Radiation ◽  
Origin Of Angiosperms ◽  
Crucial Test

Angiosperms are the single most important plant group in the current ecosystem. However, little is known about the origin and early evolution of angiosperms. Jurassic and earlier traces of angiosperms have been claimed multiple times from Europe and Asia, but reluctance to accept these records remains. To test the truthfulness of these claims, palaeobotanical records from continents other than Europe and Asia constitute a crucial test. Here I document a new angiosperm fruit, Dilcherifructus mexicana gen. et sp. nov, from the Middle Jurassic of Mexico. Its Jurassic age suggests that origin of angiosperms is much earlier than widely accepted, while its occurrence in the North America indicates that angiosperms were already widespread in the Jurassic, although they were still far away from their ecological radiation, which started in the Early Cretaceous.

Traces of ancient range shifts in a mountain plant group (Androsace halleri complex, Primulaceae)

2007 ◽  
Vol 16 (18) ◽  
pp. 3890-3901 ◽  
Author(s):  
CHRISTOPHER J. DIXON ◽  
PETER SCHÖNSWETTER ◽  
GERALD M. SCHNEEWEISS
Keyword(s):  
Range Shifts ◽  
Plant Group ◽  
Mountain Plant

scholarly journals Constraining the temperature history of the past millennium using early instrumental observations

2012 ◽  
Vol 8 (3) ◽  
pp. 1653-1685 ◽  
Author(s):  
P. Brohan ◽  
R. Allan ◽  
E. Freeman ◽  
D. Wheeler ◽  
C. Wilkinson ◽  
...  
Keyword(s):  
Temperature Change ◽  
Large Scale ◽  
Climate Model ◽  
Ice Cores ◽  
East India Company ◽  
Temperature History ◽  
British Library ◽  
Model Simulations ◽  
Climate Model Simulations ◽  
Proxy Reconstructions

Abstract. The current assessment that twentieth-century global temperature change is unusual in the context of the last thousand years relies on estimates of temperature changes from natural proxies (tree-rings, ice-cores etc.) and climate model simulations. Confidence in such estimates is limited by difficulties in calibrating the proxies and systematic differences between proxy reconstructions and model simulations. As the difference between the estimates extends into the relatively recent period of the early nineteenth century it is possible to compare them with a reliable instrumental estimate of the temperature change over that period, provided that enough early thermometer observations, covering a wide enough expanse of the world, can be collected. One organisation which systematically made observations and collected the results was the English East-India Company (EEIC), and their archives have been preserved in the British Library. Inspection of those archives revealed 900 log-books of EEIC ships containing daily instrumental measurements of temperature and pressure, and subjective estimates of wind speed and direction, from voyages across the Atlantic and Indian Oceans between 1789 and 1834. Those records have been extracted and digitised, providing 273 000 new weather records offering an unprecedentedly detailed view of the weather and climate of the late eighteenth and early nineteenth centuries. The new thermometer observations demonstrate that the large-scale temperature response to the Tambora eruption and the 1809 eruption was modest (perhaps 0.5 °C). This provides a powerful out-of-sample validation for the proxy reconstructions – supporting their use for longer-term climate reconstructions. However, some of the climate model simulations in the CMIP5 ensemble show much larger volcanic effects than this – such simulations are unlikely to be accurate in this respect.

scholarly journals Preliminary taxonomic study on homestead flora of four districts of Bangladesh: Magnoliopsida

2020 ◽  
Vol 27 (1) ◽  
pp. 37-65
Author(s):  
Goutam Kumer Roy ◽  
Saleh Ahammad Khan
Keyword(s):  
Plant Genetic Resources ◽  
Floristic Composition ◽  
Current Status ◽  
Native Plant ◽  
Rauvolfia Serpentina ◽  
Native Plant Species ◽  
Plant Group ◽  
Pterocarpus Santalinus ◽  
Plant Taxon ◽  
Data Book

This study has documented the contemporary taxonomic information on the species of the class Magnoliopsida (Dicotyledons) extant in the homestead areas of Dhaka, Gazipur, Manikganj and Tangail districts of Bangladesh. In these areas, the Dicotyledons are comprised of total 455 species under 302 genera belonging to 78 families. Fabaceae with 41 species is the largest family and Solanum and Lindernia are the largest genera. Total 238 species are herbs followed by 129 species of trees and 88 species of shrubs. Total 332 species are economically useful. The composition and distribution of the species of this plant group are remarkably variable in the homestead areas of the four districts. The current status of seven threatened species viz., Abroma augusta, Andrographis paniculata, Aniseia martinicensis, Mucuna bracteata, Pterocarpus santalinus, Rauvolfia serpentina and Tournefortia roxburghii, included in the Red Data Book of Bangladesh and extant in the study area, has been evaluated and described. This study has identified some threats to the homestead flora and formulated some recommendations for the conservation of threatened and declining native plant species of the study area. The data provided by this study will serve as an important baseline to track the trend of changes in the floristic composition and diversity and sustainable development of plant genetic resources in the homesteads of the study area. Bangladesh J. Plant Taxon. 27(1): 37-65, 2020 (June)

scholarly journals Technoecosystem of the cooling pond of the South Ukrainian Nuclear Power Plant: group dynamics and transformation

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Tatyana Novoselova ◽  
Anzhelika Sylaieva ◽  
Yuliya Gromova ◽  
Tanita Menshova ◽  
Irina Morozovskaya ◽  
...  
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Group Dynamics ◽  
Nuclear Power ◽  
Cooling Pond ◽  
The South ◽  
Plant Group

scholarly journals Floral capitula and essential oil production analysis of chamomile (Chamomilla recutita) cultivars at different times of harvest

2018 ◽  
Vol 12 (2) ◽  
pp. 484-490
Author(s):  
Milton S. Matsushita ◽  
Cícero Deschamps ◽  
Cirino Corrêa Júnior ◽  
Marília P. Machado
Keyword(s):  
Essential Oil ◽  
Chemical Constituents ◽  
Harvest Time ◽  
Experimental Station ◽  
Plant Group ◽  
The World ◽  
Oil Percentage ◽  
Definition Of ◽  
Asteraceae Family ◽  
Essential Oil Production

Chamomile [Chamomilla recutita (L.) Rauschert] belongs to the Asteraceae family and is part of a large medicinal plant group that is cultivated and used in Brazil and in the world. The objective of this study was to evaluate the floral capitula productivity and essential oil content and composition of four cultivars of chamomile in three harvesting periods. The experiment was conducted at the Canguiri Experimental Station (UFPR) from May 15th to September 9th, 2015. Four cultivars of chamomile were evaluated, from commercial products purchased in different countries: Twinings (England), Auchan (Spain), Lipton (Scotland) and Mandirituba (Brazil), which is traditionally grown in Paraná. The experiment design used randomized blocks in a 4×3 factorial scheme (4 cultivars and 3 harvesting periods), with four replicates. At 96 days after planting, manual harvests were performed, for a total of three harvests. After each harvest, the floral chapters were dried. The extraction of the essential oil and the identification of the chemical constituents of the essential oil were carried out in the Laboratory of Ecophysiology of UFPR. The harvest time affected the productivity of the floral capitula and essential oil, being higher in the first (276.9 and 0.71 kg ha-1, respectively) and third harvests (262.6 and 0.77 kg ha-1, respectively). The cultivars and harvests did not influence the essential oil percentage (0.22 to 0.29%) obtained from the floral capitula; however, they contributed to the definition of the produced chemical compound.

The Atlantic Meridional Overturning Circulation (AMOC) simulated during interglacials and its impact on climate

2021 ◽  
Author(s):  
Zhiyi Jiang ◽  
Chris Brierley ◽  
David Thornalley ◽  
Sophie Sax
Keyword(s):  
Spatial Structure ◽  
Surface Temperature ◽  
Global Climate ◽  
Atlantic Meridional Overturning Circulation ◽  
Meridional Overturning Circulation ◽  
Last Interglacial ◽  
Overturning Circulation ◽  
Poleward Heat Transport ◽  
Meridional Overturning ◽  
Proxy Reconstructions

<p>The Atlantic Meridional Overturning Circulation (AMOC) is a key mechanism of poleward heat transport and an important part of the global climate system. How it responded to past changes inforcing, such as experienced during Quaternary interglacials, is an intriguing and open question. Previous modelling studies suggest an enhanced AMOC in the mid-Holocene compared to the pre-industrial period. In previous simulations from the Palaeoclimate Modelling Intercomparison Project (PMIP), this arose from feedbacks between sea ice and AMOC changes, which also depended on resolution. Here I present aninitial analysis of the recently available PMIP4 simulations. This shows the overall strength of the AMOC does not markedly change between the mid-Holocene and piControl experiments (at least looking at the maximum of the mean meridional mass overturning streamfunction below 500m at 30<sup>o</sup>N and 50<sup>o</sup>N). This is not inconsistent with the proxy reconstructions using sortable silt and Pa/Th for the mid-Holocene. Here we analyse changes in the spatial structure of the meridional overturning circulation, along with their fingerprints on the surface temperature (computed through regression). We then estimate the percentage of the simulated surface temperature changes between the mid-Holocene and pre-industrial period that can be explained by AMOC. Furthermore, the analysis for the changes in the AMOC spatial structure has been extended to see if the same patterns of change hold for the last interglacial. The simulations will be compared to existing proxy reconstructions, as well as new palaeoceanographic reconstructions.</p>

scholarly journals Land use alters soil propagule banks of wetlands down the soil-depth profile

2020 ◽  
Vol 71 (2) ◽  
pp. 191 ◽  
Author(s):  
Samantha K. Dawson ◽  
Jane A. Catford ◽  
Peter Berney ◽  
Richard T. Kingsford ◽  
Samantha Capon
Keyword(s):  
Land Use ◽  
Depth Profile ◽  
Soil Depth ◽  
Continuous Cultivation ◽  
Land Use Impacts ◽  
Terrestrial Plants ◽  
Human Disturbances ◽  
Plant Groups ◽  
Propagule Banks ◽  
Plant Group

Many studies have investigated the effects of human disturbances on floodplain propagule banks, but few have examined how these propagule banks change down the soil depth profile. Changes in soil propagule banks with depth can indicate the state of past vegetation and potentially demonstrate the effects of different land uses on the soil profile. Here, we examined changes in soil propagule banks down the soil-depth profile in an Australian floodplain wetland with five different land-use histories, ranging from a, in this case, relatively minor disturbance (clearing) through to more major disturbance (continuous cultivation). Land use had a larger influence than floodplain geomorphology on the propagule distribution of wetland plant-group numbers. An observed decrease in individuals over the depth profile also altered terrestrial plant groups in fields with longer land-use histories. Overall, soil-propagule profiles for terrestrial plants were not as affected by land use as were those of wetland plants. The geomorphological position on the floodplain also altered the soil propagule bank, with areas subject to the most flooding having the highest number of wetland species and retaining more of these species with greater depths. In conclusion, land-use impacts alter soil-propagule banks down the profile, despite most studies focussing on the top few centimetres.

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