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Responses of soil microbiota and nematodes to application of organic and inorganic fertilizers in grassland columns
No full textRüdlingerite, Mn2+2V5+As5+O7·2H2O, a New Species Isostructural with Fianelite
No full textThe new mineral species rüdlingerite, ideally Mn2+2V5+As5+O7·2H2O, occurs in the Fianel mine, in Val Ferrera, Grisons, Switzerland, a small Alpine metamorphic Mn deposit. It is associated with ansermetite and Fe oxyhydroxide in thin fractures in Triassic dolomitic marbles. Rüdlingerite was also found in specimens recovered from the dump of the Valletta mine, Canosio, Cuneo, Piedmont, Italy, where it occurs together with massive braccoite and several other As- and V-rich phases in richly mineralized veins crossing the quartz-hematite ore. The new mineral displays at both localities yellow to orange, flattened elongated prismatic, euhedral crystals measuring up to 300 μm in length. Electron-microprobe analysis of rüdlingerite from Fianel gave (in wt%): MnO 36.84, FeO 0.06, As2O5, 25.32, V2O5 28.05, SiO2 0.13, H2Ocalc 9.51, total 99.91. On the basis of 9 O anions per formula unit, the chemical formula of rüdlingerite is Mn1.97(V5+1.17 As0.83Si0.01)Σ2.01O7·2H2O. The main diffraction lines are [dobs in Å (Iobs) hkl]: 3.048 (100) 022, 5.34 (80) 120, 2.730 (60) 231, 2.206 (60) 16-1, 7.28 (50) 020, 2.344 (50) 250, 6.88 (40) 110, and 2.452 (40) 320. Study of the crystal structure showcases a monoclinic unit cell, space group P21/n, with a = 7.8289(2) Å, b = 14.5673(4) Å, c = 6.7011(2) Å, β = 93.773(2)°, V = 762.58(4) Å3, Z = 4. The crystal structure has been solved and refined to R1 = 0.041 on the basis of 3784 reflections with Fo > 4σ(F). It shows Mn2+ hosted in chains of octahedra that are subparallel to [-101] and bound together by pairs of tetrahedra hosted by V5+ and As5+, building up a framework. Additional linkage is provided by hydrogen-bonding through H2O coordinating Mn2+ at the octahedra. One tetrahedrally coordinated site is dominated by V5+, T(1)(V0.88As0.12), corresponding to an observed site scattering of 24.20 electrons per site (eps), whereas the second site is strongly dominated by As5+, T(2)(As0.74V0.26), with, accordingly, a higher observed site scattering of 30.40 eps. The new mineral has been approved by the IMA-CNMNC and named for Gottfried Rüdlinger (born 1919), a pioneer in the 1960–1980s, in the search and study of the small minerals from the Alpine manganese mineral deposits of Grisons
End-Permian (252 Mya) deforestation, wildfires and flooding—Anancient biotic crisis with lessons for the present
No full textCurrent large-scale deforestation poses a threat to ecosystems globally, and imposes substantial and prolonged changes on the hydrological and carbon cycles. The tropical forests of the Amazon and Indonesia are currently undergoing deforestation with catastrophic ecological consequences but widespread deforestation events have occurred several times in Earth’s history and these provide lessons for the future. The end-Permian mass-extinction event (EPE; ∼252Ma) provides a global, deep-time analogue for modern deforestation and diversity loss. We undertook centimeter-resolution palynological, sedimentological, carbon stable-isotope and paleobotanical investigations of strata spanning the end-Permian event at the Frazer Beach and Snapper Point localities, in the Sydney Basin, Australia. We show that the typical Permian temperate, coal-forming, forest communities disappeared abruptly, followed by the accumulation of a 1-m-thick mudstone poor in organic matter that, in effect, represents a ‘dead zone’ hosting degraded wood fragments, charcoal and fungal spores. This signals a catastrophic scenario of vegetation die-off and extinction in southern high-latitude terrestrial settings. Lake systems, expressed by laterally extensive but generally less than a few-metres-thick laminated siltstones, generally lacking bioturbation, hosting assemblages of algal cysts and freshwater acritarchs, developed soon after the vegetation die-off. The first traces of vascular plant recovery occur ∼1.6m above the extinction horizon. Based on analogies with modern deforestation, we propose that the global fungal and acritarch events of the Permo-Triassic transition resulted directly from inundation of basinal areas following water-table rise as a response to the abrupt disappearance of complex vegetation from the landscape. The δ13Corg values reveal a significant excursion toward low isotopic values, down to −31ppt (a shift of ∼4deg), across the end-Permian event. The magnitude of the shift at that time records a combination of changes in the global carbon cycle that were enhanced by the local increase in microbial activity, possibly also involving cyanobacterial proliferation. We envisage that elevated levels of organic and mineral nutrients delivered from inundated dead forests, enhanced weathering and erosion of extra-basinal areas, together with local contributions of volcanic ash, led to eutrophication and increased salinity of basinal lacustrine–lagoonal environments. We propose that the change in acritarch communities recorded globally in nearshore marine settings across the end-Permian event is to a great extent a consequence of the influx of freshwater algae and nutrients from the continents. Although this event coincides with the Siberian trap volcanic activity, we note that felsic–intermediate volcanism was extensively developed along the convergent Panthalassan margin of Pangea at that time and might also have contributed to environmental perturbations at the close of the Permian.Also funded by the Royal Swedish Academy of Sciences, and by a collaborative research grant from the National Science Foundation USA (EAR-1636625)</p
Revisions of British and Irish Lichens vol. 3 - Peltigerales: Collemataceae (including the genera Blennothallia, Callome, Collema, Enchylium, Epiphloea, Lathagrium, Leptogium, Pseudoleptogium, Rostania and Scytinium.
No full textRevisions of British and Irish Lichens is a free-to-access serial publication under the auspices of the British Lichen Society, that charts changes in our understanding of the lichens and lichenicolous fungi of Great Britain and Ireland. Each volume will be devoted to a particular family (or group of families), and will include descriptions, keys, habitat and distribution data for all the species included. The maps are based on information from the BLS Lichen Database, that also includes data from the historical Mapping Scheme and the Lichen Ireland database. The choice of subject for each volume will depend on the extent of changes in classification for the families concerned, and the number of newly recognized species since previous treatments. To date, accounts of lichens from our region have been published in book form. However, the time taken to compile new printed editions of the entire lichen biota of Britain and Ireland is extensive, and many parts are out-of-date even as they are published. Issuing updates as a serial electronic publication means that important changes in understanding of our lichens can be made available with a shorter delay. The accounts may also be compiled at intervals into complete printed accounts, as new editions of the Lichens of Great Britain and Ireland
Controls on the 14C Content of Dissolved and Particulate Organic Carbon Mobilized Across the Mackenzie River Basin, Canada
No full textThe Mackenzie River Basin (MRB) delivers large quantities of organic carbon (OC) into the Arctic Ocean, with significant implications for the global C budgets and ocean biogeochemistry. The amount and properties of OC in the Mackenzie River's delta have been well monitored in the last decade, but the spatial variability in OC sources transported by its different tributaries is still unclear. Here we present new data on the radiocarbon (14C) content of dissolved and particulate OC (Δ14C‐DOC and Δ14C‐POC) across the mainstem and major tributaries of the MRB, comprising 19 different locations, to identify factors controlling spatial patterns in riverine OC sources. The Δ14C‐DOC and Δ14C‐POC varied across a large range, from −179.9‰ to 62.9‰, and −728.8‰ to −9.0‰, respectively. Our data reveal a positive spatial coupling between the Δ14C of DOC and POC across the MRB, whereby the most 14C‐depleted waters were issued from the mountainous west bank of the MRB. This 14C‐depleted DOC and POC likely originates from a combination of petrogenic sources, connected with the presence of kerogens in the bedrock, and biogenic sources, mobilized by thawing permafrost. Our analysis also reveals intriguing relationships between Δ14C of DOC and POC with turbidity, water stable isotope ratio and catchment elevation, indicating that hydrology and geomorphology are key to understanding riverine OC sources in this landscape. A closer examination of the specific mechanisms giving rise to these relationships is recommended. For now, this study provides a road map of the key OC sources in this rapidly changing river basin
Langhofite, Pb2(OH)[WO4(OH)], a new mineral from Långban, Sweden.
No full textLanghofite, ideally Pb2(OH)[WO4(OH)], is a new mineral from the Långban mine, Värmland, Sweden. The mineral and its name were approved by the International Mineralogical Association Commission on New Minerals, Nomenclature and Classification (IMA2019-005). It occurs in a small vug in hematite–pyroxene skarn associated with calcite, baryte, fluorapatite, mimetite and minor sulfide minerals. Langhofite is triclinic, space group P1, and unit-cell parameters a = 6.6154(1) Å, b = 7.0766(1) Å, c = 7.3296(1) Å, α = 118.175(2)°,β = 94.451(1)°, γ = 101.146(1)° and V = 291.06(1) Å3 for Z = 2. The seven strongest Bragg peaks from powder X-ray diffractometry are[dobs, Å (I )(hkl)]: 6.04(24)(010), 3.26(22)(11-2), 3.181(19)(200), 3.079(24)(1-12), 3.016(100)(020), 2.054(20)(3-11) and 2.050(18)(13-2). Langhofite occurs as euhedral crystals up to 4 mm, elongated along the a axis, with lengthwise striation. Mohs hardness is ca. 2½,based on VHN25 data obtained in the range 130–192. The mineral is brittle, with perfect {010} and {100} cleavages. The calculated density based on the ideal formula is 7.95(1) g⋅cm–3. Langhofite is colourless to white (non-pleochroic) and transparent, with a white streakand adamantine lustre. Reflectance curves show normal dispersion, with maximum values 15.7–13.4% within 400–700 nm. Electron microprobe analyses yield only the metals Pb and W above the detection level. The presence of OH-groups is demonstrated with vibration spectroscopy, from band maxima present at ∼3470 and 3330 cm–1. A distinct Raman peak at ca. 862 cm–1 is related to symmetricW–oxygen stretching vibrations. The crystal structure is novel and was refined to R = 1.6%. It contains [W2O8(OH)2]6– edge-sharingdimers (with highly distorted WO6-octahedra) forming chains along [101] with [(OH)2Pb4]6+ dimers formed by (OH)Pb3 triangles. Chains configure (010) layers linked along [010] by long and weak Pb–O bonds, thus explaining the observed perfect cleavage on{010}. The mineral is named for curator Jörgen Langhof (b. 1965), who collected the discovery sample
A new species of Bidessus from Anjozorobe-Angavo and a review of Malagasy Bidessus (Coleoptera, Dytiscidae)
No full textWe review the species of Bidessus of Madagascar and describe Bidessus anjozorobe sp. nov. from material collected in Anjozorobe forest. Anjozorobe is part of the Anjozorobe-Angavo Protected Area, which is an important corridor of transition forest between typical eastern humid forests and the residual sub-humid forest of the Central Highlands. Bidessus longistriga Régimbart, 1895 and Bidessus perexiguus Kolbe, 1883 are widespread but endemic low-altitude species on Madagascar. Bidessus nesioticus Guignot, 1956 is an alpine species described from near the peak of the Ankaratra mountain massifs at 2500 m a.s.l. We recollected the species for the first time since its description, in Ankaratra and in a new area above 2000 m a.s.l. in the Andringitra mountain further south. Bidessus cf. nero Gschwendtner, 1933 is tentatively recorded for Madagascar for the first time but further studies are needed to test the status of mainland and insular populations. Bidessus apicidens Biström & Sanfilippo, 1986 has not been recollected on Madagascar since 1970. All species are endemic to Madagascar except potentially Bidessus cf. ceratus and Bidessus cf. nero described from Uganda and the Democratic Republic of the Congo, respectively. The older records of the two non-endemic species Bidessus complicatus Sharp, 1904 and Bidessus ovoideus Régimbart, 1895 on Madagascar could not be verified
Paleocene–Eocene palynomorphs from the Chicxulub impact crater, Mexico.Part 2: angiosperm pollen
No full textAt the end of the Cretaceous Period, an asteroid collided with the Earth and formed the Chicxulub impact structure on the Yucatan Platform. International Ocean Discovery Program (IODP) Expedition 364 drilled into the peak ring of the Chicxulub impact crater. The post-impact section of the core was sampled for terrestrial palynological analysis, yielding a high-resolution record ranging from the early Paleocene to the earliest Eocene (Ypresian), including a black shale deposited during the Paleocene–Eocene Thermal Maximum (PETM). The IODP 364 core provides the first record of floral recovery following the K–Pg mass extinction from inside the Chicxulub impact crater. The systematic taxonomy of the angiosperm pollen provided here follows a separate publication describing the systematic paleontology of the plant spores and gymnosperm pollen from the IODP 364 core (Smith et al. 2019). The Paleocene section of the core is nearly barren, but with unusually high relative abundances of the angiosperm pollen Chenopodipollis sp. A (comparable to the Amaranthaceae), possibly indicating an estuarine pollen source. Pollen recovery is higher in the PETM section, and variable but generally increasing in the later Ypresian section, with excellent preservation in several samples. Estimated absolute ages of several potentially useful regional biostratigraphic events are provided. One new genus (Scabrastephanoporites) and five new species (Brosipollis reticulatus, Echimonocolpites chicxulubensis, Psilastephanocolporites hammenii, Scabrastephanoporites variabilis, and Striatopollisgrahamii) are formally described
The Eomyidae in Asia: Biogeography, diversity and dispersals
No full textIn Asia, the first find of an eomyid rodent was reported almost one century after the first studies of the family Eomyidae in North America and Europe. Since then, eomyid rodents have been increasingly found in Asia particularly over the past two decades. Here, we review the Asian record of this family at the genus level. Currently, 22 species within 14 genera were reported from Asia, including seven endemic genera and rare materials of apeomyine eomyids. Eomyids emphasize the palaeogeographic importance of Asia in considering intercontinental dispersal events of small mammals. With newly compiled data for Asian eomyids, we also compare genus-level diversity trends through time among North America, Europe, and Asia. Despite data standardizations limited with respect to potential biases in the fossil record, we found that the Asian eomyid diversity closely follows ecological shifts induced by climate changes. In general, Asian eomyid genera disappeared earlier than their European counterparts. We suggest that this pattern is not dictated by differences in the quality of the fossil record and is related to the expansion of drier habitats over large areas of Asia.Y.K. received financialsupport from the Japan Society for the Promotion of Science,Tokyo, Japan (JSPS, KAKENHI Grant Number JP18K13650,Grant-in-Aid for Early-Career Scientists) and also from theNational Museum of Nature and Science as part of a researchproject called “Chemical Stratigraphy and Dating as a Clue for Understanding the History of the Earth and Life”. I.C.-V.was financially supported by the Spanish Ministerio deEconomía, Industria y Competitividad, the Agencia Estatal deInvestigación and the European Regional Development Fund of the European Union (projects CGL2016-76431-P, AEI/FEDER EU, CGL2017-82654-P MINECO/FEDER EU; andresearch contract RYC-2013-12470), and the Generalitat deCatalunya (CERCA Programme). I.C.-V. is a member of theconsolidated research group 2017 SGR 116 of the Generalitatde Catalunya. O.M.’s research is supported by a grant of theSwiss National Science Foundation (N° 200021-162359).D.C.K acknowledges the Deutsche Forschungsgemeinschaft(DFG, Bonn, Germany) for various grants to study mammalianenamel microstructure. T.M. was financially supported by The Royal Swedish Academy of Sciences (KVA, Stockholm,Sweden) and by JSPS, Tokyo, Japan. </p
Reconstructing Krassilovia mongolica supports recognition of a new and unusual group of Mesozoic conifers
No full textPreviously unrecognized anatomical features of the cone scales of the enigmatic Early Cretaceous conifer Krassilovia mongolica include the presence of transversely oriented paracytic stomata, which is unusual for all other extinct and extant conifers. Identical stomata arepresent on co-occurring broad, linear, multiveined leaves assigned to Podozamites harrisii, providing evidence that K. mongolica and P. harrisii are the seed cones and leaves of the same extinct plant. Phylogenetic analyses of the relationships of the reconstructed Krassilovia plant place it in an informal clade that we name the Krassilovia Clade, which also includes Swedenborgia cryptomerioides–Podozamites schenkii, and Cycadocarpidium erdmanni–Podozamites schenkii. All three of these plants have linear leaves that are relatively broad compared to most living conifers, and that are also multiveined with transversely oriented paracytic stomata. We propose that these may be general features of the Krassilovia Clade. Paracytic stomata, and other features of this new group, recall features of extant and fossil Gnetales, raising questions about the phylogenetic homogeneity of the conifer clade similar to those raised by phylogenetic analyses of molecular data.Funding for this work was provided by National Science Foundation grants DEB-1748286 to P.S.H., P.R.C. and F.H., and 1348456 to P.R.C. and P.S.H., the Oak Spring Garden Foundation to F.H., and Grants-in-Aid for Scientific Research (21405010 and 24405015) from the Japan Society.</p