The giant herbivorous sauropod dinosaurs that characterized by long-neck and gigantic size, dominated many terrestrial ecosystems on the planet from Jurassic to Cretaceous periods. Mamenchisauridae, a basal sauropod dinosaur family known from 4 genera and 16 species, is only discovered from western China, especially in the Sichuan basin. It evolved in geographical isolation from other sauropods, when Proto-Asia was a separate landmass. It is known as a special sauropod with the longest neck among all the dinosaur species, with huge size that have reached more than 35 meters in length and possibly weighted tens of tons.Mamenchisaurus is the youngest and the most phylogenetically derived genus among four genera of the Mamenchisaurodae, as well as the most giant dinosaur in Asia and one of the most giant dinosaurs in the world. Since all the fossils of Mamenchisaurs were excavated from Middle to Late Jurassic strata, it was traditionally assigned to be Middle-Late Jurassic in age in previous studies based on biostratigraphic correlations with other contemporary fossil assemblages. Determining the absolute age of the dinosaur-bearing formations in the Sichuan basin is critical to understanding the evolution and radiation of basal sauropods such as Mamenchisaurus in this geographically isolated system and throughout the world. However, radioisotopic age constraints for these formations are lacking since igneous events were rarely recorded within the Sichuan basin. We herein reported new zircon U-Pb age of 115±1.5 Ma for a tuffaceous sample collected from the Mamenchisaurus-bearing Suining Formation from the central Sichuan basin. These data serve to define the age of the Suining Formation, and to provide the youngest constraints yet reported for the radiation of the basal sauropods.

The Hailar Basin is located in the northeastern part of Inner Mongolia autonomous region and yields abundant Early Cretaceous coal resources. The main coal-bearing strata are from the Damoguaihe and Yimin formations. We here report a new amber site from the coal layers of the Yimin Formation in two coal mines in the Hailar Basin. The amber is small and fragmented, and some amber pieces were directly preserved in the leaves, retaining the shape. Because of the poor preservation, the details of the plant veins cannot be seen clearly, and the preliminary identification indicated that the plants belong to conifers. No inclusions were found so far. This is the first report of in-situ preserved amber in China. To establish robust age for this significant site, two interbedded tuffaceous samples were collected from the coal beds in the Zhalainuoer Coalmine and Yimin coalfield. Zircons from these samples were separated for LA-ICP-MS U-Pb dating. Our age result will provide important constraints on the biogeographic history of the field area and the geological age of the Yimin Formation in the Hailar Basin. Furthermore, this study will improve our understanding of the palynology records and Cretaceous world in general.

Abundant, well-preserved Triassic marine animals, including marine reptiles, have been discovered from South China in the past decades. These fossils mainly occur in the Jialingjiang, Nanlinghu, Guanling, Zhuganpo, and Xiaowa formations in Hubei, Anhui, Yunnan, and Guizhou provinces. Compared with other Triassic outcrops elsewhere, these fine-grained fossil-bearing deposits are currently considered among the richest in faunal diversity and most stratigraphically continuous over long periods of time. Despite a growing body of paleontological information, the fossil-bearing strata do not enjoy precise chronostratigraphic constraints. Previous radiometric ages for the fossil-rich strata were mostly obtained by zircon U/Pb LA-ICP-MS dating. The large uncertainties for most these data and the incomplete stratigraphic descriptions of the samples limits their value for high-resolution chronostratigraphy.  In this study, we investigate marine successions and aim to establish high-resolution radiometric age constraints for fossil-rich Triassic strata in South China. Based on our preliminary field work and geochronologic surveys, these formations include many interbedded tuffs containing datable material (i.e., zircons) necessary for establishing high-precision chronostratigraphic constraints on fossil-rich marine deposits. More robust age constraints for fossil-rich formations can resolve the timing of marine reptile radiation in the Triassic. Our results will contribute to understanding of the most profound mass extinction all time and how megafauna recovered from it. This research will also generally improve understanding of Mesozoic marine biodiversity and ecology.

The Cretaceous early Aptian oceanic anoxic event (OAE1a) is a globally documented climatic perturbation marked by voluminous deposition of black shales. Volcanism associated with the Greater Ontong Java large igneous province (GOJLIP) or other mechanisms may have caused this event but the exact timing of OAE1a remains uncertain. Evidence of OAE1a derives primarily from marine sedimentary records. Terrestrial records are scarce. Here, we describe a lacustrine sedimentary succession in east Shandong, China that represents a pristine and intact terrestrial record of OAE1a. Carbon and oxygen isotope chemostratigraphic and magnetic susceptibility data document the advent OAE1a within the section. This succession also included a tuffaceous layer containing zircons which were dated using U–Pb geochronologic methods. Coupled with isotopic records, the U–Pb analyses indicate that the onset of OAE1a occurred at 120.39 ± 0.46 Ma. East Asian magmatism that generated the tuffaceous layer may represent an additional significant source of volcanogenic CO₂ that contributed to perturbation of the early Aptian carbon cycle.

Several ocean biogeochemical tracers were simulated using the Earth System Model (ESM), and a comparison of the results with the observational data or other ESM simulations is required. We conducted a historical experiment using the Tracers of Ocean Phytoplankton with Allometric Zooplankton v2 (TOPAZ) biogeochemistry model coupled with the UK Earth System Model (UKESM). The climatological distributions of marine biogeochemical tracers in the Pacific and Atlantic Oceans from TOPAZ were compared with the observational data and those obtained from another ESM. The chlorophyll concentrations in the eastern equatorial Pacific were overestimated in TOPAZ compared to observational data and the Marine Biogeochemistry Model of Ecosystem Dynamics, nutrient Utilization, Sequestration and Acidification (MEDUSA) coupled with UKESM, which may be related to the over-prescribing of atmospheric iron. The distributions of nutrients such as nitrate and dissolved oxygen in the Pacific and Atlantic Oceans showed differences compared with observations, which may be related to water mass simulation in the initial data. Therefore, it is necessary to improve the supplying process of iron deposition and the initial fields to attain better simulations of chlorophyll and other major marine biogeochemical tracers. This work was funded by the Korea Meteorological Administration Research and Development Program under grant KMI (KMI2018-03513) and “Development and Assessment of IPCC AR6 Climate Change Scenario” under grant (KMA2018-00321). The main calculations were performed by using the supercomputing resource of the Korea Meteorological Administration (National Center for Meteorological Supercomputer).  

We have isolated the bacterium, Pseudomonas alcaligenes A25, from the soil, which has the capability to degrade DEHP efficiently.  At low concentrations 100 mg L^-1, it is about 24 h to degrade DEHP near 76% and at high concentrations 600mg L^-1, it is about 48 h to degrade DEHP near 87%.  The strain A25 could degrade 98% DEHP within 192 h.  We found that strain A25 produces the extracellular enzymes by DEHP induction.  The extracellular enzyme would also degrade tributyrin on the agar medium plates.  The optimal conditions for DEHP degradation were 40℃ and pH 8.0.  The addition of different nutrient sources and surfactants would have the effects on the degradation of DEHP.  Pseudomonas alcaligenes A25, as a newly discovered bacterium from our local environments, can efficiently degrade DEHP.   It has a potential to be applied on bio-remediation of environmental pollutants with DEHP.

Understanding of the geographical characteristics of aquatic invertebrate communities in rice paddies can be help to establish the strategies of effective conservation in rice paddy ecosystem. There have been many studies on the characteristics of aquatic invertebrate communities in the rice paddies. However, there is very limited information at national scales. This study was carried out to investigate the characteristics of aquatic invertebrate communities in rice paddies of South Korean. We used data collected from 290 sampling sites. The aquatic invertebrate communities were classified by applying self-organizing map. Total 21 order 60 families 114 species were collected from sampling sites. As a results, aquatic invertebrate communities are divided four clusters according to land consolidation and geographical locations. Cluster Ⅰ include the samples that were mostly conducted land consolidation projects whereas other clusters (Ⅱa, Ⅱb and Ⅱc) include samples that were rarely conducted. Furthermore, the samples of cluster Ⅱa, Ⅱb and Ⅱc were distributed eastern, western and northern region of Korea peninsula, respectively. Shannon diversity index was significantly lower in cluster Ⅰ but higher in cluster Ⅱb and Ⅱc. And number of species was also significantly lower in cluster Ⅰ but higher in cluster Ⅱa. Our results suggest that spatial heterogeneities are important for structuring the aquatic invertebrate assemblages in Korean rice paddies. Our findings have management implications that could be applied to the conservation of aquatic invertebrates in rice paddies of South Korea. Financial Support: This study was carried out with the support of "Research Program for Agricultural Science & Technology Development (Project No.01249002)", National Academy of Agricultural Science, Rural Development Administration, Republic of Korea.

Enhancements of the mixing ratios of short-lived halogenated gases were observed in air samples collected at Bachok Marine Research Station (BMRS), Peninsular Malaysia during Northern Hemisphere winters in 2013/2014 and 2015/2016. This study investigates the potential source regions and source types that influenced the variability in chlorinated very short-lived substances (Cl-VSLS) [dichloromethane, 1,2-dichloroethane, trichloromethane, tetrachloroethene] and methyl halides [methyl chloride and methyl bromide]. The UK Met Office’s Numerical Atmospheric Modelling Environment (NAME) dispersion model, was used for tracking the origin of air masses arriving at BMRS. For the purpose of identifying possible sources of these compounds, carbon monoxide (CO) emission data taken from the Representative Concentration Pathway 8.5 were used along with NAME footprints to calculate modelled CO mixing ratios. A correlation analysis between the mixing ratios of measured compounds and the modelled CO from various emission sectors was performed to assess the extent to which emission sectors might be related to the mixing ratios of halogenated gases. The results show that the events of higher mixing ratios were associated with air masses, especially from East China. During the 2013/2014 campaign, the modelled CO from industrial, solvents and agriculture (waste burning on fields) were significantly correlated with the mixing ratios of Cl-VSLS (R > 0.7) and methyl halides (R > 0.40). During the 2015/2016 campaign, the strength of these correlations reduced for Cl-VSLS (R > 0.5) and with no significant correlations for methyl halides. Instead, mixing ratios of methyl halides were correlated (R=0.4) with modelled CO from forest burning. This work provides evidence that East and South East Asia act as important sources of halogenated gases. This is of significant given the proximity of these regions to prevalent deep convection which can rapidly transport these halogen-containing gases into the stratosphere and impact the ozone layer.

Climate change profoundly affects the interannual variability (IAV) of net primary production (NPP) of terrestrial ecosystem from multiple aspects. However, the IAV of the nationwide annual NPP in China and the impacts of distinct climatic drivers are not well addressed. In this study, we investigated regional contributions to the IAV of the nationwide NPP and quantified the contributions of nine climatic drivers in different regions using the NPP estimated by the Carnegie-Ames-Stanford (CASA) model from 1982 to 2018. Our results showed that the simulated NPP exhibited an increasing trend of 15.2 Tg C yr^‑1 at the national scale. The nationwide NPP also showed large IAV ranging from ‍‑0.29 to 0.22 Pg C with the mean absolute IAV showing a descendant gradient from Southeastern to Northwestern China. Our estimates and thirteen terrestrial biosphere models verified that humid region accounted for the largest contribution (62%) to this large IAV. Attribution analyses indicated that normal and high precipitation amount (nP, HP), as well as high temperature days (HT) and daily temperature range (DTR) exerted the largest contributions to the national NPP IAV. Regional analyses indicated that DTR and HP were the major climatic drivers to NPP IAV in humid region, whereas NPP IAV in water-limited regions (i.e., semi-humid, semi-arid, and arid regions) were tightly associated with nP, HP, and HT. DTR and nP exerted the largest contributions to NPP IAV in the Tibetan Plateau. However, more attention should be paid to the negative impacts of low temperature events and potential drought on NPP IAV in humid region and that of HT in water-limited regions. This study emphasized the dominant role of humid region in controlling the national NPP IAV and the different ecosystem responses to diverse climatic drivers, and therefore can be valuable for adaptive management of ecosystems when facing climate change.