ALBERT

Description: The genus Tuber (Tuberaceae, Pezizales) is an important fungal group of Ascomycota both economically and ecologically. However, the species diversity, phylogenetic relationships, and geographic distribution of Tuber species in China remains poorly understood, primarily because descriptions of many new species relied heavily on morphological features with molecular data either not sought or ignored. The misapplication of European and North American names further added to confusion regarding the taxonomy of Chinese Tuber species. In this study, we examined more than 1000 specimens from China, and performed a comprehensive phylogenetic analysis for Chinese Tuber species using ITS sequences and multilocus sequence data. To infer the phylogeny of Chinese Tuber spp., 11 molecular datasets were assembled, including a concatenated internal transcribed spacers of the nuc rDNA (ITS), nuc rDNA 28S subunit (LSU), translation elongation factor 1-alpha (tef1-α), and RNA polymerase II subunit (rpb2) dataset as well as 10 ITS datasets (totally including 1435 sequences from 828 collections with 597 newly generated sequences, and 168 sequences from the types of 63 species). Our phylogenetic tree based on a concatenated multilocus dataset revealed that all Chinese Tuber species nested in nine phylogenetic clades (phylogroups), including Aestivum, Excavatum, Latisporum, Macrosporum, Maculatum, Melanosporum, Puberulum, Rufum and Turmericum. Of these, five phylogroups (Macrosporum, Maculatum, Melanosporum, Puberulum and Rufum) are shared across the continents of Asia, Europe and North America; two phylogroups (Aestivum and Excavatum) are shared by Europe and Asia; and the phylogroups Turmericum and Latisporum are endemic only to Asia. Phylogenetic trees based on 10 ITS datasets confirmed the presence of at least 82 phylogenetic species in China. Of these, 53 are identified as known species, including three new records for China, and 25 species are identified as new to science. Of the new species, nine are described and illustrated in this paper, and the others remain unnamed due to the paucity or absence of ascomatal materials. Accordingly, the confirmed, excluded and doubtful Tuber species in China are discussed. Tuber species showed high endemism. Of the 82 phylogenetic species found in China, 68 species occur only in China, six species are also found in other regions in Asia, and only eight species (T. anniae, T. excelsum-reticulatum, T. formosanum, T. maculatum, T. wenchuanense, Tuber sp. CHN-3, Tuber sp. CHN-10 and Tuber sp. CHN-11) are shared with other continents. Most Tuber species have a small and limited distribution in China, but a few, such as T. formosanum and T. parvomurphium, are widely distributed across China. Some phylogenetically closely related species, such as T. liaotongense and T. subglobosum, as well as T. xuanhuaense and T. lijiangense, show a pattern of allopatric distribution.

Description: Responses of global crop yields to warmer temperatures are fundamental to sustainable development under climate change but remain uncertain. Here, we combined a global dataset of field warming experiments (48 sites) for wheat, maize, rice and soybean with gridded global crop models to produce field-data-constrained estimates on responses of crop yield to changes in temperature (ST) with the emergent-constraint approach. Our constrained estimates show with 〉95% probability that warmer temperatures would reduce yields for maize (−7.1 ± 2.8% K−1), rice (−5.6 ± 2.0% K−1) and soybean (−10.6 ± 5.8% K−1). For wheat, ST was 89% likely to be negative (−2.9 ± 2.3% K−1). Uncertainties associated with modelled ST were reduced by 12–54% for the four crops but data constraints do not allow for further disentangling ST of different crop types. A key implication for impact assessments after the Paris Agreement is that direct warming impacts alone will reduce major crop yields by 3–13% under 2 K global warming without considering CO2 fertilization effects and adaptations. Even if warming was limited to 1.5 K, all major producing countries would still face notable warming-induced yield reduction. This yield loss could be partially offset by projected benefits from elevated CO2, whose magnitude remains uncertain, and highlights the challenge to compensate it by autonomous adaptation.

Description: The stable isotopic composition of rainwater (δ18Op and δDp) has been considered an effective proxy in studying atmospheric circulation and hydrological cycle processes. However, the linkage between variabilities in moisture sources and δ18Op remains poorly understood in Southwest China. Here, we utilized three long-term (10-year) δ18Op records (Beibei, Furong, and Yangkou stations) in Chongqing, Southwest China, from 2010 to 2019 A.D., integrated with a cluster analysis based on the Hybrid Single-Particle Lagrangian Integrated Trajectory model (HYSPLIT) to quantitatively demonstrate the close remote coupling of moisture sources and δ18Op on seasonal and interannual timescales. The clustering calculation results indicated that the percentage initial moisture source proportions of the westerlies and Asian summer monsoon have changed significantly at seasonal and interannual timescales, leading to the significant variation in δ18Op in Southwest China. Domination of westerlies and inland moisture contribution resulted in the positive δ18Op excursion in the dry season (November, December, January–April) while prevailing oceanic moisture led to the negative δ18Op excursions in the rainy season (May–October). On the interannual scale, δ18Op and d-excess exhibited a persistent positive/high trend, which is consistent with a decrease/increase in water vapor contributions from the ocean/westerly sources. Furthermore, δ18Op showed a good correlation with the Indian Ocean Dipole index, El Niño-Southern Oscillation, and the South Asian monsoon index, indicating that large-scale circulation patterns may affect regional δ18Op through their influence on moisture transport and convective activity in the source region. The long-term observation confirmed changes in moisture sources largely depend on the Westerly and Indian monsoon dynamics controlled by ocean-atmosphere circulation, supporting the effects of moisture sources on the rainwater isotopic composition.

Description: A massive landslide often causes long-lasting instability dynamics that need to be analyzed in detail for risk management and mitigation. Multiple satellite remote sensing observations, in-situ measurements, and geophysical approaches have been jointly implemented to monitor and interpret the life cycle of landslides and their failure mechanisms from various perspectives. In this work, we propose a framework where satellite optical and synthetic aperture radar (SAR) remote sensing techniques are combined with feature extractions using independent component analysis (ICA) and a mathematical relaxation model to assess the complete four-dimensional (4D) spatiotemporal patterns of post-failure slope evolution. The large, deep-seated Aniangzhai landslide in Southwest China that occurred on 17 June 2020 is comprehensively analyzed and characterized for its post-failure mechanism. Time series of Planet high-resolution optical images are first explored to derive the large horizontal motions for the first six months after the failure. Spatiotemporal dynamics of line-of-sight (LOS) displacement in the landslide body are then derived between November 2020 and February 2022 by combining 40 TerraSAR-X (TSX) High-resolution Spotlight (HS) images and 76 medium-resolution Sentinel-1 (S1) SAR datasets using Multi-temporal InSAR (MTI) method. The InSAR-derived results are subsequently analyzed with ICA to find common deformation components of points between optical and MTI results, indicating the same temporal evolution in the deformation pattern. Finally, the complete 4D deformation field for the whole post-failure period is modeled using a decaying exponential model representing stress relaxation after the failure by integrating multiple remote sensing datasets. Cross-correlation analysis of Planet imagery shows a decaying exponential pattern of post-failure displacements with an approximately 94% reduction in the deformation rate after six months with respect to the co-failure event. MTI analysis suggests a maximum LOS displacement rate of approximately 30 cm/year over the main failure body from November 2020 to February 2022; while the high-resolution TSX datasets show irreplaceable advantages in choosing the number of measurement points in MTI analysis with the number of measurement points being five times larger than those obtained by S1 datasets. The ICA analysis reveals three main types of kinematic patterns in the temporal evolution of post-failure deformation in MTI results, the dominant one being an exponential declining pattern similar to the results from Planet observations. Integrated 4D deformation modeling suggests that the most significant post-failure displacement mainly occurred toward the west, amounting to 28 m during the entire post-failure acquisitions from June 2020 until February 2022. Additionally, maximum displacements of 17 m and 19 m occurred in this period toward the north and downward, respectively.

Description: The extraordinary Hunga Tonga-Hunga Ha'apai volcano eruption occurred on 15 January 2022 had quite a global influence through ejecting volcanic ashes and unleashing a variety of strong waves that rippled through oceans and the atmosphere. Here we use remote sensing data to show that a tsunami triggered by the violent explosion resulted in calving from a remote Antarctic ice tongue. The volcano-triggered tsunami travelled over 6,000 km before impinging on the Drygalski Ice Tongue, resulting in the calving of a 10 km × 4.5 km iceberg from the ice front. Our study provides the most detailed observational evidence to date and confirms the linkages between the tsunami and the iceberg calving. Furthermore, it implies the stability of ice shelves in Antarctica may be influenced by extreme events outside the polar regions.

Description: Over 400 million people in Southeast Asia live in low elevation coastal zones and are susceptible to future relative sea-level (RSL) rise. Projections of future RSL rely on an accurate understanding of sea-level driving processes such as Glacial Isostatic Adjustment (GIA). Here we apply GIA models, paleo RSL records and instrumental data to demonstrate the evolution of RSL changes in Singapore and Southeast Asia and the associated impacts. We reconstructed RSL since the Last Glacial Maximum (LGM) to quantify magnitudes and rates of RSL changes through time and used GIA model to assess paleotopography changes and impacts to human populations. We applied the Intergovernmental Panel on Climate Change (IPCC) RSL projections and used the geological past to provide probability perspectives when IPCC future projections were last exceeded in Singapore. Future projections under a moderate emissions scenario show RSL rising 0.95 m at a rate of 7.3 mm/yr by 2150 which was only exceeded (〉 99% probability) during rapid ice melting events (MWPs) ~14.5 and ~9 ka BP. We inferred the human population history using 763 high-coverage whole-genome datasets. Integrated paleotopographic and population genomic analysis demonstrates the earliest documented instance of forced human migration driven by rapid sea-level rise (e.g., WMPs). We investigated the mid-Holocene highstand sensitivity revealing that Earth model variation affects the magnitude and ice model variation changes both the timing and magnitude of the highstand. Lastly, we produced a highstand “treasure map” to guide future highstand data collection efforts as the highstand is poorly constrained currently.

Description: Vertical land motion (VLM) is an important component in relative sea-level (RSL) projections, while VLM is difficult to derive because of a lack of long-term instrumental records. Geological data offer an alternative, comparing RSL data with glacial isostatic adjustment (GIA) models to isolate VLM. Here, we present a case study from the Oka estuary, northern Spain. We compare two GIA models (ICE-6G_C and ANU-ICE) with late Holocene RSL data along the Atlantic coast of Europe, showing good fit (misfit 〈 1.5) at all regions except the Oka estuary (misfit 〉 4.5), which indicates local subsidence. The nearby GPS (station SOPU, 〉 15 years) shows a VLM rate of -0.96 ±0.57 mm/yr (subsiding). The VLM rate of SOPU accounts for misfits between GIA models and RSL data, decreasing by ~90% from 〉 4.5 to ~0.5 after the subsidence correction of RSL data. The VLM rate incorporated in IPCC AR6 projections in Oka estuary is ~0.18 mm/yr (uplifting), which is contradictory in direction. Therefore, the projected sea-level rate is underestimated by 14 - 20% by 2050 and 9 - 26% by 2100 under the five Shared Socioeconomic Pathway (SSP) scenarios. The sea-level projections of Spanish authorities were based on IPCC AR5. Under RCP4.5 scenario, the future RSL in Oka estuary will increase 0.38 m by 2081-2100, which is underestimated by ~71% (0.65 m) compared with the IPCC AR6 under the SSP2-4.5 scenario by 2100 after correction for local VLM. Our study indicates the importance of local VLM component in projections.

Description: A catastrophic landslide occurred on 21 July 2020, 30 km from Enshi city, in Mazhe County of Hubei province, China. In this paper, we aimed to investigate the kinematic evolution and volumetric change related to this landslide using multi-source remote sensing measurements from synthetic aperture radar (SAR) and optical data. C-band Sentinel-1 and X-band TerraSAR-X SAR data are analyzed using several multi-temporal interferometry (MTI) time-series techniques including Persistent Scatterer Interferometry (PSI), Small Baseline subset (SBAS), and Combined eigenvalue maximum likelihood Phase Linking (CPL). The spatial pattern of surface deformation resulting from the interferometric analysis is then statistically analyzed to retrieve the pre-failure and post-failure displacements. Co-failure motions are analyzed using an image correlation technique applied to both the Planetscope and Sentinel-2 images. Moreover, 4 pairs of bistatic TerraSAR-X/TanDEM-X (TDX) data are utilized to generate high-precision digital elevation models (DEMs) and estimate the volumetric change related to the main slope failure. The pre-failure ground deformation analysis results suggest that the landslide was already active before the July 2020 failure, with the seasonality and hydraulic diffusivity being characteristics of a slow-moving landslide. Among the three different MTI methods applied, the CPL method results in a greater measurement points (MPs) density than the PSI and SBAS method when estimating the pre-failure movement of the Shaziba landslide. The July 2020 Shaziba disaster is divided into three main parts: (1) slightly horizontal deformation of 0.5–1.5 m within the northern part with ground and house cracks, (2) less collapse in the eastern part with horizontal motions reaching 30 m and (3) a highly eroded western part where vegetation was wholly lost in the main event, resulting in an collapse volume of approximately 4.98 million m3, out of which approximately around 3.4 million m3 was deposited and approximately 1.58 million m3 was washed away into the Qing River. After the failure, the marginal scrap of the main failure body, above crown of landslide and eastern part showed instability with rates of 20–30 mm/yr, suggesting that the failure zone may continue to expand.

Description: The present study classifies regional persistent extreme precipitation events (PEPEs) in North China into two types in accordance with variance contributions of different timescale rainfall variability in boreal summer. For Type 1, PEPEs are dominated by 10-20-day periodicity, and for Type 2 PEPEs are mainly influenced by a 30-60-day mode. Atmospheric circulation anomalies associated with the two types of PEPEs are characterized by a zonal wave train (the EU pattern) in the mid-high latitudes in Type 1 but a meridional wave train (the EAP pattern) in East Asia in Type 2. The common feature of the two types is anomalous southerly on the west edge of the West Pacific Subtropical High (WPSH), which favors anomalous moisture transport into the key region. Additional moisture source for Type 2 is linked to anomalous cross-equatorial flow. Both types of PEPEs result from the combined effect of intraseasonal oscillations in both the mid-high latitudes and the tropics. The impact of ENSO on the two types of PEPEs is investigated. While a La Niña and a neutral SST condition in the preceding winter favor for the occurrence of PEPEs, their subsequent transition in central and eastern equatorial Pacific will determine which of the two types of PEPEs is pronounced.

Description: El Niño events in a 1200-year coupled simulation are divided into fast-decay, slow-decay, and persistent groups to investigate the mechanisms for distinct durations. The fast-decay group features earlier onset and positive Indian Ocean Dipole mode in the developing stage, and stronger upwelling Rossby waves in the equatorial Pacific and Western North Pacific Anomalous Anticyclone (WNPAC) in tropical atmosphere in mature winter. Reflected waves at the western boundary and WNPAC-induced easterly wind stress anomalies result in upwelling Kelvin waves that are strong to terminate the fast-decay events before the following summer but much weaker in the other groups. The strength of the upwelling Kelvin waves is correlated to the equatorial Western Pacific zonal wind stress more than the Equatorial Rossby waves. During the mature winter, the fast-decay (persistent) group tends to be Eastern-Pacific (Central-Pacific) type El Niño, which causes stronger (weaker) cloud-shortwave radiation-sea surface temperature damping over the Niño-3.4 region. In the following spring, the difference of the mixed layer heat budget in Niño-3.4 between the fast and persistent groups shows the zonal advection of climatological temperature gradient by the Kelvin wave-induced geostrophic current accounts for 48% while latent heat contributes 24% of the budget difference due to reduced northeasterly trade winds by positive Pacific Meridional Mode. The slow-decay group also has a weaker cold zonal advection but a similar thermodynamic damping to that of the fast-decay group. Dynamic and thermodynamic processes in spring are both critical in regulating the duration of El Niño.