Albic soils, characterized by a prominent, compact, and nutrient-poor albic horizon, represent a major low-productivity soil type in Northeast China. Despite the development of various amelioration strategies, a systematic synthesis of their theoretical underpinnings and integrated application, particularly from a soil health perspective, is currently lacking. This limits our ability to design context-specific, sustainable management systems for these degraded soils. This review systematically analyzes the interconnected physical, chemical, and biological constraints that govern the low productivity of Albic soils. It further synthesizes and evaluates synergistic management strategies aimed at holistic soil health enhancement, drawing upon both empirical field studies and mechanistic research. The key constraints include poor structure, shallow rooting depth, acidity, nutrient deficiency, and impoverished biological activity. Effective amelioration requires integrated approaches. Physical engineering (e.g., subsoil mixing) enhances soil structure, including aggregate stability, porosity, and water infiltration, thereby increasing crop yield by 2.2–20

Black flower-like 1T/2H mixed-phase molybdenum disulfide (1T/2H-MoS2) nanosheet modified with titanium dioxide (TiO2) was successfully designed and constructed, and effectively improved the efficiency of tetracycline degradation. The properties of the TiO2@1T/2H-MoS2 were analyzed using scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and mass spectrometry (MS). The heterojunction exhibited an excellent degradation effect in ultraviolet mercury lamps. The optimized TiO2@1T/2H-MoS2 had higher degradation efficiency than the bare module, and the degradation efficiency of TiO2@1T/2H-MoS2 was 1.49 times that of 1T/2H-MoS2 and 1.98 times that of TiO2. Quenching experiments show that & centerdot;O2- dominates the dark adsorption reaction, and h+ dominates the subsequent photocatalytic reaction. The position of the valence band conduction band of the composites was calculated, and the mechanism of photocatalytic degradation of tetracycline was derived. In addition, the tetracycline intermediate products after 90 min of photocatalysis were determined using liquid chromatography-mass spectrometry (LC-MS), and its degradation path was inferred. TiO2@1T/2H-MoS2 exhibits excellent degradation after reuse, confirming its potential for photocatalytic applications. A semiconductor-coupled photocatalyst for water treatment was designed.

Albic soils are a typical problematic soil type distributed worldwide. These soils are characterized by a thin humus layer, low organic matter content, nutrient insufficiency, and weak microbial activity. Therefore, microbial-based approaches hold great potential for the amelioration of Albic soils. This review synthesizes microbial characteristics, influencing factors, amelioration mechanisms, and related technical efficacy of Albic soils. Microbial communities of Albic soils exhibit distinct regional characteristics, with Acidobacteriota and Proteobacteria dominating the bacterial community. Reasonable agricultural management practices—including deep plowing and subsoil mixing, combined organic fertilization and straw return—can increase microbial biomass by 62–248% and enhance enzyme activities by 12–303%, ultimately increasing crop yield by 1.5–13%. Such practices drive fertility enhancement and ecological functional improvement in Albic soils. Inoculation with functional microbes (e.g., Arbuscular Mycorrhizal Fungi, Trichoderma) alleviates Albic soil acidification by 1.1–3.8%, activates recalcitrant nutrients, and accelerates Soil Organic Matter (SOM) decomposition. Through extracellular polymeric substance secretion, such inoculation promotes aggregate formation, improving soil permeability and structural stability. However, challenges remain for current research, including difficult microbial agent colonization, unstable amelioration effects, and a lack of long-term field studies. Future research should utilize bio-omics technologies, artificial intelligence, and big data technologies to analyze microbial functions and regulate soil quality for cultivated land improvement and sustainable agriculture development.

Plastic pollution in paddy fields disrupts soil nitrogen biogeochemistry, prompting the introduction of biodegradable plastics like PBAT (poly (butylene adipate-co-terephthalate)) as a potential mitigation strategy to plastic pollution reduction. However, the effects of nonbiodegradable and biodegradable microplastics on the nitrogen cycle remain unclear. To clarify this, we conducted an incubation experiment, N2O isotopocules, and molecular analysis to assess the impact of additives from PBAT and non-biodegradable (polyethylene, PE) microplastics. This study aimed to investigate their effects on N2O emission from bacterial, fungal, and chemical denitrification. The results showed that PE reduced N2O production potential from denitrification (DN2O) and bacterial denitrification (BDN2O), while PBAT (poly (butylene adipate-co-terephthalate)) increased DN2O and fungal-derived N2O (FDN2O) but decreased BDN2O. PE inhibited N2O production via bacterial denitrification due to the toxicity of plastic additives such as dibutyl phthalate (DBP) and diethylhexyl phthalate (DEHP). In contrast, PBAT enhanced N2O production via fungal pathways by facilitating the release of dissolved organic carbon. Bacterial denitrification accounted for 43-56% of total N2O production potential (DN2O) in PE treatments but only 28-50% in PBAT treatments. These findings highlight the short-term risks posed by biodegradable microplastics in elevating N2O emissions and reveal new dimensions of the influence of microplastics on greenhouse gas emissions from agricultural soils.

The soil microbiome plays an important role in wetland ecosystem services and functions. However, the impact of soil hydrological conditions on wetland microorganisms is not well understood. This study investigated the effects of wetted state (WS); wetting–drying state (WDS); and dried state (DS) on the diversity of soil bacteria, fungi, and archaea. The Shannon index of bacterial diversity was not significantly different in various flooding conditions (p > 0.05), however, fungal diversity and archaeal communities were significantly different in different flooding conditions (p < 0.05). Significant differences were found in the beta diversity of bacterial, fungal, and archaeal communities (p < 0.05). Additionally, the composition of bacteria, fungi, and archaea varied. Bacteria were predominantly composed of Proteobacteria and Actinobacteria, fungi mainly consisted of Ascomycota and Mucoromycota, and archaea were primarily represented by Crenarchaeota and Euryarchaeota. Bacteria exhibited correlations with vegetation coverage, fungi with plant diversity, and archaea with aboveground vegetation biomass. The pH influenced bacterial and archaeal communities, while soil bulk density, moisture, soil carbon, soil nitrogen, and plant community diversity impacted fungal communities. This study provides a scientific basis for understanding the effects of different hydrological conditions on microbial communities in the Huihe Nature Reserve; highlighting their relationship with vegetation and soil properties, and offers insights for the ecological protection of the Huihe wetland.

Due to the development of industries such as mining, smelting, industrial electroplating, tanning, and mechanical manufacturing, heavy metals were discharged into water bodies seriously affecting water quality. Bamboo charcoal, as an environmentally friendly new adsorbent material, in this paper, the virgin bamboo charcoal (denoted as WBC) was modified with different concentrations of KMnO4 and NaOH to obtain KMnO4-modified bamboo charcoal (KBC) and NaOH-modified bamboo charcoal (NBC) which was used to disposed of water bodies containing Cu2+ and Zn2+. The main conclusions were as following: The adsorption of Cu2+ by WBC, KBC and NBC was significantly affected by pH value, and the optimum pH was 5.0. Differently, the acidity and alkalinity of the solution doesn’t effect the adsorption of Zn2+ seriousely. Meanwhile, surface diffusion and pore diffusion jointly determine the adsorption rate of Cu2+ and Zn2+. The test result of EDS showed that Mn–O groups formed on the surface of K6 (WBC treated by 0.06 mol/L KMnO4) can promote the adsorption of Cu2+ and Zn2+ at a great degree. The O content on N6(WBC treated by 6 mol/L NaOH) surface increased by 30.95

Grassland degradation could affect the composition, structure, and ecological function of plant communities and threaten the stability of their ecosystems. It is essential to accurately evaluate grassland degradation and elucidate its impacts on the vegetation–soil relationship. In this study, remote sensing data based on vegetation coverage were used to assess the degradation status of Hulunbuir grassland, and five different grassland degradation degrees were classified. Vegetation community composition, diversity, biomass, soil nutrient status, and their relationships in different degraded grasslands were investigated using field survey data. The results showed that grassland degradation significantly affected the species composition of the vegetation community. As degradation intensified, species richness declined, with the proportion of Gramineae and Legume species decreasing and Asteraceae species increasing. Additionally, the proportion of annual species initially increased and then decreased. Degradation also markedly reduced aboveground, belowground, and litter biomass within the communities. Soil moisture, electrical conductivity, organic carbon, total carbon, total potassium, and hydrolyzable nitrogen contents in non-degraded areas were higher than those in severely degraded areas. Conversely, soil total phosphorus content and bulk density gradually increased with degradation. Nitrate nitrogen and ammonium nitrogen levels in severely degraded soils were significantly higher than those in non-degraded soils. Plant diversity in the study area was significantly positively correlated with aboveground biomass and belowground biomass, and it positively correlated with soil nutrient total carbon and available carbon but negatively correlated with soil bulk density. Results of the partial least squares path model showed that grassland degradation had significant negative effects on plant diversity, soil nutrients, and biomass. Soil nutrients were the main factors affecting ecosystem productivity. The direct effect of plant diversity on biomass was not significant, suggesting that soil nutrients may play a more important role than plant diversity in determining biomass during grassland degradation. The results illustrated the relationships among soil nutrients, plant diversity, and biomass in degraded grasslands and emphasized the importance of an integrated approach in the effective management and restoration of degraded grasslands.

To understand the role of reactive oxygen species (ROS) in regulation of the plasma membrane (PM) H+-ATPase in acid-stressed Masson pine roots, different acidity (pH 6.6 as the control, pH 5.6 and pH 4.6) of simulated acid rain (SAR) added with and without external chemicals (H2O2, enzyme inhibitors and ROS scavenger) was prepared. After 30 days of SAR exposure, the plant morphological phenotype attributes, levels of cellular ROS and lipid peroxidation, enzymatic activities of antioxidants, PM nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity and PM H+-ATPase activity in pine seedlings were measured. Compared with the control, the growth of pine seedlings exposed to SAR in the presence or absence of H2O2 was well-maintained, but the application of Na3VO4, 1,3-dimethyl-2-thiourea, N, N-dimethylthiourea (DMTU) and diphenyleneiodonium chloride (DPI) caused a substantial growth inhibition. In addition, SAR exposure, SAR with H2O2 treatment, and SAR with Na3VO4 treatment increased the cellular H2O2 content, O-2(-) content and malondialdehyde (MDA) content, while the use of DMTU and DPI lead to relatively low levels. Similarly, the enzymatic activities of antioxidants, PM NADPH oxidase and PM H+-ATPase in acid stressed pine seedlings elevated with the increasing acidity. A significant stimulation of these enzymatic activities obtained from SAR with H2O2 treatment was observed, whereas which decreased obviously with the addition of Na3VO4, DMTU and DPI (P < 0.05). Moreover, a positive correlation was found between plant morphological attributes and the PM H+-ATPase activity (P < 0.05). Besides, the PM H+-ATPase activity positively correlated with the cellular ROS contents and the enzymatic activities of antioxidants and PM NADPH oxidase (P < 0.05). Therefore, the PM H+-ATPase is instrumental in the growth of pine seedlings resisting to acid stress by enhancing its activity. The process involves the signaling transduction of cellular ROS and coordination with PM NADPH oxidase.

古新世—始新世极热事件(Paleocene—Eocene thermal maximum,PETM)是发生在古新世与始新世界线附近的一次全球快速增温事件.研究显示,PETM期间全球大气CO2浓度增加,温度上升,陆地水循环加强,在陆地和海洋中产生了一系列生物—环境响应.目前,PETM研究主要集中在海相地层中,而针对陆相地层的相关报道并不多见.陆相沉积速率较快,沉积地层厚度大,并且保存有丰富的哺乳动物化石和植物孢粉,也适合开展高分辨率古气候研究.本文对北美、欧洲西部和我国典型陆相盆地的PETM研究成果进行了系统性综述,对比分析结果表明,PETM期间陆相地层中的碳同位素偏移过程可以分为快速负偏、保持低值和缓慢恢复三个阶段.陆地植物和哺乳动物在PETM期间并未经历大规模灭绝,反而通过进化、扩散和局部灭绝适应了快速变化的环境.基于最新的研究方法,包括碳酸盐岩U-Pb定年、汞同位素以及团簇同位素,对我国未来的PETM陆相记录研究提出了展望.

The circular economy decouples economic activity from finite resource consumption, creating a resilient system that can tackle global challenges such as climate change, biodiversity loss, waste, and pollution. Nuclear energy has been designated as one of the primary concerns of energy sector modernization because it allows for significant reductions in dangerous material emissions into the environment. Therefore, nuclear energy and improved technologies may become critical growth areas aligned with circular economy principles. We use Dynamic Autoregressive Distributive Lag (DARDL) and Kernel-based Regularized Least Squares (KRLS) to analyze United States data from 1985 to 2016 empirically. The DARDL result shows a positive relationship between ecological footprint and economic complexity, increasing short-term environmental costs. However, nuclear power generation and improved technology significantly reduce ecological concerns. Economic complexity is explored in this work in more nuanced terms, emphasizing the importance of considering the external environment when implementing different economic activities. Policy implications, study limitations, and future research directions are discussed. (c) 2022 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.

Reconstructing the Mesozoic paleotectonic and paleogeographic evolution of marine Qiangtang basins is essential for understanding the evolution of diverse Tethyan oceanic seaways and pre-Cenozoic mountain building in the Tibetan Plateau, with significant implications for hydrocarbon exploration. The geological knowledge of these basins is, however, largely incomplete. Here we illustrate new geological mapping, stratigraphic, structural, sedimentological, and provenance data collected along a >40-km-long, well exposed crosssection of the Biluoco fold-thrust belt in South Qiangtang, together with a compilation of regional data from the Qiangtang, Amdo, and Hoh-Xil terranes. We also provide refined biostratigraphy and chronostratigraphy of the exposed successions in the Biluoco type area. Newly achieved information indicates that the North Qiangtang and South Qiangtang basins evolved independently during the Mesozoic. The South Qiangtang basin started to subside by the Late Triassic and closed by the Late Jurassic. In contrast, sedimentation in the North Qiangtang basin commenced in the latest Early Jurassic and ended in the latest Jurassic. The Qiangtang basins received sediments from volcanic rocks exposed in the central Qiangtang and Hoh-Xil terranes since the Late Triassic, whereas Paleozoic strata in the Central Qiangtang mountain range were the primary source of detritus for the North Qiangtang basin in the early Middle Jurassic and for South Qiangtang basin in the Late Triassic and Middle Jurassic. Middle to Late Triassic volcanism and convergence associated with the closure of Paleo-Tethys within the Hoh-Xil and central Qiangtang terranes resulted in the topographic uplift of the central and northern Qiangtang regions. The Jurassic development of Qiangtang basins and their final inversion were controlled by the dynamics of the northward-subducting Bangong-Nujiang oceanic slab, microcontinent accretion to South Qiangtang, and Lhasa/Qiangtang collision.

Plant inputs and their subsequent microbial transformations drive the formation and accumulation of soil organic carbon (SOC). Rice paddy is more conducive to SOC accumulation than uplands, primarily because of predominant anaerobic conditions. However, the role of microbes and plants in the buildup of SOC under prolonged rice cultivation has not been well explored in the literature. In a millennium-scale paddy soil chronosequence, we used amino sugars (AS) and lignin phenols (LN) as tracers to investigate microbial and plant-derived necromass changes and evaluated their contributions to SOC accumulation with increasing rice cultivation duration. Across the 1000-year rice cultivation process, AS and LN contents increased with SOC accumulation. Soil pH and salinity are considered to play vital roles in regulating the retention of AS and LN. In contrast to the control of soil enzyme activity on LN accrual (e.g., peroxidase), the microbial biomass and fungi-to-bacteria ratio greatly affected AS accumulation in paddy soil. The components of AS and LN also changed with time, exhibiting a significant accumulation of galactosamine and cinnamyl phenol units in the late stage. Long-term rice cultivation is more conducive to the accumulation of bacterial residues. AS demonstrated a greater contribution to SOC than LN compounds within 100 years, whereas the contribution of LN ultimately exceeded AS in the late stage. Concurrently, we found a higher degree of oxidative lignin degradation in younger soils and reduced degradation with increasing duration of rice paddy cultivation. The accumulation of microbial necromass is more than plant necromass in the early stage, and it is the opposite in the late stage. Our results are critical to understand the formation and sequestration processes of SOC in paddy soils.

River capture is a surficial process that can lead to drainage reorganization and have significant impacts on sediment dispersal and biotic evolution. Discovery and study of river capture events are helpful in revealing the history of drainage basins, however, the present-day identification of river capture mainly depends on field and map observations by geomorphologists, who lack an automatic method. In the case of a large-scale drainage system with a complicated stream network, a field investigation is too time-consuming and costly. This study aims to develop a novel method for automatic river capture detection based on planform morphology and χ-plots of the stream network. The whole method can be described as a workflow including three steps: (1) searching candidate regions where river capture may have occurred; (2) iterating over each candidate region and roughly detecting the captor, captured, reversal, and beheaded rivers using the planform pattern of the stream network; (3) verifying the river capture with a χ-elevation plot in the candidate region found by rough detection. The description of the method is followed by two case studies from China and Spain, demonstrating the ability of the method to identify the location where the river capture might occur. We also discuss the parameters that must be optimized before extracting the river capture efficiently from the stream network.

The unmanned aerial vehicle（UAV） is an important tool for acquiring digital images of the surface and collecting samples. Recently, it has been becoming an emerging research tool in sedimentology, changing the paradigm of sedimentology.However, UAV-based sedimentological research in China is still in its infancy. This paper reviews the recently important applications of UAVs in sedimentology, discusses critical technical backgrounds and existing problems involved, and summarizes as well as prospects for future applications of UAVs in sedimentology to provide references for subsequent research.Software and hardware requirements for applications of UAVs in sedimentology and typical case studies are reviewed from three aspects: 3 D digital reconstruction of sedimentary outcrops, extraction of high-resolution sedimentary textures and structure features, and UAV-assisted sample collection. The use of UAV photogrammetry to construct digital outcrop models facilitates the observation of geometry, sedimentary facies, and facies associations for sedimentary outcrops from multiple spatial scales and perspectives. Combined with professional software for digital outcrop model interpretations, it allows for remote and efficient extractions of sedimentary textures and structure features such as grain size, cross-bedding, and bioglyph on large spatial scales. UAV-based digital outcrop models can also be applied to field practice teaching in sedimentology in the future. Also, UAVs can be modified to assist in collecting sediment samples like ice cores. The application of the UAV technology in sedimentological research has the advantages of low cost and high efficiency, ensuring the timeliness and continuity of data, and increasing safety in fieldwork. However, UAV technology also has disadvantages in data repeatability, point cloud processing, and image or model quality. Further improvements can be made in the future with the help of artificial intelligence and by developing standard specifications for UAV image acquisition and processing flow.

Due to the abuse and difficult removal of antibiotics, how to remove antibiotic resistant bacteria (ARB) and antibiotic resistant genes (ARGs) in the environment is facing significant challenges. A series of efficient and nontoxic photocatalytic technologies have been proposed to solve the problem of antibiotic resistance (AR) in wastewater. However, there is limited information on changes in cell behavior and characteristics during photocatalytic processing. In this study, the prepared BiOCl loaded with silver quantum dots was used to treat ARB and ARGs in water, and the physiological characteristics of ARB after photocatalytic treatment were discussed. Using tetracycline (Tet)-resistant and ampicillin (Amp)-resistant Escherichia coli (Tet-E. coli, Amp-E. coli) as target antibiotic resistant bacteria, and using Tet-resistant genes (Tet-RGs) and Amp-resistant genes(Amp-RGs) as target resistance genes, the effects of photocatalyst dosage and silver quantum dot content on photocatalytic performance were studied under UV 365 nm irradiation. The results showed that the optimal inactivation effect was achieved by Ag QDs(5 0 0)-BiOCl at a concentration of 300 mg/L, which were 6.91 lg (tet-resistant bacteria) and 6.83 lg (amp-resistant bacteria), respectively. The plasmon resonance effect between the supported silver quantum dots and BiOCl results in the generation of free radicals dominated by holes (h+) and superoxide anions (O2 & BULL;-) in the system. ARB in the system will be attacked by free radicals, and the permeability of cell membrane gradually increases. For the purpose of protection, the oxidative stress system of cells will first increase the activity of intracellular antioxidant enzymes. Due to the increase of free radicals, antioxidant enzymes gradually become inactive, ultimately leading to cell inactivation. At the same time, after photocatalytic treatment, the absolute abundance of the target resistance gene decreased by 2.79 (tetA) and 3.92 (ampC) lg. Correlation analysis found that inactivation of ARB contributes to the removal of ARGs in the system.

Mean residence time (MRT) of carbon (C) in soil is the most important parameter of C sequestration and stability and crucial for CO2 removal from the atmosphere. Climate and soil properties controls of MRT of upland soils are well known, but the drivers of C stability in paddies were never summarized. Here, we estimated MRT of paddies across monsoon Asia using the stock-over-flux method, i.e., soil organic C (SOC) stock over organic matter input considering the net primary production (NPP), and determined the main factors affecting SOC turnover. The average MRT of paddy soils in monsoon Asia ranges between 19 and 50 yr, depending on straw management. These estimates are similar to recent estimates for the global average MRT across all soils, but longer than for upland croplands. Tropical regions have the shortest MRT for rice paddies (16-42 yr), while the MRT of C in soils of temperate and subtropical regions are longer (20-56 yr). Across a wide range of environmental factors, MRT was most strongly affected by temperature. We estimate that 2 degrees C warming decreases MRT by 7% on average, with the strongest decreases in the western Indonesian islands and north-east China. Because C stocks per area in paddy soils are larger and the MRT is longer than in corresponding upland cropland soils, paddies play a key role in the global C cycle. Our results emphasize the need for management practices that retain stable soil C input rates to reduce possible positive feedbacks for global warming.

本研究旨在从构树青贮、玉米青贮及饲喂构树青贮的羔羊粪便中分离鉴定可饲用乳酸菌,为开发构树青贮用乳酸菌提供试验材料.以构树青贮、玉米青贮以及饲喂构树青贮的羔羊粪便为菌株分离来源,使用含有1％碳酸钙的MRS琼脂培养基分离纯化乳酸菌,获得菌株经16S rRNA测序鉴定后对其中可饲用菌株进行生长、产酸性能的筛选,评估在pH 3.0、3.5、4.0条件下存活率和对大肠杆菌、金黄色葡萄球菌和沙门氏菌的抑制能力,并对筛选菌株进行菌株之间拮抗性测定.结果表明:获得可饲用乳酸菌共37株,包括植物乳杆菌(Lactobacillus plantarum)、布氏乳杆菌(Lactobacillus buchneri)、副干酪乳杆菌(Lactobacillus paracasei)、粪肠球菌(Enterococ-cus faecalis)4种,不同的菌株在生长和产酸性能上表现出差异,在不同pH中存活率和抑菌性能也具有菌株特异性.综合比较不同菌株之间的生物学特性,植物乳杆菌GQ-3-2、GQ-3-29及GQ-5-4具有良好的生长、产酸及抑菌性能;粪肠球菌Y-3-15在发酵2 h进入对数生长期,能够为植物乳杆菌的大量繁殖创造良好环境;布氏乳杆菌GQ-3-21产酸性能良好,在发酵0～16 h pH快速下降,在pH 4.0的条件下存活率大于50％,在pH 3.5的条件下也能够微弱存活,是有潜力的青贮接种菌.最终选择菌株GQ-3-2、GQ-3-29、GQ-5-4、Y-3-15和GQ-3-21作为青贮用乳酸菌复合制剂的候选菌株,5株候选菌株之间不会互相抑制生长.综上所述,本试验筛选获得5株可饲用乳酸菌,其生物学特性良好,菌株之间无拮抗作用,可作为后续开发构树青贮饲料的乳酸菌复合制剂菌种来源.

As an important component in East Asia sediment source-to-sink systems, small mountainous rivers in Taiwan deliver disproportionately large amounts of sediments to oceans. Although the modern fluvial sediment transport processes, discharge fluxes and sediment compositions have been well investigated, the drainage evolution of these mountainous rivers remains understudied and sediment fluxes are expected to vary greatly in glacialinterglacial cycles due to the tremendous climatic fluctuations. To define how the drainage of Taiwan mountainous rivers has evolved since the last glaciation, we target a sediment core (98 m in length) from the Zhuoshui River delta, western Taiwan and conduct sediment petrography, heavy mineral analysis, detrital zircon U-Pb geochronology and clay mineralogy to investigate provenance variations and river basin evolution since 60 ka. Sediments of the last glaciation show comparatively high illite crystallinity index values, low metasedimentary lithic fragment and stable heavy mineral contents and similar detrital zircon U-Pb ages with downstream signatures, indicating prominent sediment contributions from the Coastal Plain and Western Foothills regions (elevation 1 km) during the glaciation. However, characteristics of the deglacial and Holocene sediments indicate high contributions from the higher Hsueshan Range and Central Range regions (elevation 1 km). We suggest that headward extension and drainage capture since the deglaciation, which was most likely due to the increasing monsoon rainfall, account for the provenance variations in the discharged sediments. This implies a climate-driven drainage reorganization of the small mountainous rivers in Taiwan since the last glaciation. Our findings highlight the previously-overlooked, variable provenance information from Taiwan in glacialinterglacial cycles, and the dynamic source signatures are important to East Asia sediment source-to-sink studies.

Trees in general are very tolerant of aluminum (Al, mainly Al 3+ at pH ≦ 5.0), and the small effects seen in the contaminated soils may mislead people that the contamination is unimportant. We believe that the assessments with Al-sensitive Masson pine could have revealed a bigger difference. The key point of this study was to characterize the Al toxicity for Masson Pine. The objectives were to discover the specific eco-physiological relationship between pine roots and rhizosphere Al, and to investigate the Al effects on several parameters, measured in the rhizosphere of Masson pine. Masson pine seedlings were cultivated on a hydroponic setup. Through comprehensive laboratory dose-gradient experiments, Al-triggered composition of the root-released compounds and several rhizospheric parameters were determined by chromatography or spectroscopy. This study gives an important evidence of the Al-toxicity effects on the composition of root-released compounds and the root growth of Masson pine. Results showed that higher rhizospheric Al at pH 4.5 might contribute to increased release of sugars, and also could stimulate the release of oxalic acid and malic acid. The total of secreted amino acids were correlated with the rhizosphere Al. Zero additional Al induced no rhizosphere pH elevation, but Al-induced rhizosphere acidification (pH from 4.50 to 4.22) was observed at Al 100 µM. Greater additions of Al (>300 µM) suppressed the rhizosphere acidification at pH 3.92. Added Al had a negative effect on the dry weight of pine roots, but an opposite effect on Al accumulated in the roots was observed. The four endogenous hormones were also determined in the pine roots. Gibberellic acid (GA 3 ) decreased, whereas abscisic acid (ABA) increased simultaneously with the addition of Al. Their inflexional concentrations were most frequently observed at 100 µM, which might be the threshold of Al toxicity for Masson pine. The secondary metabolites assayed have been studied in relation to the rhizospheric Al. The rhizosphere Al species at low pH can trigger pine roots to release the sugars (glucose, fructose + aldose), organic acids (oxalic acid, and malic acid), amino acids, secondary metabolites, and endogenous hormones during their growth. Meanwhile it also affected the growth of pine roots. This is an extensive study, which can help understanding the toxicity of Al to this important pioneer species of acid forest soils in south China.

碎屑锆石U-Pb年代学数据获取快,物源对比精确度高,还可以估算源区剥蚀量,在定量物源分析方面具有显著优势,广受沉积学界青睐.但由于采样、实验过程中的不确定性,常常导致一些物源判别结果存在多解性,甚至产生了很多争议.从碎屑锆石U-Pb年代学定量物源分析的原理入手,综述了由于沉积水动力、母岩锆石产率、沉积再旋回、人类活动、以及数据获取与处理5方面因素对年龄谱可能产生的影响.结果表明,河流砂相比地层中的沉积岩,物源区母岩性质明确,运移路径非常清晰,可以进行锆石产率的准确测定,并能够同时开展混合模型正演和反演,是理想的定量物源分析研究对象.对开展基于现代河流砂的定量物源分析机理研究进行了展望,指出应用新技术、新方法开展小流域碎屑锆石U-Pb年代学研究是揭示锆石侵蚀、搬运和沉积过程行为机理的重要手段、也是构建定量物源分析方法的重要基础,将为规范开展沉积地层的物源研究提供重要的理论依据.