东华理工大学

The middle–lower Yangtze River region hosts extensive aeolian deposits, among which the Poyang Lake sandy land (PYSL) constitutes a prominent and geomorphologically distinctive example. However, the relative contributions and synergistic interactions between aeolian and fluvial processes in shaping these landscapes remain insufficiently quantified, primarily due to methodological limitations and spatially fragmented research efforts. This knowledge gap impedes both robust paleoenvironmental reconstructions and the development of effective strategies for mitigating sand-related hazards. Here, an integrated provenance study of the PYSLs was conducted, combining detrital zircon UPb geochronology, heavy mineral analysis, and grain-size distribution. The multidimensional scaling (MDS) diagrams and inverse Monte Carlo models (IMCM) of detrital zircon ages indicate major provenance areas are the eastern Cathaysia Block (mainly the south and central Jiangxi ranges; 16.2–85.5%) and the Jiangnan Orogenic Belt (primarily the Jiuling Mountains; 14.5–83.8%). The results demonstrate pronounced spatial heterogeneity in sediment direct sources. The central PYSLs are primarily supplied by the Ganjiang and Xiushui rivers, whereas the northern PYSL is dominated by the Yangtze and Ganjiang rivers, and the southern PYSL derives sediment mainly from the Jinjiang river. Obviously, wind plays a subordinate role in large-scale sediment reworking, as evidenced by the marked compositional heterogeneity between the northern and southern PYSL. Nevertheless, aeolian processes remain dynamically active in the local redistribution of sediments within the central PYSLs. These findings collectively emphasize that topographic factors must be carefully considered in paleoenvironmental studies of aeolian deposits. However, surface samples provide only a limited view into longer-term landscape evolution.

Multifunctional agriculture jointly produces commodity and non-commodity outputs, yet many non-commodity benefits are underprovided due to insufficient economic incentives. This challenge is amplified in the agriculture-tourism nexus, where tourism depends on agricultural landscapes while potentially contributing to their degradation, creating interconnected externalities that distort benefit distribution and undermine joint production efficiency. This study extends joint production theory to the agriculture-tourism nexus by developing a framework for integrated terraced agriculture-ecotourism production, in which tourism generates conservation incentives by capturing economic value from landscape and environmental services. We identify the socially optimal provision of agricultural non-commodity benefits under different landscape loss scenarios and examine how externality internalization and multi-stakeholder collaboration affect joint production efficiency. The results show that achieving optimal multifunctionality requires balancing the benefits and costs of externality internalization across agricultural and tourism activities. Failure to do so may reduce joint production efficiency by distorting factor income distribution. Multi-stakeholder collaboration improves benefit allocation and lowers internalization costs, enabling the socially optimal provision of agricultural non-commodity benefits. These findings underscore the need for integrated governance mechanisms that align economic incentives with ecological conservation in mountainous regions.

In this paper, we propose a fast doubly block sparse Kaczmarz method with momentum (FDBSK-M) for solving sparse-regularized linear systems. At each iteration, the new method uses adaptive row-wise residual information, cyclic column-block updates and momentum-accelerated Bregman iteration to efficiently approximate sparse solutions. For consistent systems, the method converges linearly; in the presence of noise, the iteration error remains bounded by the noise level. Numerical experiments demonstrate that FDBSK-M achieves high recovery rates and superior convergence performance in sparse signal reconstruction, and offers better computational advantages over classical randomized block sparse Kaczmarz by averaging (RSKA) method, the fast block sparse Kaczmarz (FBSK) method, and the max-distance sketched Bregman projection (MDSBP) method. The numerical results further indicate that combining momentum with cyclic column-block strategies significantly improves convergence speed and stability, providing an efficient and scalable algorithm for large-scale sparse recovery.

Abstract Mafic continental large igneous provinces (LIPs) erupted rapidly and may have overwhelmed Earth's atmospheric and biospheric systems. However, the exact balance and interplay between short‐term climate warming caused by CO2 emissions and long‐term cooling due to LIP weathering remains poorly understood. To investigate the influence of LIP emplacement on long‐term climate change, we quantified the mass fluxes during the late Permian associated with the Emeishan LIP and its weathering products in the western Yangtze Cratonic Basin of southwestern China. The minimum value of the average denudation rate of the Emeishan LIP during the late Permian (Wuchiapingian) was 170.8 t/km2/yr, indicating enhanced capacity for atmospheric CO2 consumption at that time. The estimated minimum dissolved element fluxes from the Emeishan LIP to the surface ocean were 2.29 × 106 t/yr Si, 11.7 × 103 t/yr P, and 68 × 103 t/yr Fe, which account for 1.3%–3.4% of the fluxes from modern global rivers. These high nutrient fluxes led to an atmospheric CO2 removal rate of 8.5–85 × 106 t/yr through enhanced biological productivity, as estimated by the Fe fertilization model and dissolved Fe flux. This rate is approximately one order of magnitude higher than those resulting from Emeishan LIP basalt weathering and accounts for 0.05%–0.5% of the modern global CO2 sink, which could have led to a reduction in atmospheric CO2. Our results highlight the key role of LIPs in modulating Earth's climate over long time periods and in driving long‐term cooling due to enhanced CO2 drawdown caused by enhanced nutrient input to the surface ocean.

The Silk Road traversed diverse and challenging landscapes, with one of its most characteristic stretches spanning the extremely arid Tarim Basin. The meandering paths of trade routes gradually developed from ancient corridors of diffusion into organised and government-regulated commerce by roughly two millennia ago, institutions that remained in use until the sixteenth century. Our understanding of what caused the reduction of Silk Road trade remains limited. Conventional theories tend to take socioeconomic perspectives, particularly relying on political transformations in the Eurasian heartland and a redirection towards maritime routes. Here, we examined a potential role for hydro-environmental factors in the fall of the long-distance trade networks by compiling a unique landscape-scale dataset, comprising 164 radiocarbon dates of in situ plant remains from along palaeochannels and 254 recruitment ages of living trees in the Tarim Basin. Using Bayesian modelling, we produce a novel proxy for the time that the rivers dried up with high spatiotemporal resolution, and integrate it with palaeohydrological records from adjacent regions. Given the hyper-aridity, riparian forests became desiccated across the region as their glacial-melt streams stopped flowing, leaving a direct record of the death of river branches. We conclude that the decline of core routes of the Silk Road coincided with significant decreases in streamflow across northwest China, especially during a low-flow period around 1500 to 1650 CE in the Tarim Basin. We suggest that this dry phase was significant enough to cause the abandonment of many central trading routes, contributing to what may have been a complex set of compounding variables.