Abstract： Deep-sea fine-grained sediments are important archives of paleoenvironmental evolution, yet their characterization is often limited by the constraints of traditional outcrop and core analyses, as well as the relatively low resolution of seismic and conventional well-logging methods. High-resolution Formation MicroScanner (FMS) image logging, known as “electrical coring”, provides an important tool for the characterization of deep-sea fine-grained sediments. Using FMS image logs data, we examine the types, characteristics, and vertical distribution of Pliocene-Pleistocene deep-sea fine-grained sediments at IODP Site U1445A in the Bengal submarine fan. By integrating static image color and dynamic image structure, we identified six distinct FMS log facies (F1-F6), which we further interpreted based on core calibration and sedimentological characteristics. Our findings indicate that the sedimentary succession at Hole U1445A is mainly composed of turbiditic clay or sandy/silty clay, as well as pelagic deposits including biosiliceous- or calcareousrich sandy/silty clay and clayey biosiliceous or calcareous ooze The vertical evolution of the sediments generally followed these stages: dominance of fine-grained turbidite deposits in the Early Pliocene; dominance of pelagic deposition with intercalated turbidite deposits during the Late Pliocene, predominantly pelagic deposition during the initial Early Pleistocene; and renewed dominance of fine-grained turbidite deposits during the middle to late Early Pleistocene. Given that approximately two-thirds of the core from hole U1445A was affected by drilling disturbance, resulting in distorted core-based measurements of various physical properties, the vertical lithological sequence reconstructed from FMS imaging logging interpretation in this study provides an important supplement for traditional core-based geological analysis. This method can be extended to other well intervals with incomplete coring or cores affected by drilling disturbance.

Under the context of global warming and rising atmospheric CO₂ levels, increases in vegetation leaf area and longer growing seasons both contribute to a clear greening trend. However, whether these two factors show a trade-off or work together remains unclear. In this study, we used multi-source remote sensing data to analyze the patterns of maximum leaf area index (LAImax) and growing season length (LOS) in deciduous broadleaved forests (DBF) across China from 2003 to 2020. The results indicated that: ① An increase in leaf area is negatively correlated with the extension of the growing season. In Northeast China, deciduous broadleaf forests show relatively small increases in leaf area but more significant extensions of the growing season. Conversely, in the northern transitional zone, the opposite pattern is observed, suggesting a trade-off between these two strategies. ② Tree height plays an important role in explaining this trade-off. In the northern transitional zone, where dwarf trees dominate, forests tend to adopt a strategy of increasing leaf area with only small changes in growing season length. By contrast, in Northeast China, where tall trees are more common, forests are more likely to extend the growing season while showing limited leaf area change. This spatial difference reflects the contrasting physiological adaptations of trees with different heights. ③ These contrasting strategies are jointly shaped by climate factors and vegetation traits. Rising atmospheric CO₂ is more likely to promote leaf area increase in dwarf trees, whereas higher surface temperature has a stronger effect on growing season extension in tall trees. In addition, dwarf trees generally have lower initial leaf area and a higher leaf-to-sapwood area ratio, which favors leaf area increase, while tall trees tend to extend the growing season because of their larger basal leaf area and lower leaf-to-sapwood ratio. ④ The two strategies have different ecosystem consequences. Dwarf trees can enhance photosynthesis and ecosystem productivity by increasing leaf area. In contrast, tall trees mainly adapt by extending the growing season, but their lower photosynthetic efficiency may reduce ecosystem productivity.This expansion provides additional context to the ecological dynamics, emphasizing how specific strategies driven by tree height and climate factors interact to shape vegetation function across regions.