Accurate and effective mapping of forest aboveground biomass (AGB) in heterogeneous mountainous regions is a huge challenge but an urgent demand for resource managements and carbon storage monitoring. Conventional studies have related the plot-measured or LiDAR-based biomass to remote sensing data using pixel-based approaches. The object-based relationship between AGB and multi-source data from LiDAR, multi-frequency radar, and optical sensors were insufficiently studied. It deserves the further exploration that maps forest AGB using the object-based approach and combines LiDAR data with multi-sensor images, which has the smaller uncertainty of positional discrepancy and local heterogeneity, in heterogeneous mountainous regions. To address the improvement of mapping accuracy, satellite LiDAR data from GEDI and ICEsat-2, and images of ALOS-2 yearly mosaic L band SAR (Synthetic Aperture Radar), Sentinel-1 C band SAR, Sentinel-2 MSI, and ALOS-1 DSM were combined for pixel- and object-based forest AGB mapping in a vital heterogeneous mountainous forest. For the object-based approach, optimized objects during a multiresolution segmentation were acquired by the ESP (Estimation of the Scale Parameter) tool, and suitable predictors were selected using an algorithm named VSURF (Variable Selection Using Random Forests). The LiDAR variables at the footprint-level were extracted to connect field plots to the multi-sensor objects as a linear bridge. It was shown that forests’ AGB values varied by elevations with a mean value of 142.58 Mg/ha, ranging from 12.61 to 514.28 Mg/ha. The north slope with the lowest elevation (<1100 m) had the largest mean AGB, while the smallest mean AGB was located in the south slope with the altitude above 2000 m. Using independent validation samples, it was indicated by the accuracy comparison that the object-based approach performed better on the precision with relative improvement based on root-mean-square errors (RI_RMSE) of 4.46%. The object-based approach also selected more optimized predictors and markedly decreased the prediction time than the pixel-based analysis. Canopy cover and height explained forest AGB with their effects on biomass varying according to the elevation. The elevation from DSM and variables involved in red-edge bands from MSI were the most contributive predictors in heterogeneous temperate forests. This study is a pioneering exploration of object-based AGB mapping by combining satellite data from LiDAR, MSI, and SAR, which offers an improved methodology for regional carbon mapping in the heterogeneous mountainous forests.

The study of spatial and temporal patterns of ecosystem services and trade-offs/synergies relationships clarifies the distribution of ecological functional areas, which is a top priority for the coordinated development of regional economy-society-ecology. Using the InVEST model to assess the four ecosystem services of water yield, soil retention, carbon storage and biodiversity maintenance in Jilin Province from 2000 to 2020, analyzing their spatial and temporal patterns, analyzing trade-offs/synergies between ecosystem services and their drivers through the coupled coordination degree model and geodetector, and identifying ecological functional zones by using the SOM clustering approach. The results showed that: (1) the four ecosystem services showed significant variability over time from 2000 to 2020. Water yield increased in the western part of Jilin Province and decreased in the eastern part; total soil retention increased by 8 × 10¹¹kg, and the growth of soil retention in the eastern part was larger than that in the western part; carbon storage showed a continuous downward trend, decreasing by a total of 1.3 × 10¹¹ kg, with the strongest sequestration capacity of woodlands and grasslands; biodiversity maintenance higher in the southeast than in the northwest. (2) The two-two ecosystem service trade-offs are mainly located in the western part of Jilin Province, with quality synergies and good synergies distributed in the southern and eastern parts of Jilin Province. Precipitation was the dominant factor in the water production and biodiversity maintenance trade-offs/synergies, q = 0.8570, and slope had the greatest effect on the other five ecosystem service trade-offs/synergies. (3) Using the SOM algorithm to classify ecosystem service bundles, ecological functional zones are classified according to the characteristics of the ecosystem service clusters into ecological reserve, precautionary management zone, priority restoration zone, integrated supply zone, key management zone, and ecological conservation zone. Quantitative visualization studies of ecosystem services, trade-offs/synergies relationships among ecosystems and identification of ecological functional areas in Jilin Province can provide a theoretical basis for regional sustainable development and ecological environment optimization.

Jilin Province is an important ecological security barrier and major grain-producing region in northeast China, playing a crucial role in ensuring ecological security and promoting regional sustainable development. This study examines ecological resilience from three dimensions: resistance, adaptability, and resilience. Based on multi-source data from 2000 to 2020, an ecological resilience indicator system was constructed. Spatial autocorrelation and OPGD models were employed to analyze temporal and spatial evolution and the driving mechanisms. The results indicate that ER exhibits an overall spatial pattern of “high in the east, low in the west, and under pressure in the central region.” The eastern mountainous areas demonstrate high and stable resilience, while the central plains and western ecologically fragile regions exhibit weaker resilience. In terms of resistance, the eastern mountainous regions are primarily forested, with high and sustained ESV, while the western sandy edge regions primarily have low ESV, making ecosystems susceptible to disturbance. In terms of adaptability, the large-scale farmland landscapes in the central regions exhibit strong disturbance resistance, while water resource adaptability in the western ecologically fragile regions has locally improved. However, adaptability in the eastern mountainous regions is relatively low due to development impacts. In terms of resilience, the eastern core regions possess stable recovery capabilities, while the central and western regions generally exhibit lower resistance with fluctuating changes. Between 2000 and 2020, the ecological resilience Moran’s I index slightly decreased from 0.558 to 0.554, with the spatial aggregation pattern remaining largely stable. Among the driving factors, DEM remains the most stable. The influence of NDVI has weakened, while temperature (TEM) and NPP-VIIRS have become more significant. Overall, factor interactions have grown stronger, as reflected by the q-value rising from 0.507 to 0.5605. This study provides theoretical support and decision-making references for enhancing regional ecological resilience, optimizing ecological spatial layout, and promoting sustainable ecosystem management.

AI technology is reshaping the knowledge ecosystem, bringing both challenges and opportunities to libraries. This article examines the transformation of librarians from “knowledge guardians” to “intelligent collaborators.” It discusses the professional challenges and practical dilemmas introduced by AI through the lenses of value reorientation and paradigm shift. The paper argues that librarians should actively adopt new technologies, engage in ongoing learning, and develop more resilient knowledge service systems, while also identifying their key roles and potential pathways for transformation within smart library frameworks.

Taking Jilin Province in 2020 as the study area, this research categorizes ecosystem service supply and demand by integrating ecosystem service functions with a human well-being framework. The study evaluates the supply and demand of ecosystem services and examines their spatial distribution characteristics. To further delineate ecological management zones, the SC K-means clustering algorithm and the coupling coordination degree model are employed. The results reveal significant regional disparities in the availability and necessity of six ecosystem services. Food production services exhibit a spatial pattern characterized by an increase in the central region while declining in the eastern and western areas. In contrast, the supply of the other five ecosystem services generally follows a “low in the west, high in the east” trend. Additionally, except for soil conservation, the demand for ecosystem services demonstrates a distribution pattern of being high in the central region and lower in the surrounding areas. The overall supply of ecosystem services gradually increases from west to east, reaching its peak in the eastern region, whereas the comprehensive demand is highest in the central region and lower in both the eastern and western areas, with central cities and their surrounding counties exhibiting the most pronounced demand. Based on the dynamics of supply and demand, Jilin Province is divided into five ecological management zones. The ecological potential zone, where supply–demand coordination transitions from low to high, is suited for developing green agricultural economies and optimizing industrial structures. The ecological restoration zone, experiencing a shift from high to low supply–demand balance, faces imbalances that necessitate efforts to alleviate human-land conflicts and enhance the equilibrium between social development and ecological conservation. The ecological consolidation zone, which maintains a high-to-low supply–demand trend with relative stability, requires continued efforts in preserving its natural environment. The ecological adjustment zone, characterized by an imbalanced high-to-low supply–demand transition, should focus on industrial restructuring and eco-tourism development. Lastly, the ecological coordination zone, which maintains a well-balanced supply–demand relationship, should leverage its economic foundation to advance environmental protection technologies and strengthen conservation efforts. This study provides a systematic evaluation of the spatial patterns of ecosystem service supply and demand in Jilin Province and offers targeted ecological management strategies to promote sustainable environmental development.