The response of ecosystem vulnerability to climate change and human activities in the Poyang lake city group, China

Multiscale exploration of spatiotemporal dynamics in China's largest urban agglomeration: An interactive coupling perspective on human activity intensity and ecosystem health

Human economic construction increasingly impacts highly sensitive ecological zones, weakening ecosystem health in cross-regional urban agglomerations. Exploring the spatiotemporal dynamics of urban agglomerations from the interactive coupling perspective between human activity intensity (HAI) and ecosystem health index (EHI) is crucial for resolving human-land conflicts. This study developed a human-land coupling assessment framework integrating human footprint and ecosystem Maintain-Bearing-Service-Resilience models. Across multiple scales, from urban agglomerations and cities to grid cells, we initially employed exploratory spatiotemporal data analysis techniques to reveal HAI and EHI evolution patterns. Subsequently, we used the four-quadrant model, coupling coordination degree (CCD), and relative development model to explore their spatiotemporal interactions. Applied to China's largest urban agglomeration, the middle reaches of the Yangtze River urban agglomerations (MRYRUA), results revealed a significant spatiotemporal mismatch pattern between HAI and EHI. High HAI and low EHI areas were widely distributed in highly urbanized waterfront plains. At the urban agglomeration scale, HAI and EHI exhibited spatiotemporal differentiation patterns extending toward polarization along the Yangtze River Economic Belt, while their correlation intensity among cities indicated conflicting development patterns. At the grid scale, the spatiotemporal clustering pattern highlighted waterfront built-up areas as HAI hotspots and peripheral forest zones as EHI hotspots. The interactive relationship between HAI and EHI shifted increasingly towards Quadrant IV as HAI rose. The coupling levels between HAI and EHI will tend toward misalignment as urbanization advances, although current CCD shows positive trends. This study offers scientific guidance for achieving sustainable development in urban agglomerations across multiple scales.

Impacts of Climate Change on the Habitat Suitability and Natural Product Accumulation of the Medicinal Plant Sophora alopecuroides L. Based on the MaxEnt Model

Sophora alopecuroides L., a perennial herb in the arid and semi-arid regions of northwest China, has the ecological functions of windbreaking and sand fixation and high medicinal value. In recent years, global warming and human activities have led to changes in suitable habitats for S. alopecuroides, which may affect the accumulation of natural products. In this study, MaxEnt 3.4 and ArcGIS 10.4 software were used to predict the distribution of potentially suitable habitats for S. alopecuroides in China under climate change. Furthermore, the geographical distribution of S. alopecuroides as affected by human activities, the differences in the content of natural products of S. alopecuroides between different suitable habitats, and the correlation between natural products and environmental factors were analyzed. The results showed that suitable habitats for S. alopecuroides were projected to expand in the future, and the major environmental factors were temperature (Bio1), rainfall (Bio18), and soil pH (pH). When Bio1, Bio18, and pH were 8.4283 °C, 7.1968 mm, and 9.9331, respectively, the distribution probability (P) of S. alopecuroides was the highest. After adding a human activity factor, the accuracy of the model prediction results was improved, and the area of suitable habitats was greatly reduced, showing a fragmented pattern. Meanwhile, habitat suitability had a specific effect on the content of natural products in S. alopecuroides. Specifically, the content of natural products in S. alopecuroides in wild habitats was higher than that in artificial cultivation, and highly suitable habitats showed higher contents than those in non-highly suitable habitats. The contents of total alkaloids and total flavonoids were positively correlated with human activities and negatively correlated with land use types. Among them, total alkaloids were negatively correlated with aspect, and total flavonoids were positively correlated with aspect. In addition, it is suggested that Xinjiang should be the priority planting area for S. alopecuroides in China, and priority should be given to protection measures in the Alashan area. Overall, this study provides an important foundation for the determination of priority planting areas and resource protection for S. alopecuroides.

The vulnerability assessment and obstacle factor analysis of urban agglomeration along the Yellow River in China from the perspective of production-living-ecological space

Urban agglomerations are sophisticated territorial systems at the mature stage of city development that are concentrated areas of production and economic activity. Therefore, the study of vulnerability from the perspective of production-living-ecological space is crucial for the sustainable development of the Yellow River Basin and global urban agglomerations. The relationship between productivity, living conditions, and ecological spatial quality is fully considered in this research. By constructing a vulnerability evaluation index system based on the perspectives of production, ecology, and living space, and adopting the entropy value method, comprehensive vulnerability index model, and obstacle factor diagnostic model, the study comprehensively assesses the vulnerability of the urban agglomerations along the Yellow River from 2001 to 2020. The results reveal that the spatial differentiation characteristics of urban agglomeration vulnerability are significant. A clear three-level gradient distribution of high, medium, and low degrees is seen in the overall vulnerability; these correspond to the lower, middle, and upper reaches of the Yellow River Basin, respectively. The percentage of cities with higher and moderate levels of vulnerability did not vary from 2001 to 2020, while the percentage of cities with high levels of vulnerability did. The four dimensions of economic development, leisure and tourism, resource availability, and ecological pressure are the primary determinants of the urban agglomeration's vulnerability along the Yellow River. And the vulnerability factors of various urban agglomerations showed a significant evolutionary trend; the obstacle degree values have declined, and the importance of tourism and leisure functions has gradually increased. Based on the above conclusions, we propose several suggestions to enhance the quality of urban development along the Yellow River urban agglomeration. Including formulating a three-level development strategy, paying attention to ecological and environmental protection, developing domestic and foreign trade, and properly planning and managing the tourism industry.