Xiangyi Li

Rapid coastal urbanization poses severe threats to biodiversity through habitat fragmentation, making continuous monitoring of urban ecosystems essential. While birds serve as sensitive bio-indicators, the long-term spatiotemporal dynamics of their habitats and temporal shifts in environmental drivers remain poorly understood in high-density megacities. This study addresses this gap by developing a trend-explainable machine learning framework to evaluate avian habitat suitability across the western coast of Shenzhen from 2010 to 2020. We applied a standardized filtering protocol to citizen science data and integrated occupancy modeling with a Random Forest algorithm to simulate habitat distributions at 30 m resolution. Spatiotemporal habitat alterations were quantified using Mann–Kendall trend analysis, while SHAP was utilized to diagnose the changing importance and non-linear thresholds of ecological drivers over the decade. Our findings reveal pronounced spatial heterogeneity among six avian guilds. Habitat quality for terrestrial birds, raptors, and songbirds degraded severely in northern industrial regions, whereas targeted ecological restoration facilitated recovery in southern and western urban cores. The analysis further demonstrates dynamic temporal shifts in environmental responses. The restrictive impact of anthropogenic stressors including population density and nighttime light weakened for terrestrial and canopy-dwelling guilds but intensified for waterfowl. Concurrently, natural elements such as vegetation coverage and proximity to water bodies became increasingly important. Based on these spatiotemporal patterns, we delineated five ecological zones to guide targeted conservation interventions. This research provides an analytical framework linking predictive modeling with mechanistic insights, supporting evidence-based biodiversity conservation and sustainable urban planning in rapidly developing coastal landscapes.

Small urban parks and green spaces, serving as essential recreational venues for city residents, also play a vital and irreplaceable role in maintaining urban biodiversity. It is of great importance to design and plan these areas in a way that integrates multiple habitats for various species while accommodating residents’ usage. This study, carried out at the Futian Mangrove Ecological Park located in Shenzhen, Guangdong Province, China, chose birds as indicator species to assess biodiversity within the park. Site inventory was undertaken from May to September 2022 and from October 2022 to April 2023. We quantitatively described the park’s habitats by examining primary environmental factors, along with 3 primary environmental factors and 11 secondary factors. A correlation analysis was then performed between these factors and bird diversity to gain insights into birds’ habitat preferences across different habitat types and at a finer scale of plant communities. Furthermore, bird clusters in the study case were categorized by foraging guilds and foraging patterns, and their distributions were studied at both the habitat patch scale and the plant community scale. Our findings reveal that, at the habitat patch scale, water surface area and grass coverage significantly positively impact bird diversity. At the plant community scale, plant communities with different structural characteristics vary in their importance to bird clusters with distinct characteristics. In areas with high human disturbance, shrub coverage is crucial for bird habitat protection. Additionally, we discovered that the impact of anthropogenic sound differs among bird species, highlighting the complexity of human disturbance factors on bird habitat preferences. Accordingly, we proposed several design recommendations aimed at enhancing bird diversity in parks, including increasing water body areas, reducing the distance between habitats and water surfaces, enhancing herbaceous plant coverage, and controlling anthropogenic sound.

Objective measurement of the supply–demand of ecosystem services (ESs) has received increasing attention from recent studies. It reflects the relationship between green spaces and human society. However, these studies rarely assess the mountainous cities. To fill this gap, this study takes a typical mountainous city as a research case to reveal the supply–demand relationship of ecosystem services, then development and management strategies are proposed for different districts according to their spatial differentiation characteristics. Results shows that: (1) there are differences of ESs supply between each district, and supply from Banan District is significantly higher than others. (2) The demands for ES also vary widely, which are higher in the core urban areas. (3) There are different degrees of imbalance between supply and demand in each district. We classified green spaces into four types based on their supply–demand characteristics, and optimization strategies are proposed. We found that most of the districts are lack of ES supply while there is a relatively high demand for ES in Chongqing, and the balance of supply and demand between different districts varies greatly. Our study indicates that targeted urban green spaces strategies for different districts must be considered to adequately optimize ES in mountainous cities.