The National Park of Hainan Tropical Rainforest (NPHTR) plays the crucial role of an ecological barrier for Hainan Island. It also serves as a valuable repository of tropical biological heritage for the world. The scientific establishment of an ecological security pattern (ESP) for the NPHTR is therefore essential for ensuring the robustness and stability of this regional ecosystem, safeguarding tropical biodiversity, and promoting sustainable development. This study integrates ecosystem service functions (ESFs) and ecological sensitivity to identify ecological sources (ESs) so that regional integrity is promoted and ecological security is ensured. Ecological corridors (ECs) are established on the basis of a minimum cumulative resistance (MCR) model and circuit theory. We integrate ESs, nodes, and corridors to construct the ESP of the NPHTR. The areas of extreme importance and sensitivity in the NPHTR account for 25.17% and 25.47% of its overall area, respectively, and are predominantly situated in the higher elevations of its eastern and central regions. Further, the ESs are mainly distributed in its western region, specifically Ba Wangling (BWL), Jian Fengling (JFL), and Ying Geling (YGL), covering an area of 1624.67 km² (38.06% of the total area) of the NPHTR. After correction, 47 ECs with a distance of 870.9 km have been established, with BWL and YGL serving as the core areas. The ecological pinch- and barrier points in the NPHTR cover areas of 11.49 km² and 16.35 km², respectively, primarily consisting of man-made landscapes such as farmlands and buildings. These areas are significantly disturbed by human activities. The NPHTR has an ESP of “one screen, one district, three belts, multiple points, and multiple corridors”. BWL and YGL, which contain numerous sources and corridors, are crucial ecological functional zones. To ensure the horizontal connectivity of rare wildlife, such as of Nomascus hainanus and Cervus eldii hainanus, the NPHTR should establish buffer or development zones. These findings offer valuable insights for the development and planning of ecological civilization on Hainan Island, as well as for the establishment and management of the ESP of other national parks and nature reserves.

Free trade zones are key regions experiencing rapid economic growth, urbanization, and a sharp increase in population density. During the development of free trade zones, these areas undergo drastic transformations in landscape types, large-scale urban construction, heightened resource consumption, and other associated challenges. These factors have led to severe landscape ecological risk (LER). Therefore, conducting comprehensive assessments and implementing effective management strategies for LER is crucial in advancing ecological civilization and ensuring high-quality development. This study takes Hainan Island (HI), China, as a case study and utilizes multi-source data to quantitatively evaluate land use and land cover change (LULCC) and the evolution of the LER in the study area from 2015 to 2023. Additionally, it examines the spatial patterns of LER under three future scenarios projected for 2033: a natural development scenario (NDS), an economic priority scenario (EPS), and an ecological conservation scenario (ECS). Adopting a spatiotemporal dynamic perspective framed by the “historical–present–future” approach, this research constructs a zoning framework for LER management to examine the temporal and spatial processes of risk evolution, its characteristics, future trends, and corresponding management strategies. The results indicate that, over an eight-year period, the area of built-up land expanded by 40.31% (504.85 km²). Specifically, between 2015 and 2018, built-up land increased by 95.85 km², while, from 2018 to 2023, the growth was significantly larger at 409.00 km², highlighting the widespread conversion of cropland into built-up land. From 2015 to 2023, the spatial distribution of LER in the study area exhibited a pattern of high-risk peripheries (central mountainous areas) and low-risk central regions (coastal areas). Compared to 2023, projections for 2033 under different scenarios indicate a decline in cropland (by approximately 17.8–19.45%) and grassland (by approximately 24.06–24.22%), alongside an increase in forestland (by approximately 4.5–5.35%) and built-up land (by approximately 23.5–41.35%). Under all three projected scenarios, high-risk areas expand notably, accounting for 4.52% (NDS), 3.33% (ECS), and 5.75% (EPS) of the total area. The LER maintenance area (65.25%) accounts for the largest proportion, primarily distributed in coastal economic development areas and urban–rural transition areas. In contrast, the LER mitigation area (7.57%) has the smallest proportion. Among the driving factors, the GDP (q = 0.1245) and year-end resident population (q = 0.123) were identified as the dominant factors regarding the spatial differentiation of LER. Furthermore, the interaction between economic factors and energy consumption further amplifies LER. This study proposes a policy-driven dynamic risk assessment framework, providing decision-making support and scientific guidance for LER management in tropical islands and the optimization of regional land spatial planning.

Aboveground biomass (AGB) is a key indicator of forest structure and carbon sequestration, yet its dynamics under concurrent anthropogenic disturbances remain poorly understood. This study investigates the spatiotemporal dynamics and driving mechanisms of AGB in the Jianfengling tropical lowland rainforest (JFLTLR) within Hainan Tropical Rainforest National Park (NRHTR) from 2015 to 2023. Six machine learning models—Extreme Gradient Boosting (XGBoost), Gradient Boosting Machine (GBM), Support Vector Machine (SVM), k-Nearest Neighbors (KNN), Decision Tree (DT), and Random Forest (RF)—were evaluated, with RF achieving the highest accuracy (R² = 0.83). Therefore, RF was employed to generate high-resolution annual AGB maps based on Sentinel-1/2 data fusion, field surveys, socio-economic indicators, and topographic variables. Human pressure was quantified using the Human Influence Index (HII). Threshold analysis revealed a critical breakpoint at ΔHII ≈ 0.1712: below this level, AGB remained relatively stable, whereas beyond it, biomass declined sharply (≈−2.65 mg·ha⁻¹ per 0.01 ΔHII). Partial least squares structural equation modeling (PLS-SEM) identified plantation forests as the dominant negative driver, while GDP (−0.91) and road (−1.04) exerted strong indirect effects through HII, peaking in 2019 before weakening under ecological restoration policies. Spatially, biomass remained resilient within central core zones but declined in peripheral regions associated with road expansion. Temporally, AGB exhibited a trajectory of decline, partial recovery, and renewed loss, resulting in a net reduction of ≈ 0.0393 × 10⁶ mg. These findings underscore the urgent need for a “core stabilization–peripheral containment” strategy integrating disturbance early-warning systems, transportation planning that minimizes impacts on high-AGB corridors, and the strengthening of ecological corridors to maintain carbon-sink capacity and guide differentiated rainforest conservation.

Land use reconfiguration can substantially alter regional carbon source–sink patterns, yet integrated evidence remains limited for spatially constrained island systems where development and ecological land are closely juxtaposed. Using Hainan Island (HI) as a case, this study applied an integrated analytical framework linking land use mix, coefficient-based land use carbon emission (LUCE) accounting, spatial redistribution, spatially varying associations, interaction detection, and decoupling analysis across 18 administrative units from 2000 to 2023. Estimated LUCEs increased more than sevenfold during the study period, with emission growth concentrated mainly in coastal development areas, while the interior remained comparatively low in emissions. The spatial distribution of LUCEs gradually expanded inland, and socioeconomic development, built-up land, terrain, and their interactions exhibited heterogeneous associations with LUCEs across the island. The decoupling relationship between land mixed use and LUCEs generally improved after 2005 but remained unstable in several coastal cities. These results indicate that island-wide LUCE evolution is characterized by spatially differentiated relationships between land development and ecological land configuration rather than by a uniform regional process. By integrating land use structure, coefficient-based carbon accounting, spatial redistribution, heterogeneity in factor associations, and decoupling within a common coast–interior framework, this study provides an analytical perspective that can support comparable land use carbon assessments in islands and coastal regions experiencing concentrated development and strong ecological constraints.