National parks face ecological threats from climate change and human activities. Sanjiangyuan National Park (SNP), a major ecological area in China, lacks a systematic evaluation of its ecological environmental quality changes and their driving factors. This study explores these dynamics to provide a scientific basis for regional ecological management. By constructing the remote sensing ecological index (RSEI) and using the optimal multivariate-stratification geographical detector (OMGD) model, we assessed ecological changes from 2014 to 2024. The results showed the RSEI remained stable at approximately 0.66, peaking at 0.732 in 2022, indicating a general improvement in ecological quality. The vegetation coverage rate (NDVI) increased from 0.591 to 0.680. Driving factor analysis revealed considerable regional variation, with temperature and human activities as the primary drivers. Higher RSEI values were associated with conditions where precipitation was moderate (~100 mm), evapotranspiration levels were high (>50 mm), temperatures were above average (>4 °C), and nighttime light indices were low (<0.6). These findings suggest that specific combinations of these factor thresholds may enhance ecological quality, informing protection strategies for SNP and providing a reference for similar plateau ecosystems.

Climate change is intensifying the frequency and severity of droughts, posing a significant threat to global crop production. Accurately quantifying drought impacts is challenging and critical for mitigation. Here, we use a high-resolution, bottom–up assessment framework to analyze drought impacts on yields of four major crops—maize, soybean, rice, and wheat—at county, provincial, and national levels over 1997–2021. Results show yield losses escalate dramatically with spatial granularity, from 3.3% at the national level to 10.8% at the county level, with soybeans (16.3%) and maize (11.4%) being the most vulnerable. Despite an increase in drought frequency, drought-induced crop losses declined significantly, owing to the improvements in irrigation. Notably, a 10% increase in agricultural water use was significantly associated with a 1.71% reduction in yield losses. Our findings not only highlight the critical importance of scale-dependent risk assessments but also provide robust evidence and spatial pattern for the significant role of irrigation in mitigating drought risks.

In the context of global climate change and rapid urbanization, integrating urban blue-green infrastructure into the built environment is essential for mitigating the urban heat island effect and enhancing climate resilience. Focusing on urban riparian corridors as vital natural cooling systems, this study aims to: (1) quantify their cooling performance in terms of intensity and distance; (2) identify the key landscape drivers and their relative importance; (3) uncover nonlinear relationships and determine ecological thresholds for optimal thermal regulation; and (4) translate these findings into science-based guidelines for climate-adaptive design and sustainable management. Taking 27 representative riparian green spaces in Zhengzhou, China (average area: 17,539 m², range: 10,027–42,690 m²) as a case study, nine key factors characterizing vegetation structure and composition, corridor morphology, and blue-green spatial pattern were used as predictors in a Boosted Regression Tree (BRT) model to analyze their contributions and marginal-effect thresholds. Results show that these corridors provide substantial cooling, with an average intensity of 5.43 °C extending over 215.56 m. Canopy Density, 3D Green Volume per Unit Area, and Green Cover Ratio emerged as the three core drivers, jointly explaining >86% of the cooling performance. The key innovation lies in identifying explicit, design-oriented ecological thresholds—for example, cooling efficacy stabilizes when Green Cover Ratio reaches ~77%, Canopy Density attains 0.7, and the Blue-Green Space Width Ratio approaches 1:1. These thresholds can be directly translated into performance benchmarks for sustainable urban planning and landscape engineering, providing evidence-based parameters for optimizing vegetation structure and spatial configuration. This study demonstrates that applying quantified ecological thresholds can transform riparian corridors into efficient climate-resilient infrastructure, thereby synergistically improving thermal comfort, enhancing ecosystem services, and promoting sustainable land use in urban environments.

Achieving the "30 × 30" target is a core commitment of the Kunming–Montreal Global Biodiversity Framework. However, the key challenge lies in effectively managing large-scale protected areas, particularly for emerging economies facing significant development pressures. China has implemented the Ecological Protection Redline (EPRL) system, which scientifically delineates 32% of its terrestrial territory as ecological space, thereby establishing a systematic conservation network that covers 90% of terrestrial ecosystem types and 85% of key species. This approach has significantly curbed ecological degradation and promoted species recovery. This study proposes that designating approximately 12% of the EPRL area—which has high conservation value but remains outside the formal protected area system—as "other effective area-based conservation measures" (OECMs) could swiftly confer strict protection under the existing governance framework. This pathway would bridge the conservation gap with lower costs and institutional resistance. The EPRL to OECM strategy not only offers a feasible solution for China to achieve its 30 × 30 goal but also provides a replicable model of innovating governance for other countries facing similar challenges, emphasizing functional conservation outcomes over mere spatial coverage.