The interaction between the natural environmental and socioeconomic factors is crucial for assessing the dynamics of plateau ecosystems. Therefore, the remote sensing ecological index (RSEI) and CatBoost-SHAP model were employed to investigate changes in the ecological quality and their driving factors in the Diqing Tibetan Autonomous Prefecture, China, from 2001 to 2021. The results showed an increase from 0.44 in 2001 to 0.71 in 2021 in the average RSEI for the Diqing Prefecture, indicating an overall upward trend in the ecological quality. Spatial analysis shows the percentage of the area covered by different levels of RSEI and their temporal changes. The results revealed that “good” ecological quality accounted for the largest proportion of the study area, at 42.77%, followed by “moderate” at 21.93%, and “excellent” at 16.62%. “Fair” quality areas accounted for 16.11% and “poor” quality areas only 2.57%. The study of ecological and socioeconomic drivers based on the CatBoost-SHAP framework also indicated that natural climate factors have a greater impact on ecological quality than socioeconomic factors; however, this effect differed significantly with altitude. The findings suggest that, in addition to strengthening climate monitoring, further advancements in ecological engineering are required to ensure the sustainable development of the ecosystem and the continuous improvement of the environmental quality in the Diqing Prefecture.

The air pollutant NO₂ is one of the major constraints on plant growth, and the ecological value of the ornamental plant Bougainvillea glabra can be weakened by NO₂. In this study, an indoor 4 μL·L⁻¹ NO₂ simulated fumigation test was conducted with three treatments, CK (normal growth with clean air), T1 (4 μL·L⁻¹ NO₂ + 8 h/d), and T2 (4 μL·L⁻¹ NO₂ + 24 h/d), which were set up with considerations for time and concentration. The results demonstrated that most of the morphological parameters of B. glabra ‘Elizabeth Angus’, except for the floral organs, were decreased in the root, stem, leaf, and bract. Continuous fumigation significantly attenuated the growth rate and reduced the water and pigment contents of organs. Excessive NO₂ reduced the number and transfer rate of photoelectrons by destroying the photosynthetic reaction center, which in turn weakened photosynthesis, but the plants with intermittent fumigation recovered after fumigation. The Kaplan-Meier (K-M) survival curve displayed median survival periods of 41 and 55.5 h for T1 and T2, respectively, and the morphological structure and most of the indicators of photosynthetic reaction centers changed significantly during stress. Acute injury to B. glabra ‘Elizabeth Angus’ was caused by 4 μL·L⁻¹ NO₂, and B. glabra ‘Elizabeth Angus’ had limited ability to regulate high concentrations of NO₂ acute stress.