Climate change continues to threaten global biodiversity, making it essential to assess how keystone species may shift their distributions and to use these findings to inform conservation planning. This study evaluated the current and future habitat suitability of D. macropodum, an important tree species within subtropical evergreen broad-leaved forests in China, using 354 occurrence records and a suite of environmental variables. A parameter-optimized MaxEnt model (calibrated with ENMeval; RM = 4, FC = QHPT) was applied to simulate the species’ present distribution and projected changes under three climate scenarios (SSP126, SSP245, SSP585). The main factors influencing distribution were determined to be moisture and temperature seasonality, with the precipitation of the coldest quarter (Bio19, 36.3%), the mean diurnal range (Bio2, 37.5%), and the precipitation of the warmest quarter (Bio18, 14.2%) jointly contributing 88.0% of the total influence. The model projections indicated a 40.1% reduction in the total number of suitable habitats under high-emission scenarios (SSP585) by the 2090s, including a loss of over 80% of highly suitable areas. Centroid movements also diverged across the scenarios: a southwestern shift under SSP126 and SSP245 contrasted with a southeastern shift under SSP585, with each accompanied by significant habitat fragmentation. Key climate refugia were identified primarily in central Taiwan Province and the mountainous zones of Zhejiang and Fujian Provinces, which should be prioritized for conservation activities. These insights offer a foundational understanding for the conservation of D. macropodum and other ecologically similar subtropical evergreen species. However, direct extrapolation to other taxa should be made cautiously, as specific responses may vary based on differing ecological tolerances and dispersal capacities. Further research is needed to test the generalizability of these patterns across diverse plant functional types.

Global warming is accelerating the poleward and upward shifts in climatically suitable ranges of species. Panicum virgatum (switchgrass) is recognized for its dual value in China’s dual-carbon strategy: mitigating food–energy land competition and restoring marginal ecosystems. However, the accuracy of habitat projections is constrained by three limitations: reliance on North American provenance data, uncalibrated model parameters, and insufficient scenario coverage. To address these, 48 switchgrass occurrence records and 22 climatic–topographic variables were integrated. The MaxEnt model was optimized with ENMeval (RM = 4.0, FC = LQH) and coupled with three SSP scenarios (SSP1-2.6, SSP3-7.0, SSP5-8.5) to quantify habitat area changes and centroid shifts across China. The key findings were as follows: (1) The mean temperature of the coldest quarter (Bio11) and elevation were identified as the key limiting factors for the suitable distribution of switchgrass, with their corresponding optimal thresholds determined as −8.79 to 8.11 °C and 0 to 2893 m, respectively. (2) The current suitable habitat covers 583.58 × 10⁴ km², concentrated in the North China Plain. (3) Under SSP5-8.5, the high-suitability habitat is projected to reach 229.44 × 10⁴ km² by the 2090s, with the centroid migrating 305 km northwestward to the Inner Mongolia–Jilin belt. This study highlights the climate–topography coupling that drives northward migration and proposes cold-tolerant cultivar development, priority zoning of marginal lands, and ecological corridor establishment to inform climate-smart biomass energy planning in China.

The accumulation of microplastics in agricultural soils poses a serious threat to both crop production and ecosystem health. To explore potential remediation strategies, we conducted a two-factor pot experiment (PE-MPs × TSB). This study was designed to systematically analyze the interactive effects of polyethylene microplastics (PE-MPs) and tobacco stalk-derived biochar (TSB) on soil properties, physiological characteristics, and growth indicators of wheat. Results indicated that TSB addition significantly increased soil pH, organic matter, and available potassium content, which was associated with a mitigation of the soil acidification and nutrient imbalance observed under PE-MPs. Physiologically, TSB was linked to higher activities of antioxidant enzymes (SOD and POD) and maintained leaf chlorophyll content and photosynthetic function, thereby consistent with a reduction in oxidative stress and better maintenance of growth in the presence of PE-MPs. Furthermore, partial least squares structural equation modeling (PLS-SEM) supported a hypothetical cascading pathway for TSB’s dominant influence: soil improvement → physiological mitigation → growth recovery. The total effect of TSB on biomass (0.71) was substantially greater than that of PE-MPs (0.01). This study proposes a conceptual model and provides correlative evidence that is consistent with multi-level processes through which TSB may alleviate PE-MPs stress, thereby providing theoretical support for the resource utilization of agricultural waste and the green remediation of microplastic-contaminated soil.

Microplastic pollution has become a major environmental challenge for terrestrial ecosystems; however, the mechanisms by which it affects the growth of medicinal plants and their rhizosphere microecology remain unclear. This study selected the important medicinal herb P. capitata as the research subject. A pot experiment was conducted to investigate the effects of different concentrations (0%, 1%, 4%, and 8% w/w) of polyethylene microplastics (PE-MPs) on its growth performance, physiological responses, and rhizosphere bacterial communities. The main findings are as follows: (1) PE-MPs exhibited a hormetic effect on the biomass of P. capitata. A low concentration (1%) slightly promoted total biomass (44.78 g) compared to the control (40.94 g), whereas higher concentrations caused significant inhibition. Total biomass decreased by 28.5% and 53.5% under the 4% and 8% treatments, respectively, indicating that the transition from stimulation to inhibition occurred between the 1% and 4% PE-MPs. (2) Chlorophyll a was more sensitive to stress, with its content significantly increasing under the 1% treatment but declining at higher concentrations. (3) Regarding the antioxidant system, POD activity was significantly inhibited at low and medium concentrations, while MDA content increased significantly only under the 8% treatment (by 72%). SOD and CAT showed no significant changes, indicating that POD and MDA were more sensitive indicators of oxidative damage. (4) PE-MPs significantly reduced rhizosphere bacterial community richness (Chao1 index), and the loss of microbial diversity was highly coupled with the decline in plant biomass and the exacerbation of oxidative damage. In conclusion, this study confirms a threshold effect in the toxicity of PE-MPs to P. capitata, with the transition from hormetic stimulation to toxic inhibition occurring between 1% and 4% (w/w). Furthermore, rhizosphere microecological imbalance is identified as a key indirect mechanism underlying phytotoxicity. These findings provide a new theoretical basis for understanding the potential impacts of microplastic pollution on medicinal plants and agroecosystems.

The purpose of this study was to investigate the effects of the addition of rice straw (RIS), corn straw (CS), pepper straw (PS), and rape straw (RAS) on the release and speciation of heavy metals in coal gangue. Results showed that the addition of rape straw and corn straw significantly increased the pH value of the leachate. Straw addition increased the iron (Fe), manganese (Mn), copper (Cu), zinc (Zn), and cadmium (Cd) concentrations in leachate but inhibited the release of lead (Pb) from coal gangue, with RIS having a particularly significant inhibitory effect. Straw addition promoted the transformation of heavy metals from a reducible to an oxidizable state in coal gangue, with significant differences in the impact on exchangeable heavy metals. Rape straw reduced the exchangeable Fe and Mn concentrations, whereas RIS decreased the exchangeable Zn concentration. The results of the RAC risk assessment indicated that by the end of the trials, RAS significantly reduced the ecological risks of Fe, Mn, Cu, Pb, and Cd. In summary, when using straw to remediate and improve coal gangue, dynamic changes in the activity of heavy metals need to be considered, and the use of RAS should be prioritized to avoid potential secondary environmental pollution.

This study employed a pot experiment to compare the effects of varying application rates of chili straw biochar on seed germination and seedling growth of alfalfa (Medicago sativa L.) cultivated in electrolytic manganese residue (EMR) and to elucidate the underlying mechanisms. We aimed to provide a theoretical basis for vegetation restoration and manganese pollution control at EMR disposal sites. Our results indicated that while chili straw biochar did not affect the seed germination rate, it significantly enhanced the germination energy. In addition, treatment with 5% biochar significantly increased the germination index. Biochar application increased alfalfa seedling height (6.13 cm in the control group vs. 6.63–7.20 cm in the treated groups). Concurrently, the aboveground fresh biomass significantly increased by 49–77% compared to the control. Additionally, biochar application elevated chlorophyll content and reduced malondialdehyde content in alfalfa leaves. Correlation analysis revealed that the primary mechanisms underlying biochar-mediated improvement in seed germination and seedling growth involved enhancing the organic matter, available nitrogen, and available phosphorus content in the EMR, while decreasing the available manganese content. Overall, the application of 5% biochar in EMR optimally improved alfalfa plant growth and development.