Magnolia wufengensis is a newly discovered rare and endangered species endemic to China. The primary objective of this study is to find the most suitable species distribution models (SDMs) by comparing the different SDMs to predict their habitat distribution for protection and introduction in China under climate change. SDMs are important tools for studying species distribution patterns under climate change, and different SDMs have different simulation effects. Thus, to identify the potential habitat for M. wufengensis currently and in the 2050s (2041–2060) and 2070s (2061–2080) under different climate change scenarios (representative concentration pathways RCP2.6, RCP4.5, RCP6.0, and RCP8.5) in China, four SDMs, Maxent, GARP, Bioclim, and Domain, were first used to compare the predicted habitat and explore the dominant environmental factors. The four SDMs predicted that the potential habitats were mainly south of 40° N and east of 97° E in China, with a high distribution potential under current climate conditions. The area under the receiver operating characteristic (ROC) curve (AUC) (0.9479 ± 0.0080) was the highest, and the Kappa value (0.8113 ± 0.0228) of the consistency test and its performance in predicting the potential suitable habitat were the best in the Maxent model. The minimum temperature of the coldest month (−13.36–9.84 °C), mean temperature of the coldest quarter (−6.06–12.66 °C), annual mean temperature (≥4.49 °C), and elevation (0–2803.93 m), were the dominant factors. In the current climate scenario, areas of 46.60 × 10⁴ km² (4.85%), 122.82 × 10⁴ km² (12.79%), and 96.36 × 10⁴ km² (10.03%), which were mainly in central and southeastern China, were predicted to be potential suitable habitats of high, moderate, and low suitability, respectively. The predicted suitable habitats will significantly change by the 2050s (2040–2060) and 2070s (2060–2080), suggesting that M. wufengensis will increase in high-elevation areas and shift northeast with future climate change. The comparison of current and future suitable habitats revealed declines of approximately 4.53%–29.98% in highly suitable habitats and increases of approximately 6.45%–27.09% and 0.77%–21.86% in moderately and lowly suitable habitats, respectively. In summary, these results provide a theoretical basis for the response to climate change, protection, precise introduction, cultivation, and rational site selection of M. wufengensis in the future.

Magnolia wufengensis, a newly discovered ornamental species in the Magnoliaceae family, is susceptible to salinity. Moreover, Ca²⁺ is an essential element for plant growth and is receiving increasing attention for its ability to mitigate the negative effects of environmental stress on plants. In the present study, we investigated the effect of Ca²⁺ on the growth and transcriptome of M. wufengensis under salt stress. The treatments used here were as follows: control, NaCl (150 mmol/L), CaCl₂ (5 mmol/L), and NaCl (150 mmol/L) + CaCl₂ (5 mmol/L). After a 60-day treatment period, plant growth indices were determined, and leaves were collected for physiological analysis and transcriptome investigation. The combined application of NaCl and CaCl₂ alleviated phenotypic damage and restored seedling growth. Moreover, RNA sequencing data revealed that in the Na vs. control group and the NaCa vs. Na group, there were 968 and 2632 differentially expressed genes, respectively, which were both primarily enriched in secondary metabolism, glutathione metabolism, signaling hormone metabolism, glucose metabolism, and amino acid metabolism. These pathways were analyzed to screen key genes: the adenosine triphosphate (ATP)-binding cassette efflux transporter G1 (ABCG1) genes, which are related to transmembrane transport; the calmodulin genes, which are related to signal transmission; and the glutathione S-transferase (GST), glutathione peroxidase (GPX), and peroxidase (POD) genes related to antioxidant enzymes. Lastly, we constructed a hypothesis model of Ca²⁺-enhanced salt tolerance in M. wufengensis. This study reveals the potential mechanisms by which Ca²⁺ enhances the salt tolerance of M. wufengensis and provides a theoretical reference for its cultivation in saline areas.