Predicting potentially suitable Bletilla striata habitats in China under future climate change scenarios using the optimized MaxEnt model.

Bletilla striata, an important traditional Chinese medicine resource, holds high medicinal and ornamental value. However, unscientific habitat selection for its cultivation has led to low yields and poor quality as medicinal materials in China. The optimized MaxEnt model is a powerful tool for analyzing the potential impacts of environmental factors on species distribution and predicting habitat changes under climate change. It offers great significance for the protection and development of B. striata in China. Based on 269 B. striata distribution records in China and 15 major environmental factors, this study simulated the distribution patterns of potentially suitable B. striata habitats under four different climate change scenarios (SSP1.26, SSP2.45, SSP3.70, and SSP5.85) and three time periods (the current period, 2050s, and 2070s). The analysis was conducted using the MaxEnt model which exhibited high predictive accuracy and minimal overfitting. Solar radiation, annual temperature range and mean diurnal range were revealed as the dominant factors affecting B. striata distribution, and their thresholds were ≤ 16,265.39 kJ/m·d, ≤ 39.7 ℃ and ≤ 12.6 ℃, respectively. The results showed that the total potentially suitable B. striata habitats in China were 30.07 × 10 km under current climate conditions, mainly distributed in 14 provinces or regions in southern China. Under future climate change conditions, the predicted potentially suitable B. striata habitats will decrease significantly over time, and the centroid of the predicted potentially suitable habitats at all levels will shift northward. The research results can guide future B. striata resource conservation, variety selection, and cultivation.