Climate change will decrease the coverage of suitable niches for Asian medicinal orchid (Bulbophyllum odoratissimum) and its main phorophyte (Pistacia weinmannifolia).

Considering the global biodiversity crisis and the growing demand for medicinal plants, it is crucial to preserve therapeutically useful herbs. From a conservation management perspective under climate change, identifying areas that enable valuable natural resources to persist in the future is crucial. Machine learning-based models are commonly used to estimate the locations of climate refugia, which are critical for the effective species conservation. The aim of this study was to assess the impact of global warming on the epiphytic medicinal orchid-Bulbophyllum odoratissimum. Given how the long-term survival of plants inhabiting shrubs and trees depends on the availability of suitable phorophyets, in this research potential range changes in reported orchid plant hosts were evaluated. According to conducted analyses, global warming will cause a decline in the coverage of the suitable niches for B. odoratissimum and its main phorophyte. The most significant habitat loss in the case of the studied orchid and Pistacia weinmannifolia will be observed in the southern part of their geographical ranges and some new niches will simultaneously become available for these plants in the northern part. Climate change will significantly increase the overlap of geographical ranges of P. weinmannifolia and the orchid. In the SSP5-8.5 scenario trees will be available for more than 56% of the orchid population. Other analyzed phorophytes, will be available for B. odoratissimum to a very reduced extent, as orchids will only utilize these species as habitats only occasionally. This study provides data on the distribution of climatic refugia of B. odoratissimum under global warming. Moreover, this is the first evaluation of the future geographical ranges for its phorophytes. According to the conducted analyses, only one of the previously reported tree species which are inhabited by B. odoratissimum, P. weinmannifolia, can serve as a phorophyte for this orchid in the future. In this study, the areas designated as suitable for the occurrence of both orchids and their phorophytes should be considered priority conservation areas for the studied medicinal plants.