Climate change reshapes habitat suitability of ancient tea trees in Yunnan: insights from an optimized MaxEnt model

Introduction Ancient tea trees, as important germplasm resources of tea plants worldwide and key carriers of tea domestication origins, possess irreplaceable ecological, economic, and cultural value. Under global warming, the distribution pattern of suitable habitats for ancient tea trees may face an increasing risk of fragmentation, which may in turn affect the conservation and management of ancient tea tree resources. Therefore, identifying the key environmental variables driving the potential suitable zones of ancient tea trees and their spatial distribution is of great significance for resource conservation and management. Methods As the most important reservoir of ancient tea tree resources in China, Yunnan Province contains 97.70% of the country’s ancient tea trees. Therefore, this study adopted an optimized MaxEnt model for the simulation of the variation in the spatial pattern of potential suitable zones for ancient tea trees in Yunnan under contemporary and future climate scenarios, and for the assessment of how climate change shapes the distribution of these potential suitable zones. Results According to our findings, precipitation of the coldest quarter (bio19), precipitation of the warmest quarter (bio18), temperature seasonality (bio4), precipitation of the wettest month (bio13), min temperature of the coldest month (bio6), and elevation were confirmed as the key environmental variables that affected the potential suitable zones of ancient tea trees in Yunnan. Precipitation, temperature, and topography jointly constrained the distribution pattern of the potential suitable zones. The current potential suitable zone of ancient tea trees in Yunnan covers an area of 17.39×10 4 km 2 , of which the highly suitable zone accounts for 0.14×10 4 km 2 . Affected by the four future climate scenarios, the potential suitable zones of ancient tea trees in Yunnan are all projected to show a net expansion, and these potential suitable zones will shift toward higher latitudes and higher elevations in response to climate-change-induced environmental stress. Discussion The findings in the present study can provide a scientific basis and decision support for the conservation and management of ancient tea tree germplasm resources under climate change, and may also contribute to a better understanding of the environmental background associated with some forest-associated ancient tea tree habitats.