Religious temples are long-term refuges for old trees in human-dominated landscapes in China

Old trees hold significant biological and cultural value.^1,2,3 However, understanding how human culture has contributed to the long-term persistence of old trees in human-dominated landscapes is limited. Buddhism and Taoism, the most popular religions in China, have significant cultural and spiritual associations with specific trees.^4,5 Over the past two millennia, Buddhist and Taoist temples were widely constructed in the country, accompanied by intentional tree cultivation within temple grounds. This study examined the role of these religious cultures in conserving old trees within human-dominated landscapes and in facilitating the spread of religion-related species in China. We established a database encompassing 46,966 old trees from 5,125 Buddhist and 1,420 Taoist temples throughout China. Preserving old trees in religious temples was common in eastern China. The density of old trees in temples was thousands of times higher than outside temples, and tree age was also greater. There were 5,989 old trees from 61 threatened species (with eight species found exclusively in temples) preserved in temples, demonstrating crucial refuges for these species in human-dominated landscapes. The range of old trees of Buddhist species (tree species important to Buddhist culture) significantly exceeded that of non-Buddhist species. Some key Buddhist species have been introduced and cultivated in many Buddhist temples in areas far beyond their natural distribution, indicating a strong cultural influence on their spread. In summary, our findings demonstrated that religious grounds have provided refuges for old trees and facilitated the spread and protection of favored tree species in ancient China.