A Thousand-Year Preserve
For over a millennium, Putuoshan Island has been a sacred site in Chinese Buddhism, dedicated to Guanyin, the bodhisattva of compassion. This religious reverence created an unintended, yet effective, nature preserve. The island, which has a total area of about 12.5 square kilometers, became a sanctuary where ancient trees and rare plants could survive, shielded by monastic tradition from the deforestation that altered much of the mainland. In its most active periods, the island supported over 80 temples and more than 4,000 monks and nuns. This long history of Buddhist presence established a long protection of the island's forests, which cover its steep slopes.
The result is a subtropical broadleaf forest that is a living botanical museum. The island hosts 282 documented ancient trees. Among the most notable are numerous camphor trees (Cinnamomum camphora), with some specimens estimated to be 1,000 years old. One camphor at the Puji Temple has a circumference of six meters. The forests also contain 67 maple trees and 10 large ginkgo trees over a century old. This ecosystem, preserved by faith, has become a focus for scientific study, revealing a level of biodiversity lost in surrounding regions. A 2025 study identified 874 species of terrestrial vascular plants naturally distributed on the island.
The Last of Its Kind
The most significant botanical resident of Putuoshan is the Putuo hornbeam, Carpinus putoensis. This species is an example of a "living dead" species—a species that is technically extant but no longer able to reproduce in the wild. On the west side of Huiji Temple, a single, wild Putuo hornbeam survives. This one tree, estimated to be over 200 years old, is the last of its kind in existence outside of cultivation. Discovered by botanists in 1930, it stands about 12.5 meters tall and is listed as critically endangered by the International Union for Conservation of Nature (IUCN).
The tree is monoecious, meaning it has both male and female flowers, but the different blooming times hinder natural pollination. Recognizing the extreme vulnerability of the species, scientists initiated a conservation program. Using seeds from the original tree, researchers have successfully cultivated thousands of offspring since the year 2000 through techniques like grafting and tissue culture. This effort ensures the species will not disappear. Beyond this famous specimen, the island's temple gardens shelter other rare species, such as Neolitsea sericea, an evergreen tree now listed as endangered in China.