Aims: Polypores are an important group of wood-decaying fungi with important ecological functions. Previous studies on the diversity and floristic composition of polypores were mostly in natural forests. Studies on the species, distribution and floristic composition of polypores in botanical gardens were largely unknown. This study systematically investigated the species, distribution and floristic composition of polypores in 31 botanical gardens in China, aiming to clarify whether the botanical gardens can effectively protect polypores while protecting plants.
Methods: In this study, investigations on polypores in 31 botanical gardens from 31 Chinese provinces were carried out during 2010-2021. On the basis of species identification, we analyzed the species diversity, composition and distribution of polypores in botanical gardens and forest ecosystems.
Results: A total of 164 polypore species was found based on the specimens collected from these gardens, and identified to 79 genera, 23 families and 6 orders. Among the 31 gardens, the species-richest gardens are Xishuangbanna Tropical Botanical Garden of the Chinese Academy of Sciences (XTGB) in Yunnan, Danzhou Tropical Botanical Garden in Hainan and Guangxi Botanical Garden of Medicinal Plant in Guangxi, and 90, 46 and 37 polypores were found, respectively; While the most species-poorest gardens are Lanzhou Botanical Garden in Gansu Province, Xining Botanical Garden in Qinghai Province and Urumqi Botanical Garden in Xinjiang Autonomous Region, where only 4, 3 and 2 polypores were found, respectively. Among the 164 polypores, the three most common species Trametes versicolor, Irpex lacteus and Bjerkandera adusta were found in 24, 18 and 18 botanical gardens, respectively. Other 32 species, like Abundisporus mollissimus, were found in a single botanical garden only. Among the 164 polypores, the common species, occasional species and rare species are respectively 114, 40 and 10. The polypore and rare species in the investigated gardens account for 16% and 3.1% of the total Chinese polypores and the rare ones, respectively. Among the ten rare species, six were found in natural forests in XTBG, four were only found in plantations, and they account for 2.4% of total polypores found in the gardens and 1.3% of total rare Chinese polypores, respectively. Tropical, subtropical, temperate, widely distributed in North Hemisphere and boreal elements were discovered in the garden polypores, and corresponding species are 50, 45, 38, 20 and 11, and they account for 30.5%, 27.4%, 23.2%, 12.2% and 6.7% of the total garden polypores, respectively.
Conclusion: Botanical gardens have less function for conservation of polypores, particularly for rare species. The majority polypores growing in botanical garden in our investigations are the common species. Nature reserves, national park or forest parks are the most important areas for conservation of polypores, especially the rare species.