Reintroduction and assisted colonization of Spicer’s paphiopedilum in South China

Summary

Spicer's paphiopedilum, an orchid prized in horticulture, was known in China from only a single wild population of 38 mature plants discovered in 2006 on a seasonally flooded riverbank in Yunnan's Pu'er Prefecture, a site threatened by surrounding coffee plantations, household waste and erosion. From 2010, researchers at Xishuangbanna Tropical Botanical Garden built an ex situ collection, developed an in vitro seed germination protocol, and studied the orchid's pollination ecology and mycorrhizal fungi partners, concluding the species tolerates a broad range of fungal associates but may be limited by a shortage of effective pollinators. In June 2015, having raised thousands of seedlings, the team planted 30 back into the original habitat and another 30 into the TianZi Reserve near the China-Myanmar border, at an elevation roughly 400 metres higher, as a trial in assisted colonization. Monitoring every three months over the next two years found just 40 percent of the original-habitat plants surviving to June 2017, against 80 percent survival at the higher, more protected TianZi site. All seedlings descend from a handful of mother plants, raising concerns about genetic diversity, and the team suspects a lack of compatible pollinators may cap long-term establishment. The project is rated a failure for now, with success or otherwise only likely to be clear after several more years of monitoring.