The forests of the mountains that form the border between Vietnam and Lao PDR contain a surprisingly rich and diverse range of conifers including the unusual flat needled Pinus krempfii, disjunct populations of Taiwaniaand Cunninghamia, thousand-year-old stands of Fokienia and some of the most extensive pine forests remaining in mainland Southeast Asia.

Recent discoveries include new stands of Amentotaxus poilanei, previously only known from a single locality in central Vietnam, as well as stands of Pinus dalatensis in southern and central parts of Lao PDR. Perhaps the most significant discovery are stands of the Critically Endangered Glyptostrobus pensilis on and around the Nakai plateau in Khammouan, Lao PDR. This species, the sole extant representative of a lineage that dates back about 100 million years, was previously only known from southeastern China and two degraded stands in southern Vietnam. In China, a long history of agricultural expansion and forest conversion has almost taken it to the brink of extinction with only a few trees surviving, mostly around temples or in feng-shui forests and along river levees. In Vietnam, there are about 150 senescent trees isolated in small reserves surrounded by coffee and pepper plantations.

In Lao PDR the first stands of Glyptostrobus were reported in 2007 during ecological surveys associated with the construction of the Nam Theun II hydroscheme. These were inundated in 2009 when the reservoir was formed. Subsequent surveys from 2008-2014 located a few additional stands in the surrounding watersheds, mostly near villages and on land that was being converted for rice cultivation. Attempts at propagating these trees met with little success.

In 2015, an expedition funded by the National Geographic and involving staff from the ICCP, the University of San Francisco and local collaborators surveyed two old-growth stands in the watershed to the east of the reservoir. Almost 500 trees, some almost 50 meters high with diameters over three meters were recorded. In addition several remnant stands were located near villages within the watershed. Unfortunately, one of the old-growth stands was illegally felled in 2016.

Subsequent expeditions have focussed on collecting seed, DNA samples and cores for dendro-climatological research. Propagation trials have been successfully undertaken with almost 2,000 seedlings successfully raised. In July 2019 trial plantings at various locations on the plateau were initiated and planning is underway for a larger community-based restoration and education programme involving most of the villages within the watershed. Further surveys are also planned as there are still areas with suitable habitat that may contain additional stands.