VietNamNet Bridge – Yews (Glyptostrobus pensilis), called “thuy tung” in Vietnamese, grow in water and need water. However, the yews in the central province of Dak Lak are dying because of too much water caused by nearby dams.

Yews, a species listed in the Red Book, are considered the living fossils of conifers (Gymnospermae) which appeared on earth 10 million years ago.

The plant not only has important scientific significance, but also economic value thanks to its fragrance, colors and patterns, and suitability for making fine arts and handicraft products.

However, in the past, yews were listed as a kind of low-quality wood. Only in 2008, when rumors were spread that yews could treat cancer did people rush to hunt for yews. They tried to excavate the irrigation dam area to unearth yews which had been cut down many years ago.

Only two groups of wild yews have been found in Ea H’leo and Krong Nang districts of Dak Lak province. They have been put under special protection.

The group of yews in Trap K’sor Commune includes 21 yews. The youngest trees have the trunk diameter of 30 cm, while the older ones have trunks large enough for three or four people to enclose with their arms.

In 2012, the provincial authorities decided to build a dam 300 meters long in the swamp area to store water to feed yews and provide water for irrigation.

However, due to improper calculation, the water in the area has been kept at a high level for a long time, thus badly affecting the trees.

Dr. Bao Huy from the Tay Nguyen (Central Highlands) University, said the yew grows well in swamp areas.

However, like many other wetland species, yews can only develop when their pneumatophores are not submerged and can receive oxygen.

Meanwhile, scientists have found that while pneumatophores were just 20-50 cm from the swamps, the water level in the swamp in Trap K’sor was always at 80-90 cm.

In the rainy season, the water level may rise to one meter, thus suffocating the trees.

The Central Highlands Institute of Agriculture and Forestry Science and Technology has come to a conclusion that submergence was the cause of the death of a series of yews recently.

Eighty-four young yews planted in Trap K’sor under a pilot program have also died because of too much water.

However, Tran Xuan Phuoc, director of the Dak Lak provincial Yew Habitat Conservation Center, said it will still need one more survey to discover the exact reasons behind the death of many yews before arriving at a solution.

Over the last few years, scientists have tried many measures to multiply and protect yews. They tried to graft yew branches onto the foot of bold cypress (Taxodium), a plant of the same family as the yew.

However, when growing 260 young plants in the two groups of yews in Ea Ral and Trap K’sor communes, the result was below expectations.

Thanh Mai