Documenting Endangered Species in the Remote Mountains of Laos

We have been in the mountains for fifteen days and the team is weary but triumphant. We have crossed lakes and traversed rivers, camped in the rain and trekked through the dense forest in search of the endangered Chinese swamp cypress tree.  After adventurous road travel and even sinking boats, we have located remote forests and found the trees we seek.

Expedition Laos Team in Forest
Expedition Laos Team, locating the Swamp Cypress trees Laos Highlands

Our first location took our team up the Nam Xot River to the village Ban Nahou where we had information that ancient stands of the Chinese swamp cypress trees could be living.

Villagers celebrating the New Year at Ban Nahou Village, Laos
Villagers celebrating the New Year at Ban Nahou Village, Laos

Our heavily laden longtail boat takes us midstream, right into a river celebration with the villagers gesturing and inviting us ashore to join a traditional feast. Awaiting the second boat, we are anxious to move upstream but the village head man – whose permission is required- urges us to stay. “We will anger the village spirits,” he informs us, so we make camp and join the festivities eating, toasting to the spirits and imbibing the local beverage called Lao Lao. As the advance guard, I take my camera to a small sand  island mid-river, crossing a rickety bridge built of boats.  Slipping, I wet my primary camera in the river, but have another to continue my work. Later, I am able to restore functions to my camera using rice and a few tricks of the trade.

Up the Nam Xot with armed guard, Laos
Up the Nam Xot Headwaters with armed guard, Laos

The headman and another guide join us early the next day and we head upriver to hike up the first mountains and down into a valley saturated with rain and muck. Both guides are equipped with automatic rifles and camo gear made in China, but accessorised with ball cap and flip flop sandals. These men are part of the local militia, and guide us to protect us from potential poachers, or potentially from unexploded ordinance dropped near the Ho Chi Minh Trail during the Vietnam War.

Each morning we hike over the mountain from our base camp at the river’s edge. Our meals are sticky rice local ferns and fish caught from the river. The following days are successful and we document a stand of over 100 trees, taking measurements and tissue for DNA analysis. Dr Thomas and the Laos botanists collect flowers and leaves and describe the trees and plant species associated with the Cypress forest. A few of us scout ahead, attempting to spy the birds and monkeys we hear in the high canopy.  Birds like scarlet Bulbuls, Greater Flamebacks and Trogon sing unseen in the canopy, flitting ahead of the larger group as they document and measure the trees.

DBH Measurement
Measuring the Diameter Breast Height of a huge Swamp Cypress.

Trekking through the swamplands is difficult with areas knee deep in mud devouring our sandals and making progress difficult. Pandanus and razor-sharp rattan rips at our clothing and exposed flesh. Mosquitos and leeches make hiking festive. But all this is worth it when we enter a glade and discover the trees we seek, larger than life itself. The research and the habitat model generated by Dr. Coffman and University of San Francisco graduate student Robin Hunter are bearing fruit, and we have already more than doubled the estimate of these trees worldwide.

Planked trees
Illegally harvested trees in the National Protected Forest

Like the redwoods of California, the bark is rough, thick and red and the trees are very tall. The swamp cypress tower overhead, measuring one hundred and forty feet high. Diameter Breast Height (DBH) measurements place some of the trunks at nearly 3 meters in diameter. We also find signs of extraction with freshly cut trees, planks and shingles in the deep forest.  We have been told that poachers cross over the Vietnam border and poach these trees, and other valuable woods like Rosewood, cutting the logs into sections and hiking them out. This location however, is far from the border and over difficult terrain, making local consumption more likely.

2 houses
A traditional house of Cypress planks and roofing, and a newer house at left of the more common Dipterocarpus tree and metal roof

Nominally protected, the tree is valued for building materials due to high rot resistance. In the villages we see roof tiles and siding made of the weather resistant wood, and boats plying the rivers with keels cut from the trees.  As the population expands, settlers from the river villages move uphill, clearing the forest for rice paddies.  At the edge of the rice paddy clearings we find many large trunks where large trees have been removed from a large grove.  At one location our guide shows us a stump with new trunks sprouting from a tree h felled in 1965 to build his house, long before they became protected.  

Swamp Cypress and paddy
Swamp Cypress growing at edge of Rice Paddy in highlands of Laos

 The forest feels ancient with long lianas vines crawling up the trunks and hanging like fat snake, and orchids and ferns festooning the branches. We take cores to date the trees back in the lab, but the ring counts from some smaller fallen trees indicate they are well over a century old. Dr. Coffman estimates one tree at over two hundred years and some could possibly be as old as the California Redwoods dated at 2000 years!

double trunk
A split trunk Mai Heng Sam, the Chinese swamp Cypress

Around the grove of trees, Cypress knees protrude from the water saturated soils, some almost three feet above the surface. These woody projections from the root system serve as organs of gas exchange and provide stability for the swamp cypress. The large canopy shades the wetland below and outcompete even the tallest trees.

A large cypress knee or pneumatophore, exchanges gas and provides stability for the swamp cypress
A large cypress knee or pneumatophore, exchanges gas and provides stability for the swamp cypress

The large canopy and wide stretching roots and knees must play an important role in shaping the local ecosystem, and a very different community will exist in the absence of the large trees.  The team busily collects the data on the entire stand before returning over the ridge through the dense trail at nightfall. We are wet, muddy and tired, but satisfied that we have already more than doubled the known number of these rare trees.  Tomorrow we will decamp and climb into the boats to another stand rumored to exist at the peak of a river even more remote than this location.

Read All Posts From the 2015 Chinese Cypress Expedition



Meet the Author
A marine biologist and adventurer, David McGuire writes, photographs and explores the natural world, documenting wildlife and works to protect threatened sharks and critical marine ecosystems though the non profit Shark Stewards.