Holding back a mountain

Earthquakes and typhoons plague Taiwan. Stories of the lives and property they sweep away are staples of the local media. Less frequently reported is what happens after the tragedy: the Herculean projects that, over months and years, painstakingly put back what took only moments to be destroyed. For Taiwan's Forestry Bureau, it's a drama that builds sapling by sapling and stone by stone. The bureau recently showed the Taipei Times a trio of reforestation projects in Chiayi County. We saw fields of dirt and piles of rock, but we learned a key facet of Taiwan's ecology: It's easy to move a mountain. What's really difficult is holding one back

Words and Photos by David Momphard  /  STAFF REPORTER

Sun, Jan 23, 2005 - Page 17

River of ruin

Highway 18 is lined with alternating trees and shrubs. The shrubs are stocky with bright red and yellow leaves at the top, and the trees are taller, deep green and punctuated with pink blossoms. It's a gaily outfitted parade that never moves, but looking at it through the window of a car moving 70kph, it's a five-alarm fire of blurry color.

Chances are that if you're driving this route you're heading for Alishan. It's the nation's highest-profile tourist attraction and those pink and red trees and shrubs were put there by the Taiwan Forestry Bureau to make it all the more high-profile. With so much color on the roadside and the excitement of a trip to a sacred mountain, you can be forgiven for not noticing the bureau's more formidable project: Naoliao Creek.

The creek is an eyesore. Most days it hasn't but a trickle of water in a bed banked by a chasm of boulders dozens of meters across. But a closer look at those boulders shows that Naoliao isn't always just a trickle. During typhoon season, the creek can quickly become a torrent of water rushing down the mountain -- often taking the mountain with it.

"Naoliao Creek is considered Chiayi County's priority-one landslide area," said Yeh Shang-liang (葉賢良), the director of the Forestry Bureau's Chiayi district office. He explained that, during the giant quake of September 1999, 53 hectares of forested mountain area in the Naoliao Creek watershed slid into the creek itself. That was followed by a series of typhoons -- Nari, Toraji, Aere, Mindulle and a dozen others -- that caused further landslides and compromised soil structure in the steeply graded area.

"The real hazard of soil erosion isn't the loss of land." Yeh said, "It' s the tainting of a water source used for drinking."

The problem predates the 1999 earthquake. Since 1984 the Naoliao Creek watershed has been the site of 72 projects designed to retain soil either by planting trees -- the roots of which reinforce the soil structure -- or restructuring riverbeds to prevent flooding. More than half those projects have been undertaken in the past five years.

All told, the projects have carried a price tag of NT$238 million, a small price to pay compared with the NT$700 million in damage to forests and agriculture caused by typhoon Toraji in 2001.

The lion's share of that sum went to taming Naoliao Creek. The creek drops more than 1,000m over 5.4km from an altitude of 1,380m above sea level to just 310m above sea level. The site of the most construction is in the creek's final stretches, where the terrain flattens out and flooding has previously caused the most damage. Here the banks of the creek have been lined with boulders stacked one by one to create 4m-high walls. At one particularly tight bend in the creek the walls reach more than twice that height.

The scale of the project is hard to fathom. Seeing it is believing and the Forestry Bureau has accommodated this by laying a path of flat stones on the highest bank to serve as a walkway. It leads to an area several hectares in size where the bureau has planted hundreds of saplings, now just knee-high, that will one day be a forest of ficus and a tourist attraction worthy of the route to Alishan.

Yunlin wood to Alishan doth come

Further back on Highway 18, about 15km from where it branches off of Highway 1, the trees come up much faster. The area, 2 hectares, is currently a field of dirt, but in a matter of months it will be a full-grown forest. No, they aren't "Frankentrees" or the product of biotechnology, but are from a different type of industry. This is Taiwan's first "Tree Bank" -- a kind of fiduciary forest -- and an investment the Forestry Bureau hopes to profit from in subtle ways.

"We set up the tree bank to protect old trees and unique trees that have been deemed worthy of saving," said Chen A-hsing (陳阿興), the Forestry Bureau's chief of reforestation and production.

Macbeth knew fortune would smile on him until "Burnam Wood to Dunsinane doth come," but in the case of Chiayi's Tree Bank, the moving of a forest is an auspicious sign.

The project includes a workshop that will serve as an ecological classroom, walking paths and a man-made lake now awaiting a good rain. There will also be a small parking lot since the Forestry Bureau envisions the Tree Bank doubling as rest area for travelers to Alishan.

But it's primary function is the protection of unique species of flora threatened by encroaching development, though a few of the bank's initial deposits came from the Naoliao Creek basin.

On the day of our visit, a Cockscomb Erythrina -- a type of jasmine tree -- had just been replanted from its original home in Yunlin County. It lived for more than a century in a plot of land that recently became a government construction site. Rather than fell the tree, the government brought it here, where it is the Tree Bank's newest deposit.

"Any tree that fits the criteria will be eligible for transplantation in one of the Tree Bank's two designated areas," Chen said. "[It will be] a permanent and a temporary sanctuary."

The permanent area will contain centenarian trees, large trees with a diameter of 1.5m or a circumference of 4.7m, and rare or unique species. The temporary area will house trees, like the Cockscomb Erythrina, that are in the path of public construction. Those trees will be withdrawn from the Tree Bank within a year of the construction project's completion and will be returned to their original location.

Because of Taiwan's dramatic difference in climate from north to south, only trees from Chiayi, Yunlin, Tainan, Kaohsiung or Pingtung counties will be deposited in the Chiayi Tree Bank. Another bank, in Ilan County, is planned for transplanting trees in northern Taiwan.

"The Tree Bank is one of the Forestry Bureau's proudest projects," Chen said. "It allows for sightseeing, conservation, education and, after the trees have matured, the government can transplant them in future public construction sites."

Coming down the mountain

On the western shoulder of Alishan is where it all begins. An average 286cm of rain falls on the several thousand hectares of the Naoliao Creek watershed. It drips off the needles of high-altitude pines, trickles down steep granite faces, joins forces in quick mountain streams and roars into the valley.

While it takes boulders to rein in the torrents at the lower stretches of the Naoliao Creek, in the upper reaches of its watershed, strips of bamboo suffice. The third project on the Forest Bureau's tour sits on a mountain saddleback about 2,000m above sea level.

The devastating quake of September 1999 shook a 3-hectare portion of this pine forest from its roots and sent it tumbling down the mountain. Unlike in other landslide areas, though, there was no domino effect. Rather, the uprooted forest was stopped by the trees and rocks below. As with an avalanche of snow, Forestry Bureau scientists saw this accumulation of debris as a grave threat. Should another large quake come or if the soil were to become saturated from heavy rains, the entire mountain face could be lost.

The solution was a good deal daintier than the threat it subdued. First, the debris from the landslide was cleared. Then, in the landslide area itself, small bamboo fences were staked into the soil in a zigzag pattern. The fences covered a full hectare of damaged area and, between them, the bureau planted hundreds of saplings. Additionally, 640m of stones were laid to form a drainage canal.

The idea was that when rains came, instead of washing increasing amounts of soil down the mountain, rainwater would accumulate behind the bamboo fences, terraces that are naturally more resistant to landslides and that force the water to drain properly.

The project was finished in December of 2002 at a cost of NT$3.9 million. Three years later, on the tour of their proudest projects in Chaiyi County, Forestry Bureau Director General Yen Jen-the (顏仁德) posed for photos in front of a new-growth mountain forest, already a few meters high and deeply rooted in the soil.

"We have recovered 48 of the 53 hectares in the Naoliao Creek basin that have been lost to earthquakes and heavy rains," Yen said. He's justifiably proud of the massive amount of work his bureau has put into holding back a mountain -- an effort that he hopes won't be wasted.

Asked if the bureau's reforestation efforts are enough, Yen offered a hopeful response: "We have prepared for the worst and done the best we know how, but nature is a lot more powerful than we are... It would be heartbreaking to see it all come sliding down the mountain, but we would start over again."