The Last-Pond Battle for Taiwan's Water Plants

Taiwan has an abundant diversity of aquatic plants. Among these, four are rare endemic species that are native only to Taiwan. But with environmental destruction caused by humans, these rather unremarkable-looking plants are rapidly disappearing. The alarm has been rung, and conservation measures are being taken with growing speed. Some of these efforts are beginning to bear fruit.

Chen Te-hung, head of the Wanli station of the Wetland Plants Sheltering Center of the Society of Wilderness, explains that water plants' role in the ecological food chain is similar to the role that a foundation plays in a house. Water plants provide food and habitat for insects and amphibians. Even when human effluent covers the surface of the water in a suffocating manner, water plants rely on their vascular tissues to bring oxygen from the surface down to the roots, allowing microbes to break down pollutants and turn them into nutrients. Without consuming energy or employing chemical treatments, they return clean water to rivers and the earth.

Crisis at the ecological foundations

Water plants are also an important source of food for people. Wetland rice, lotus roots, water caltrop, water bamboo, water convolvulvus and other water plants are common foods. Taiwan has some 350 native water plants, but about one-half of these are now facing extinction. It's a startling statistic that demands our consideration: What kinds of ecological problems are we facing? Why are water plants, the oldest and most resilient plants in the world, unable to avoid these difficulties?

The term "water plants" refers to plants that live within the medium of water. Narrowly speaking, the term refers to plants that live their entire lives in water, such as water lilies. More broadly speaking, the term encompasses wetland plants such as reeds that need to live in water or marshland for only one period of their life.

Water is the medium that these plants need to survive. They can be found in lakes, swamps, ponds, creeks and rivers, irrigation channels, rice paddies and tidal zones throughout Taiwan. But many of Taiwan's swamps, creeks and irrigation channels have been filled in and destroyed. And rice paddies have also been converted to dry fields, or cultivation on them has ceased altogether. And in paddies that are no longer being cultivated, because the soil is no longer being turned or because they lack irrigation, weaker water plants will find themselves being crowded out by land plants, such as grasses (family Poaceae).

What's more, with the silting up of rivers and irrigation ditches and the large-scale use of pesticides, exotics, such as the golden apple snail or the common water hyacinth, have invaded and damaged the living environment of Taiwan's native water plants, causing a great variety of water plants to quickly disappear. Today many of these plants facing extinction can only be found in manmade ponds created as ecological refuges.

There had long been calls to turn Shuanglienpi into a nature preserve, but plans weren't finalized until 2005. Although the decision overjoyed the conservation community, it has proven impossible to return the lake to its formerly pristine condition.

Saving precious endemic species

Taiwan is located along the migration paths of many bird species, and flocks of birds come and go, bringing the seeds of water plants from many countries. Consequently, Taiwan has many of the water plants found in Siberia, northeastern China, Japan, and the Philippines. In comparison, the small number of species endemic to Taiwan are rarer and even more precious.

Only a few species have been verified as being endemic to Taiwan, including Taiwan quillwort (Isoetes taiwanensis) from Taipei City's Menghuan Lake; Nuphar shimadae (a water lily species) from Taoyuan County's Lungtan, Hygrophila pogonocalyx from Taichung County's Chingshui; and Salix kusanoi (a willow species) from Ilan's Shuanglienpi. Listed as either "endangered" or "critically endangered" by the World Conservation Union in 1994, they have attracted international attention and also been the focus of efforts by domestic conservation groups.

Case 1: Taiwan quillwort (Isoetes taiwanensis)

During usually chilly and wet March, the sun made a rare appearance one day when this reporter, wearing rain boots and accompanied by Tsung Pei-chih, head of the conservation research division at Yangmingshan National Park, joined Chen Te-hung on a visit to Menghuan Lake. There we saw the triangular-stemmed ricefield bulrush (Schoenoplectus mucronatus subsp. robustus) with flowers that had already dried out in the wind; lamp rush (Juncus effusus var. decipiens), which can be used for the wick of an oil lamp and whose small needles those of resemble Eleocharis congesta subsp. japonica, a spike-rush (which makes it hard for non-specialists to distinguish between the two plants); Miscanthus sinensis f. glaber, a form of Chinese silvergrass with white-striped leaves, which rings the edge of the pond; and lakeshore sedge (Carex phacota), which also looks a lot like Miscanthus sinensis f. glaber.

Unlike Sphaerocaryum malaccense (a grass) and Eleocharis congesta subsp. japonica, both of whose leaves dry out in the winter, Taiwan quillwort, which has been artificially propagated for two years with success, is green year round. Consequently, it is very easy to distinguish in the early spring. Based on its Chinese name, which includes the character for "garlic chives," those who are unfamiliar with this Taiwanese endemic species might ask: "Is Taiwan quillwort a kind of chive?" In fact, the plant is a perennial aquatic fern. Most plants of this type grow in temperate wetlands in the northern hemisphere. Taiwan quillwort, which grows only in Menghuan Lake, exists at a lower latitude than any other perennial aquatic fern.

After Yangmingshan National Park was established in 1985, the lake was designated as an ecological preserve. Yet in recent years, this precious lake and the wetlands around it, have, as a result of earthquakes and accumulating humus, been turning into dry land. Under competition from hardy plants such as Eleocharis congesta, Sphaerocaryum malaccense, Schoenoplectus mucronatus subsp. robustus, Chinese water-chestnut (Eleocharis dulcis), Isachne globosa (a grass), sphagnum moss and Chinese silvergrass (Miscanthus sinensis), Taiwan quillwort is under threat of extinction.

Water levels have posed another problem for the plant.

According to the Central Weather Bureau, average rainfall during the past five years has been only four-fifths of what it was during the 30 years from 1970 to 2000. In conjunction with seismic movement from earthquakes, which has "drained" some of the lake's water, less rainfall has resulted in insufficient water levels. Land plants have been encroaching on their space. Dried and dead stems and leaves float on the surface of the water, blocking sunlight, with the result that the Taiwan quillwort plants, which are only seven to 25 centimeters tall and are submerged below the surface of the water, are unable to carry out photosynthesis for large parts of the year.

Man helps nature out

Picking or propagating Taiwan quillwort was long prohibited, since it was a rare and precious plant protected under the Cultural Heritage Preservation Act. Consequently, although conservation groups were concerned about it, their hands were tied with regard to aggressive action. It wasn't until 2001, when the Council of Agriculture relaxed its regulations, that the Yangmingshan National Park Administration asked Chen to come up with a plan to propagate and protect the plant outside its natural habitat. Yet despite excellent results, Tsung Pei-chih insists that the only effective long-term plan will be to help the plant to reproduce in its natural habitat.

Toward this end, two years ago the park administration mobilized volunteers to move some of the park's dominant species of plants to provide more room for Taiwan quillwort. They also trampled the mud of the lakebed to form a layer of puddled clay and so stem the seepage of water from the lake.

In June of the same year, spores of the plant that had naturally accumulated in the mud sprouted one after another, and by the following year mature plants from those spores were producing spores of their own. Even small floatingheart (Nymphoides coreana) and Eriocaulon buergerianum (a species of pipewort), which had long been absent there, reappeared. That news created quite a sensation within the conservation community.

The academic community has long been opposed to interfering with natural ecologies, but as far as the park administration is concerned, to preserve biodiversity and protect Taiwan's endemic species, human intervention is unavoidable. Tsung Pei-chih emphasizes that none of the plants native to Menghuan Lake have disappeared as a result of this interference, but allowing natural processes to turn the lake into dry land would prompt a shift from biodiversity to monoculture. It would be bad for the ecological balance.

4. Drosera indica, which like Drosera burmannii is a carnivorous plant, is found in Taiwan proper only at Lienhua Temple in Hsinchu. Groups of the plant growing wild on the island of Kinmen have been the focus of protection and propagation efforts in recent years.

Case No. 2: Salix kusanoi

In comparison to the Taiwan quillwort, whose population has moved from the single digits to over 10,000 thanks to conservation efforts focused on reviving its population, Salix kusanoi, a willow species endemic to Taiwan, has met with less success.

Originally found in northeastern Taiwan in wet areas of farmland and along the banks of high mountain lakes, Salix kusanoi, which lives both in the water and on land, flowers in the late winter around Chinese New Year's. Bright gold, the male plant was called "golden willow" by the Japanese. And when the female plants' seeds mature they become silver-white fluff that floats in the wind to spread future generations.

In the 1970s, the banks of many of Taiwan's rivers and irrigation channels were lined with concrete. Consequently, plants that farmers had long used to stabilize earthen banks, such as Salix kusanoi, Cephalanthus naucleoides (a species of buttonbush), and fish-poison wood (Barringtonia racemosa), ended up displaced, growing only in Ilan's Shaunglienpi Lake. Although the academic community frequently called for the lake to be turned into nature preserve, the area around Shuanglienpi had been designated as private land due to poor land policies in the early years after the ROC government relocated to Taiwan in 1949. The government had no effective way of controlling those who owned land there and preventing ecological damage.

Located in Ilan County's Yuanshan at an elevation of only 500 meters, Shuanglienpi doesn't have frost in the winter, so less hardy water plants won't die from cold there. And in the summer the ample fog can help stem the spread of invasive plants. Moreover, because the lake is sufficiently large and the water suitably deep, it supports five kinds of plants: emergent plants, submerged aquatic plants, free-floating plants, floating-leaved rooted plants and wetland plants. Such biodiversity is extremely unusual.

Chen Te-hung emphasizes: "The 17 hectares of water and wetlands in Shuanglienpi not only provides habitat for many rare fish and frogs, but it also is home to more than 100 species of water plants, about one-third of all water plant species endemic to Taiwan. It could be described as a water-plant museum and a national treasure." But around 1990, just as calls to establish a nature preserve there were growing louder, the landowner began raising tilapia and grass carp in the lake, which damaged its ecology and greatly distressed the ecological community.

Unlike many fragile aquatic plants, Salix kusanoi, which can grow both in and out of water, is a tree that may reach 20 meters tall. When it blooms around Chinese New Year's, the male trees are festooned with golden blossoms (inset). That beautiful sight is the source of its Japanese name: "golden willow."

Private vs. public interest

"In order to protect their young fish, tilapia 'dig holes' for them with their tails. That in turn destabilizes the area where the plants root. Because the vascular tissues of the roots are full of air, when the roots are loosened they may float to the surface and dry out because of exposure to the sun. As for grass carp, they are called that because they eat water plants, so obviously they are absolute killers for the plants!" Chen can't help but get excited when talking about this "debacle."

At the end of 2001, the landlord went so far as to use an excavator to take sediment from the lake and form earthen dykes, and he told outsiders that there were no species in the lake that needed to be conserved. The Society of Wilderness and Chiou Chin-ho, an instructor at Ilan Community University, could see that they were getting nowhere by pleading with the owner. They knew that the longer they waited, the worse it would be for the plants, so they actively strived to save certain native plants, such as Salix kusanoi and Cephalanthus naucleoides, which they transplanted to the nearby Chienhu Tang (a Chen family ancestral temple) and the Luotung Sports Park. This was the "Shuanglienpi incident" that so galvanized the ecological community.

Interestingly, Salix kusanoi has female and male plants. When the plants were removed, they were brought to two separate places. After two or three years, it was discovered that all the males had been brought to one place and all the females to the other. So as that they would set seed, people specially hand pollinated them.

Three years ago, when the government spent more than NT$57 million to acquire Shuanglienpi and neighboring private land, the plan for an 84-hectare wildlife refuge there was finally adopted. Shuanglienpi has suffered much damage over the years, and it may never be able to return to its original pristine state, but the plan has nonetheless been the source of great hope within the conservation community.

What's more, Chiou Chin-ho and other conservationists could see how other wetlands in the Lanyang Plain were constantly being damaged, including wetland along the Tungshan River, where some century-old Cephalanthus naucleoides trees and Barringtonia racemosa were dug up and removed because water resources agencies were repairing irrigation channels there. Some of Toucheng's Hygrophila habitat was filled in for the construction of the Toucheng section of the Taipei-Ilan Freeway. And there are numerous examples of paddy fields and wetlands that have been paved over. Chiou and the other conservationists realized that it had become necessary to spread the risk for these endangered species. Consequently, they have been actively organizing volunteers to create ecological ponds in parks, communities and schools.

Chen Te-hung of the Wetland Plants Sheltering Center of the Society of Wilderness, based in Wanli, stresses that if you want to protect animals you've got to protect plants first. By protecting biodiversity in the natural environment, we can together create a beautiful new Taiwan.

Case No. 3: Nuphar shimadae

In recent years, one of the most popular plants in manmade ponds that serve as refuges for water plants has been Nuphar shimadae, a species of water lily that is endemic to Taiwan.

The "Taiwan water lily" mentioned in the 1952 Taiwanese song "Solitary Love Flower" (lyrics by Chou Tien-wang and music by Yang San-lang) is in fact Nuphar shimadae, which has bright yellow blooms and extends above the surface of the water all year round. The plant is mainly distributed in irrigation ponds in Taoyuan and Hsinchu Counties. One used to be able to see it in paddy fields throughout the island, but now it is found in the wild in only a few irrigation ponds in Taoyuan's Lungtan.

Long ago, the Tanshui River, which cuts through the Taipei Basin, captured the flow of the Tahan River, which once fed into the Nankan River in the Taoyuan Tablelands. This resulted in a shortage of water for irrigation in Taoyuan. The farmers who settled there dug irrigation ponds shovelful by shovelful or otherwise made use of the preexisting lakes in the tableland to retain rainwater for irrigating paddy fields. These irrigation ponds molded Taoyuan's "pond culture." They also provided a home for abundant water plants, including Nuphar shimadae.

With the establishment of modern water supply systems, these old ponds fell into disuse. And with the rising price of land, the ponds were zoned for other uses or became filled with garbage. With the added impact of wastewater pollution and other factors, the water plants in these ponds quickly began to disappear. As early as 1970, Flora of Taiwan noted that "Nuphar shimadae is facing extinction."

2. Hygrophila pogonocalyx, which has beautiful purple blooms, receives various special protections as an endemic species of Taiwan. Today the number of colonies in the wild has stabilized.

Weeder mobilization

Chen, who has been working to save the plant for more than ten years, noted that over the course of just a few years the number of ponds with Nuphar shimadae had fallen to just two. In 2002, on the day before Chinese New Year's eve, he and a few volunteers rescued a bunch of Nuphar shimadae from Taoyuan. In order to save them from the threat of the golden apple snail, they had to be specially cleaned and disinfected before being replanted. A group of volunteers thus spent one New Year's vacation protecting these plants, and now it has become a tradition for volunteers to gather at the Wetlands Sheltering Center on the day after Chinese New Year's. They are like families who, according to custom, visit their maternal grandparents on that day.

In recent years, the Society of Wilderness has taken Nuphar shimadae to symbolize the spirit of the society. Its Taoyuan chapter has surveyed the plant and its numbers in irrigation ponds. They have witnessed how ponds have dried up and become choked with weeds, and how Nuphar shimadae has suffered as a result. In September of last year, the society issued a "code red" mobilization order, calling for active human intervention. Volunteers came in to pull weeds out of the ponds and generally clear out space for their beloved flower to grow.

1. Growing only in Taipei's Menghuan Lake, Taiwan quillwort (Isoetes taiwanensis) numbered in the single digits only two years ago. With people intervening to help propagate the plant, the figure now stands at over 10,000.

Case No. 4: Hygrophila pogonocalyx

Hygrophila pogonocalyx, an endemic plant of Taiwan with beautiful purple blossoms, is another plant threatened with extinction in the wild.

A survey conducted by Huang Chao-chin of the Taiwan Endemic Species Research Institute in 1993 found Hygrophila pogonocalyx growing only along the Taichung County coast in Ta-an, Chingshui and Lungching. It mostly is found around water paddies and fishponds. Consequently, many different factors, including the building and development of harbors, sea dykes, fishponds, sand and gravel extraction, the lining of irrigation channels with cement, and farmers' excessive use of herbicides and burning stubble, have caused sharp reductions in Hygrophila pogonocalyx habitat.

The survey also discovered that of the six wild colonies of the plants that were found, only one, at the mouth of the Wenliao River in Ta-an Township, set seed. The remaining colonies only flowered. Huang Chao-chin notes that although Hygrophila pogonocalyx is a plant that feeds peacock pansy butterflies, its main pollinators are bees. A principal concern is that "aging" of the wild plant colonies, leading to low rates of setting seed, may threaten this rare endemic species' ability to reproduce.

Because Hygrophila pogonocalyx is easy to propagate through cuttings, many scholars believed it should not be difficult to revive its populations. But in 2002, when propagation was tried through cuttings, because the genetic material of the plants was so similar, the process did not yield viable seeds. Eventually a few further surviving colonies of wild plants were discovered in a military camp at Chingshui, providing additional native genetic material for propagation.

Unlike many fragile aquatic plants, Salix kusanoi, which can grow both in and out of water, is a tree that may reach 20 meters tall. When it blooms around Chinese New Year's, the male trees are festooned with golden blossoms (inset). That beautiful sight is the source of its Japanese name: "golden willow."

Don't let them disappear

Chen Te-hung stresses that most water plants are very hardy. As long as they have suitable environments, propagating them isn't a problem. Yet those collecting seeds and pollinating the plants ultimately hope that the plants will survive in the wild.

Happily, thanks to the work of the relevant government departments and conservation groups, Taiwan quillwort plants are growing safely within Yangmingshan National Park; the area where Salix kusanoi grows was designated as important habitat three years ago; and the areas where Hygrophila pogonocalyx and Nuphar shimadae grow, though not large, are regularly monitored by volunteers, so the plants are not likely to be wiped out.

At the same time that these endemic species are receiving attention, Taiwan has more than 100 other endangered or rare species that are also a source of concern. Lin Chun-chi, who wrote Taiwan Water Plants, explains: "Water plants are the weakest link in Taiwan's chain of life. The rate at which they are disappearing is truly too fast. Many rare plants that have been located with great difficulty are also in peril.

For instance, the last place that Hygrophila lancea grew in the wild was a small pond in Hsichih. Unfortunately, that pond was filled in eight years ago. Ambulia (Limnophila heterophylla) grows only in ponds in Kaohsiung's Meinung. But because it grows amid crested floatingheart (Nymphoides hydrophylla), which is regarded as a delicacy, it has almost been picked clean. Freshwater fish love to hide amid coontail (Ceratophyllum demersum); unfortunately the plants have been eaten by exotic golden apple snails to the point where they are now rare.

3. As a result of major environmental damage, many water plants are in dire need of human assistance. The carnivorous Drosera burmannii can be found at scattered locations in Hsinchu, Taoyuan and Chiayi, but after several years of hard work by conservation organizations, large groups of the plants are now growing in Kinmen's Tienpu.

Dream of a newly wild Formosa

In Taiwan the Wildlife Conservation Act completely overlooks what serves as the ecological foundation: plants. Chen Te-hung believes that to protect wild animals, you must first protect wild plants, thus putting the operations of nature's ecological net on a healthy footing. Hence, the Society of Wilderness has specially set up a Wetland Plants Sheltering Center, and Chen has provided five hectares of terraced paddy fields in the mountains of Wanli, Taipei County, which now serves a refuge for more than 150 species of water plants.

Over the past two years, Chen's conservationist tentacles have extended to efforts on behalf of the insect-eating sundew species Drosera burmannii and Drosera indica on Kinmen. Chiu Chin-ho has also actively been helping schools and communities throughout Taiwan to establish ponds that are refuges for plants.

As they say: "If Taiwan's water plants could thrive in their original habitats, Taiwan's living environment would be better for it, and nature would be richer and more beautiful!"

The discoverers and names of some of Taiwan's water plants