Performing biological research in the field is not an easy task in Taiwan. The island’s land mass rises from the Taiwan Strait, crosses the densely populated western plains, ascends through tangled subtropical forests to the alpine environment of the Central Mountain Range, then drops precipitously into the Pacific Ocean on the east side. In addition to East Asia’s highest peak, 3,952-meter Jade Mountain, more than 200 peaks stand taller than 3,000 meters on the 36,000-square-kilometer island. But the topographic features and multiplicity of vegetation zones that make fieldwork difficult in Taiwan also make the island a field biologist’s dream, as they result in greater biodiversity per unit area than is found in most other parts of the world.
Hsieh Chang-fu, a professor at National Taiwan University’s (NTU) Institute of Ecology and Evolutionary Biology, points out that while most other countries located along the Tropic of Cancer are predominately desert, Taiwan is home to a variety of flora and fauna species that exist in different climactic patterns ranging from tropical to cold zones. “There are also species that survived the ice age more than 10,000 years ago and have found suitable habitats, mostly in middle and high elevation areas such as that around Alishan,” says Hsieh, referring to a renowned scenic spot in southern Taiwan.
In terms of plant distribution and migration, Taiwan is home to a convergence of species from both the northern and southern regions of East Asia. According to the floristic groupings of botanist Armen Takhtajan (1910–2009), a central figure in the world of plant evolution and taxonomy, Taiwan’s plant families lie somewhere between those of the Holarctic Kingdom, or the temperate-to-arctic flora found mostly in the northern continents of the world, and those of the Palaeotropical Kingdom, or the humid forests, deciduous forests and savannas commonly found in southern continents.
To catalogue the great variety of plant life found in Taiwan’s lush forests, which cover more than half of the island, a series of plant resource surveys and classification efforts have been carried out over the years. One recent endeavor to detail the habitat distribution of specific species resulted in the exhaustive National Vegetation Diversity Inventory and Mapping Project, the results of which are now providing land managers with an important new tool for the management and conservation of natural areas.
Documenting Distribution
Taiwan’s long history of plant research began in 1854, when Scottish gardener Robert Fortune (1812–1880) paid a visit to northern Taiwan to collect local plant samples. In 1896, Augustine Henry (1857–1930) of Ireland, who was sent to Taiwan as a medical officer to study plants, published A List of Plants from Formosa that included 1,288 flowering species. Henry’s work represents the first known effort to document plants and their geographic distribution on the island.
Field surveyors hike into their research area during the mapping project. (Photo Courtesy of Forestry Bureau)
Another early effort was the 1896 botanical map of northern Taiwan in the book From Far Formosa: The Island, Its People and Missions by George Leslie Mackay (1844–1901). The map shows that the land area of the time was mostly covered by primeval forest or by major crops including rice, tea and sugar. Mackay was a Presbyterian missionary who became deeply devoted to Taiwan, his adopted homeland, and developed an enthusiasm for cataloging and collecting local plant specimens.
More extensive plant studies were carried out during the period of Japanese colonial rule (1895–1945) over Taiwan. Among other major achievements, Bunzo Hayata (1874–1934), a Japanese botanist and professor at the Imperial University of Tokyo, published the 10-volume Icones Plantarum Formosanarum (Iconic Plants of Formosa) from 1911 to 1921. Hayata’s volumes recorded 170 plant families, 1,197 genera and 3,647 species. Although Hayata’s work reveals in-depth knowledge of Taiwan’s plant varieties and taxonomies, it contains little information on plant habitats. “There are just a handful of maps showing preliminary findings about regional or general plant distribution in Taiwan during the Japanese period,” NTU’s Hsieh says.
In-Depth Effort
In 1972, the publication of the first volume of Flora of Taiwan, which was produced under the auspices of the Cabinet-level National Science Council, marked the early results of a more in-depth survey effort. An additional five volumes were released through 1979 to complete the first edition of the set, while an updated second edition was published from 1993 to 2003. One of the most notable of Flora of Taiwan’s findings was that Taiwan claimed more than 4,100 native vascular plant species, of which about 1,070 were unique to the island. In 2004, the International Association for Plant Taxonomy in Vienna, Austria awarded the second edition of Flora of Taiwan its Engler Silver Medal, the association’s highest honor.
Early in the new century, an unprecedented project to catalogue the distribution and habitats of plants nationwide was suggested by the Executive Yuan’s National Council for Sustainable Development. As a result, the National Vegetation Diversity Inventory and Mapping Project was launched in 2003 and administered by the Forestry Bureau under the Cabinet-level Council of Agriculture. Fieldwork was completed in 2008 and the resulting Actual Natural Vegetation Map of Taiwan, which consists of a large foldout map and a large-format, 420-page book, was published in December 2009.
A central goal of the new project was the development of a more uniform system for demarcating plant distribution. Despite the abundant accumulation of previous plant studies, the identification of specific plant types and their habitats had been quite inconsistent among researchers and academics over the years, leading to a somewhat chaotic and misleading reference base. Unlike the seven-rank Linneaen system that is commonly used to classify organisms by biological type, the system used for the Actual Natural Vegetation Map of Taiwan was designed to indicate the relationship between plant types and their environment.
The categorization system used in the project was based on an older, widely accepted scheme from 1984, but also incorporated elements of one released in 2003. Hsieh explains that the resulting scheme sets class of vegetation as the highest level, followed in descending order by subclass and formation. The class level, which differs in purpose from class as used in the Linneaen system, identifies the dominant growth forms of forest, thicket, herbaceous vegetation and sparse vegetation.
An example of subalpine needle-leaved forest, one of the formations identified in the new mapping project (Photo Courtesy of Forestry Bureau)
Morphological Groupings
On the subclass level, plants are grouped according to leaf morphology, such as needle-leaved and broad-leaved plants, as well as according to whether they are evergreen or deciduous. The forest class, for example, is divided into the subclasses of needle-leaved, mixed-needle broad-leaved, sclerophyllous broad-leaved, evergreen broad-leaved, semi-deciduous broad-leaved and deciduous broad-leaved.
The formation level takes into account the environmental factors of elevation and topography, as well as other plant habitat features. The needle-leaved forest subclass, for example, is divided into the formations of subalpine, upper montane, montane, lower montane and lowland forests.
The colossal job of conducting the survey was divided among seven teams of professors and research assistants—many of whom were students working toward graduate degrees—from seven universities, with each team performing field surveys in areas close to their school. Research teams in northern Taiwan included the NTU group led by Hsieh as well as one from National Taiwan Normal University in Taipei. National Chung Hsing University in Taichung covered central Taiwan, while teams from National Sun Yat-sen University in Kaohsiung and National Pingtung University of Science and Technology covered the south. On the east coast, research in Hualien and Taitung counties was conducted by the team from National Dong Hwa University in Hualien, while National Ilan University performed the work in Yilan County, northeastern Taiwan. As it was responsible for two counties, a much larger area than those of the other schools, the taskforce from National Dong Hwa University was also assisted by the other teams during the latter phase of the fieldwork, says Hsieh, who was the overall coordinator of the project.
In conducting their research, the teams delineated and sampled more than 3,000 permanent survey plots throughout Taiwan, each of which measured 400 square meters. In rugged mountain areas, surveying the plots was a demanding and sometimes dangerous task, Hsieh says. The teams hiked to the research areas in every case save one, when a helicopter was used. Each field trip usually lasted for 10 or more days, during which time researchers reported seeing almost all of Taiwan’s species of venomous snakes, slept in rain gear on the wet ground when the wind was too strong to erect a tent, and were forced to cover their heads with mosquito netting to continue working when repellant failed to keep clouds of the insects at bay. “We’re lucky to have completed the work safe and sound,” Hsieh says.
The project delineated the distribution of plants across 95 percent of Taiwan’s land area that is covered with natural vegetation, or nearly 60 percent of the island’s total surface, and recorded the habitats of about 67 percent of Taiwan’s total native vascular plant species.
The base map for the project was assembled from more than 3,000 aerial photographs taken at the extremely detailed scale of 1:5,000. Data from field researchers was collected and integrated by Chiou Chyi-rong, a professor at NTU’s School of Forestry and Resource Conservation, then overlayed on the base map to indicate plant distributions.
Those involved in the project say that the data generated by the massive survey will help to resolve major issues related to plant research, stimulate new thinking on conservation theories and improve conservation practices. Kuan Li-hao, director of the Forestry Bureau’s Conservation Division, points out that at many universities and research institutes, the bulk of attention in biology has increasingly turned to molecular biology and genetic research in the laboratory. The Actual Natural Vegetation Map of Taiwan project thus helped inject new energy into field biology, which had become somewhat neglected in Taiwan, and also provided conservation scientists with a critical new tool.
Performing biological field research is arduous and sometimes dangerous work in Taiwan. (Photo Courtesy of Hsieh Chang-fu)
Focus on Conservation
Kuan also notes that as the Forestry Bureau was established more than a half century ago as a business unit designed to earn a profit through logging, previous forest surveys were chiefly directed at the utilization of timber resources. “In contrast, this project has clear environmental and ecological significance,” he says, adding that as in many other countries in the world, forestry administration in Taiwan has shifted to focus more on conservation concerns.
The new project’s comprehensive scope makes it a much more useful tool for land management and conservation, NTU’s Hsieh says, as past surveys were confined to collecting species in limited geographic areas, or to researching the habitat of a dominant plant type in an area while ignoring other species. The scope of the groundbreaking project is quite advanced by international standards, he says, as few other nations have established such an inclusive vegetation information system. About 20 scientists from countries including Austria, the Czech Republic, Germany, Japan, the Netherlands, Russia, South Africa and the United States were invited to Taiwan during the project’s six-year span to attend symposia, during which they were asked to provide input based on their vegetation mapping expertise and experience. “Some foreign plant experts were envious,” Hsieh says of the scale and scope of the project.
The extensive findings of the Actual Natural Vegetation Map of Taiwan have paved the way for more effective national land planning efforts aimed at, for example, the demarcation of ecological conservation areas. “In the past, a protected area was often established for a star species such as the mangrove tree or based on a vague conservation concept,” says Hsieh, who also serves as director of the board of the Taiwan Biodiversity Conservation Society. “But now this kind of conservation effort can be based on a comprehensive databank.” The professor points out that, among other things, researchers will be able to reference the survey’s data on the geographic distribution of specific types of plants when planning future fieldwork. Subsequent fieldwork indicating changes in the distribution of a species would also provide crucial information on the impact of climate change, he says.
In the end, the National Vegetation Diversity Inventory and Mapping Project has resulted in a much clearer, more consistent and more detailed picture of the habitats of the island’s plants. Taiwan owes its thanks to the project’s largely unsung field biologists, whose years of arduous toil have resulted in a solid foundation that will help preserve plant species in the future.
Write to Pat Gao at kotsijin@gmail.com