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stable igneous and metamorphic rocks. But in southern Taiwan the bedrocks are mainly sedimentary, including sandstone, shale, and mudstone. Located along the Rim of Fire, earthquakes are frequent. The most severe one in recent memory was the Richter 7.3 scale quake that occurred in central Taiwan in 1999 which shocked the whole island and caused many casualties and tremendous economic loss. The indirect damage of this earthquake and the following aftershocks include the loosening of the sedimentary rocks, which are thus prone to landslide and slope failures. Abnormal precipitation and steep slopes in the mountain region suffered the worst catastrophes due to slope failure, landslide, and accelerated erosion. The direct impact on the aboriginal tribes includes the effect upon the sustainability of their lifestyles and preservation of cultural traditions. Many engineering practices ignored basic soil and water conservation principles, aggravating problems created by the earthquake. Thus the threat of climate change is twofold in Taiwan. The most commonly regarded concerns the coastal plain and floodplains on the west side of Taiwan, which suffered ground subsidence due to overdrawn groundwater and the rising sea level. More than 80 percent of the total population (23 million) of Taiwan lives on these plains. The next is the combination of steep terrain compounded by the poor geological conditions and abnormal weather patterns such as unusual intensity of precipitation. Climate change poses an even greater immediate threat to the fourteen aboriginal tribes living in mountainous terrain than that faced by the people living on the plains. These mountain people account for less than 2 percent of the total population in Taiwan, where the majority are Han Chinese. The tribal people are ethnically related to South Pacific Islanders and each tribe has its unique language and customs. But facing the increased level and frequency of disasters, the sustainability of their Agroborealis 2013
The Lukai Tribe’s farmland, up in a narrow valley in the mountains. The main crops are taro and millet.
lifestyles and cultures is in question. My investigations in Taiwan concentrated on finding out the extent of the damage caused by the increased intensity of precipitation brought by typhoons and their impact on the sustainability of the lifestyle of the aboriginal tribes. To investigate the impact of climate change on the ecosystem of southern Taiwan, the first step I took was to study the government webpage for background information, and then I went on field visits to the damaged areas along the three major drainages from the floodplains all the way to the source areas high up in the mountains in southern Taiwan. Since 1996 earthquakes and typhoons caused major disasters, particularly from: • July 1996: Typhoon Herbert • September 1999: Jiji Earthquake • September 2001: Typhoon Nelly • July 2004: Typhoon Manduli • August 2009: Typhoon Morakot Each of the typhoons brought a tremendous amount of precipitation within a short period, usually within two to three days. The intensity of the
precipitation often far exceeded the holding capacity of the shallow forest soils on the mountain slopes, resulting in massive slope failures, debris, and mudflow. Professors R.F. Cheng and C.H. Weng provided me with the opportunity to visit several damaged drainages: the Laonong River, the Moulin National Recreation area, the Zhuokou River, and Nanzihsian River (a tributary of the Laonong Stream), all heavily damaged by the most recent disastrous storm— Typhoon Morakot. At one stop I was invited to the annual tribal festival on a high mountain. At the only coffee shop of the native village there I met a high school teacher, Mr. Huang, who belongs to the Piewan Tribe. He was quite astonished by my lack of knowledge of the native culture of his people and decided to give me a crash course. We spent the whole weekend traveling from the disaster relief housing project to the torrent-damaged river and eventually upstream to the end of the road and the “Cloud Village” inhabited by the Lukai Tribe. In addition, Professor Cheng told me the natural history of the island and Professor Liao introduced me to the religious heritage of the island, from Daoism to Buddhism and their role in the daily life of the people.