The purpose of this two-year study is to compile ecological information and current status of Jhuoshuei River System into an ecological resource database in order to provide a basis for ecological engineering planning. The study area focuses on the main river and the major tributaries, including Chen-Yu-Lan River, Tonpuze River, and Cingshuei River. In addition to the compilation of abiotic factors (physical conditions, water quality indices, engineering constructions, and recreation usages), conducted were seasonal biological surveys on algae, aquatic insects, shrimps, crabs and freshwater fishes in aquatic ecosystem, and riparian vegetations, mammals, birds, reptiles, amphibians, and butterflies in terrestrial ecosystem.
A ground survey with the aid from remote sensing imagery indicates that the riparian areas had been highly disturbed by human activities. The upstream area was developed as high-mountain agricultural lands, while the downstream region was intensively urbanized.
In the aquatic ecosystem, 35 species of fishes, 14 species of shrimps and crabs, and 219 genera of algae were collected. Overall, the species show radiant changes from upstream to downstream. Some species (i.e., shrimps and crabs) showed a seasonal change in abundance due to the migration, while most of the species maintained a fairly constant population size.
In the terrestrial ecosystem, there were 15 species of mammals, 63 species of birds, 20 species of reptiles, 14 species of amphibians, 17 species of dragonflies, and 377 species of plant. In general, most of the species were common animals that represented the ecological status in the region. Some of them, especially birds, butterflies, and dragonflies, may be used as indicators for future resource monitoring.
A resource database in GIS environment was established, in which various layers of abiotic and biotic factors were digitized and can be overlaid for advanced analysis. These thematic maps in GIS include administration, topography, rivers, human development, water survey, pollution index, and biological resources.
The current ecological status of Jhuoshuei River System indicates
severe human disturbance. To have a better protection on
biodiversity in this region, we provided various recommendations on
how to design and to manage the river resources. However, our work
on investigating the current status of Jhuoshuei System is only a
beginning for effective management of the natural resources. It is
expected that similar work should be continued and conducted in
other rivers of Taiwan in the future, and these data should be
compiled in a well-designed database. Also, a web-based query system
can be expected to be established and installed so that users may
remotely access the maps from remote computers. These status reviews
should provide a starting point for more comprehensively
understanding about precious river resources in Taiwan.