The special terrain of Taroko Gorge was created when the original Permian limestone was transformed into marble by the late-stage mountain-forming process of orogeny and the accompanying metamorphism. After a long period of tectonic movements and metamorphism, marble and other rocks formed complex geologicalfolds, and these folds and faults resulted in the repeated emgergence of marble in the Taroko area.
Taroko Gorge has been pushed upward constantly because of continuous collisions between the Philippine Sea Plate and theEurasianPlate. The region also undergoes continuous undercut erosion by the Liwu River, but the dense lithology of marble prevents the gorge walls from collapsing. The steep, narrow, and almost vertical U-shaped gorge was formed by the Liwu River flowing through the marble region in Taroko National Park.
There are great differences in the elevation range of Taroko National Park, ranging widely from less than 50 meters above sea level to 3,742 meters above the sea at Nanhu Mountain to the north. The climate, terrain, and plant distribution are quite complex as well, going from ground level to mixed broadleaf and coniferous forests, alpine grasslands, and the Nanhu glacial cirque, which is similar to the alpine tundra. Since the ecological zones are very different and there are few man-made damages, virgin forests or native vegetation in the national park still maintain their original appearances. A large number of animals from a wide range of species have made the park their habitat too.
Although the base plate of high mountains in the area is connectedtoeachother, each peak touches theskyindependently. From a biological perspective, they represent many “mountain islands” that have the effect of isolating reproducttion, and each biological island is rich in differentenvironmentalfactors that manipulate the natural selection pressure on evolution and promote the function of speciation, thereby screening successively the region’s unique species and biota (ecology) from the very start.
Accordingto research, there are atleast34mammalspecies (including 6 that are endemic), 144 bird species (including all 14 endemic species that are in Taiwan), 15 amphibianspecies (3 endemic), 32reptilespecies, 18 freshwater fishspecies, 251butterflyspecies, 18 shellfish species, 13 freshwater shrimpspecies, and6crabspecies (of which the Platyeriocheir formosamitten crab is endemic to eastern Taiwan) in Taroko National Park.
Two salamander species of the Cryptobranchoidea, a family of amphibianswith a long tailthat has survived the ice ages and are foundin mountainous areas 2,000metersabovesealevel, have lived in the Taroko area since thousandsofyearsago. The Xueshan grass lizard (Takydromus hsuehshanensis), which enjoys sun bathing on stones, is the most famous endemicspeciesinthearea and the only one of its kind thatis distributed at such ahigh altitude.
Moreover, the Taiwan weasel (Mustela nivalis formosana), Taiwan field mouse (Apodemus semotus), and Oldfield white-bellied rat (Niviventer culturatus) are also endemic to Taiwan and found in Taroko. White-bellied rats are large in size and beautiful with a milky white belly.
Walkingfrom low grasslands into a bushy arrow bambooforest, the forest scent can be slowly inhaled and the endemic Formosan rock monkeys are often seen jumping among trees in groups. In additon to mammals, three species of common pheasants (Phasianus colchicus) — the Mikado pheasant (Syrmaticus mikado), Swinhoe's pheasant (Lophura swinhoii), and ring-necked pheasant (Phasianus colchicus) — have been spotted at thebottomofthe Taroko forest. The Mikado pheasant and Swinhoe's pheasant are endemic species. Since the vegetation in this area is well-preserved with 85% of forests in the hinterland being natural, the area has become the best living environment for wild animals.
Preliminary research shows that thereare1,224 species of vascularplantsin154families in Taroko National Park, and 132 among them areendangered species. Sincethe altitude in the national park varies fromsealevelto a 3,742-meter-tall mountain,thereare complex climatezones and many types of vegetation in Taiwan can befoundhere.
Alpine tundra ecosystem:
The alpine tundra ecosystem is found in mountains higher than 3,500meters above sea level. This area is covered by bare rocks with no soil accumulation on them because the terrain is severely weathered. There are about four months of snow and ice per year and constant strong winds, giving rise to extremely low temperatures.
In addition to plants often seen on high mountains, including Juniperus Sqyanata Lamb.var. morrisonicola (Hayata),Angelica morrisonicola, and Rhododendron lapponicum, there are 40 rare plant species in Nanhu glacial cirque. The Epilobium nankotaizanense is considered the most beautiful variety in the area.
Coniferousforestecosystem:
Also known as a cloud forest, the coniferous forest ecosystem is distributed in mountains at 2,000 to 3,500 meters above sea level where it is very wet and enshrouded by fog throughout the year. The dominant tree species are the Taiwan fir (Abies kawakamii),Taiwanhemlock (Tsuga chinensis), and Taiwan red pine (Pinus taiwanensis). The abundance of lichens (Usnea) such asU. barbata and Taxillus chinensis is a further indication of the region’s wetness
Mixed broadleaf and coniferousforestecosystem:
This ecosystem is distributed in mountains at an elevation of 1,000 to 2,000 meters in the national park, and schist and marble are the main types of rock here. There are a wide varietyoftrees and the main conifer species are Taiwan redcypress (Chamaecyparis formosensis Mats.),Taiwancypress (Chamaecyparis taiwanensis Mas. et Suzuki), Taiwan cedar (Taiwania cryptomerioides), China-fir (Cunninghamia), and Chinese white pine (Pinus armandii). The major broad-leaved tree species here are Mori oak (Chclobalanopsis morii), Nanban Tanoak (Pasania hancei Benth.), Red Nanmu (Machilus thunbergii), Morrison sweet-leaf (Symplocos morrisonicola), and wheel tree (Trochodendron aralioides), the latter of which is a living fossil from the ice ages. The ecosystem here is one of the important habitats for wildlife in Taiwan.
Broadleaf forest ecosystem:
This ecosystem, which is rainy in summer, is distributed in areas less than 1,500 meters above sea level. Common plants are the ring-cupped oak (Quercus glauca), large-leaved Nanmu (Machilus kusanoi Hay.), and Hauili fig tree (Ficus septic Burm.F.var.septica Moraceae). Below these trees grow Taiwan sweet-leaf (Symplocos modesta), species from the Dadoxylon andSymplocos families, and Taiwan Diplofatsis (Fatsia polycarpa Hayata). The most common ground-covering plants are Dryopteris formosana, Pyrrosia sheareri and Selaginella doederleinii Hieron. In addition to breeding a rich plant community through evolution, there are such hardy rock plants as Taroko oak (Quercus tarokoensis) and Taiwan giant reed (Arundo formosana Hack.) in the Taroko Gorge area.
Taroko National Park is comparable with Grand Canyon National Park, which is listed as a UNESCOWorldHeritage Site. The 1,500-meter-deep gorge in the Grand Canyon is cut and eroded by theColoradoRiver. It has a spectacular landscape with an altitude difference ranging from sealevelto2,500meters above the sea. The unique geological landscape has created a diversity of climates and habitats, including terrain ranging from mountain todesert and fairly abundant animal and plant resources.
The terrain of TarokoNationalPark is more diverse, because it was developed when the continental plate was crumpled and uplifted. In addition to grand canyons, there are morethan100 streams and waterfallsinthepark. Sincetheelevationofthepark variesfromsealevelto3,742meters above the sea,the changes in climateandterrain have created rich animal and plant resources and such natural formations as mountains, cliffs, streams, and waterfalls.
ThebiggestdifferencebetweenTaroko Gorge and Grand Canyon is the U-shapedTaroko marblegorge resulting from the uplift of the Earth’s crust, erosion by the Liwu River, and effects of long-term weathering. The narrow and steep gorge of morethan1,000metersdeep is nearly vertical, and as long as the uplift of the Earth’s crust and erosion by the river continue, both sides of the world’s largest marble gorge will continue to grow steeper and the valley will become even deeper.