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The People's
Republic of China probably contains more mountain and highland
territory than any other country in the world. These range from
the high Himalaya, Pamirs, and Tien Shan, to the low coastal mountains
of the southeast coast. From a climatic and vegetational point
of view they range from subarctic in northeastern Manchuria, to
extremely dry continental interior with no forest belt (for example,
the Qilian Shan), to the tropical monsoon rainforest-covered middle
hills of southern Yunnan. To select only one region, the Hengduan
Mountains, and even then to emphasize a single small area, Naxi
Autonomous District, once more illustrates the problem of representative
coverage that afflicts the entire Mountain Agenda-UNCED 1992 project.
The mountains of western Sichuan and northwestern Yunnan, in a general sense, are a southeastern extension of the Himalaya proper and the Tibet Plateau. They have a surface area of about 500 000 km2 (about the size of France) and the two main culminations are the Gongga Shan, 7556 m (Minya Konka), at about 30 degrees North and the Yulongxue Shan, 5 569 m (Jade Dragon Mountains), at about 27 degrees North.
The Hengduan Mountains have been known to a few Western travellers and scientists as some of the most difficult and complex country in the world. They are often referred to in the literature as the River Gorge Country or the Transverse Mountains (Rock, 1930; Kingdon Ward, 1960). The name River Gorge Country is derived from the gigantic sub-parallel gorges of the Irrawaddy, Salween, Mekong, and Yangtze (Jinsha Jiang) that, in their deepest sections have cut more than 4 000 m into the plateau surface.
The marked north-south topographical trend of the entire region, as well as the location of the river gorges, is a reflection of some of the more active seismic forces anywhere in the world. Actual fault scarps dominate large sections of the landscape, many of which are more recent than the maximum of the last Ice Age, and earthquakes occur frequently. The seismic activity, together with the considerable relief and steep slopes, deep subtropical weathering and, at higher levels, extensive glacial deposits, and rapid stream down-cutting, produce some of the world’s most frequent high magnitude debris flows and landslides.
Maximum altitudes fall gradually from over 7 000 m in the north to 2 000? 500 m in the south. The subtropical latitude and the monsoonal climate, together with the great altitudinal range, have produced a natural flora and fauna that ranks amongst the richest, most varied and complex in the world. Of particular importance, both in terms of commercial exploitation and urgently needed conservation, are the rich forests which, until recently, have sheltered a prodigious fauna. A single example of floral richness is the occurrence of more than 60 species of rhododendron; total species number in excess of 6 000.
For several thousands of years the Hengduan region has been inhabited by a large number of distinct mountain minorities. These include Bai, Naxi, Yi, Tibetan, in all more than 30 different nationalities with distinct languages, customs, and land management practices. Significant Han penetration occurred as recently as the 19th century. In contrast, substantial civilizations prospered in this rich region in the more distant past. For example, the Naxi claim that the origins of their written language predate Chinese; Dali, the capital of the Bai people with its magnificent pagodas, dates from the Three Nations period of the eighth and ninth centuries.
Since 1950 the entire region has been progressively integrated with the Chinese core area and a rudimentary road and railway network has been forged across some of the most technologically demanding terrain in the world. Han settlers have increasingly penetrated the region, especially during the last 100 years, occupying mainly the irrigable valley bottoms. Much of the region remains closed to the outside world and large sections have local government in the form of autonomous counties and districts. Dali was opened to visitors as recently as 1984 and Lijiang, capital of the Naxi nation, in 1986.
The combination of spectacular scenery, colourful minority people and rich architecture is resulting in a rapid expansion of many forms of tourism. Massive timber exploitation by the central government of the PRC and for local use has been an especially significant feature of the last 40 years. The region is second in importance for timber production in China. Consequently, it is not surprising that post-1979 assessments, from both within and outside of China, lead to the conclusion that large-scale forest clearance on steep slopes is producing massive soil erosion, disruption of the hydrologic cycle, and downstream flooding and siltation. Southwest China (Hengduan Mountains) has produced its own equivalent of the Theory of Himalayan Environmental Degradation (Ives and Messerli, 1989).
The Lijiang-Yulongxue Shan region will be used to highlight the environmental and development issues of the Hengduan Mountains. It is transected by latitude 27 degrees North and lies in the great bend of the Jinsha Jiang at 100 degrees East. It is reached by road from Kunming, capital of Yunnan province, approximately 620 km to the southeast (Figure 5.5, Ives and Messerli, 1984: 61).
The Naxi Autonomous District has a total population of about 300 000 (1985); Naxi constitute the largest single group, with smaller numbers of Han, Bai, Yi, Tibetan, and other nationalities. Lijiang is the regional capital, a city of about 60000 and lies at an altitude of 2 475 m. The highest summit of the Yulongxue Shan (Shan-
Tzutou, 5 596 m) lies about 20 km due north of Lijiang and is the culmination of an impressive range of ice-capped limestone peaks extending NNE-SSW for about 25 km. The anomalous northward flow of the Jinsha Jiang cuts off the northern end of the range from the Habaxue Shan (5 396 m) forming one of the world’s most spectacular river gorges (the Xia-qiao-tou, or Tiger Leap Gorge) giving a local relief in excess of 3 700 m in a horizontal distance of 6 km.
The character of the eastern face of the Yulongxue Shan is determined by a series of massive NNE-SSW faults causing the crestline to stand as much as 3 000 m above a line of tectonic basins (graben), the largest of which forms the Lijiang Plain, extending between 2 400 and 2800m. The line of hills forming the eastern margin of the graben only reach elevations of 3 400 to 3500m. The western face of the Yulongxue Shan is very difficult of access and was only partially observed from a distance.
Most of the region is underlain by limestone, Carboniferous to Devonian in age, metamorphosed to varying degrees, with some being marble. The result of weathering on the extensive limestone exposures is a variety of karst phenomena, including lapies, dolines, and razor-sharp micro-fretting. There is also a general paucity of surface water, especially in the pre-monsoon season.
Above about 3 900 m the eastern side of the range is dissected by glacial cirques and by two large U-shaped gorges from which sizeable glaciers debouched during the last glacial episode, with termini extending down to at least 2 700 m. Today they are marked by huge end moraines. Several small cirque glaciers, ice caps, and hanging valley glaciers are active today with a regional snowline at about 5 000 m (cf. Shi, 1980; Ives and Messerli, 1984). Many of the peaks are unclimbed.
Between the upper timberline at about 3900m and the lower forest limit, at
2600 -
2650m, is a series of distinct forest belts varying with aspect. These are primarily needle-leaf coniferous forests of Abies, Picea and Pinus spp. Larix, Quercus, and tree Rhododendrum, are locally important. Extensive areas, especially where disturbed by fire or clear cutting, support dense thickets of shrub oak, rhododendron, berberis and bamboo. Scattered groves of Acer, Sorbus, Populus and Salix occur within the coniferous forest belts. There are also some magnificent stands of evergreen oak (Quercus).
Below the lower forest limit the land is extensively cultivated. The presence of palms and bananas at the lowest levels indicates the range of vegetation belts from subtropical forest to alpine meadow, rock desert, and permanent snow in a very short horizontal distance.
Until recently the area contained tiger, leopard, snow leopard, two species of bear, wolf, deer, and a large number of other mammals. Excessive hunting has either eliminated these, or reduced them to very small endangered populations confined to the more remote areas. The same is true of a fascinating variety of pheasants. This region has long been famous for its endemic pheasants, several of which were believed to be extinct or exceptionally rare. However, discussion with local Naxi village elders in 1985 verified that several species, including Chrysolophus amherstiae, Phasianus colchicus colchicus, Ithagenes kuseri Beebe, and the very rare Yunnan white-eared pheasant, Crossoptilon crossopitlon lichiangense, are
currently known to the local farmers. A specimen of C. c. lichiangense was taken for its plumage in early May 1985. Wolves were also being hunted in the vicinity of one of our mountain camps where they had killed two sheep (Ives, 1985: 382-383).
Sedentary human occupation is generally below about 3 000 m. The Yi cultivate barley up to this level, and rice is grown up to 2 700 m. The most conspicuous human activity, except for intensive irrigated farming in the lower Lijiang plain, is lumbering. Many mountain slopes are bare, or almost bare of trees, and indications of widespread soil erosion and gullying are readily apparent. Cut stumps, indications of forest fire over wide areas, and a stream of timber-laden trucks trundling south 24 hours a day lead to the supposition that environmental disaster is imminent.
The United Nations University and Chinese Academy of Sciences expedition of 1985 (Ives, 1985) was organized to undertake a first-level assessment of the degree of environmental instability. The observations quoted above, of course, are sufficient to indicate that sensitive resource management practices need to be developed. Nevertheless, the 1985 fieldwork (Ives, in press) indicated that the actual situation in Lijiang Autonomous District and surrounding areas is certainly not one of progressive environmental collapse. One of the major research tools used to reach this conclusion was to replicate a sample of some of the magnificent large-format landscape photography taken in the 1920s and 1930s by Joseph F. Rock (1947). Several thousand prints and photographic plates are in the archives of the National Geographic Society, Washington DC. A small selection was made available to the expedition courtesy of Dr Barry C. Bishop, Chair, NGS Committee on Exploration and Research. The admittedly limited, replication led to the following conclusions:
1) some areas today have a much better forest cover than 60 or more years ago;
2) some areas have a situation comparable to that of today;
3) some areas have been extensively over-cut.
These findings were further supported by extensive interviewing of local people and officials, survey of altitudinal transects through the forest belts to the upper timberline, and extensive reconnaissance dendrochronology. The above findings could then be supplemented as follows:
1) over the wider region between Lijiang and Kunming, much of the forest clear-cutting and soil loss down to bedrock is very old (i.e. hundreds if not more than a thousand years);
2) the local people have managed the lower forest belts such that although wide areas may have been fired and/or clear cut, natural revegetation is extremely rapid from the individual mature trees left as seed sources. In two instances, tree core examination demonstrated that a submature forest had become established following clearing that occurred some time after Rock's photographs were taken in the 1920s and 1930s.
3) initial search of other literature sources in other areas of the Hengduan Mountains, particularly in western Sichuan (Ives and Messerli, 1984) led to similar conclusions (cf. Imhof, 1974).
The above discussion is not intended to imply that the Lijiang-Yulongxue Shan area in particular and the Hengduan Mountain region in general is not subjected to enormous pressure on the natural resource base. Rapid population growth, large-scale extraction from the forests by a timber-hungry China, accelerating tourist impact, and general resource development all indicate the need for holistic resource management systems and for provision of the means for continued improvement of the well-being of the mountain peoples. However, as with most other mountain regions, a much better understanding of the cultural-natural relations dynamics is urgently needed to support rational development policy if sustainability is to be adequately taken into consideration.
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