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Chapter 1: An Introduction to Mountains
Alton C. Byers, Larry W. Price and Martin F. Price
Most people are familiar with the importance of oceans and rainforests (Byers et al. 1999), thanks in part to the dozens of books, documentaries, programs, and internet sites developed by education and conservation groups over the past two decades. Yet, there is at least as strong a case for arguing that mountains are also of critical importance to people in nearly every country of the world (Messerli and Ives 1997, Debarbieux and Price 2008).
For example, as much as 80 percent of the world's freshwater originates in mountains, where all of the world's major rivers have their headwaters. More than half of humanity relies on the fresh water that accumulates in mountains for drinking, domestic use, irrigation, hydropower, industry, and transportation (Viviroli et al. 2007; Bandyopadhyay et al. 1997: Chapter 12). Hydropower from mountain watersheds provides 19 percent of the world's total electricity supply, and more than 97 percent of the electricity generated by "alternative" methods such as solar, wind, geothermal, and biomass (Schweizer and Preiser 1997; Mountain Agenda 2001). Mountain forests provide millions of people with both timber and non-timber forest products (e.g., mushrooms, medicinal plants), and play vital downstream protection roles by capturing and storing rainfall and moisture, maintaining water quality, regulating river flow, and reducing erosion and downstream sedimentation (Price and Butt 2000; Price et al. 2011). Because the same geologic forces that have raised mountains have also helped concentrate assemblages of minerals useful to human society, the mines in today's mountains are the major source of the world's strategic non-ferrous and precious metals (Fox 1997).
Many mountains are "hotspots" of biodiversity (JenÌk 1997, Körner and Spehn 2002, Spehn et al. 2006: Chapters 7 and 8).With increasing altitude, changes in temperature, moisture, and soils can create a dense juxtaposition of differing ecological communities, sometimes ranging from dense tropical jungles to glacial ice within a few kilometers. This phenomenon is well illustrated by the six bioclimatic zones of the Makalu region of eastern Nepal that are found between 100 m and 8,000 m over a mere 20 horizontal kilometers: over 3,000 plant species are found within this range, including 25 species of rhododendron, 50 of primroses, 45 of orchids, and 80 of fodder trees and shrubs (Shrestha 1989). Such biodiversity does not only have intrinsic value, it can have great economic and health values. For instance, 962 species of medicinal plants occur in the temperate to alpine zones of the Indian Himalaya, of which 175 are being used by herbal drug companies (Purohit, 2002). Many mountains can be thought of as "islands" of biodiversity, such as Mount Kenya and Kilimanjaro in East Africa (Hedberg 1997), that rise above vast plains of human-transformed landscapes below. Mountains are often sanctuariesfor plants and animals long since eliminated from these more transformed lowlands, such as the volcanoes of Rwanda and Uganda, where the last of the world's mountain gorillas, now numbering less than 300, survive (Weber and Vedder 2001). Many plant and animal species are endemic to mountain regions,having evolved over millennia of isolation to inhabit their specialized environments. Equally, many mountain ranges also function as biological corridors, connecting isolated habitats or protected areas and allowing species to migrate between them (Worboys et al. 2010).
Many of the most important food staples in the world-including potatoes, wheat, corn, and beans-were domesticated in mountains, and mountain peoples long ago developed elaborate agricultural production systems and strategies based on altitudinal and ecological zonation (Grötzbach and Stadel 1997: Chapter 11). Many other crops, cultivated for centuries in the Andes, have the potential to add to the increasing need for food as the world's population continues to grow (National Research Council 1989). Mountain people, particularly women, are unusually knowledgeable about, and make use of, the many medicinal and food plants found in mountain fields and forests (Dannegelis 1997). Of the hundreds of plants in the mountains of Nepal used for medicinal purposes, 100 are undergoing commercial exploitation that can generate significant income for local people (Karki and Williams 1999; Guangwe 2002).
Biological and cultural diversity are often closely inter-related, and mountains contain an amazing diversity of human cultures and communities. For example, of the 1,054 languages spoken in New Guinea, 738 originate in mountainous regions, which cover only 33 percent of the island (Stepp et al. 2005). The late Anil Agarwal, founder and director of the Centre for Science and Environment in New Delhi, states that "cultural diversity is not an historical accident. It is the direct outcome of the local people learning to live in harmony with the mountains' extraordinary biological diversity" (Centre for Science and Environment 1991, cited in: Denniston 1995:18). Mountains are also home to many indigenous peoples, or the original inhabitants of a place before people of a different ethnic origin arrived-for example, the Quechua people of Bolivia, Ecuador, and Peru; Naxi and Yi people of Yunnan Province, China; Batwa pygmies of the Ruhengeri Prefecture, Rwanda; and Rais and Sherpas of the eastern Himalaya and Mount Everest region.
The physical and cultural diversity found in many mountain countries is one of the major draws for world tourism. Tourism is the world's largest and fastest growing industry, and tourism to mountain areas represents a significant portion of this activity (Price et al. 1997, Godde et al. 2000: Chapter 12). Visitors go to the mountains for adventure, recreation, scenic beauty, solitude, and the opportunity to meet and interact with the people who live there. This large influx of visitors to mountain regions can have positive economic benefits for a community, helping to promote sustainable development and the capacity to balance human needs with the preservation of the environment. However, there is also the potential for negative environmental and cultural consequences, such as the impacts of large numbers of people and pack animals on fragile high-altitude environments (Byers 2008, 2009), and loss of traditional cultural values (von F¸rer-Haimendorf, C. von 1984; Mountain Forum 1998; Ortner 1999).
In many cultures, mountains have special spiritual, cultural, and sacred significance. Inspirational to most, mountains are held sacred by more than one billion people worldwide (Bernbaum 1997, Mathieu 2011: Chapter 9). As the highest and most impressive features of the landscape, mountains tend to reflect the highest and most central values and beliefs of cultures throughout the world. In the United States, mountain environments like those found in the Rocky Mountain West or the Appalachians of the East enshrine cultural and spiritual values basic to American society, embodying what is interpreted as the original, unsullied spirit of the nation; others are sacred to native American peoples. The Japanese reverence for beauty in nature, an integral part of religious observance, bestows upon Mt. Fuji a symbolic meaning for the entire nation. At 6,705 m (22,000 ft.), Mount Kailash in Tibet is sacred to over a billion Hindus, Buddhists, Jains, and followers of the Bon religion.
Everyone can agree that every mountain has a summit. But how high should a feature be to be considered a "mountain", and how much of the Earth's surface do mountain areas cover? Such questions have long been discussed by geographers, explorers, mountain people, and mountaineers (Mathieu 2011).
During the 1930s, it became fashionable among members of various alpine clubs in the United States to travel about, climbing the highest point in each of the continental 48 states. The highest of all was Mount Whitney in California at 4,418 m (14,496 ft.), the lowest, Iron Mountain in Florida at 100 m (330 ft.) (Sayward 1934). No one would doubt that Whitney is truly a mountain, but there is considerable question about Iron Mountain. Webster's dictionary defines a mountain as "any part of a land mass which projects conspicuously above its surroundings." By this definition Iron Mountain may be properly named, but most of us would judge this as euphemism. At the opposite extreme, there is the story about a British climber in the Himalayas who asked his Sherpa guide the names of several of the surrounding 3,500 m (11,500 ft.) peaks. The guide shrugged his shoulders, saying that they were just foothills with no name.
The difference between the two situations is one of conspicuousness. The lesser peaks were lost in the majesty of the high Himalayas, while even a small promontory on a plain may be a "mountain" to the local people. Thus, Iron Mountain in Florida or landforms of only slightly larger stature, such as the Watchung Mountains in New Jersey, are important local landmarks to which the name "mountain" apparently seems appropriate even though they may not exceed 150 m (500 ft.) in elevation. A similar pattern of place names can also be found in South Africa (Browne et al. 2004). Nevertheless, calling a feature a mountain does not make it one.
Roderick Peattie, in his classic Mountain Geography (1936), suggests several subjective criteria for defining mountains: (1) mountains should be impressive, (2) they should enter into the imagination of the people who live within their shadow, and (3) they should have individuality. He cites Fujiyama in Japan and Mount Etna in Italy as examples. Both are snow-capped volcanic cones that dominate the surrounding landscapes, and both have been immortalized in art and literature. They produce very different responses in the minds of the people who live near them, however. Fujiyama is benign and sacred, a symbol of peace and strength. Etna, on the other hand, is a devil, continually sending out boiling lava and fire to destroy farms and villages.
To a large extent, then, a mountain is a mountain because of the part it plays in popular imagination. It may be hardly more than a hill, but if it has distinct individuality, or plays a more or less symbolic role to the people, it is likely to be rated a mountain by those who live about its base (Peattie 1936). For similar symbolic reasons, mountains can come and go. For instance, the initial explorers who mapped the area around the Gulf of St. Laurence in the 17th century identified the Wotchish mountains, presenting a barrier to westwards travel. As the region became more accessible, these low mountains, with summits just over 500 m, became recognized as just one part of the immense Labrador plateau (Debarbieux 2000).
It is difficult to include such intangibles in a workable definition. A more objective basis for defining mountains is elevation. For instance, a landform must attain at least a certain altitude (e.g., 300 m) to qualify. While this is an important criterion, by itself it is still insufficient. The Great Plains of North America are over 1,500 m (5,000 ft.) high, and the Tibetan Plateau reaches an elevation of 5,000 m (16,500 ft.), but neither would generally be classified as mountainous. In Bolivia, the Potosi railway line reaches an elevation of 4,800 m (15,750 ft.) near the station of El Condor, high enough to make your nose bleed, but it is situated in fairly level country with only occasional promontories exceeding 5,000 m (16,500 ft.) (Troll 1972: 2). By contrast, western Spitsbergen in Norway, situated only a few hundred meters above sea level, has the appearance of a high mountain landscape with its glaciers, frost debris, and tundra vegetation.
In addition to elevation, an objective definition of mountainous terrain should include local relief, steepness of slope, and the amount of land in slope. Local relief is the elevational distance between the highest and lowest points in an area. Its application depends upon the context in which it is applied. When compiling a global database of 'mountain protected areas' (national parks etc.), the UNEP World Conservation Monitoring Centre, working with the World Conservation Union (IUCN), recognized only those that had at least 1500 m (5,000 ft.) of relief (Thorsell 1997). Several early European geographers believed that for an area to be truly mountainous, there should be at least 900 m (3,000 ft.) of local relief. If this standard is used, only the major ranges such as the Alps, Pyrenees, Caucasus, Himalayas, Andes, Rockies, Cascades, and Sierra Nevada qualify. Even the Appalachians would fail under this approach. On the other hand, American geographers working in the eastern and midwestern United States have thought that 300 m (1,000 ft.) of local relief is sufficient to qualify as mountainous. Various landform classifications have been proposed with specifications ranging between these figures (Hammond 1964).
Local relief by itself is, like elevation, an incomplete measure of mountains. A plateau may display spectacular relief when incised by deep valleys (e.g., the Grand Canyon). Such features are, essentially, inverted mountains, but we are accustomed to looking up at mountains, not down. (On the other hand, if one is at the bottom of the Grand Canyon looking up, the landscape can appear mountainous). Still, this particular area of high local relief is of relatively limited extent and is surrounded on either side by primarily flat-lying surfaces. An opposite but comparable landscape is that of the Basin and Range Province in the western United States: most of the area is in plains, but occasional ridges protrude 1,500 m (5,000 ft.) above their surroundings. Such landscapes are problematic, since they do not fit nicely into the category of either plain or mountain.
Mountains are usually envisaged as being both elevated and dissected landscapes. The land surface is predominantly inclined and the slopes are steeper than those in lowlands. While this is true as a generalization, the actual amount of steeply dissected land may be rather limited. Much depends upon geological structure and landscape history. In mountains such as the Alps or Himalayas, steep and serrated landforms are the dominant features; in other regions, these features may be more confined. The southern and middle Rocky Mountains display extensive broad and gentle summit uplands, and similar conditions exist in the Oregon Cascades. It is the young Pleistocene volcanoes sticking above the upland surface that give distinctiveness to the Cascades. The Sierra Nevada of California contains many strongly glaciated and spectacular features, but there are also large upland areas of only moderate relief. Yosemite Valley is carved into this undulating surface, and most of the impressive relief in this region derives from the occurrence of deep valleys rather than from the ruggedness of the upland topography. While the world of mountains is basically one of verticality, slope angles of 10o to 30o are characteristic; it is the intermittent cliffs, precipices, and ridges that give the impression of great steepness. Nevertheless, the horizontal distances between ridges and valleys, which establish the texture and framework for slope steepness, are just as fundamental to the delineation of mountains as the vertical distances that establish the relief.
Mountains may be delimited by geologic criteria, in particular, faulted or folded strata; metamorphosed rocks; and granitic batholiths (Hunt 1958, Ollier and Pain 2000). Most of the major mountain chains have these features, and they are also important in identifying former mountains. Good examples are found along the south shore of Lake Superior in Michigan and throughout much of southeastern Canada, where all of these characteristics are present, but erosion has long since removed the ancient peaks that once were mountains. Implicit in this definition is the idea that mountains are features of construction, built and produced by some internal force. This is certainly true of the major ranges, but mountainous terrain may also result from destructive processes, i.e., erosion. For example, a strongly dissected plateau may take on a mountainous character although it contains none of the geologic characteristics listed above. Certain areas of the southwestern United States do in fact display such dissection. Curiously, these landscapes are often perceived very differently from those of constructional origin. They are viewed as ruins, pathetic features, rather than as initial expressions of grand nature. They evoke "the sentiment of melancholy" (Tuan 1964).
Another basis for defining mountains is by their climatic and vegetational characteristics. An essential difference between hills and mountains is that mountains have significantly different climates at successive levels (Barry 2008). This climatic variation is usually reflected in the vegetation, giving mountains a vertical change in plant communities from bottom to top that hills lack (JenÌk 1997, Körner 2003). It is argued that 600 m (2,000 ft.) of local relief in most partsof the world suffices to bring about a distinct vegetation change. This is not always evident, because some plants, such as sagebrush (Artemesia spp.) in the western United States, or heather (Calluna vulgaris) in Scotland, have great altitudinal range and may cover entire mountains. However, even if the vegetation is homogeneous, there are climatic changes with altitude which are measurable (Thompson 1964, Körner 2003, Barry 2008,). The major advantage of this approach is that it recognizes ecology as well as topography. Clearly, one of the most distinctive characteristics of mountains, in addition to high relief and steepness of slope, is great environmental contrast within a relatively short distance (Chapters 7 and 11).
German-speaking peoples differentiate between the Hochgebirge (high mountains) and Mittelgebirge (medium mountains). The Harz Mountains and the Black Forest are Mittelgebirge, while the Alps are the classic example of Hochgebirge (Troll 1972: 2). French has the comparable terms hautes montagnes and moyennes montagnes; and in English we speak of the High Sierra or the High Cascades, as opposed to the Sierra or the Cascades. The coastal ranges of the western U.S.A are low mountains and the Rockies are high mountains, but what distinguishes high mountains from low? Elevation alone is not sufficient: compare the high plateaus of Tibet with the modest elevations of western Spitsbergen. High relief is not reliable, either: the California coastal ranges are on the whole probably more rugged than are most parts of the Rockies. Climate is the best determinant of where the alpine zone begins. For this reason, high mountain landscapes occur at different altitudes under different environmental conditions. In Java, the volcano Pangerango, which rises from sea level to 3,000 m (10,000 ft.), is covered with tropical rainforest to its summit. "It is a high mountain without a high mountain landscape" (Troll 1972: 2).
The word "alpine" is European in origin dating to pre-Roman times, with its roots in "alp" or "allo" meaning "mountain" (Körner 2003; Löve 1970). In Europe, New Zealand, and Japan, the term is commonly applied to whole mountain ranges that can include valleys, forests, and pastures. In biogeographical terms, however, the alpine life zone is confined to vegetation above the natural high-altitude forest or timberline. This is generally lowest in the polar regions, where "alpine" and "arctic" life zones with very similar geomorphological and ecological characteristics merge, and rises in elevation toward the equator. It is not a simple, straight line relationship, however. The highest elevations at which trees grow occur at about 30∞ latitude in the arid zones of the Andes and Himalayas, rather than in the humid tropics (Körner 2003). Timberline also tends to rise from coastal areas toward the continental interiors. Thus, on Mount Washington in New Hampshire, the alpine zone begins at 1,500 m (5,000 ft.); in the Rockies of Wyoming, it occurs at over 3,000 m (10,000 ft.); and, in the Oregon Cascades, it declines again to 1,800 m (6,000 ft.) (Daubenmire 1954: 121). Although the upper timberline is probably the major criterion for determining where the high mountain environment begins, it should not be the sole determinant. Since different tree species have different climatic requirements, contrasting abilities and potentials are involved in different regions. Geological or other natural factors may result in abnormally low timberlines. In addition, many timberlines have been greatly affected by human interference, especially through the agency of fire, cutting and grazing, so they are not easily compared (Hedberg 1972, 1995; Braun et al. 2002; Broll and Keplin 2005).
Accordingly, a geoecological approach has been suggested for determining the lower limit of high mountain environments. There are three main criteria: high mountains should rise above the Pleistocene snow line, the zone of rugged and serrated topography associated with mountain glaciers and frost action; high mountains should extend above the regional (natural) timberline; and high mountains should display cryonival (i.e., cold climate) processes such as frost-heaving and solifluction (Troll 1972, 1973). Although each of these may exist at various altitudes, and one may be more important in some areas than in others, when considered together they provide a fairly good basis for delimiting high mountain environments. "According to this concept, high mountains are mountains which reach such altitudes that they offer landforms, plant cover, sod processes, and landscape character which in the classical region of mountain geography in the Alps is generally perceived as high-alpine" (Troll 1972: 4).
All of the approaches to defining mountains presented above rely on a detailed analysis of one or more factors, usually based on fieldwork and/or ground-based topographic mapping. More recently, modern technologies based on remote sensing have been applied to the definition of mountains at both regional and global scales. In 1996, the U.S. Geological Survey completed its GTOPO30 global digital elevation model (DEM). With a horizontal grid spacing of 30 arc seconds, the altitude of every square kilometer of the earth's land surface was recorded in a database which could be used to derive a detailed typology of mountains based on not only altitude, but also slope and terrain roughness (local elevation range, LER). Kapos et al. (2000) iteratively combined parameters from GTOPO30 to develop such a typology, starting from first principles and in consultation with scientists, policy-makers, and mountaineers. First, 2500 m, the threshold above which human physiology is affected by oxygen depletion, was defined as a limit above which all environments would be considered 'mountain'. Second, they considered that at middle elevations, some slope was necessary for terrain to be defined as 'mountain', and that slopes should be steeper at lower elevations. Finally, to include low-elevation mountains, the LER was evaluated for a 7 km radius around each target cell: if the LER was at least 300 m, the cell was defined as 'mountain'. According to this typology, 35.8 million km≤ (24 percent of global land area) was classified as mountainous.
A further statistic of at least equal relevance is the global population in mountain areas, long estimated at about 10 percent (e.g., Ives and Messerli 1997). Using the mountain area defined by Kapos et al. (2000), Huddleston et al. (2003) estimated this to be approximately 720 million people (12 percent of the global population). Meybeck et al. (2001), using an aggregated version of GTOPO30, have also estimated that 26 percent of the global population live within or very close to mountain areas. Thus, with about a quarter of the Earth's land surface covered by mountains, and about a quarter of the global population living in or near them, mountain issues clearly have an important place on the global development and environment stage. Hence, mountains are on political agendas; and we should note that the definition of mountains is also a political process. For instance, decisions regarding the extent of mountains in Europe are closely linked to the availability of subsidies for mountain farmers and other mountain (Price et al. 2004).
In summary, a universally accepted definition of what a mountain is will always remain evasive. For our purposes, however, a mountain can be defined as a conspicuous, elevated landform of high relative relief. Much of its surface has steep slopes, and it displays distinct variations in climate and vegetation zones from its base to its summit. A high mountain landscape is the area above the climatic timberline where glaciation, frost action, and mass-wasting are dominant processes. Additionally, a landform is a "mountain" when local people rate it as such because it plays an important role in their cultural, spiritual, and working lives.
Mountain Challenges and Opportunities
Mountain people are typically independent, innovative, resourceful, adaptive, and outstanding entrepreneurs. At the same time, they include some of the poorest, most remote, and disadvantaged people in the world (Ives 1997, Huddleston et al. 2003). High elevations and cold climates exclude productive agriculture and limit animal husbandry. Poverty levels are often exceptionally high, and access to education, decision-making power, health services, financial resources, and land rights are inequitably distributed between upland and lowland communities (Pratt 2004; Körner and Ohsawa et al. 2005). Populations are scattered, and mountain peoples are typically distrustful of central governments and outsiders because of histories of exploitation with little compensation or long-term benefit (Libiszewski and Bächler 1997; Starr 2004; Chapter 12).
National governments typically do not connect with their citizens in peripheral mountain areas, despite the potential threats to the state that may emerge from such neglect in mountain areas (Mountain Agenda 2002). At the end of the 20th century, more than half of the world's 48 on-going wars and conflicts, strongly linked to the poverty and historic marginalization of highland peoples, were taking place in mountains (Libiszewski and Bächler 1997). This trend continues, resulting not only in the tragic loss of human life but also in unprecedented levels of environmental degradation. In democratic states such as Germany, Italy, and Spain, however, the relative independence of mountain areas has often led to relative political autonomy.
The complex topography of mountain areas, and the often high frequency of natural hazards, such as landslides, avalanches, and floods, means that communications are typically poor, and roads and infrastructure marginal to non-existent (Kohler et al. 2004). However, although traditional means of communication may not be well-developed, modern technologies such as the internet and mobile phones are rapidly expanding in mountain areas (Ceccobelli and Machegiani 2006).
Because of their diversity of environments over small distances, mountains contain a huge potential for the local production of alternative energy through small-scale wind, solar, and hydro-electric power (Schweizer and Preiser 1997). Such small-scale facilities can also allow for the development of local industries, bringing new sources of income - often from the rejuvenation of traditional crafts - and also provide light for children to study by (Banerji and Baruah 2006). Equally important, modern sources of energy can help to mitigate chronic shortages of wood-based heating fuel, the principal source of energy for the majority of mountain people (Schweizer and Preiser 1997).
High altitudes and cold climates can initiate health problems such as Acute Mountain Sickness, caused by the body's inability to adapt to the decreased oxygen and pressure, with mild symptoms (headache, loss of appetite) occurring for some people as low as 3,000 m (West 2004). Care must be taken to acclimate, or physically adjust, to higher altitudes by not ascending too quickly, drinking plenty of water, and "climbing high/sleeping low" during the rest or acclimatization days (Houston 1998). People who have lived at elevations above 4,000 m for generations, such as the Sherpa of Nepal or Quechua of Peru, seem to have a natural ability to live and work at elevations that are at least initially uncomfortable for the sea level lower altitude dweller. Goiter, a swelling of the thyroid gland in the neck, is caused by a lack of iodine in the diet that, until recently, was a relatively common occurrence in remote populations in the Hindu Kush-Himalaya and other mountain ranges (Fisher 1990), The use of fuelwood in improperly ventilated homes has been directly linked to high rates of bronchitus and other respiratory diseases in millions of mountain homes.
Work seasons are short in the mountains, and skilled labor forces often lacking, especially in areas characterized by the out-migration of young people (Chapters 10, 11, 12) . This is common in many mountain areas, from the Appalachians to the Hindu Kush, and many traditional mountain cultures are being rapidly assimilated into mainstream cultures as modern communications technologies and tourists reach even the most remote mountain villages. Yet, emigrants often send remittances which can be vital sources of income and investment and, when they return, can bring new ideas which can often be combined with traditional ideas and approaches, contributing to sustainable development. Examples include new means of producing and marketing the many high-quality and high-value products for which mountains are known, including textiles, food and drink. In all of this, women are of critical importance to home life, the work force, farm maintenance, and as retainers of traditional biodiversity knowledge - yet they typically remain marginalized with regard to decision making, equity, and education (Byers and Sainju 1994, Ives 1997).
A key set of challenges derives from the fact that mountains are naturally dynamic environments, and low-frequency/high-magnitude events such as volcanic eruptions, landslides, and glacial lake outburst flood (GLOFs) are capable of immense damage (Hewitt 1997; Chapter 5). As many of the larger glaciers have melted in the Hindu Kush-Himalaya (HKH) (Bajracharya and Shrestha 2011), hundreds of new glacier lakes, holding millions of cubic meters of water, have been created. Usually contained by dams of loose boulders and soil, these lakes present a risk of glacial lake outburst floods (GLOF). Triggering factors for GLOFs include "...lake area expansion rate; up-glacier and down-valley expansion rate; dead-ice melting; seepage; lake water level change; and surge wave by rockfall and/or slide and ice calving" (Watanabe et al. 2009). GLOFs unleash stored lake water, often causing enormous devastation downstream that can include high death tolls as well as the destruction of valuable farmland and costly infrastructure (e.g., hydroelectric facilities, roads, and bridges).
One of the more extreme examples of catastrophic events was the 1970 Huascar·n earthquake and debris flow in Peru that buried the town of Yungay (population 20,000) within minutes, and killed an estimated 80,000 people throughout the region (Browning 1973). In some regions, the rapid melting of snow and ice has resulted in an increase in the formation of high-altitude glacial lakes, sometimes too fast to monitor accurately, increasing the potential for catastrophic down-valley floods that can destroy everything in their paths.
A number of other physical attributes of mountains argue not only for their importance to policymakers in the immediate term, but also for the special consideration necessary to ensure their sustainable use to meet the demands of both mountain people and those living downstream in the years to come (Ives et al. 1997: Chapter 12). For example, while mountains may be seemingly indestructable-and are occasionally sources of great destruction-they include some of the most fragile ecosystems in the world (Jodha 1997, Hamilton and Bruijnzeel 1997). Their steep slopes and young, thin soils make them particularly susceptible to accelerated soil erosion, gully formation, landslides, desertification, and downstream river siltation, particularly if the vegetation cover that protects slopes is disturbed. Improper forest harvesting practices, overgrazing, mass tourism, the constuction of ill-designed transport roads, and mining are the most frequent forms of land use leading to these advanced states of degradation and habitat destruction in the mountains. Particularly at higher elevations, off-road vehicle tracks, overgrazing, and the impacts of burning can take many decades to heal (Byers 2005). Knowledge - both scientific and traditional - of how to limit such damage, and mitigate its consequences, is often available, but not used effectively, if at all (Hamilton and Bruijnzeel 1997). The wide dissemination of case studies of good practice is therefore essential (e.g., Stocking et al. 2005).
The impacts of climate change on mountain ecosystems, especially regarding the retreat of the most of the world's glaciers that has occurred over the past century, has received considerable attention in the past decade (Barry and Thian 2011). As temperatures increase, many alpine plants and animals may be at risk because they are not able to migrate upslope fast enough to cooler, more suitable habitats similar to those in which they evolved; thus, in particular, the design and location of protected areas may have to be reconsidered (Price 2008). The melting of permafrost; increased risk of other high-magnitude events such as debris flows and landslides; accelerated erosion from increased glacial runoff; changes in agricultural patterns; the predicted depletion of glacier-fed freshwater for hydropower, agriculture, and drinking water; negative impacts on mountain tourism; and an increase in infectious diseases previously confined to the lowlands, are real or predicted impacts of climate change in the mountains that are receiving increasing study and attention (Price and Barry 1997; Huber et al. 2005; Singh et al. 2011: Chapters 3, 4, 7, 12). Finally, the impacts of acid rain, smog, and metal deposition from precipitation, all of which have lowland industrial sources, are often seen first in mountain regions, and some believe that mountains are among the most sensitive "barometers" of global climate change, and in some cases the "canaries in the coal mine," in the world (Hamilton 1997).
For these and other reasons, many geographers, development workers, and government officials feel that the future of the world's mountains, and the significant proportion of the global population who depend on them, will depend largely on achieving the same levels of international recognition and conservation efforts given to oceans, rainforests, wetlands, and deserts (Ives and Messerli 1997, Debarbieux and Price 2008; Rudaz 2011). Notable progress has been made during the past two decades to increase local and global awareness for the importance of mountain environments and their peoples (Chapter 12), but much remains to be done, particularly with regard to the concept of ecosystem services provided by mountain areas to wider populations. While this is increasingly being used as an argument for investing in mountain areas (e.g., Rasul et al 2011), there is still debate about the utility of the concept (GrÍt-Regamey et al. 2012). Education will be key to this process of awareness-raising, and the objective of this book, an update and expanded version of Larry Price's superb mountain geography textbook from 1981, is to facilitate the awareness-building process through the continued development and dissemination of mountain-related educational and resource materials.