The mountainous regions of the world are major geomorphological units found on continents, with the oceans being another key geomorphological feature. Continents can be grouped into two categories: first, the extensive, flat, and stable landmasses that have been eroded close to sea level; second, the uplifted regions caused by tectonic activity, typically characterized by deformation of crustal rocks that formed mountain belts as seen in the present-day world.
The characteristic feature of a mountain region is its altitude above the mean sea level. Generally, mountainous regions are located at the margins and interiors of continents, across both sides of the equator. Within these continents, the mountainous regions are often characterized by linear arrangements of mountain belts.
While it may seem that mountainous regions are randomly distributed across the Earth, they are actually found in specific zones.
Mountainous regions are mainly located in two major zones based on their age (less than 100 million years old).
In addition to these younger mountain regions, there are also older mountain chains in the first category of landforms (continents). Examples include the Appalachian Mountains in the eastern part of the United States and the Urals in Russia. These mountains have been worn down by the processes of weathering and erosion over a long span of time.
The largest and highest mountain land area is found in the Himalayan-Tibetan Massif region. The longest continuous mountain range spans from Alaska in North America to Chile in South America, along the west coast of the Americas. Other significant mountain regions include:
In addition, many smaller and lesser-known mountain chains exist across the globe.
The geographical location and distribution of the mountainous regions of the world can be visualized in the image below.
Many of you are aware of the fact that the location of a given place on the globe invariably governs and determines the climate or weather conditions of that region. The climate is considered a fundamental natural constituent that helps sustain and nurture any kind of natural environment, be it mountain, desert, coastal, or plain environment.
Owing to the factors of diverse terrain and the variable nature of energy and available moisture content, mountain areas are generally characterized by climatic contrasts within a span of one kilometer or even lesser distance. If you have done trekking in a mountainous area, you might have experienced such contrasts while ascending and descending a mountain or summit.
On this basis, can you identify and highlight the climatic conditions that prevail in the mountain regions of the world? Are these conditions identical, or do they vary spatially across mountain regions in different latitudes and altitudes? Are there any other factors that govern the climate of a region in such places? These kinds of questions, along with many others, may arise as you explore this topic.
Mountain regions are magnificent features on the face of the Earth, characterized by a sharp rise from the surrounding territory, generally taken as 300 meters above mean sea level globally, with some variations depending on the location of a particular mountainous region. Geographic regions with lesser elevations than this are known as hills.
Such high mountains not only influence the climate of the surrounding area but also affect wind patterns and the distribution of precipitation. This elevation causes significant alterations in the climate and physical landscape, influencing the type and suitability of natural habitats for living organisms.
Mountain regions that are situated far from the equator experience moderate sunshine hours. This leads to moderate temperature conditions during the short summer months and low to very low temperature conditions in the winter months. You know that temperature decreases at a rate of approximately 6.5°C per 1000 meters of elevation.
Other factors that govern temperature values include sun-drenched and shady portions of the mountain slopes. The southern parts of the mountain slopes receive more sun’s energy compared to the northern parts in the northern hemisphere.
The amount of solar radiation received on the Earth's surface increases in direct proportion to the altitude of the mountains. The diurnal range of temperature also remains high due to the differential heating and cooling effects of the mountains. As a result, temperature values and crop-growing seasons decline with rising altitude. In higher climates of the Himalayan Mountains, farmers are able to grow and reap only a single crop in one agricultural year due to harsh environmental conditions.
Mountains receive more precipitation compared to lowlands, often in the form of snow during the winter months. This stored water is used during the brief summer months to grow crops, which are channeled through gravity channels known as ‘Kuhls’ in the Kullu and Lahaul areas of the western Himalayas.
Mountain regions are also characterized by seasonal and diurnal variation in temperature. Temperature values seldom exceed 30°C during the peak summer months in different locations of the Himalayan ranges, and they can plummet below -30°C in some parts of the mountainous regions during the year. The mean monthly and annual temperatures in mountainous regions remain around 15°C.
The mornings in mountainous regions remain cool and moderate. Due to their location, orographic rainfall is common, leading to precipitation mainly in the form of snowfall during the long winter months. The annual precipitation in some parts of the mountainous regions in the Himalayas is around 989 millimeters.
The soil of mountainous regions is characterized by typical conditions unlike other geographical regions. The rugged topography, cold climatic conditions, and other factors create serious impediments to the proper development of the soil horizon. The soil profile is not fully developed except on river terraces or in similar geomorphological units like plateaus or plains. Here, the soil profile is often characterized by skeletal soil cover, stony character, thinness, and immature mountain soil.
The soil varies with altitudinal variations across different segments of mountain regions. It is typically characterized by stony clay with a thin soil cover. There is a difference in the soil cover between low-lying portions near river terraces and higher areas in the mountain uplands or highlands. The prevalence of near sub-zero temperature values for a significant portion of the year, coupled with heavy snowfall, often triggers the process of mechanical weathering in the mountainous regions.
The soils of the mountainous regions are stony clay with very poor mineral content. These soils are highly acidic in nature, which retards the growth of plants, as roots cannot absorb the required nutrients. The intense and heavy snowfall in the region also damages the topsoil layer more prominently than in other geographical regions. In this manner, the soil profile generally remains devoid of the much-required nutrients for plant growth.
You may be well aware of the fact that a good soil cover or soil profile offers the ideal conditions for the growth and sustenance of vegetation in any geographical region across the globe.
Now, you have already learned about the climatic conditions of the mountainous regions. The low temperature and scanty to moderate rainfall in the mountainous regions allow the growth of rich and varied vegetative cover, some of which are medicinally valuable. The characteristic feature of the flora of this area can be summarized as follows:
One of the most common and conspicuous features that characterize the natural vegetation in mountainous regions is altitudinal zonation. A clearly striking feature is the change in the type of vegetation with increasing altitude. Initially, the vegetation cover may resemble that of low-lying surrounding regions. However, the vegetation and climate belts change with increasing altitude in a similar way as they change from the equator towards the poles on a globe in mountainous regions of the world.
The altitude of both the snowline and treeline often increases towards the mountainous regions of the equatorial areas. However, the location of mountains near the equatorial regions is greatly influenced and affected by many physical and other factors, including wind systems, exposure to sunshine, moisture content, evaporation rate, and snow depth.
The mountain areas found in temperate latitudes are commonly grass-producing regions with two distinct zones. The first is located near the village boundaries, mostly at valley bottoms, and the second is located at higher reaches as alpine pastures, particularly in the Alps, Himalayas, and similar mountainous regions.
If you happen to be a mountain resident or have visited the mountainous regions, you may have noticed the diverse types of natural vegetation changing with increasing altitude. In the higher altitudinal areas, especially in the cold desert regions like some Himalayan valleys (Ladakh, Zanskar, Lahaul-Spiti, Manas, and Malari, etc., of India), the vegetation cover virtually disappears as you ascend away from the foothills, barring a few xerophytic plants like juniper and a very few resilient varieties of shrubs with medicinal properties.
Owing to the altitudinal gradient and the prevalence of varied climatic conditions, the mountainous region supports diverse types of natural vegetation. The types of natural vegetation vary with altitude, slope aspects, amount of sunshine, and topographical characteristics. The mountainous region is considered a storehouse of medicinal herbs and plants along with numerous plant species. The diversity of vegetation ranges from xerophytic coniferous forests to temperate evergreen forests.
Some of the prominent plant species are pine, cedar, junipers, and shrubs such as seabuckthorn (with medicinal properties), among others.
The mountainous regions do not only contain a diverse variety of natural vegetation but are also home to many faunal species, including a few endangered species. The snow leopard, ibex, yak, and llama are a few large animals that are native to diverse mountainous regions of the world. Generally, two broad types of faunal life exist in the mountainous regions of the world:
The first category covers animals living at the elevation of the natural forests.
The second category covers alpine animals living in the uplands, with most of these animals being herbivores. These animals tend to migrate during the onset of winter when grasses dry up due to the cold and low temperatures to the lower and slightly warmer elevations, similar to the transhumance activity in which the Gaddis (shepherd community), Gujjar of lower Shivalik Himalayas, and Bakerwals of Jammu region tend to migrate with their animal flocks.
The major mountainous ranges of the world are home to many animal species as well as thousands of species of birds. These animals and birds are of paramount importance for both the sustainability of ecosystem services and the well-being of human communities and societies. Hence, all of you will certainly agree that the faunal diversities must be preserved.
It is of utmost importance the way humans develop their relationships with their immediate environment through a chain of spatial economic activities. Because mountain regions are characterized by fragile and complex topographical or physical characteristics, unlike other regions. It is understood that while deriving a host of services, humans also try to influence the environment, and in turn, the environment also influences the activities of humans. This is a two-way interaction that takes place between the humans and their environment. Such interaction is determined by the interplay between three factors: knowledge, skill level, and a set of available technological inputs.
If we compare these factors in plain regions versus mountainous regions, we observe that the first two factors may not create significant hindrances in both regions. However, the third factor—technological inputs—due to the high altitudinal location of mountainous regions, may create considerable hindrances at the ground level. Additionally, the mountain people may lag behind in terms of capital input, which makes the human-environment relationships in mountain regions more complex compared to other geographical regions. Here, humans try to modify the environmental constraints with the help of available knowledge, skill, and technological inputs, while also adapting to the environmental dictates. This interaction varies across the altitudinal gradient as well as among different human communities in mountain regions, as it can greatly differ from one region to another.
It is needless to mention that the physical environment of a particular geographical region not only governs but also exerts a direct influence upon the human beings living in that region. In order to survive and carry out spatial economic activities, people of that region try to modify the bounties of nature within the dictates of natural forces, while also adapting themselves to the physical environment. One of the classic ways to do so is by suitably modifying their agricultural practices, which holds more relevance in mountainous regions that are characterized by specific resource sets and environmental constraints.
The pursuit of agriculture and allied activities in its various forms has long been one of the major sources of livelihood in mountainous regions. In most of the mountainous areas of the world, different forms of agriculture are still practiced, mainly characterized by traditional or indigenous subsistence farming, sedentary and mixed agriculture, pastoralism, and agro-forestry. However, with time, it has gradually transformed into modern forms of agriculture, barring a few interior locations, particularly in parts of developing countries where technology and capital are limited, with some exceptions.
It is notable that due to the lack of ample arable land, rugged topography, skeletal mountain soil cover, soil erosion, lack of proper irrigation facilities, and transportation, the agriculture sector is not well developed in many mountainous regions. However, some notable exceptions exist, such as in the cold desert valleys of Ladakh and Lahaul in India, where agriculture is well developed. On gently sloping mountain areas, terrace farming is practiced. In some lowland river terraces with milder climates and thicker soil covers, besides growing food grains, temperate fruits (such as apples, pears, and plums) and European vegetables are also grown, both for subsistence and commercial purposes. Mechanization of farming techniques is evident in some lowland areas of the western Himalayas, where flat arable land is found in agriculturally prosperous valleys.
Animal husbandry is an integral component of agriculture in the highlands of mountainous regions. It serves as an important substitute economic activity apart from crop cultivation. Various kinds of domesticated animals are taken for grazing in high alpine mountain pastures during summer and are grazed on lower valley slopes during winter. Sheep and goats are commonly reared in the highlands, whereas cattle are mostly reared in the lower mountainous areas. The rhythm of human life typically revolves with the change of seasons in the mountainous regions of the world.
The natural environment of any geographical region influences human habitation, economic activities, health, and many other socio-cultural pursuits. While mountains are often believed to be unsuitable for human habitation, this is not entirely true. Despite harsh environmental constraints, many mountainous regions are suitably inhabited across the globe. Mountains offer a variety of natural resources and scenic attractions—such as snow-clad mountain ranges, waterfalls, temples, forests, alpine pastures, and recreational avenues—that boost tourism activities.
The Ural mountains in Eastern Europe are rich in metallic minerals like iron ore, while cement is extracted from the sedimentary rock strata of the lower Himalayan mountains. In the Rockies of North America, valuable minerals like gold, zinc, copper, and silver are commercially extracted. Some mountain regions are settled as administrative units, such as Shimla in Himachal Pradesh, established by the British to escape the intense heat of the plains. Additionally, mountains have often provided refuge to people displaced during wars, struggles, and conflicts. Mountain societies are known for their closed communities and self-preservation of cultural norms and values.
The proximity to mountains also influences house types in different parts of mountainous regions. Houses are generally built with locally available natural resources like rocks, sand, soil, timber, and wood. Over time, modern housing styles have become popular, although some regions show a fusion of traditional and modern architectural elements. In the mountainous areas of the western Himalayas, particularly in Kullu Valley, earthquake-resistant houses known as Kath-kuni House Structures were traditionally built using locally available materials. This architectural style, which can still be seen in remote villages of Kullu Valley and other parts of Himachal Pradesh, is known for its ability to withstand earthquakes, as evidenced by the devastating Kangra Earthquake of 1905. Today, however, modern architecture has become more common, although these traditional houses still offer unique architectural value.