Cold desert – Ladakh

Geetha Iyer

One fifth of the Earth’s surface is desert. As mentioned in part 1 of this article (published in Teacher Plus, March 2023), whatever be the type of desert, one defining characteristic is the extreme temperature, both seasonally and daily. Cold deserts are characterized by cold winters and high precipitation of snow. Occasional rains during winters are not uncommon in cold deserts. Antarctica is considered, by most scientists, to be a cold desert. It is the largest cold desert in the world. The Gobi Desert in Central Asia is among the coldest deserts, where winter temperatures drop to -40° C. In India, Spiti in Himachal Pradesh and Ladakh in Jammu and Kashmir are examples of cold deserts.

Characteristics of a cold desert
Cold deserts are mostly found in temperate regions at higher latitudes. They have sand, ice, or snow covered land. Snowfall in winter is common but in places it may also occur during summer. Depending on the region, rainfall occurs mainly during the months of April or May and during autumn. Summers are moderately warm to sometimes being hot with mean average temperatures ranging from 21-36° C. With climate change setting in, the warming of temperatures in this region has been noticed of late. While the environment of a hot desert is orangish in colour, cold deserts appear gray or blue-gray.

Cold desert soil shares some features with hot desert soil. Their surface horizons are dry and contain gravel. The soil is relatively porous with salt and silt permitting drainage to leach out a lot of the salt. A zone of accumulation of water-soluble salts is followed by a permanently frozen layer beneath, which may be ice-cemented in its lower part.

Cold deserts of India
The cold desert landscape of India is in the Himalayas – Ladakh in Jammu and Kashmir and Spiti in Himachal Pradesh are cold deserts. The harsh climatic conditions here are the result of two factors. One is their location on the leeward side of the Himalayas, which makes them a rain-shadow zone not being accessible to the annual south eastern monsoon winds, which bring rains to the rest of the country. The low precipitation creates desert conditions. The second factor is the altitude. The very high elevation ranging from 3000 – 5000m ASL makes the environment very cold. These characteristics also result in seasonal variation ranging from short and dry summers with harsh sunlight to long, windy, and freezing winters. Due to these conditions, blizzards, snowstorms, and avalanches are common in cold deserts. The soil is not very fertile and the climatic conditions allow very short growing seasons making it a bare landscape. Water resources are minimal and comprise glacier-fed streams. These cold climatic conditions have led to the emergence of not only a unique cold desert ecosystem, but have also influenced the culture of the community found in these places.

For the classroom Do a research using the references given in this article to find out about the biodiversity present in Ladakh. Create a food web for one of the wildlife sanctuaries. Find out how many in your food web are threatened species and draw a plan for their conservation. What is the status of Ovis vignei vignei in Ladakh? Examine the close connection between this sheep, humans, and the cold desert habitat to understand why this species has been declared a threatened species. 1,4Resource for reference: https://roundglasssustain.com/species/urial

Ladakh
Ladakh’s cold desert covers an area of about 68,321 sq km. It is also known as Khapa Chan or Land of the Snow and Little Tibet. Leh the capital of Ladak was earlier known as Maryul or low land by some and Kha-chumpa by others. Fa-Hein referred to it as Kia-Chha and Hiuen Tsang as Ma-Lo-Pho. It is generally cold and dry for most of the year. Located at an altitude that ranges from 3000m in Kargil to 8000m in Karakoram, the air is very thin and the sun’s heat intense, even at very low temperatures. Sometimes you can get both frostbite and sunstroke during the brief summers. Ladakh is contiguous with Xinjiang and Tiber and is close to Central Asia. During ancient times, Ladakh was an important gateway in the Indo-Central Asian exchange of materials, as caravan routes linked it to the Silk Route. Ladakh is classified as a high altitude cold desert characterized by extreme climatic conditions and low productivity. Though not as rich as other Himalayan ecosystems, the region is surprisingly diverse in species assemblages and life forms.

Biodiversity in cold deserts
An area of approximately 17000 sq km in Jammu and Kashmir comes under the Protected Area Network. Located in this area are five national parks, 14 wildlife sanctuaries and 37 conservation reserves. Of these, the Hemis National Park, The Karakoram (Nubra-Shyok) Wildlife Sanctuary, and the Changthang Cold Desert Wildlife Sanctuary are located in Ladakh. Yaya Tso, the high-altitude lake and its catchment area located at an altitude of 4820 m, which falls under the Chumathang village panchayat was declared on 17^th January 2023 as Biodiversity Heritage Site under the Biological Diversity Act.

Ladakh, along with Tibet, is quite unique in its assemblage of wild herbivores and predators, as well as their domesticated relatives. As many as 36 species of mammals are found in Ladakh. Of them eight are ungualtes and six are globally threatened species. The Tibetan Gazelle or Goa is believed to be on the verge of extinction. The Great Tibetan Sheep (Nyan or Argali) and Ladakh urial or shapu (Ovis vignei vignei) are threatened species of wild sheep.

Floral diversity and adaptations for survival
The vegetation of the cold desert Trans-Himalayas consists of a highly specialized group of plants with strategies suited for maximizing their activity in harsh climatic conditions. Ladakh being a high alpine zone, the plants here exhibit not only morphological adaptations but physiological and ecological too. The metabolic and reproductive strategies adopted by them help in maximizing their physiological needs under harsh climatic conditions. The vegetation is mostly annual and some perennial herbs along with some stunted shrubs. About 611 species of flowering plants have been recorded from Ladakh (Kachroo et al., 1977). Other than some isolated patches of Junipers and Birch in some valleys and cultivated varieties of Poplar and Willow, Ladakh is practically treeless.

Because of arid soils, the roots run deep and spread extensively to absorb water from deep down. These roots running deep down also help the plants withstand snow blizzards, strong winds, etc. As the favourable growing period is limited to only a few months, most plants, namely the shrubs, are stunted in their growth or short and bushy with many branches. This condition is brought about due to suppression of internodes, which in turn is due to the brief growing periods. The physiological adaptation seen is to withstand frosty weather which can lead to ice crystal formation within the cells of plant tissues. Plants here have developed the ability to inhibit or reduce crystal formation.

For the classroom
^2,3Seabuckthorn is popularly known as ‘Wonder Plant’, ‘Ladakh Gold’, ‘Golden Bush’, or ‘Gold Mine’. Find out if the plant has characteristics to justify the above titles. Use the reference given below for your study.

Threats to biodiversity
As seen across the country, habitat destruction is the leading culprit for biodiversity loss, especially plant species, which are already struggling in the harsh climate to stay alive. Widespread plantation activities, over-exploitation, and tourism are some other concerns. Road kills are the threat faced by herpetofauna, while poaching for meat and trophy are specific threats to large mammals. Sheep breeders consider snow leopards a threat to their livelihood. Stream waters diverted for irrigation pose a threat to fishes.

There are also many volunteers and NGOs who are working in the educational field to give the Ladakhis a greater understanding and appreciation of their fragile ecosystem, as well as the need to conserve it. There is a responsibility that lies with any and every one who visits Ladakh to enjoy the magnificent landscape. Perhaps the greatest threat comes from those adventure seeking tourists who in their excitement fail to take note of the small and beautiful creatures that are not easily visible but important in keeping the cold desert biome intact.

References

1. https://www.wti.org.in/news/endangered-ladakh-urial-shows-increase-in-numbers/
2. https://www.researchgate.net/publication/315725987_Seabuckthorn_Hippophae_rhamnoides_L_in_trans-Himalayan_Ladakh_India
3. Mohit Husain et al. (2018): Seabuckthorn: A multipurpose shrubs species in Ladakh cold desert. Journal of Entomology and Zoology Studies 2018; 6(2): 1330-1337
4. The Ladakh Urial – https://www.youtube.com/watch?v=o7c-tm6dHqA

The author is a consultant for science and environment education. She can be reached at scopsowl@gmail.com.