Soil Fauna in Ladakh

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STATUS OF SOIL FAUNA IN LADAKH

Indian Cold Desert:

Indian Cold Desert The major parts of the Indian cold desert is confined to Ladakh in J. &.K , Lahaul Spiti in Himachal Pradesh, and a very small pocket in Garhwal (Niti and Mana) beyond Badrinath and Neelang Region in Uttarkashi districts of Uttarakhand The Indian Cold Deserts comes under the Trans-Himalayan Zone, under the Biogeographic Classification of India, that comprises 5.6% of the total geographical area of the India.

Geographical Area:

Geographical Area The area of the Cold Desert Ladakh ( also known as “Mini Tibet”), in J. &K. lies between 32 0 15’-36 0 N and 75 0 15”-36-80 0 15’E covering approximately 68,321 sq.km under India and 27,555 sq.km under occupation of Pakistan and China, Himachal Pradesh the Cold Desert lies between 31 0 44’ 57”N and 76 0 46’ 29”- 78 0 41’ 34”E and covers approximately 12210 sq.km.

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Is that of a plateau or tableland intersected by a complex network of barren mountain ranges The altitudes ranging from about 9,000 ft (2,750 m) at Kargil to 25,170 ft (7,672m) at Saser Kangri, in the Karakoram Range. GENERAL TOPOGRAPHY

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Ladakh is a land abounding in awesome physical features, set in an enormous and spectacular environment. Bounded by two of the world's mightiest mountain ranges, the Karakoram in the north and the Great Himalaya in the south, It is traversed by two other parallel chains, the Ladakh Range and the Zanskar Range. PHYSICAL FEATURES

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Is determined by the snow capped mountains, daunting heights and characteristic landscapes The climate of the cold desert is characterized by the extremes of heat and cold, coupled with excessive dryness. Intensive solar radiation and Rarification of the atmosphere that causes the southerly winds. The air thus moves towards the north pole in southerly current, and offers a slight check on transmission of sun rays that the noon temperature often reaches up to 25 o C to 40 o C more than any part of India, while the night temp falls below freezing points. CLIMATE

THE TEMPERATURE,:

THE TEMPERATURE , During winter months reaches to -30 0 C (in Leh) and -59 0 C (in Drass Valley). The summer mean temperature reaches to 35 0 C (in the month of July). Surprisingly though, the thin air makes the heat of the sun even more intense than at lower altitudes. In Ladakh can a man sitting in the sun with his feet in the shade suffer from sunstroke and frostbite at the same time.

RAINFALL:

RAINFALL Surprisingly, the rainfall is very little with exception in parts of Lahaul Spiti, it drizzles at most parts. The snow falls more often but the quantity is not much being more than six to eight inches , sometimes even in summer months. The average relative humidity remains around 40-50%, which makes the area totally arid. Absence of humidity also helps to keep the atmosphere clear. Drass Valley, however, is the second coldest and inhabited place in the world.

AGRICULTURE AND ACTIVITY OF SOIL FAUNA:

AGRICULTURE AND ACTIVITY OF SOIL FAUNA Due to prolonged and extreme winters the agriculture season is very short and extends from April to September The faunal emergence and its activities , especially of Invertebrate Soil fauna, emerging from below the melting snow, therefore , is confined to a very short period of activity.

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The Indian Cold Desert Region of Himalayas is usually considered as barren mountains with very sparse vegetation due to harsh and characteristic eco-environments. And due to which its most parts have been inaccessible and cut off from the rest of world and remained unexplored and undocumented, except for little information on the larger mammals, birds and reptiles . VEGETATION

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The dominant crops are mustard, wheat, barley, peas, potatoes, cabbage, cauliflower, radish, carrot, turnip, spinach, knoll-kholl and beans etc. While the tree species seems to have come up recently planted in the valleys are Willows, Poplar, Juniper , Tamarix , Myricaria and Sea buckthorn .

AREAS SURVEYED:

AREAS SURVEYED For exploration and inventorying the faunal diversity the Cold Desert has been divided into eight valleys Leh or Indus valley Nubra Valley Changthang Valley Drass Valley Suru Valley Zanskar valley Lahaul Valley and Spitivalley

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During July 2008 surveys were carried out in various localities in Indus Valley, Nubra Valley and Chamthang Valley , ranging between the altitudes 3190 m to 6000m ASL for the collection of Soil Fauna, in general and Myriapods in particular But after finding soil faunal diversity not sufficient in the soil system that should be responsible for degeneration and decomposition of the organic matters, leaf litters and soil detritus, probed into the causes for their conspicuous absence or their relative low percentage presence , despite the general features of the ecosystem in the cold desert presumably, otherwise looking apparently suitable for such faunal elements

Observations :

Observations Very little soil faunal diversity. Lack of predators like Coleopterans, Cockroaches, Termites, Mantids, Centipedes and Millipedes that acts as degraders and decomposers. Lack of sufficient deposits of leaf litters, soil detritus and humus due to high velocity winds. Extensive heat and solar radiation. The flora of Ladakh and Lahaul Spiti area comes under Alpine and high alpine zones and is dominated by annual and perennial herbs followed by few stunted shrubs and bushes. The vegetative growth starts with the commencement of summer when the melting snow provides abundant moisture. The flora is at full boom in the month of August but starts disappearing in September (Chaurasia and Gurmet, 2003) so as to support the faunal diversity for a very short period, during which the predators also have to complete their life cycles or perish or go to diapause waiting for the next season. All vegetation and plantations are too scanty and too localized and seems to have been recently planted, with miles and miles of gaps of desert land covered with sand and sand dunes or barren hilly and fragile rocks, capped with snow. The barren desert lands acts as a very big barrier for the movements of the hapless soil fauna. The vegetation of the cold desert, in Ladakh have been classified into Alpine Mesophyte Temperate Vegetation Oastic Vegetation and Desert Vegetation While the vegetation of Lahaul part is slightly different from other parts of cold desert because of high humidity.

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The mountain slopes, meadows and alpine pasturelands give a spectacular display of flowers of cold desert barren mountains. Most of the fauna remains inactive during most part of the year. Active only during the months of June to September, when snow melts, during which it has to complete its activities, including life cycles. Rainfall between 500-1000 m p/year and relative humidity is also too low. Mountains are not as much a big barrier for the migration of the fauna as the deserts are, and the Cold Desert of Ladakh has both the mountains and Deserts and hence the cryptic and crepuscular soil fauna, like centipedes and millipedes , whose dispersal is again very slow on account of their long life cycles and large number of stadia with frequent molts, may not have been introduced or found access to a suitable habitat in Ladakh to have any role in the degradation and decomposition of soil organic matter. Millipedes are largely mesophyllic (subsisting on soft tissues of plants/leaves) and hydrophilic (growing in moist places) hence their taxonomic richness, diversity and life forms are restricted to tropical and sub tropical regions. Being extremely slow in their movements and cryptic in habit these animals have limited power of dispersal . Though there is a record of the centipedes representing adjoining land mass in Pakistan, Afghanistan, China, Tibet, Spiti Valley, Pin Valley, and J. & K etc they have not been sighted/ collected in the Ladakh region of the Indian Cold Desert. Direct high index of ultra-violet radiation and the radiation reflected to the substrate by the hard and barren rocks and also by the snow covered hills may be cause for their difficult survival and , therefore, resulting into negative faunal diversity.

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Since the animals in the soil participate significantly in the processes of soil formation, function and maintenance, the soil fauna also serve as sensitive indicators of the states of soils and of the impacts of environmental changes. The biomass of fauna is a relatively small proportion of the total soil mass, particularly in a mineral soil, yet the activity of these animals is important in moving material upward against the forces of gravity and of the flow of fluids, in altering soil fabric and micro-topography, in changing distribution patterns of soil materials and plant nutrients and in relating processes and assemblages of materials and organisms. Soil and litter organisms also play a vital role in the dispersal of seeds and spores ( Khanna 1991) while the humus improves the physical condition of soil, supports soil organisms, increase permeability and aeration, stabilizes soil temperature, holds soil moisture, serves a store house of plant nutrient and also as a fine ecosystem for the subsistence of the Soil fauna. While the soil biota (belowground biodiversity) is important from the point of view of inventory, their functional qualification is more useful in evaluating and managing their functions.

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Soil Invertebrate Categories (Based on their sizes) (Khanna, 2005) Micro fauna- - Microscopic size - Protozoa, Nematodes Mesofauna -In-between size -Mites, Collembola, Nematodes Macrofauna -Larger animals-Earthworms, Millipedes, Centipedes, Ants, Termites etc IV. Composition of Soil and Litter Fauna: Based on their functions ((Khanna, 2005) the soil fauna has been categorized as below: Detritivores (animals which feed on decomposing material), Herbivores, Carnivores (predators), Fungivores, Parasitic organisms and Omnivores. V. And according to their mouth parts and feeding activity they may further be Classed as Shredders, Suckers Bioturbators Grazers Pests Parasites Burrowers and Vermicomposters

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. Degradation and Decomposition of Dead and decaying Organic Matter: Solar Decomposition Hypothesis -“ Khanna Hypothesis ”: On the basis of the above observation it is hypothesized here that in Ladakh Region of the Indian Cold Desert the dead and decaying organic matters in the soils are disintegrated, decomposed and converted to organic soil nutrients (used for the fertility of the soil and its consumption by the flora) and are made available to the crops by the activities of the high index of ultraviolet solar radiation - 1. Received direct from the sun and 2. By the solar energy reflected from the snow capped hills and hard rocks of the barren and dry hill slopes in the Ladakh Cold Deserts.

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While the presence of the soil fauna that that converts the dead organic matters into nutrients and minerals has a very limited role to play or is not at all required for litter decomposition, in the in the soil ecosystem in Ladakh Region of the Indian Cold Desert, where the humidity, humus, leaf liter and detritus deposits are either very little or nearly non-existent.

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Micronutrients have been found deficient in most of the villages of Ladakh and as there is no practice of application of micronutrients by farmers of this region it becomes necessary to apply all the nutrients regularly, especially in nutrients deficient areas (Chaurasia and Gurmet, 2003). Content of Sulphur- di-oxide in the Valleys where the hot water springs occur, is too high. Most of the Sulphur gas readily combines with water and ammonia those deposits in the soil increases soil fertility. It may increase soil fertility in areas where sulphates are deficient. Additionally, all vegetation and plantations are too scanty and too localized and recently planted, with miles and miles of gaps of land covered with sand and sand dunes or barren hilly and fragile rocks, capped with snow so as to be big barrier for the migration and survival of the soil fauna. The vegetation remains green for a very short period from June to September during which it supports the faunal diversity that can complete their life cycles and other activities in that much a short time .And it is only during which the predators also have to complete their life cycles or perish.

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The fertility of the soil for the growth of crops depends mainly on the natural inorganic nutrients available in the soil and partly on the organic nutrients available after the solar decomposition and also by the little decomposition process carried out by the soil fauna. The strong velocity winds in the valleys do not permit the leaf litters to settle down and result in the formation of humus or soil detritus that normally supports the soil fauna. Humidity is at very low ebb.

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After having surveyed the area exhaustively and recording the negative presence of the group, the author has come out with the “ Solar Decomposition Hypothesis”. These groups of animals are believed to have no role in the decomposition Leaf Litter, humus and detritus; as such their conspicuous absence is acceptable. Secondly because of their long life cycle and short period of activity available and limited power of dispersal their occurrence is doubtful. Thirdly, because of the “Oasis in the deserts” in the form of patchy vegetations separated by the miles and miles of desert around, would not allow the migration of the species from one patch to another, since the mountains are not as much a big barrier for the migration of the species as the desserts are and Ladakh has both mountains and deserts. And lastly, since their is no waxy waterproofing layer on the cuticle of the centipedes and millipedes that permits them to remain only near damp or moist situations, in soil and humus and beneath stones, bark, and logs. , and are, therefore, generally found in leaf litters, in woods and forests or in rotting timber . They can not therefore survive in the extremes of wet or draught conditions.

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Lack of proper food chain for the soil fauna, is also interpreted as having no roles of centipedes for the decomposition of organic matters like the absence of vultures and crows and other scavengers. The scavengers that represent the area are Red billed Chough, Yellow billed Chough and Raven, which too are not in plenty. Insect pests belonging to the group Lepidoptera and Hymenoptera are quite dominant and possibly only those species, that have a short life span to corroborate with vegetative seasons, cropping systems and crops grown in the area, are available. They complete their life cycles and vanish the site before the next snow fall in September and they reoccur before the next cropping season. It has also been observed that the farmers do not use pesticides in the fields that may be one of the causes for the occurrence of the insect pests in great numbers. Dipteran bio-degraders are quite deficient in the area. While the Isopterans (Termites) are not reported and the dung beetles (Carabidae and Scarabeidae) are also not too abundant, to decompose the dung cakes which are being dried up by excessive heat generated by the sun that decomposes them. The soil fauna, in Ladakh ,mainly comprises Isopods (Soil Crustaceans) predominantly followed by the two- three species of Ants (Hymenopterans) and a lesser number of Carabid and Scarabeidae beetles that probably supplement the decomposition process leftover by the “Solar radiation decomposition and degradation” of soil and leaf litters, to some extent. The soil alkalinity in the marshland is too high. Proper soil pH plays a large role in the availability of soil nutrients. Soil alkalinity is associated with the presence of sodium carbonates or (soda) (Na2CO3) in the soil, either as a result of natural weathering of the soil. Alkaline soils are difficult to take into agricultural production. Due to the low infiltration capacity, water stagnates on the soil easily and, in dry periods, irrigation is hardly possible. Agriculture is limited to crops tolerant to surface water logging (e.g. rice, grasses) and the productivity is low. That also results in the formation of marshy grass land in Ladakh, which are too abundant. When the soil pH is too "acid" (low pH) or "alkaline" (high pH), nutrients present in the soil become locked-up or unavailable.  Correcting the pH has the same effect as applying fertilizer since it "unlocks" plant nutrients already present(http://www.donnan.com.).

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Both the atmospheric air and water (dissolved O2) are oxygen deficient. Lack of presence of fungal attack on soil system that otherwise also helps in the degradation of soil organic matters. Water retention quality in the soil of the Cold Desert is too low. The habitats apparently look quite suitable for the soil fauna but on exploration the soil faunal diversity was found to be very low and scanty. The strong velocity winds in the valleys do not permit the soils and leaf litters to settle and result in humus or soil detritus that normally supports the soil fauna. The soils, in general, have been classified as gray, light arid soil of low fertility status (Chaurasia and Gurmet, 2003). In most parts the soil is poor in organic matters and nitrogen content. The organic nutrients to plant, however, are sufficiently available in the soils due to almost nil weathering in the rocks, which is due to extremely low precipitation and temperature conditions (Chaurasia and Gurmet, 2003). Content of Sulphur- di-oxide in the valleys (like in Panamic and Chumathang), where the hot water Sulphur springs occur, is too high. Most of the Sulphur gas readily combines with water and the ammonia that deposits in the soil, increases the soil fertility in areas where sulphates are deficient. It also acts as a fungicide to help controlling diseases like black spot of roses. Though the gas reduces the growth of many plants, e.g. barley, wheat, lettuce, while others such as lichens may be killed. So the tolerance of lichen and moss species to Sulphur dioxide is very valuable and they serve as the indicator species for measuring Sulphur dioxide pollution.

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The soils are rich in potassium and its availability to plants is also high, since the weathered complex containing potash cannot be leached out under low precipitation. (Chaurasia and Gurmet, 2003). The phospho-microorganisms combination with rock phosphate in acid sulfate soils results an increase in height, nutrient uptake, and soil fertility (Bunjirtluk Jintaridth, 2006). Micronutrients have also been found deficient in most of the villages of Ladakh and there is no practice of application of micronutrients by farmers of this region. Hence it becomes necessary to apply all the nutrients regularly, especially in nutrients deficient areas (Chaurasia and Gurmet, 2003). The discontinuous distribution of centipedes and other soil fauna in Ladakh is hypothesed here, probably is because of their Lack of their role in decomposition of soil, and other organic material. Their distribution restricted on account of the harsh climate in Ladakh. Lesser mobility and limited power of dispersal. Long life cycles and a greater number of stadia. Short period of activity span There is no waxy waterproofing layer on the cuticle of the Centipedes and millipedes, which permit them to remain, only near damp or moist situations, in soil and humus and beneath stones, bark, and logs. and are, therefore, generally found in leaf litters, in woods and forests or in rotting timber . They can not , therefore, survive in the extremes of wet or draught conditions. Since the linkage between the below ground diversity and above ground diversity has been established (Khanna. 2006) the larger above ground fauna is also not too abundant.

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The animals in the soil participate in numerous processes of soil formation and affect the usefulness of soils. The classical role of the soil fauna is in the breakdown of dead plants and animals, which are returned to the soil. Accompanying this decaying process is the release of nutrients from the organic body of plants and animals into the soil. Effects of animals in and on soil results in changes in soil fabrics, i.e., the size, shape, arrangement of soil components and changes in soil composition.