Geology of Himalaya

Himalaya Mountain is a result of formation of tectonic forces and it is a process of two continental collisions. This great mountain modify by weather and erosion continuous process. Himalaya – Tibet region is identifying as an Asia visible water tank. It supplies fresh water for one-fifth of the world population. 

Formation of Himalaya

The Indian subcontinent pushes towards to north in the late Precambrian and Paleozoic period. Himalaya known as a young – folded mountains if compare with Appalachian old mountains which located in America. Himalaya formation is take places in recent earth history. Theory of Himalaya formation is started to develop in 1912 with Alfred Wegner continental drift theory. According to his theory earth joint by giant tectonic plates and today continents are formed from one single land mass and it called as “Pangaea”. Continents are drifted apart from each another due to tectonic activity from this land mass and formed today continents and oceans that we know today. 

Around 200 million years ago the middle era of Precambrian there was a region with an extensive sea stretched presently occupied by Himalaya region. Eurasian north landmass known as Lorezia and South Indian land mass called as Gondwana. These two land masses were divided by Tethys Sea. During this period super continent Pangaea land mass began to split into different land masses and start to move various directions. The Indian plate breaks off from the Pangaea and move northwards toward Eurasian plate. As a result shallow Tethys Sea gets deposited by large amount of sediments. The two land masses Eurasian and Indian sub-continent come to close each other. Indian plate was move 16 cm per year (6 inch per year). 

The initial mountain building process started around 70 million years ago. During this period these land masses get collide and depart from another. As a result Tethys Sea began to fold folded and raised their shallow valleys. Next 65 million years ago second mountain building process started and Tethys sea bed again began to rise. The Sea get backward and sea bed start to elevated with higher mountain ranges. 

Later 25 million years ago, formation of lower Shivalik mountain ranges start the next phase of mountain building and periodic mountain building phases occurred. Indian plate pushed against the Eurasian plate and raise the Himalayan ranges further.

  Function of Himalaya

Himalaya still raising it elevation in small rate after passed it uplift phase. Indian continent continually move toward to north in the rate of 2cm per year. As a result Himalaya is raising it elevation in the rate of 5mm per year. This show the Himalaya is geologically activity and it unstable structure. 

Beneath the Himalaya the earth crust is 60-780 km thicker and this thicker crust formed crustal root to go downward into the mantle and it is an important process for mountain building. Because buoyancy of the root allows the high reaches of the mountain. 

The Himalaya continues to raise it massive weight bear up by crust which located beneath the mountain and it buried into earth crust. If this rock pressed down into mantle, it will start to melt and began to follow slowly. This process creates mountain collapse lower. Several scientists believed this stress cause large earth quakes in this region and there was recorded of severe earth quake incidences. Recent earth quake occurred in Nepal-Himalaya region on April 2015 and it cause large impact in those areas and millions of people get affected.

Biodiversity of Himalaya region

Himalaya region is an accommodation for richness of biodiversity. It is a hotspot for hundreds of specific species and wild animals. Hindu kush – Himalaya (HKH) region is known as a living place for large number of ecosystems in the world. It extends more than 3500m and includes variety of ecosystems. Varied altitude, climate conditions, geography-biophysical conditions and soil formation are contributed for this region biodiversity richness. 

Himalaya Mountain ranges are divided as a complex geology structure. It contains snowcapped peaks, large snow valleys, deep river gorges and high variety of plants. Complex climate conditions, geology process, usage of resources and economic status are the main reason for resource degradation and environment consequences in Himalaya region (jodha, 2001). 

Rodgers (1988) divided the Himalaya regions as a 5 biotic provinces under the biogeography zones:

Trans Himalayas, North West Himalayas, West Himalayas, Central Himalayas and Eastern Himalayas.

Western Himalaya bio zone is a cool and include vegetation cover that opposed to dry conditions. Conifers, legumes and grasses are dominant plants in this region. Eastern Himalaya zone is composites of sub-tropical wet vegetation cover and include magno lias, oaks, laurels, epiphytes, orchids, and fens are seen as a high rate. 

 These biogeography zones are reflecting variety of ecosystems and include cool desert. North ranges of Himalaya represent cool desert ecosystems and it temperature is below -75^oC and this region annually getting 500-800 mm rainfall. This desert occupied with 4500-6000 feet high plateau and it described as a Himalaya transitional biogeography zone by Rodgers & Pawar (1988). This zone extent along to Tibet plateau the origin place for Hindu, Sutlej, Brammaputhra and Yangtze rivers and it invade 2.6 billion square kilometer region. 

Himalaya region is the accommodation for large number of plant species. It include all kind of plants such as, the tropical wet ever green plants to sol forests, marshes, swamps which are belongs to deciduous wet plant species, mix deciduous forests, sub-tropical coniferous forest, Broad leafed temperature forests, temperature wet broad leafed deciduous forests, temperature conifer forests, sub alpine, Alpine plants, Alpine grasses and Alpine savanna.

It occupied with snow leopards, Himalayan brown bear, red banda, Himalayan Lynx, Kahmir stag, Himalayan Musk Deer, Yak, Himalayan Ibex, Himalayan thar and Himalayan Beared vulture wild animals. Vertebrates and invertebrates animals also consider as important wild animals. 

Threats of Biodiversity

Richness biodiversity of Himalaya region expect a sever threats and becoming endangers. Deforestation, over exploitation of resources, filling of wetland drainage system, settlements, fragmentation of lands, population growth is the main reasons for biodiversity loss. Plant species are becoming threats by deforestation, agricultural activities, river valley projects, industry, and urbanization activities (MOEE 1999).

Agro- pastoral is the main reason for resource degradation. Most part of the people in this region depends on agro – pastoral activities. Over grazing activity leads to insufficient food supply and cause spread of diseases, decline in egg products to wild animals. Hunting by wild animals is the main problem for domestic animals. 

Natural disasters and wild fire are other reasons for biodiversity loss. Habitat destruction and fragmentation cause pressure in laying eggs and high mortality. Construction of dams and infrastructure facility, transport systems activities also contribute for habitat fragmentation and of destruction of biodiversity. Hunting wild animals and illegal commercial activities are increasing the risk for species of Himalayan region. Himalayan plants, musk deer, Himalayan black bear, butterflies and Tibetan antelopes are having a high value in international market.  

Indian government takes many steps to prevent these activities and promote to protect the Himalayan region and its biodiversity. Such as protected area networks-biological reserves, national parks and sanctuary and sign in multilateral environment agreements (CITES, CBD……).

Although high rate of arrivals, population pressures, economic development and concomitant excessive utilization of the regions resources are being induce the threats for Himalaya ecosystem and its habitat. 

Himalaya region and climate change

Tibet plateau is a vulnerable place to reflect the world climate conditions. Glacier covers 104,850 km² of areas. This region Temperature rising 0.3^oC per decade and this rate double the world average and glacier reduce by 7% per year. 

Uplift of Himalaya-Tibet plateau cause effects on region and global climate. Estimation shows that Himalaya uplift and climate impacts on Tibet plateau are enhanced the winter and summer monsoons and increase the drought in Central Asia. This trend helps to created Gobi and Mongolian desert and cause dust particles. These dust particles are carried by westerly from the east part of the desert to china and there deposited as a sediment on lands and ocean. 

Himalaya ranges occupied with 37,000km² of ice sheet covers and include more than 15,000 ice sheets. These are annually supplies great amount of fresh water and therefore called as an “Asia water tank” (Dyurgerov and Maer, 1997). Ice sheets include 17% of mountain regions, and other 30-40% is seen as a season snow cover. 

This Asia water tank supplies fresh water for more than 100 million of  population due to dry seasons and provide water for Asian large seven rivers; Ganga, Hindu, Brahmaputra, Salween, Mekong, Yankizen and Guwango. These river valleys are accommodation for 1.3 billion of populations. 

The longest ice sheet of Gangothri which located in Central Himalaya disappearing 3 times faster than last decade. This was 29 km long and 2-6 km width. Lose of this ice sheet cause shortage of water in many rivers and create economic, environment problems for west china, Nepal, Pakistan and North Indian people. Lose of ice sheets reduce the July-September monsoon flow by 2/3 and increase the water shortage for 500 million of population and 37% of Indian agricultural lands. 

Nepal-Himalaya glacier ecosystems got impact by climate change in last several decades and also Nepal consider as a one of the vulnerable country for climate change. 

Dust particles that collected in eastern china seen as a climate records and these are evidence for uplift period and sediments are 8 million years old. Himalaya ranges prevent the precipitation and humidity for Gobi and Mangolian deserts around 8 million years and turn to South and East Tibet plateau. 

Himalaya region ice sheets decline very fast than other parts of the world ice sheets (IPCC). Annually 10-60 m of Himalayan ice sheets are disappearing and if this lose rate continue 80% of the ice sheet will disappear in 2025. 

 References :

(1) THE HIMALAYA MOUNTAINS THEIR AGE, ORIGIN AND SUB- CRUSTAL RELATIONS authored by D. N. WADIA published in 1965

(2) http://library.thinkquest.org/10131/geology.html

(3) Michael Allaby, Dr. Robert R. Coenraads, Dr. Stephen Hutchinson, Karen McGhee, Dr. John O'Byrne, Dr. Ken Rubin (2008): The Encyclopedia of Earth, Sydney.

Biological Diversity

1. Introduction to biodiversity

The variety of plant and animals life on earth, including genes, species and ecosystems, is known as biological diversity. There are three major types of biodiversity.

(i) Habitat diversity (ecosystem diversity) – The variety of habitat types and biologic richness of those habitats in an ecosystem.

(ii) Genetic Diversity – The amount of variability that is available among the DNA of individuals with in a population or species. Genetic variability gives chances to species to compete, adapt, and survive.

(iii) Species Diversity – The concepts of species richness and evenness. Species richness refers to the number of species in a community. Species evenness is the relative abundance of individual within each species. 

2. The role of biological diversity in living systems

Biological diversity plays vital part in evolution of the new species. Evolution results from genetic variability, mutation and natural selection. For example, when individuals are force to adapt to a new environment whose characteristics allow and adaptation successfully to the changes they will survive and produce offspring with the same characteristics. The emergence of a new species by this process or other mechanisms is called speciation. 

A number of circumstances lead to the isolation of a group of individuals. For example, group of individuals could migrate across a river during a dry season and later when the water is higher they might be cut off from their native place or main population. This process is called divergent evolution. 

Biodiversity help to regulate the air, soil, and water purification and maintain their quality. Cycling of nutrients provides essential minerals for living beings. Examples are biogeochemical, nitrogen, sulphur and carbon cycles. Another natural process of decomposition is help to regulate the environment through breaks down the biodegradable matter into constituents. Biodiversity provides ecologic benefits also. For example, wetland provides variety of environmental services such as it’s a place for ground water storage and purifying toxins from soils and water. Rain forests act as a carbon sequestration. In addition biodiversity help for plant pollination. Insects, birds, bats and bees are important for much plant pollination. 

3. Threats to Biodiversity

3.1. Habitat loss and fragmentation of biodiversity

Biodiversity loss are caused by (i) habitat loss, fragmentation & degradation (ii) over exploitation (iii) pollution (iv) introduction of invasive species and (v) climate change

Habitat loss connected with direct destruction of habitats. Complete loss of the habitat means loss of the total occupying biodiversity in particular area. There are three types of habitat loss was identified (i) destruction (ii) fragmentation and (iii) degradation.

Fragmentation means breaking up a habitat ecosystem into smaller fragments or patches which have a smaller total area. Habitat fragmentation occurs when the size of natural habitat area is reduced or when that area is cut off and isolated by development activities. Fragmentation can damage the quality of habitat. For example some species require habitat into the forest interior and they can’t survive in the edge of forest or transitional zone because near the edge of forest ecosystem characteristics are similar into adjacent areas. This is called edge effect. New edge will occur when the forest area is clear by development activities. 

The subject of habitat fragmentation comes from island bio-geography. The Theory of Island Biogeography (Robert MacArthur and Edward Wilson) provides the relationship between area and the number of species (or species richness) which is described by the following equation.

S=CAz

 

S – Number of species in an island

A – Area of that island

C – Constant and will depend on both the taxon and the bio-geographic province

z – Fitted constant (with 0.15-0.35)

The basic principle of this theory is species diversity in an isolated area is balance with the loss of species through extinction and the arrival of new species through colonization (immigration). Briefly the S indicated here the rate of arrival of new species is equal to the rate of disappearance of species. 

An island is large and it located near the land it’s a place for large habitat diversity and support more species and greater chance to colonization and its give a path for low extinction. If an island is small and far away from the mainland it support for low species population and chance for low colonization and high extinction. 

3.2. Threats of extinction

In earth history life was being shape up by through extinction within a short geologically time. Several catastrophic episodes has influenced on species modification and extinction of disappear. For example dinosaurs became extinct 65 million years ago by a giant meteorite impact. Generally extinctions are caused by climatic change, volcanism or other catastrophic environmental changes. But human activities are become as a dominant factor for today’s extinction. 

An endangered species are the most vulnerable to extinction. Example includes the black rhino, Siberian tiger, giant panda, mountain gorilla and many others. A species show significant sign of decreases in population they will consider as endangered species. Example is the gray wolf and sea otter. Some species are more vulnerable and slow reproducers they will get more time to recovery from natural catastrophe or human exploitation. Some are require unique types of environment for their survival. Some species biologic and life style factors has influence on their living habitat. For example Panda lives only in specific places with certain conditions of environment. 

Illegal harvesting and over-exploitation of wild species for commercial allow to greatest threats to biodiversity. Animals and birds are hunting for their horns, feathers or any other various purposes. A rhinoceros or an elephant is hunt for their horns. Many exotic fish, birds and plants are transported illegally under poor conditions and they get die in that process. 

Introduction of exotic species is another major threat to biodiversity. Exotic species may flourish in the new environment and become as an invasive species. They take dominant place and wipe-out or force to migrated endemic species from their native place.

4. Conservation of biodiversity

Conservation biology is the applied science of maintaining the earth’s biological diversity. Susan Jacobson (1990) describes his structure of conservation biology in educational view. 

Fig: A Schematic view of the relationship between conservation biology and other disciplines (Jacobson 1990)

Conservation biodiversity requires mixture of approaches that include the concepts of conservation. The basic principle of biodiversity conservation depends on management of ecosystem. Managing ecosystem include protected area network, managing cultivated and built ecosystems and restoring the degraded ecosystems. There is important to ensure the habitat of species living without threatened. Providing resources (water, physical environment, supplying foods, etc……), control of predators, grazers, competitors and parasites which are cause threats to endangered species. 

Another technique is development of the zoos, aquaria and botanical gardens which are conserve the species through ex-situ conservation. The management of farms, forests, grasslands and wetlands also include the framework of biodiversity conservation. 

Another possible approach is tried to assign a value on ecosystem services – fresh water, clean air, recreational benefits and so on. First step for this process has to be valuing natural capital. Pavan Sukhdev, lead author of the 2010 The Economics of Ecosystems & Biodiversity (TEEB) report is saying ‘you cannot manage what you do not measure’. This is proposing with the value of changes of ecosystem service flows. The safeguarding ways is ‘designing payments for ecosystem services’ and going with the communities and land owners who need to be pay considered to keep wetlands and forests intact. In Mexico deforestation has been halved by 2003 law that allowed paying water charges by land owners and willing to reduce the agricultural clearances.

In other countries design ‘biodiversity credits’ that offer a rewarding to people that those who willing to have desire to protect and manage biodiversity habitats. In New South Wales, the state government department has setup a ‘Bio Banking’ scheme for developers and land owners those can trade biodiversity offsets.

Protecting natural ecosystems can enhance the value for money in direct sense (E.g. Protected areas….). But this approach is depending on effective way of implementation. Force of law is the practical work to adapt these strategies. The Convention on Biological Diversity, Convention on Climate change adapted a strategic plan for the decade to 2020 is ‘Living in harmony with nature’. The plan directs by governments and takes actions to restore biodiversity and ecosystem services through protected areas, habitat restoration, species recovery programs and other targeted conservation interventions’.

References:

1. Barbara murck (2005); Environmental Science – A self-Teaching guide; John wiley & sons; Inc; USA

2. Mark Lynas (2012); The God species – How Humans Really can save the planet……; Fourth Estate; London

3. http://www.algebralab.org/practice/practice.aspx?file=Reading_IslandBiogeography.xml
4. http://www.geolounge.com/island-biogeography/