The environment can be broken down into some basic units: biomes, ecosystems and habitats. A biome is like a city. An ecosystem is like a community in a city. There are many ecosystems in a biome. A habitat is like a home of the plant and animal species that live there. There are many homes in an ecosystem. Every ecosystem contains a number of different habitats. The existence of these basic units depends upon the biodiversity.
Biodiversity or biological diversity (E.O. Wilson in 1985) is the variety and variations of all species on earth. It is the different plants, animals and micro-organisms, their genes and the terrestrial, marine and freshwater ecosystems of which they are a part. It helps to describe the connections between species and is essential in maintaining and balancing the environment we rely on to live. It measures health of biological systems and to see if there is a danger that too many species become extinct. Climate change affects the habitats and behaviour of many different species. Many will not be able to adapt fast enough and may become extinct.
Levels of Biodiversity:
There are three levels of biodiversity namely: Species diversity, Genetic diversity and Ecosystem diversity.
1. Species Diversity (Taxonomic Diversity):
Species diversity refers to the variety of different types of living things, such as bacteria, fungi, insects, mammals, plants, etc., on Earth. The different plants, animals and other forms of life interact with each other.
A species can be defined as a group or population of similar organisms that reproduce by interbreeding within the group. Members of a species do not normally reproduce with members of any other species. Right now, more than 1.7 million species have been discovered and named. Different species have different roles to play.
Many species of plants and animals depend on one another. For example, some plants can only be pollinated by a certain kind of bird or insect. In relationships like these, if one species becomes extinct, the other species could too. The complex relationships between species are often disturbed when organisms are transported to new places or a new element is introduced (e.g., chemicals from pesticides). Human beings, for example, belong in a single species (Homo sapiens). Although there are different populations of humans, with different characteristics in different parts of the Earth, they can all successfully interbreed with each other.
2. Genetic Diversity (Morphological Diversity):
Genetic diversity describes the variation in the number and types of genes as well as chromosomes present in different species. The magnitude of variation in genes of a species increases with increase in size and environmental parameters of the habitat. Genes of individuals of the same species are different from each other. The small genetic variation in individuals of the same species gives rise to the variations in colours or size. It arises by gene and chromosome mutation. Genetic diversity helps in speciation or evolution of new species and is useful in adaptation to changes in environmental conditions. It is important for agricultural productivity and development. It is essential for the survival of healthy populations in natural communities like groups of plants and animals, including people. It allows groups to adapt the changes in their environment (like an outbreak of disease or a change in the climate). A larger group has more genetic diversity because this group will be stronger and better able to adapt to change.
3. Ecosystem Diversity (Ecological Diversity):
Ecosystem diversity is a term that incorporates both habitat and community diversity. A habitat is the environment in which an organism or species lives and includes the physical characteristics (e.g. climate or the availability of suitable food and shelter) that make it especially well suited to meet the life cycle needs of that species. A community consists of populations of plants and animals that occupy an area and their environment and interactions with each other. An ecosystem is a unique combination of plants, animals and
microorganisms and their physical characteristics interacting as a functional unit. Inherent in ecosystem diversity are both biotic (living) and abiotic (non-living) components, which makes it different from both genetic and species diversity.
Ecosystem diversity is the variation in the ecosystems found in a region or the variation in ecosystems over the whole planet. It includes the variation in both terrestrial and aquatic ecosystems. It can also take into account the variation in the complexity of a biological community, including the number of different niches, the number of trophic levels and other ecological processes. An example of ecological diversity on a global scale would be the variation in ecosystems, such as deserts, forests, grasslands, wetlands and oceans.
Ecological diversity is the largest scale of biodiversity and within each ecosystem, there is a great deal of both species and genetic diversity.
Bio-Geographic Zones of India (or Bio-Geographic Classification of India):
Biogeography is the study of the distribution of species, organisms and ecosystems in geographic space through geological time. Bio-geographic classification of India is the division of India according to bio- geographic characteristics (climate, soil and biodiversity). India has different climate and topography in different parts. Due to these variations there is variability in flora and fauna. India occupies 10th place among plant rich countries of the world. Bio-geographers classified India into ten bio-geographic zones: Trans- Himalayan zone, Himalayan zone, Desert zone, Semiarid zone, Western Ghat zone, Deccan plateau zone, Gangetic plain zone, North east zone, Coastal zone and Islands present near the shore line.
1. Trans-Himaylayan Zone:
The trans-Himalaya zone ranges immediately north of the Great Himalayan range and is an extension to the Tibetean plateau. This region harbours the high-altitude cold desert in ladakh (Jammu and Kashmir) and Lahaul Spiti (Himachal Pradesh). It covers 186200 square km area and accounts for 5.7% landmass of the country. Important flora and fauna in this region are pine, deodar, wild sheep, yak, Tibetan ass, snow leopard, marmot, wolf and black necked crane.
2. Himayalan Zone:
The Himalayan zone is the northern boundaries of India. The entire mountain chain is running from Kashmir in the North-west to Assam in the north-east. It comprises of a diverse range of biotic provinces and biomes and includes North-West, West Central and East Himalayas. The Himalayas consist of the youngest and loftiest mountain chains in the world. It covers 232900 square km area and accounts for 7.2% landmass of the country. Important flora and fauna in this region are pine, deodar, cork tree, sal, dhaak, castor, wild bear, samber, leopard, stag and musk deer.
3. Desert Zone:
The Desert zone is extremely dry area west of the Aravalli hill range comprises both the salty desert of Gujarat and the sandy desert of Rajasthan and includes Kutch, Thar and Laddakh. It covers 185000 square km area and occupies around 6.9% of the country's land mass. Important flora and fauna in this region are acacia, zizyphus, khejri, date palm, camel, bastard, wild ass, desert cat, fox and rat.
4. Semi-arid Zone:
The semi-arid zone lies between the desert and the Deccan plateau and its biotic province are presnt in Central India, Gujrat and Rajwara. It covers 508000 square km area and occupies approximately 15.6% of the country's landmass. This region is characterized by discontinuous vegetation cover with open areas of bare soil and soil-water deficit throughout the year. Important flora and fauna in this region are acacia, date palm, peepal, thorny scrubs, birds, jackals, leopards, eagles, snakes, fox, buffaloes and Gir lion.
5. Western Ghats Zone:
The Western Ghats zone is a mountain range that runs along the western cost of India. They are a range extending north-south from southern tip of Gujarat in the north to Kanyakumari in the south. It covers 159000 square km area and occupies approximately 5.8% of the country's landmass. The mountains along the west coast of peninsular India are the Western Ghats, which extend from the southern tip of the peninsula (8°N) northwards about 1600 km to the mouth of the river Tapti (21°N). The mountains rise to average altitudes
between 900 and 1500 m above sea level, intercepting monsoon winds from the southwest and creating a rain shadow in the region to their East. Important flora and fauna in this region are sheesham, peepal, tuna, bahera, tortoise, frog, lizards, snakes, areca nut and pepper.
6. Deccan Plateau Zone:
The Deccan plateau zone is a large triangular plateau south of the Narmada valley. Three sides of the plateau are covered by mountains slopes towards east. Its biotic province includes South- central plateau, Eastern plateau and Chhota Nagpur Central highlands. This is the largest unit of the Peninsular Plateau of India and is the one of largest zones covering the southern and south-central plateau with mostly deciduous trees.
Important flora and fauna in this region are acacia, palaash, tuna, pine, castor, samber, sloth beer, tiger, cheetal, four horned stag, wild elephant and wild buffaloes.
7. Gangetic Plain Zone:
The Gangetic plain covers the area between the south Himalayas to the tropic of cancer. Its biotic province includes upper and lower Gangetic plains. These planes were formed by the Ganges river system and are relatively homogeneous. This region experience 600 mm rainfall annually. Sunderbans forests are located in this region. It covers 359400 square km area and occupies approximately 11% landmass of the country.
Important flora and fauna in this region are sal, acacia, jamun (black berry) mango, bael, black chinkara, stag, rhinoceros, gazzel, alligator and turtle.
8. North-East Zone:
These are plains and non-Himalayan ranges of north-eastern India and have a wide variety of vegetation. Its biotic province is Brahamputra valley and North-Eastern Hills. It covers 171400 square km area and accounts for 5.2% landmass of the country. Important flora and fauna in this region are bamboos, sal, jack fruit, tuna chestnut, castor, rhinoceros, yak, deer and porcupine.
9. Coastal Zone:
The Coastal zone includes West and East coast. India has a large coastline distributed both to east and west with distinct differences between two. Indian coasts vary in their characteristics and structures. West coast is narrow except around the Gulf of Cambay and Gulf of Kutch. Backwaters are characteristic features of this coast. East coast plains, in contrast are broader due to depositional activities of the east-flowing rivers owing to the change in their base levels. It covers 13000 square km area. Important flora and fauna in this region are coconut, banana, cashew nut, dugong, dolphin, turtle, alligator and molluscs.Important flora and fauna in this region are rice, coconut trees, bamboos, Sal, jack fruit, tuna chestnut, castor, rhinoceros, yak, deer and porcupine.
The Islands includes Andaman, Nicobar and Lakshadweep Islands. The Islands in the Bay of Bengal has almost 300 big and small islands. Among these, only five islands are inhabited. Only tribes are found in the island of Nicobar. These islands have a highly diverse set of biomes. The two groups of islands, i.e., the Arabian Sea islands and Bay Islands differ significantly in origin and physical characteristics. It covers 8507 square km area and accounts for 0.03% biomass of the country. Important flora and fauna in this region are bahera, harak, jack fruit, cardamom, coconut, cloves, dolphin, turtle, alligator and molluscs.
Biodiversity Pattern and Global Biodiversity Hotspots:
(A) Biodiversity Pattern:
Ecologists studied biodiversity in the environment and they observed a regular pattern in which diversity was distributed over the entire area of the planet. This is the well defined and well- known pattern of biodiversity studies till date. According to this pattern, the species diversity follows a regular pattern as we move from the equator to the Polar Regions. Ecologists discovered two broad kinds of diversity patterns, namely: Latitudinal gradient and Species-area relationships.
(i) Latitudinal Gradient:
This is the most well-defined and well-known pattern of biodiversity studies till date. According to this pattern, the species diversity follows a regular pattern as we move from the equator to the Polar Regions. The plant and animal diversity observed to be maximum at the equator and generally it decreases as we move towards the poles.
We find species richness in plants and animals at the equator. India, located in the tropical regions, shows high species richness. However, the great Amazon rainforests show maximum biological diversity in terms of the number of species residing in that region. It is believed that in spite of being the region with the highest biodiversity, many species in Amazon are yet to be discovered and identified. The reason for this increased level of biodiversity at the tropics is thought by ecologists to be as follows:
Tropical areas have a more stable climate compared to that of the temperate areas. As a result, the tropics succeed in supporting a higher number of species as the species do not have to keep adapting to a changing season.
Temperate regions have suffered a lot of glaciations in the recent past as a result of which they have had a very unstable environment. Whereas, the tropics have been comparatively stable. Thus, speciation has been more favoured in the tropics compared to that of the temperate lands.
The tropical regions are comparatively more susceptible to solar energy. As a result, the plants in this region receive more energy during photosynthesis. This, in turn, transfers more energy to the successive tropic levels in the food chain. Thus, more energy supports more diversity.
(ii) Species-Area Relationships:
The great geographer and naturalist, Alexander von Humboldt (German) observed the relation between an area and the species richness found in it. He found that the plant and animal diversity increases with increase in explored area of observation up to a certain level. This relationship can be explained by the equation:
S = CAZ
Here C is a constant which depends on the unit used for area measurement, and equals the number of species that would exist if the habitat area was confined to one square unit. The graph looks like a straight line on log- log axes and can be linearized as:
log S = log C + Z log A
Where, S = richness of species, C = Y-intercept, Z = regression coefficient and A = Area. The value of Z is found to lie in the range of 0.1 to 0.2 for comparatively smaller area such as countries while for very large area such as entire continents, the slope of the line is much steeper with Z value lying from 0.6 to 1.2. The equation can be represented by the following diagram:
(B) Global Biodiversity Hotspots:
Hot spots are the areas with high density of biodiversity or mega diversity which are most threatened at present. The concept hotspot was suggested by a British ecologist, Norman Meyer (1988). He selected 25 hotspots. In 1990 Myers added a further some hotspots and now there are 35 hot spots in the world which is only 15.7% of the earth land surface. In India there are two hotspots namely North-East Himalayas and Western Ghats. The 86% of hotspots have been already destroyed. Conservation International adopted Myers’ hotspots as its institutional blueprint in 1989. The biodiversity hotspots hold especially high numbers of endemic species. The hot spots are determined considering following factors:
Total species (Species richness) Unique species (Degrees of endemism ) Number of species at risk (Threat of extinction) There are two specific criteria for hotspot diversity:
(i) It must contain a minimum of 1,500 species of vascular plants, equalling to more than 0.5% of the total plant species of the world as endemics. Vascular plants are a category of high plant that assures the circulation of nutrients such as water, mineral and photosynthetic product. They have vascular tissues that conduct the water and nutrients from bottom to top and end up in transpiration, absorption or conduction. In this way, vascular plants assure great productivity to the ecosystem.
(ii) It has to have lost at least 70 percent of its original habitat. The lost of species comes frequently from overconsumption and from the destruction of natural forest for agriculture. The isolated situation makes it very vulnerable, since there is no possibility of reproduction in case of extinction. Overall, the hotpots gather the most important population that faces extinction on the planet.
The world’s 35 biodiversity hotspots are given as:
World’s 35 Biodiversity Hotspots:
S. No. Continents Hotspots
1 Africa (Total 8) Cape Floristic Region, Coastal Forests of Eastern Africa, Eastern Afromontane, Guinean Forests of West Africa, Horn of Africa, Madagascar and the Indian Ocean Islands, Maputaland-Pondoland-Albany and Succulent Karoo
2 Asia-Pacific (Total 14)
East Melanesian Islands, Himalaya, Indo-Burma, Japan, Mountains of Southwest China, New Caledonia, New Zealand, Philippines, Polynesia-Micronesia, Southwest Australia, Forests of Eastern Australia (new), Sundaland, Wallacea and Western Ghats and Sri Lanka 3 Europe and Central
Asia (Total 04)
Caucasus, Irano-Anatolian, Mediterranean Basin and Mountains of Central Asia 4 North and Central
America (Total 04)
California Floristic Province, Caribbean Islands, Madrean Pine-Oak Woodlands and Mesoamerica
5 South America
Atlantic Forest, Cerrado, Chilean Winter Rainfall-Valdivian Forests, Tumbes-Chocó Magdalena and Tropical Andes
India as a Mega Bio-Diversity Nation:
India has different climate and topography in different parts and hence is termed as a mega diversity Nation.
Geological events in the landmass of India have provided conditions have high levels of biodiversity. There are about 93 major wetlands, coral reefs and mangroves. Indian forests cover 64.01 million hectares having a rich biodiversity of plants in the Trans-Himalayan, North-West, West, Central and Eastern Himalayan forests, Western Ghats, Coasts, Deserts, Gangetic plains, Deccan Plateau and the Adman, Nicobar and Lakshadweep islands. Among the biologically rich nations, India stands among the top 10 or 15 countries for its great variety of plants and animals, many of which are not found elsewhere. India has 350 different mammals (rated eight highest in the world), 1,200 species of birds (eighth in the world), and 453 species of reptiles (fifth in the world) and 45,000 plant species, of which most are angiosperms, (fifteenth in the world).
These include especially high species diversity of ferns (1022 species) and orchids (1082 species). India has 50,000 known species of insects, including 13,000 butterflies and moths. It is estimated that the number of unknown species could be several times higher. It is estimated that 18% of Indian plants are endemic to the
country and found nowhere else in the world. The eastern Himalayas from a humid region having high monsoon rain fall milder temperature and less snowfall. The mighty mountains with their snow-pick and extremely rich forest exert a tremendous influence on the flora and fauna of the region.
Endangered and Endemic Species of India:
(i) Endangered Species:
A plants, animals or microorganisms that are in immediate risk of biological extinction are called endangered species or threatened species. In India, 450 plant species, 100 mammals and 150 birds are estimated to be endangered. According to the Red Data List of International Union for Conservation of Nature (IUCN), there are 132 species of plants and animals in India listed as critically endangered (as of 5 September 2019). India's biodiversity is threatened mainly due to: Habitat destruction, Degradation and Over exploitation of resources.
Red Frog Sangai Gaur Indian lion Indian Cobra
Bengal Tiger Pelican Asiatic Lions Sapria Himalayana Indian Rhinoceros
Nilgiri tahr Bengal Fox Indian Elephant Asiatic Cheetah Markhor There are a large number of species of plants and animals that are endangered but might become extinct in the near future if not protected and their number has been reduced to a critical number. Unless it is protected and conserved, it is in immediate danger of extinction. Some of the rarest animals found in India are: Asiatic cheetah, Asiatic Lion, Asiatic Wild Ass, Bengal Fox, Gaur, Indian Elephant, Indian Rhinocerous, Marbled Cat, Markhor, etc.
Factors affecting Endangered Species:
Human beings dispose wastes indiscriminately in nature thereby polluting the air, land and water. These pollutants enter the food chain and accumulate in living creatures resulting in death.
Over-exploitation of natural resources and poaching of wild animals also leads to their extinction.
Climate change brought about by accumulation of green houses gases in the atmosphere. Climate change threatens organisms and ecosystems and they cannot adjust to the changing environmental conditions leading to their death and extinction.
(ii) Endemic Species:
Species that are found only in a particular region are known as endemic species. Almost 60% the endemic species in India are found in Himalayas and the Western Ghats. Endemic species are mainly concentrated in:
North-East India, North-West Himalayas, Western Ghats and Andaman and Nicobar Islands. Alpine, Acacia, Conifer, Rhododendron, Sapria Himalayana, Ovaria Lurida, Nepenthis khasiana, etc. are examples of endemic
flora (plants) species. Amigos, Indian rhinoceros, Black buck, Gibbon, Lion tailed macaque, Nilgiri langur, Brown palm civet, Nilgiri tahr, etc., are examples of endemic fauna (animals) species.
Factors Affecting Endemic Species:
Habitat loss and fragmentation due to draining and filling of inland wetlands.
Pollution also plays an important role.
Frog eggs, tadpoles and adults are extremely sensitive to pollutants especially pesticides.
Populations can be adversely affected by introduction of non active predators and competitors.
Disease producing organisms also play an important adversary in reducing populations of endemic species.
Threats to Biodiversity:
The human population requires resources to survive and grow and these resources are being removed unsustainably from the environment. The greatest proximate threats to biodiversity are habitat loss, poaching of wildlife, man wild life conflicts, biological invasion, overharvesting, climate change and introduction of exotic species.
(i) Habitat loss:
Habitat loss occurs when natural environments are transformed or modified to serve human needs. It is the most significant cause of biodiversity loss globally. Common types of habitat loss include cutting down forests for timber and opening up land for agriculture, draining wetlands to make way for new development projects, or damming rivers to make more water available for agriculture and cities. Habitat loss can also cause fragmentation, which occurs when parts of a habitat (the local environment in which an organism is usually found) become separated from one another because of changes in a landscape, such as the construction of roads. Fragmentation makes it difficult for species to move within a habitat, and poses a major challenge for species requiring large tracts of land such as the African forest elephants living in the Congo basin. Though some habitat loss is necessary to meet human needs, when natural habitats are changed or modified with little concern for biodiversity the results can be very negative.
(ii) Poaching of Wildlife:
Poaching is defined as hunting wild animals for food and entrepreneurial exploitation, including the bush meat trade for local and urban trade, trafficking (locally and cross-border) and trade in live animals and body parts.It is now usually done for sport or commercial profit, both in legal and black markets. Poaching can be a serious threat to many wild species, particularly those protected in wildlife preserves or national parks.
Many animal species have been limited in range or depleted in numbers, sometimes to the point of extinction, by the depredations of market hunters and unregulated sportsmen. Animal poaching is illegal, it is cruel, it puts entire species at risk and it is increasing.
Effects of Poaching:
One of the most dangerous and lasting effects of poaching is the decimation of native animal populations.
When a certain animal, such as the African elephant, is targeted by poachers, it can take decades for the animal's population to recover. This, in turn, affects the ecosystem to which the animal belongs. A reduction in predators like tigers, for example, may cause prey populations to grow out of hand, while a reduction in fruit- eating mammals may affect seed dispersal, altering the fauna of an ecosystem. Poaching does not only affect wildlife. Park rangers and game wardens are also victims of violence.
Plants are also susceptible to poaching. For example, even when forests are not completely cleared, particularly valuable trees such as rosewood or mahogany may be illegally logged from an area, eliminating both the tree species and all the animals that depend on it. Some species are illegally collected not to be killed but to be kept alive and sold as ornamental plants, and the survival of various carnivorous plants, cycads, cacti, and orchid species is threatened by collectors.
Some following species are currently at risk of going extinct because of animal poaching:
Pangolin, a small scaly anteater, is our planet’s most trafficked mammal. Its scales are prized in Asia so locals in Africa are tempted to steal them from the wild. Entire crime networks exist to transport pangolin (dead or alive) from the wilds to the market place in Asia.
The horns of Rhino, a large herbivore, are brutally removed and smuggled.
Africa's lion populations have also been affected by poaching. Since 1994, they have been reduced by 42 percent, and the species is now "vulnerable to extinction."
Many species of parrots are in danger because of the pet trade.
Many tropical fish collected illegally for aquaria.
Rhino horns Pangolin Coral reef fish (Tropical fish)
(iii) Man-Wildlife Conflict:
Growing human population, deforestation and loss of habitat are few major reasons behind man-wildlife conflict. Natural wildlife territory is overlaps with the human existence and various forms of man-wildlife conflict occur with various negative results. Conflict between people and animals is one of the main threats to the continued survival of many species in different parts of the world and is also a significant threat to local human populations. If solutions to conflicts are not adequate, local support for conservation also declines.
(iv) Biological Invasions:
When an animal, plant or microbe moves into a new area, it can affect the resident species in several different ways. New species can parasitize or predate upon residents, hybridize with them, compete with them for food, bring unfamiliar diseases, modify habitats, or disrupt important interactions. One famous and striking example of an invasive species is the brown tree snake in Guam. Native to Australia, the snake was accidentally transported to Guam in ship cargo following World War II. Because Guam had basically no predators to keep the snake population in check, it rapidly multiplied and caused the extirpation of most of the resident bird species. Extirpation means extinction within a region: the species survives elsewhere, but not in that region.
Overharvesting is a serious threat to many species, but particularly to aquatic species. Human population growth has increased the need for protein foods that are not being met from agriculture. There are many species that are threatened by the bush meat trade. The populations of some species have declined in response to harvesting, indicating that the harvest is not sustainable at those levels. The pet trade on some terrestrial species such as turtles, amphibians, birds, plants, etc, is also concerns about the threats to biodiversity. Harvesting of pangolins for their scales and meat and as curiosities, has led to a drastic decline in population size for this fascinating creature.
(vi) Climate Change:
Carbon dioxide released from burning fossil fuels and biomass, deforestation and agricultural practices contributes to greenhouse gases, which prevent heat from escaping the surface of earth. With the increase in temperature expected from increasing greenhouse gases, there will be higher levels of air pollution. It causes greater variability in weather patterns and changes in the distribution of vegetation in the landscape. Some species will not be able to adapt to these changes in the environment and will become extinct.
(vii) Introductions of Exotic Species:
Exotic species are typically introduced into ecosystems without their co-evolved predators and parasites, which enables an alien invader to out-compete native species with similar ecological requirements. In British Columbia, plants such as Knapweed, introduced to arid grasslands, and Purple Loosestrife, introduced to marsh and riparian areas, are rapidly becoming dominant plant species in their respective ecosystems. The interactions between native species are altered or destroyed by these exotic species and can result in the loss of native biodiversity.
Conservation of Biodiversity:
Conservation of biodiversity is protection, upliftment and scientific management of biodiversity. It is the proper management of the biosphere by human beings and gives maximum benefits for the present and future generations. Conservation of biodiversity has three basic objectives:
To maintain essential ecological processes and life supporting systems.
To preserve the diversity of species.
To make sustainable utilisation of species and ecosystems.
To conserve biodiversity some important following strategies should be undertaken:
All the possible varieties (old or new) of food forage and timber plants should be conserved.
All the economically important organisms in protected areas should be identified and conserved.
There should be sustainable utilisation of resources.
Care should be taken for the development of reserves and protected areas.
Efforts should be made to reduce the level of pollutants in the environment.
Public awareness should be created regarding biodiversity and its importance.
The habitats of migratory birds should be protected by bilateral and multilateral agreement.
The useful animals, plants and their wild relatives should be protected both in their natural habitat (in- situ) and in zoological botanical gardens (ex-situ).
Conservation Methods of Biodiversity:
There are two types of conservation methods: in-situ and ex-situ conservations.
1. In-situ Conservation (On Site Conservation):
The conservation of species in their natural habitat or natural ecosystem is known as in situ conservation. In the process, the natural surrounding or ecosystem is protected and maintained so that all the constituent species (known or unknown) are conserved and benefited. The protected areas are bio-geographical areas where biological diversity along with natural and cultural resources are protected, maintained and managed through legal and administrative measures. The factors which are detrimental to the existence of species concerned are eliminated by suitable mechanism.
The different advantages of in situ conservation are as follows:
• It is less expensive and easy to manage.
• It offers a way to preserve a large number of organisms simultaneously, known or unknown to us.
• It provides opportunity to adjust in different environmental conditions for a better life form.
• The flora and fauna live in natural habitats without human interference.
• The life cycles of the organisms and their evolution progresses in a natural way.
• It provides the required green cover and its associated benefits to our environment.
• The interests of the indigenous people are also protected.
The only disadvantage of in situ conservation is that it requires large space of earth which is often difficult because of growing demand for space. In situ conservation involves certain specific areas which include:
national parks, Wild-life Sanctuaries and Biosphere reserves.
(a) National Parks:
These are small reserves meant for protection of wild life and their natural habitats. These are maintained by government. The activities like grazing forestry, cultivation and habitat manipulation are not permitted in these areas. There are about 105 national parks in India. Some important national Parks of India are:
• Biological Park, Nandankanan, Orissa,
• Gangotri and Jim Corbett national Park Nainital, U.K. (First national Park)
• Kaziranga (Jorhat) and Oranga national Parks, Assam
• Nawgaon and Tudula national Parks, Maharashtra
• Hazaribagh national Park, Hazaribagh, Jharkhand
• Kanha, Madhav, Omkar and Bandhavgarh national parks, M.P.
• Bandipur national park, Karnataka
• Reibul Lamjao National Park, Manipur
• Periyar National Park, Kerala (Kerala ki Pari) (b) Wild-Life Sanctuaries:
These are the areas where only wild animals (fauna) are present. The activities like harvesting of timbers, collection of forest products, cultivation of lands etc. are permitted as long as these do not interfere with the project. The visiting of tourists in sanctuaries is permitted for recreation. In India, about 530 sanctuaries are present that is only 3.58% area of the total geographic area.
(c) Biosphere Reserves:
Biosphere reserves or Natural reserves are multipurpose protected areas with boundaries circumscribed by legislation. The main aim of biosphere reserve is to preserve genetic diversity in representative ecosystems by protecting wild animals, traditional life style of inhabitant and domesticated plant/ animal genetic resources.
These are scientifically managed allowing only the tourists to visit. Some importance of biosphere reserves is as follows:
• These help in the restoration of degraded ecosystem.
• To preserve genetic resources, species, ecosystems, and habitats without disturbing the habitants.
• These maintain cultural, social and ecologically sustainable economic developments.
• These support education and research in various ecological aspects.
Some important biosphere reserves in India are: Simlipal (Orissa), Sunderban (West Bengal), Kanha (M.P.), Kaziranga (Assam), etc.
2. Ex-situ Conservation (Off Site Conservation):
The conservation of selected plants and animals in selected areas outside their natural habitat is known as ex- situ conservation. It involves maintenance and breeding of endangered plants and animals under partially or wholly controlled conditions in specific areas like zoo, gardens, nurseries etc. The stresses on living organisms due to competition for food, water, space etc. can be avoided by ex-situ conservation there by providing conditions necessary for a secure life and breeding. Some important areas under this conservation are: Seed gene bank, Field gene bank, Botanical gardensand Zoos.
Ex-situ conservation has several purposes:
Rescue threatened germplasm.
Produce material for conservation biology research.
Bulk up germplasm for storage in various forms of ex situ facility.
Supply material for various purposes to remove or reduce pressure from wild collecting.
Grow those species with recalcitrant seeds that cannot be maintained in a seed store.
Make available material for conservation education and display.
Produce material for reintroduction, reinforcement, habitat restoration and management.
The strategies for ex-situ conservations are:
Identification of species to be conserved.
Adoption of Different ex-situ methods of conservation.
Long-term captive breeding and propagation for the species which have lost their habitats Short-term propagation and release of the animals in their natural habitat
Animal translocation Animal reintroduction
Advanced technology in the service of endangered species.
The different advantages of ex-situ conservation are:
It gives longer life time and breeding activity to animals.
Genetic techniques can be utilised in the process.
Captivity breed species can again be reintroduced in the wild.
Some disadvantages of this method are:
The favourable conditions may not be maintained always.
Mew life forms cannot evolve.
This technique involves only few species.
Ecosystem and Biodiversity Services:
1. Ecosystem Services:
Ecosystem services are defined as the benefits provided by ecosystems to humans. These services are many and varied benefits that humans freely gain from natural environment and from properly functioning ecosystems. Such ecosystems include, for example, agro, forest, grassland and aquatic ecosystems. The ecosystems functioning properly provide such things like agricultural produce, timber and aquatic organisms such as fishes and crabs. These services are integral to the provisioning of clean drinking water, the decomposition of wastes and the natural pollination of crops and other plants.
Honey bee on Avocado crop Social forestry in Andhra Pradesh Upland bog in Wales
Ecosystem services make human life possible by, for example, providing nutritious food and clean water, regulating disease and climate, supporting the pollination of crops, pest control and soil formation and providing recreational, cultural and spiritual benefits. To ensure the provision of essential ecosystem services, ecosystem functions need to be supported, sustained and the biodiversity protected.
2. Biodiversity Services:
Biodiversity is the most precious gift of nature mankind is blessed with. It is essential to ecosystems function and services delivery. Many key ecosystem services provided by biodiversity, such as nutrient cycling, carbon sequestration, pest regulation and pollination, sustain agricultural productivity. Changes in biodiversity can influence the supply of ecosystem services. Living elements which interact with each other and their non- living environments-provide benefits or services, to the world. Biodiversity, as with ecosystem services, must be protected and sustainably managed.
Biodiversity has a fundamental value to humans because we are so dependent on it for our cultural, economic and environmental well being. It provides benefits to human beings that support the existence of biological life and other benefits which are difficult to quantify. Some of the major services of biodiversity are as follows: Ecological, Economic, Social, Ethical, Aesthetic and Informational values.
(i) Ecological Values:
Ecological diversity is the intricate network of different species present in different ecosystems and the dynamic interaction between them. All living creatures are supported by the interactions among organisms and ecosystems. Loss of biodiversity makes ecosystems less stable, more vulnerable to extreme events and weakens its natural cycles like: Energy, Water, Carbon, Oxygen and Nitrogen cycles.
Energy Cycle: Plants and photosynthetic bacteria transform energy from the sun into stored chemical energy.
Water Cycle: Forests moderate water flows by catching, holding and recycling rainwater. Plants release absorbed rainwater into the air through the loss of water through their leaves (transpiration). Wetlands and estuaries purify water and control flooding
Carbon and Oxygen Cycles: Carbon dioxide in the atmosphere is generated by animal respiration, plant decay and the burning of fossil fuels.
Nitrogen Cycle: Nitrogen is needed by all living organisms, and it makes up a large component of Earth’s atmosphere. In its natural atmospheric form, nitrogen is not directly accessible to most organisms, so it needs to be converted, primarily by bacteria living on the roots of certain plants. Their daily activities help ecosystems functioning. In turn, these ecosystems support life. Healthy ecosystems are more stable and more adaptable to any change, such as extreme events like drought or floods which can alter entire ecosystems (ii) Economic Values:
Nature provides the raw materials we need for survival and forms the basis for the global economy.
Everything we buy and sell originates from the natural world. For economic growth of countries, many products are commercially sold in national and international market. For example: Textile, leather, silk, paper and pulp industry, etc. It is the source for many medicines such as aspirin, heart stimulants, antibiotics, anti- malarial and cancer fighting compounds. The economic potential of biodiversity is also immense in terms of food, fodder, ethical and social values. The salient features regarding the economical potential of biodiversity are given below:
The major fuel sources of the world including wood and fossil fuels have their origin due to biodiversity.
It is the source of food for all animals and humans.
Many important chemicals have their origin from the diverse flora and fauna, used in various industries.
Diverse group of animals are used for medical research during the testing of new drugs.
(iii) Social and Cultural Values:
The biodiversity in different parts of the world has been largely preserved by the traditional societies. Many plants and animals are considered holy and sacred in India and are worshipped like Tulsi, Banyan, peepal, cow, snake, etc. In Indian society great cultural value is given to forest and as such tiger, peacock and lotus are
named as the national animal, bird and flower respectively. Thus apart from the local use or sale of products of biodiversity there is the social aspect in which more and more resources are used by affluent societies.
(iv) Ethical Values:
These values are related to conservation of biodiversity where ethical issue of ‘all life forms must be preserved’ is laid down. There is an existence value which is attached to each species because biodiversity is valuable for the survival of human race. Moreover all species have a moral right to exist independent of our need for them.
(v) Aesthetic Values:
Natural landscapes at undisturbed places are a delight to watch and also provide opportunities for recreational activities like bird watching, photography, etc. It promotes eco-tourism which further generates revenue by designing of zoological, botanical gardens, national parks, wild life conservation, etc.
(vii) Informational Values:
Biodiversity holds potential insights for solutions to biological problems, both current and future. It holds the potential for applied knowledge through the discovery of how different species have adapted to their varied environments (Wilson 1992).We might discover bacteria that inhabit hot springs and have evolved enzymes that function at unusually high temperatures
Biodiversity has often served as an early-warning system that has foretold threats to human health before sufficient data had been collected to detect effects directly. Wildlife studies have shown evidence of effects of various chlorinated organic compounds on the immune systems of animals (reviewed in Repetto and Baliga 1995) and on their reproductive physiology (Colborn and others 1993).
Nature reserves may also be known as a natural reserves, wildlife refuge or sanctuaries, biosphere reserves, natural reserves or nature conservation area. These are areas selected to preserve and protect, in perpetuity, representative (typical) and special natural ecosystems, plant and animal species, features and natural processes. Scientific research and education are the primary uses of nature reserves and recreation is generally restricted. These are areas of land that is protected and managed for various ecological reasons. It could be designated to protect and preserve wildlife, flora, fauna, geological features or other special interest that plays a part in our ecosystem and Earth’s biodiversity. Habitats that have its flora and fauna near endangerment are of a particular concern. They are often protected and conserved in nature reserves to prevent them from extinction and also to provide study, research and nature appreciation opportunities.
The first nature (or ecological) reserves grew out of efforts associated with the International Biological Program (IBP), conducted in 58 countries from 1964 to 1974. These efforts aimed to identify and preserve ecosystems of the world for present and future biological research and education, for preservation of species, their genes and habitats and as benchmarks for comparison with ecosystems managed by humans (Peterson, 1974).In Nova Scotia, the IBP research team identified sixty-nine sites, consisting primarily of fragile, relatively undisturbed ecosystems such as relict old-growth forest, sand dunes, river floodplains, coastal islands, lakeshores, and estuaries. Final report called for ecological reserves legislation to be enacted by each province (IBP-CT, 1974).
In 1981, the province proclaimed the Special Places Protection Act, which provided for the designation of
"ecological sites". The Special Places Program was assigned to the Department of Education (Nova Scotia Museum), and over the period 1981-1994, additional sites of ecological significance were identified and seven ecological sites (known as "nature reserves") were designated under the Act, including two on private lands, with landowner permission.
Nature is in our hand to nurse
Nature reserves of habitat of Singapore
In 1994, responsibility for protected areas, including nature reserves, was transferred to the Department of Natural Resources (DNR). Work continued towards the identification of new sites of ecological significance and the designation of additional nature reserves, and in 1998, responsibility for protected areas moved to the Department of the Environment.
Nature reserves differ from a national park usually in being smaller and having as its sole purpose the protection of nature. They protect very specific habitats and form a representative network of the richness of the territory. These are created by the State and under its responsibility. Since 2002 the regions have the possibility of creating regional reserves. The national and regional nature reserves form the network Nature Reserves of France.
Nature reserves in Cameroon Tiger reserve in India
Nature Reserves are protected under the Special Places Protection Act. Many countries have adopted the International Union for the Conservation of Nature (IUCN) system of categorization to classify their protected area in accordance to their management objectives. The different categories consist of:
Strict Nature Reserve Wilderness Area National Park
Natural Monument of Feature Habitat/Species Management Area Protected Landscape/Seascape
Protected Area with sustainable use of natural resources
The objectives of nature reserves conservation are enumerated by law:
Protection of animal and plant species and habitats in danger of disappearing Protection of remarkable habitats (biological or geological)
Protection or creation of stages on the great migration routes of wildlife
Realization of scientific or technical studies that are indispensable for development of human knowledge Nature reserves are established to:
Provide areas suitable for scientific research and education
Protect representative examples of natural ecosystems
Provide examples of ecosystems that have been modified by humans and offer an opportunity to study the natural recovery of ecosystems from modification
Protect rare or endangered native plants or animals in their natural habitats
Provide educational or research field areas for the long-term study of natural changes and balancing forces in undisturbed ecosystems
Human Population Growth:
A population is defined as a group of individuals belonging to the same species, which live in a particular geographical area at a given time and have the capability of interbreeding. All individuals within a certain population usually have a common, binding characteristic. Population growth is the increase in the number of people living in a particular area. Global human population growth is around 75 million per year or 1.1% per year. The global population has grown from 1 billion in 1800 to 7 billion in 2012. Out of which 93 % is growing in developing countries. Reasons for population growth are:
• Spread of public health programmes in developing countries.
• Rise in food production after World War II.
• Every second 4-5 children are born and 2 people die.
• Nearly 2.5 persons get added every second.
The last 100 years have seen a massive fourfold increase in the population, due to medical advances, lower mortality rates, and an increase in agricultural productivity made possible by the Green Revolution. The rapid growth of the global population results from the difference between the rate of birth and death. Population growth shows the dramatic increase in global population in the past 160 years. It will continue till equilibrium is achieved (no. of births = no. of death). Year wise global population growth trends in billions are given as:
Years Population (in billions) Years Population (in billions) Years Population (in billions)
1700 0.6 1960 3 2050 9.1
1850 1 1987 5
1930 2 2000 6.1
The projected population for first 10 largest countries for 2050 is:
(In Millions) S.
1 India 1628 6 Pakistan 285
2 China 1369 7 Brazil 244
3 United States 404 8 Bangladesh 211
4 Indonesia 312 9 Ethiopia 188
5 Nigeria 304 10 Congo 182
Human population growth can be explained by following geographic terms:
(i) Population Density:
It is a measurement of population per unit area or unit volume and is a quantity of type number density. It is frequently applied to living organisms and particularly to humans. It is a key geographic term.
(ii) Carrying Capacity:
Carrying capacity is maximum population size that can be supported by environment. It can be increased by:
• Clever use of science and technology
• Limit to max population size in given space and resource base.
Population has been able to maintain Exponential Growth during past 100 years.
(iii) Exponential and Logistical Population Growth:
When resources are unlimited, populations exhibit exponential growth, resulting in a J-shaped curve.
When resources are limited, populations exhibit logistic growth. In logistic growth, population expansion decreases as resources become scarce, levelling off when the carrying capacity of the environment is reached, resulting in an S-shaped curve. Human population growth rate is measured as annual average growth rate, as:
Average annual growth rate %
Where, P1 and P2 are population sizes in previous and present Census, respectively. N = No of years between two Census.
In 1980, the population in Lane County was 250,000. This grew to 280,000 in 1990. What is the annual percentage growth rate (PR) for Lane County?
, = 1.2 %
The population of Lane County grew 12 percent between 1980 and 1990 or at a rate of 1.2 percent annually.
Factors affecting Population Growth Rate:
Population growth rate depends on several factors:
1. Rate of Birth (Fertility):
(a) Birth Rate:
It is the number of babies produced per 1000 individuals.
(b) Total Fertility Rate:
It is the average number of children that would be born to women in her lifetime.
(c) Replacement Level:
It is the number of children a couple must produce to replace them. It is always higher than two, since some children die before reaching reproductive age.
2. Mortality Rate:
Mortality is death rate per thousand individuals. Mortality rate is decreasing because of industrial revolution, improved personal hygiene, modern medicines, etc.
It is the movement of individuals into or out of place/country (within country).
4. Age and Sex Structure:
Exponential growth Logistic growth Population Growth Rate
Age structure is proportion of individuals of different ages within that population is. Proportion of active males and females in a population influence the population growth.
Impact of Human Population Growth:
(i) Impact of on the Environment:
The rapid increase of human population putting an incredible strain on our environment.
Developed countries continue to pollute the environment and deplete its resources while developing countries are under increasing pressure to compete economically and their industrial advancements are damaging as well.
One of the largest environmental effects of human population growth is the problem of global warming which will lead to rising sea levels and extreme weather conditions in the future. Many non-renewable resources are being depleted due to the unrestrained use of fuel and energy. Many parts of the world also suffer from a shortage of food and water.
huge population pressurizes and degrades the environment physically, chemically and biologically.
The environment on earth is suffering from the growth of global population. The depletion of resources and biodiversity, the production of waste and the destroying of natural habitat are serious problems that must be addressed in order to ensure that life on earth will be sustainable throughout the next century. Effects of human population growth on our environment results:
Generation of Waste:
Due to the destructive activities of humans, wastes are dumping into the environment which causes degradation and the capacity of environment to absorb more waste is reduced. Further, waste leads to air and water pollution.
Threat to Biodiversity:
Due to his destructive activities, man has extracted more and more minerals from the earth. Animals have been hunted and plants have disappeared. There has been loss of biodiversity. These have led to ecological imbalance.
Strain on Forests:
is proportion of individuals of different ages within that population is. Proportion of active males and females in a population influence the population growth.
human population is putting an incredible strain on our environment.
Developed countries continue to pollute the environment and deplete its resources while developing countries are under increasing e economically and their industrial advancements are damaging as well.
One of the largest environmental effects of human population growth is the problem of global warming which will lead to rising sea levels and extreme weather conditions in the renewable resources are being depleted due to the unrestrained use of fuel and energy. Many parts of the world also suffer from a shortage of food and water. The huge population pressurizes and degrades the environment physically, chemically and
The environment on earth is suffering from the growth of global population. The depletion of resources and biodiversity, the production of waste and the destroying of natural habitat are serious problems that must be e that life on earth will be sustainable throughout the next century. Effects of on our environment results:
Due to the destructive activities of humans, wastes are dumping into the environment which causes adation and the capacity of environment to absorb more waste is reduced. Further, waste leads to air and
Due to his destructive activities, man has extracted more and more minerals from the earth. Animals have hunted and plants have disappeared. There has been loss of biodiversity. These have led to ecological
is proportion of individuals of different ages within that population is. Proportion of active
The environment on earth is suffering from the growth of global population. The depletion of resources and biodiversity, the production of waste and the destroying of natural habitat are serious problems that must be e that life on earth will be sustainable throughout the next century. Effects of
Due to the destructive activities of humans, wastes are dumping into the environment which causes adation and the capacity of environment to absorb more waste is reduced. Further, waste leads to air and
Due to his destructive activities, man has extracted more and more minerals from the earth. Animals have hunted and plants have disappeared. There has been loss of biodiversity. These have led to ecological
Man has established new housing colonies. National highways and hydropower projects have been built and orests have been wiped out. These destructive activities have increased and led to ecological imbalance.
Rapid growth of population has led to urbanization which has adversely affected environment. Due to population pressure, natural resources in the cities are depleted at a fast rate due to population pressure.
Population does not have proper sanitation facilities and pure drinking water. As a result, the health of the people is adversely affected.
Underdeveloped countries are following the policy of heavy industrialization which is causing environmental degradation. The establishment of such industries as fertilizers, iron and steel, chemicals and refineries has led to land, air and water pollution.
Intensive farming and excessive use of fertilizers and pesticides have led to over-exploitation of land and water resources. These have led to land degradation in the form of soil erosion, water logging and salination.
Environmental degradation is also due to transport development in the different parts of the world. The automobiles release huge quantities of poisonous gases such as carbon monoxide, nitrogen oxides and hydrocarbons.
Climatic changes are irregular due to green house gases. The thin skin of air that surrounds the planet is being affected by human activities. Urban people are still being exposed to unaccepted levels of toxic pollutants.
Further, forests are still being degraded by acid deposition generated by faraway industries and greenhouse gases continue to accumulate in the atmosphere.
Environmental degradation not only harms health but also reduces economic productivity. Dirty water, inadequate sanitation, air pollution and land degradation which cause serious diseases on an enormous scale in developing countries like India. These, in turn, reduce the productivity levels in the country. Soil and hazardous wastes have polluted ground water resources which cannot be used for agricultural and industrial production. Soil degradation leading to soil erosion, drought, etc. have led to siltation of reservoirs and blocking of river and canal transport channels. Deforestation has led to soil erosion and consequent loss of sustainable logging potential.
Presently, environmental pollution is caused by old technology which releases gases and pollutants causing chemical and industrial pressure on environment.
Carbon footprint is the amount of greenhouse gases (GHGs), primarily carbon dioxide, released into the atmosphere as a result of direct or indirect activities of the humans. It is the term used to explain the impact of greenhouse gases (GHGs) released in the atmosphere. These GHGs are responsible for the global warming which further leads to the climate change. The primary GHGs in the atmosphere of earth are carbon dioxide (CO2), water vapour (H2O), methane (CH4), nitrous oxide (N2O), ozone (O3) and chlorofluorocarbons. Of these six GHGs, CO2 is the dominant one released into the atmosphere by power stations, vehicle emissions, fuel burning at homes, etc.
A carbon footprint can be a broad measure or be applied to the actions of an individual, a family, an event, an organization or even an entire nation. It is the sum of all emissions of CO2, which were induced by your activities in a given time frame. Usually a carbon footprint is calculated for the time period of a year. When you drive a car, the engine burns fuel which creates a certain amount of CO2, depending on its fuel consumption and the driving distance. Heating houses with oil, gas or coal, then you also generate CO2. Even if you heat your house with electricity, the generation of the electrical power may also have emitted a certain amount of CO2. The production of the food and goods also emit some quantities of CO2.
Types of Carbon Footprint:
The main types of carbon footprint for organizations are:
(i) Organizational Carbon Footprint:
Emissions from all the activities across an organization, including buildings' energy use, industrial processes and company vehicles.
(ii) Value ChainCarbon Footprint:
It includes emissions that are outside an own operations of organization (also known as Scope 3 emissions).
This represents emissions from both suppliers and consumers, including all use and end of life emissions.
(iii) Product Carbon Footprint:
These are the emissions over the whole life of a product or service, from the extraction of raw materials and manufacturing right through to its use and final reuse, recycling or disposal.
(iv) Supply Chain Carbon Footprint:
These are the emissions from the raw materials and services that are purchased by an organisation in order to deliver its services and products.
Methods of Reducing Carbon Footprint:
Methods of reducing your carbon footprint include:
Driving more-efficient vehicles (or making sure that your current vehicles are properly maintained)
Taking public transportation
Using energy-efficient appliances, insulating your home to reduce heating and air conditioning costs Consuming food that doesn't require as much transportation
Eating less meat, which has a higher carbon footprint than fruits and vegetables
Individuals and companies can also offset some of their CO2 emissions by purchasing carbon credits, the money from which can go into projects such as planting trees or investing in renewable energy.
Methods of Calculating Carbon Footprint:
When calculating a carbon footprint, a lot of factors are taken into consideration. For example, driving to the grocery store burns a certain amount of fuel and fossil fuels are the primary sources of greenhouses gases. But that grocery store is powered by electricity and its employees probably drove to work, so the store has its own carbon footprint. In addition, the products that the store sells were all shipped there, so that must also be factored into the total carbon footprint. Beyond that, the fruits, vegetables, and meats that the store sells were all grown or raised on farms, a process that produces methane, which has a greenhouse effect 25 times
India's Challenges over Carbon Foot Print