Threats to Biodiversity and Conservation of Biodiversity

Threats to Biodiversity: Habitat loss is mainly due to human population growth, industrialization and changes in the land use patterns, poaching of wild life and man wildlife conflicts. Man has begin to overuse or misuse most of these natural ecosystems. Due to unsustainable resource-use, once productive forests and grasslands have been turned into deserts and wastelands have increased all over world. Scientists have estimated that human activities are likely to eliminate approximately 10 million species by the year 2050.

1) Human population growth, industrialization and changes in the land use patterns: Around 1.

8 million species of plants and animals are known to science. The actual number of species have been existing is >10x1.8millions. Though new species have been continually identified, the rate of extinction is very high (10-20,000 species per year i.e., 1000 to 10,000 times faster rate). Human actions are expected to exterminate 25% of world’s species in next 20-30 years. The mega extinction spasm is related to human population growth, industrialization and changes in the land use patterns in India.

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The reasons are:

i Forests and grasslands are changed to agricultural land. Encroachments are being repeatedly legalized. ii Natural wetlands are drained to establish crop lands leading to loss of aquatic species. iii Mangroves have been cleared for fuel wood and prawn farming, which has led to decrease in the habitat essential for breeding of marine fish. iv Grasslands are changed to other forms, degraded by overgrazing. Loss to cattle, goat and sheep.

v Natural forests are being deforested for timber and replanted for teak, sal etc.

Such monoculture does not support biodiversity as in forests which has closed canopy and rich undergrowth. Excess collection of fire wood by lopping of branches of trees canopy is opened up altering the local biodiversity.

vi Foraging cattle retard regeneration of forest as young seedlings are trampled. vii Ever increasing population gradually decrease buffer zones and forested areas. A prime example is Gir national park, the last bastion of Asiatic lion with a meter gauge railway line, state expressway and 3 temples.

viii Repeated fires by local grazers to increase growth of grass ultimately reduce regeneration of grasses. ix Introductions of exotic weeds eg. lantana bushes, Eupatorium shrubs and ‘congress’ grass are invading at the expense of indigenous undergrowth species. Following traditional farming techniques like slash and burn in Himalayas, and rab, lopping of tree branches for making wood ash fertilizer in Western ghats are now leading to loss of biodiversity.

x Over harvesting of fish by large trawling boats is leading to depletion of fish stocks. Marine turtles caught in the net are massacred of the coast of Orissa. The rare whale shark, a highly endangered species, is being killed off the coast of Gujarat. 2) Poaching: Specific threats to certain animals are related to large economic benefits. The skin and bones from tigers, ivory from elephants, horns from rhinos and perfume from the musk deer are extensively used abroad. Bears are killed for their gall bladders. Corals and shells are also collected for export or sold on the beaches of Chennai, Kanyakumari and the Andaman and Nicobar islands. Tortoises, exotic birds and other small animals are packed into tiny containers and smuggled abroad for the pet trade. A variety of wild plants with real or sometimes, dubious medicinal values are being overharvested. The commonly collected plants include Rauwolfia, Nux vomica, Datura, etc. The garden plants collected for illegal trade include orchids, ferns and mosses.

3) Man wild life conflicts: Conflicting situations with wild life starts causing immense damage and danger to man. Ex: In Sambalpur, Orissa 195 humans are killed in last 5 years by elephants and in retaliation villagers killed 98 elephants and badly injured more than 30 elephants. Similarly incidents with tigers, leopards etc. are in news.Shrinking forest cover, human encroachment, ill and weak animals, lack of food (one adult elephant needs 200 kg green fodder and 150 kg of clean water) for animals, protecting villagers by putting electric fence are the main reasons for such happenings. As the compensation by government. is not enough, conflicts occur between forest department and villagers. Endangered & endemic species in India

Several species of plants and animals have been endangered due to human activities. The Species whose existence is in danger by human activities are called Man-wild life harmony

Man- wild life conflicts endangered species. These endangered species have been categorized into four viz, 1) Vulnerable 2) Rare 3) Intermediate 4) Threatened. Endangered species which are on verge of extinction are called threatened species. Most of the endangered species are found today only in protected areas (PAs). Some eg of the species being Tiger, rhino, elephant; bird species include Siberian crane, great Indian bustard, Florican, vultures; reptiles and amphibians. Habitat loss caused by human activity is causing threat to plants species like orchids. Over harvesting as ingredients in medical products or cosmotics is also threatening species. To protect endangered species India has created a wildlife protection act. Under this plants and animals are characterized according to thereat to their survival.

The species which are unique to a locality/region are called endemic species. Some species are found only in India and are thus endemic (restricted to our country). Some have very localized distribution and are considered highly endemic. Some species of this category being Indian wild ass, angular kashmiri stag, golden langur, pigmyhog. Conservation of biodiversity: is of two types i.e., In situ and Ex situ In situ conservation: Conserving a species in its own environment by creating national parks and wildlife sanctuaries.

Habit is protected with all the other spp that in it in nature Biodiversity at all levels can be best preserved in situ by setting aside wildness as protected areas (in national parks and wildlife sanctuaries) with distinctive ecosystem included in the network. Such net work preserve the total diversity of life of the region. Biologists view point is to deal with areas which are 1) Species rich 2) Rare /threatened/endangered species / endemic species are found should be given imp as there spp would easily become extinct due to human activity. For eg. Elephants utilize open grasslands after the rains (when it is nutritious) but move into forest to feed on foliage in dry season. Hence a PA for elephant must be large to include a diverse habitat that supports a complete complement of interlinked species.

India has 589 PAs of which 89 are national parks and 500 are wildlife sanctuaries. Over 100 PAs are created in Andaman and Nicobar to preserve the special island ecosystem. The great Himalayan national park is the largest sanctuaries in the ecosystem and is the home of snow leopard. Dachigam sanctuary for hangul or kashmiri stag; Kaziranga national park for animals like elephant, guar, wild boar and swamp deer, and birds like ducks geese, pelicans and storks; Manas sanctuary forGolden langur, pigmy hog and wild boar are some of the examples worth mentioning under in situ conservation. Ex situ conservation: Conserving the species outside the natural habitat in a carefully controlled situation, such as botanical garden for plants or zoological parks for animals, expertise exists to multiply species under artificially managed condition. Gemplasm is preserved in a gene bank for future need, this is taken up for expensive endangered /extinct species. Care is taken to avoid inbreeding such that weak offspring would not develop. Breeding programmes in zoos provide animal needs including enclosures that simulate their wild habitat. Modern zoo’s function is to breed endangered species as a conservation. Successful examples are

1. Madras crocodile trust bank has successfully bred the 3 crocodiles. Here crocodiles lay two clutches of eggs in one year year instead of one in wild . 2. Guchali zoo has bred pigmy hog 3. Delhi zoo has bred the rare Manipur brow antlered deer.

The successful breeding programme also to aims at reintroduction of the species into wild habitat, with simultaneous removal of problems like poaching disturbances and man made influences.

Conservation of cultivars and livestock breeds: Fifty years ago nearly 30,000 rice var. were grown in India now only a few of these are cultivated. The new varieties being developed use the germplasm of these original types. But if all these traditional types vanish, it would be difficult to develop new disease resistant varieties for future. Use of varieties from gene banks have been expensive and risky. Farmers need to be encouraged to grow traditional varieties. This is a concern for future of mankind. Gene banks have at present 34,000 creeds and 2200 pulses). Traditional breeds/ varieties have to be encouraged for genetic variability. In contrast men interested in cash returns in short time wouldn’t appreciate the benefits of growing indigenous varieties.

Biological Diversity act 2002: Biological diversity is a national asset of a country, hence the conservation of biodiversity assumes greater significance. The first attempt to bring the biodiversity into the legal frame work was made by way of the biodiversity bill 2000 which was passed by the Lok sabha on 2nd December 2002 and by Rajya Sabha on the December 2002. Objectives of the act:

1. To conserve the Biological Diversity 2. Sustainable use of the components of biodiversity 3. Fair and equitable sharing of benefits arising out of the use of the B.D A national biodiversity authority has been established by the Biodiversity Act 2002 to regulate act implementing rules 2004 has been operationalised since coming in to force. Act: Regulating access well as pushing the officially sponsored documentation of biological resources and traditional practices through people’s diversity registers at the local and data bases at the national levels, respectively. It further probes the extent to which the principles of conservation have realized.

Threats to biodiversity hotspots

Referring to examples, discuss the threats to biodiversity hotspots and why these threats could prove critical (15 marks) Biodiversity hotspots are areas in the natural environment that contain some of the biggest concentration of flora and fauna in the world, often containing many rare and endangered species. However many of these ecosystems are threatened by the likes of climate change, increased urbanisation/land use and tourism developments which can prove critical for the wellbeing of their environment.

One area that has witnessed degradation in recent years is Galapagos which is an example of a biodiversity hotspot that is threatened by alien species. This island off the coast of Ecuador is home to a huge range of these ‘alien species’ with up to 60% of the 180 endemic plants in Galapagos now considered under threat. There has been 490 introduced insect species on the island, and 43 species of other invertebrates – of these, 55 are high risk with the potential to cause severe damage to native biodiversity. New vertebrate species arrive every year and aggressive invasive species such as mainland snake predators could soon establish themselves in Galapagos.

The new alien species destroy the natural landscape of the environment, eating food that is only for the animals living within the ecosystem. This threatens biodiversity and could prove critical as the environment is being destroyed and species may also become extinct as a result of alien species. However, actions have been taken to preserve the unique biodiversity of the area, these include: eradicating rodents and feral cats and removing the quinine tree, which is one of the most serious alien plant invaders.

The Arctic is an example of a biodiversity hotspot under threat by global warming. The tundra, with its rare arctic plant ecosystem, will shrink as rising sea levels are drowning coastal areas. Increased forest fires and insect infestations are expected to destroy coniferous forests and therefore reduce both the biomass and the biodiversity. Global warming will also result in warmer sea temperatures, thus having negative implications on the sea life; the number of marine fish species will decline and reduce fish stocks as a result. Fragile food webs could become easily damaged leading to a loss of tundra mosses that provide food for animals such as reindeer.

Declining deer numbers will affect species that hunt for them, such as wolves and so this will lead to a domino effect, resulting in a decline of species within the food chain. Climate change can prove critical as what the Arctic is facing will also affect ecosystems much further south as many migrant bird species depend on summer feeding and breeding grounds in the Arctic. In the future, migrant birds will have to fly further north and spend more time searching for suitable feeding areas – therefore the threats to biodiversity hotspots are also effecting other nearby ecosystems.

Deforestation is also a highly critical threat to ecosystems as the clearance of forests results in the loss of biodiversity and resources for the indigenous populations. It will also have a negative knock-on effect on the food chain, as aforementioned. However there are also wider environmental impacts as the removal of forest cover leads to increased soil erosion which in turn increases the negative effects flooding.

Over exploitation of the environment puts bio diverse areas under threat such as overfishing in the North Sea, for example, unbalances food webs, which in turn, can lead to species become extinct. However the impacts can be reduced with relatively simple solutions such as creating hedgerows, ponds and shelter belts. Tourism can also be seen a threat and damaging ecosystems for example, trampling, increased urbanisation and pollution will threaten local ecosystems and could potentially prove critical in the long run. However because tourism often contributes highly towards the growth of the local economy (some even rely on it) it is difficult to use some of these solutions if they impair tourist activities or are visually polluting etc. Because tourism supports the local economy, such as providing more job opportunities for people in that area and preserving cultural heritage it is difficult to choose between maintaining an areas biodiversity and helping the locals to thrive.

Mangrove ecosystems are critical for marine and freshwater biodiversity, enabling fish, shrimp larvae and crabs to grow and produce. Shrimp farming in Thailand poses a large threat to mangroves, although it has been practiced in Thailand for over 60 years, between the 70’s and 90’s, the coastal shrimp aquaculture industry has expanded dramatically due to the encouragement of the Thai government in an effort to boost the economy. One of the impacts of shrimp farming is the discharge of waste into mangroves, which has harmful effects on the vegetation. Depletion of biodiversity in shrimp farms and their surrounding areas could also prove critical as combined with other threats such as over-harvesting, the number of mangroves could rapidly decrease.

The destruction of mangroves means the benefits of them cannot be used for example they cannot effectively act as a buffer, which would normally lessen the danger of hazards such as hurricanes and cyclones. It is questionable whether the typhoon in 2001’s devastating effects could have been lessened if mangroves were better intact. A knock on effect of this is the coastline will erode quicker due to having no barrier, the wearing away of the land and taking of sediments/rocks along with means houses are vulnerable to these kinds of hazards and could potentially have to re-locate.

In conclusion humans are having a constant and critical effect on biodiversity hotspots. However it can be argued that some are less critical and more easily manageable than others. For example global warming threats to the Arctic are harder to control for than using zoning strategies in Thailand.