In the previous two posts in this Biodiversity, we have learned about the Meaning of Biodiversity, its types, pattern and importance. Next, we also got an introduction to Biodiversity in India and its different types. In this third post on Biodiversity, we will learn about the major threats to Biodiversity at present.
FOLLOWING ARE THE MAJOR THREATS TO BIODIVERSITY
- Encroachments: organised encroachment of forest land started as early as 1950s. The direct impact of encroachment is habitat loss, besides the existence of constant threat on the forests by the fringe people. In addition to their involvement directly in the illegal activities they provide shelter for the unscrupulous offenders of the plains who are engaged in all kinds of illegal activities.
- Cattle grazing: Grazing by cattle in forest, although not rampant as elsewhere in the country, is identified as a threat to biodiversity. The grazing not only removes the biomass and competes with wild herbivores, but also spread contagious diseases to wild animals. Intensive grazing will lead to domination of a single or a few species, changing the species composition of natural vegetation. Cattle grazing speeds up the invasion of weeds.
- Collection of Fire Wood: Firewood collection directly poses threat in the form of removal of biomass, which affects microhabitat of flora and fauna, and indirectly leads to extensive fire and other illegal activities. The proximity of settlements to the forests is the main factor, which determines the intensity of firewood collection. The firewood collection leads to degradation of habitats which subsequently alters the species composition and vegetation types.
- Man-Animal Conflict: A major problem associated with the conservation of wild animals especially the herbivores like elephants in India is that of crop depredation and man-slaughter. Animals such as elephants, gaur, sambar, wild boar and birds like peacock, cause extensive damage to the crops. This phenomenon has registered significant increase in recent years due to habitat fragmentation and degradation of natural forests and corridors. Almost all the Protected Areas and Non-Protected Areas contain a large number of settlements either inside or on the periphery. This leads to degradation of surrounding habitats. The traditional tolerances among the people who live inside the forests or its adjacent areas are fast disappearing and people have become increasingly antagonistic. As a result, the people tend to kill the animals either by poisoning or by other means, like keeping crackers in fruits, etc.
- Poaching: The abundance of wild animals and high demand for their products in the clandestine, market pose threat to wild animals. Hervibvores like gaur, sambar, chital etc are being poached for their meat. A lot of other not so spectacular species of animals ranging from reptiles to birds as well as plants and medicinal herbs are all part of the illegal wildlife trade. The major impact of poaching is species loss and change in their demography apart from extensive fire and other illicit activities.
- Illegal and unsustainable/unscientific collection of Non-Timber Forest Produce: Non-Timber Forest Produce (NTFP) collection is one of the major livelihoods of the local people. The NTFP consist of a variety of products, which are sources of food, fibre, manure, construction materials, cosmetics and cultural products. The users of NTFP range from local individuals to multinational companies. With the development of modern techniques, the number of products and uses based on NTFP has increased by many folds. This market driven utilization became instrumental in their unsustainable exploitation and resulted in degrading the natural vegetation.
- Mining: Mining is also a severe threat to the biodiversity. Sand mining is prevalent in the central and southern parts. It is a threat to the stability of a landscape, which results in land sliding and lowering of water table. The removal of habitat will endanger the survival of riparian species since most of them occupied a very narrow habitat niche.
- Mass Tourism and Pilgrimage: Mass Tourism and Pilgrimage are considered to be one of the major and increasing threats to biodiversity conservation. Approximately 13 million people visit forest areas annually either as pilgrims or visitors. Among all the Protected Areas in India, Periyar Tiger Reserve receives a maximum number of tourists. The large influx of people into the forests in short duration makes severe changes to habitat. The major impact of tourism and pilgrimage is littering and over-utilization of resources such as soil erosion; fire, disturbance to wild animals for feeding, ranging etc are also reported due to a large number of pilgrims and unruly behaviour of visitors.
- Forest Fires: Fire is one of the major threats facing the forests of India. People who are engaged in grazing livestock often burn the area to get fresh shoots for their cattle, during lean season. Apart from this, those who are involved in illicit activities such as ganja cultivation, poaching, tree felling, NTFP collection and very often the ignorant tourists and pilgrims are also responsible for big forest fires. The effect of fire depends on the type of vegetation, frequency and intensity of fire and season of burning. Fire causes extensive damage in deciduous forests and grasslands due to heavy fuel load.
- Illicit Felling: Tree felling is one of the severe threats to biodiversity conservation in the state. The primary effect of tree felling on bio diversity is the removal of biomass and loss of habitat for many epiphytic and arboreal species. Tree felling leads to soil erosion and change of the soil properties. In some cases people involved in tree falling set fire to the forests.
- Invasive species: These are non indigenous or non-native plants and animals that adversely affect the habitats and bio regions they invade economically, environmentally and ecologically. Examples of plant invasion include Water hyacinth (Elchornia crassipes) and Lantana (Lantana Camara).
Water hyacinth, a fast-growing plant with population known to double in as little as 12 days blocks waterways, limiting boat traffic, swimming and fishing. The weed prevents sunlight and oxygen from reaching the water column and submerged plants. By crowding out native aquatic plants, it dramatically reduces biological diversity in aquatic ecosystems. Examples of animal invasion in our state include like Tilapia fish (Oreochromis mossambica), Sucker catfish (Plecostomus multiradiatus) and the African Giant Snail (Achatina fulica). Considering the damage caused to native fish species and biodiversity, Tilapia is termed a ‘biological pollutant’ by the Food and Agriculture Organization.