Biodiversity is often used as a measure of the health of ecosystems which represents all the human population and species existing on Earth’s surface. Biodiversity is defined as the totality of genes, species and all ecosystems of a region. The biodiversity we see today is fruit of a billion of years of evolution on Earth as a result of natural processes and human activities. The loss of this unique biodiversity is considered irreversable by conservationists.
Decline or loss of biodiversity on Earth is considered as reduction in the number of species, loss of habitat, loss of ecosystems, and variety of species present on Earth’s surface. It is estimated that almost 15,889 species on Earth are at the risk of extinction. In almost 20 years only, between 1980 to 2000, one fourth of mangrove area of the world has been lost, one fifth of coral species have vanished and 15 million hectares of tropical rainforests have been lost. Several birds, mammals, amphibians, fishes etc are on the risk of collapse due to environm ntal degradation. To understand the risks arising out of biodiversity loss, essential to understand the types of biodiversities.
Types of Biodiversity
Following are the types of biodiversity
• Species Diversity
Species diversity refers to the variety of species on Earth. The aspects of species diversity can be measured in a number of ways. The most important among these are species richness, species abundance and taxonomic diversity. At the global level, an estimated 1.7 million species have been described till date. Total number of species are estimated at 5 million to almost 100 million. The most of species richness is concentrated in equatorial regions.
• Genetic Diversity
Genetic diversity refers to the variation in species. New genetic variations produce newer features in species. There are wide genetic variations in species due to variety of habitats and their complexity. It also depends on the different ways with which organisms obtain their living from the nature. Genetic diversity affects the survivability, adaptability of species.
It includes differences between types of ecosystems, diversity of habitats and various processes occuring within each ecosystems type. It is not easier to define ecosystem diversity than species or genetic diversity as the limits of ecosystem are more fluid. Managing and classifying ecosystems is a major challenge for the scientific community as biodiversity degradation and decline will affect the ecosystem and species badly. Many species may go extinct and many others may be vulnerable. Various threats to biodiversity exists which can be controlled to reduce biodiversity loss.
Factors Threatening Biodiversity
• Earth’s biodiversity is the result of billions of years of evolution which is caused by natural as well as human factors. The factors that threaten biodiversity include the following.
• Habital Fragmentation
Habital fragmentation and loss is the primary cause of biodiversity loss. Habital fragmentation is the result of felling of forests, diversion of forest land for non-forest use, mining activities, construction of dams and roads in forest areas, overgrazing by domestic cattle population, and pesticide pollution etc. Several forest lands have been diverted for commercial Eucalyptus plantations and food crops. As the population of the world has increased, increased areas of agricultural fields is required for more production of food crops. This has resulted in diversion of natural lands at an extremely faster rates.
• Pollution and Disturbance
Pollution due to man made activities leads to decline in biodiversity because unwanted materials in the ecosystem severely affects the living organisms. Sensitive species are mainly affected due to large pollutants in the ecosystem. Disturbances in ecosystems results in large scale death of various species such as fires, natural calamities, defoliation by insects etc.
• Over Exploitation
Over-exploitation of resources such as hunting, over collection of produce, rapid and large scale fishing results in reduction of species of wild animals and plants. Illegal poaching, threatens the survival of species such as elephant, tiger etc. Loss of exotic marine biodiversity is aggravated by the promotion of unsustainable fishing practices and selective harvesting of wild resources. Traditional practices of gathering and hunting also possess threats to biodiversity.
• Climate Change
The range and tolerance of plant and animal species are changed drastically due to change in climatic conditions. Species which cannot adapt to changed climatic conditions tend to migrate to newer areas where they are not able to survive due to change in weather. Resultant increase in the summer and dry season also increases the risk of forest fires in forests which sweeps away various important species.
• Political Reasons
Political causes are also responsible for the loss of biodiversity. The developing countries which have rich biodiversity do not possess sufficient resources to conserve biodiversity. The developed countries exploit the diverse resources of developing countries at low costs. This affects biodiversity conservation efforts at the global scale. There is also lack of political coordination, differences in interests among various countries, incomplete information on biodiversity in political decision making and distortion of political incentives.
• Absence of Local Institutions
It is believed that local institutions are closer to nature and help in their conservation but absence of local communities and local institutions results in over exploitation of natural resources. There is general lack of awareness among people if the local institutions are absent. Th people are not aware about the utility of biodiversity and conservation. All these factors leading to decline in biodiversity results in multiple harmful effects on the humans as well as nature.
Impact of Biodiversity Loss on Human Lives
• Loss of Nutrition
Biodiversity plays a crucial role in nutrition of humans through improvements in world food production through sustainable productivity of soils. Biodiversity provides genetic resources for all crops, livestock foods etc. Intensified and enhanced food production through irrigation, use of fertilisers, plant protection by pesticides, or introduction of food crop varieties and cropping patterns affect biodiversity and it impacts global nutritional status and human health.
• Loss of Valuable
Genes Loss of biodiversity results in the loss of valuable genes. The present day genes are the result of millions of years of evolution. The loss of genes results in significant economic loss as well as social degradation. Genes provide resistance to the crops against various diseases as well as give nutrient value to the food crops. Neglecting diversity results in risking our own survival on Earth.
• Loss of Ecosystems
Genetic diversity decline results in loss of ecosystems which provides us various valuable services. Loss in biodiversity results in significant changes in aesthetic, inspirational and educational role of mankind. Loss of various species may also negatively influence the emotional, spiritual well being of human race. Loss of ecosystems may also result in extinction of endemic species. Larger species, which are valuable for ecosystems are highly susceptible to extinction.
• Rise of Infections
Biodiversity loss results in significant changes as well as disturbances in the environment. Such disturbances reduce the abundance of some organisms and increases the population of others. These wide disturbances alters the interaction between organisms and their physical environment. Infectious diseases are sensitive to these disturbances. As there is disturbance in form of deforestation, land use changes, irrigation, water management, uncontrolled urbanisation etc, it results in accidental or unintentional introduction of harmful pathogens in humans. These harmful infections puts human lives at great risk.
• Health Impacts
Biodiversity provides us with various medicines that are extensively used by world populations for their healthcare needs. Many communities rely upon natural plants collected from forests for making traditional medicines, which are also used by a large number of people worldwide. There is also a global demand for traditional natural medicine in the world. The deficiency in availability of traditional as well as natural medicine will significantly impact the healthcare system around the world. The scientific community relies on biodiversity to understand and treat diseases affecting humans.
• Unclean Water
The continuous loss of biodiversity affects the quality of water required for human use in households and agriculture. The availability of clean drinking water has become a major concern in world’s large cities. Loss of forests, loss of species that naturally filters water, loss of watershed quality results in supply of unhealthy and unclean water unfit for human consumption.
Biodiversity is the primary and most fundamental requirement for the existence of biological organisms. It provides economic as well as social benefits for humanity. It has a large habitat for microorganisms, flora as well as faunal species. Enormous benefits have arisen from the conservation of components of biological diversity. Diverse nutritional food is a gift of biodiversity that sustains 7 billion people. These services are under threat due to habitat destruction, degradation, fragmentation, poaching, loss of wetland, hunting, global warming, invasive species etc. It calls for national as well as international level cooperation. The local level participation in conservation efforts is also necessary for conserving biodiversity at the national level. It is required to strengthen the capacity of natural systems so that our own welfare can be ensured.