BIOLOGICAL DIVERSITY refers to the variety and variability among living organisms and the ecological complexes in which they occur. Diversity can be defined as the number of different items and their relative frequency. For biological diversity, these items are organized at many levels, ranging from complete ecosystems to the chemical structures that are the molecular basis of heredity.
Extinction is a natural event and, from a geological perspective, a routine. We now know that most species that have ever lived have gone extinct. In the modern era, due to human actions, species and ecosystems are threatened with destruction to an extent rarely seen in earth history.
We can attribute the loss of species and ecosystems to the accelerating transformation of the earth by a growing human population. As the human population passes the six billion mark, we have transformed, degraded or destroyed roughly half of the word’s forests. It is little wonder that species are disappearing and ecosystems are being destroyed.
The major threat to biodiversity is extinction. Any type of plant or animal can die out, meaning that in its absence, all of the ecosystems that it inhabited (the chains of which it was a link) must change or risk dying out themselves. Either option will have a profound effect on the ecosystem’s output, which in turn affects the “ingredients” it will produce for human consumption, thus altering humans’ lifestyles as well. Some of the major threats to biodiversity include:
• Killing animals obviously reduces their numbers and endangers their species.
• Often habitats are demolished, for example to make way for buildings and roads. A specific type of habitat loss is deforestation, or cutting down trees.
• The introduction of non-native species (for example, stocking a pond with fish from another part of the world) again means that an ecosystem must cope with a threat to its natural order.
• Pollution contaminates natural ecosystems and again poses a threat.
• Differing temperatures, amounts of snowfall or rainfall and a variety of other symptoms of climate change can all affect ecosystems in a given area.
Over-hunting is another human activity that has endangered many species of animals. Some of them are on the verge of extinction. From time immemorial humans have been hunting animals for food, ornaments and clothes. However, in modern time, poaching and indiscriminate hunting of animals has brought many animal species to near extinction. Wild animals have been hunted to extinction from hunting pressure.
Habitat loss and destruction is usually a direct result of human activity and population growth. It is a driving force in the loss of species, populations, and ecosystems: when people cut down forests, dig mines, build cities, or make roads, they destroy habitats. When the habitats become smaller, less food and shelter are available. As a result, species living in these habitats compete with each other and with humans for limited resources. Since their populations are so small, they have fewer mates with whom to have offspring, diminishing the genetic diversity of their populations.
The introduction of alien (exotic or non-native) species can disrupt entire ecosystems and have a major impact on populations of native plants or animals. The invaders can affect native species by eating them, infecting them, competing with them, or mating with them. Invasion can happen through many different ways: seeds catch on people’s clothes, rats hitchhike on ships, marine species are transported around the world through ballast water from ships and insects can be introduced with the international trade for food or timber.
At times species of plants and animals that are not native to a place have invaded the region resulting in extinction of the endemic species. When new species of plant or animal are introduced into a region, it will compete with the native species for food. As the native species do not have the required defense or adaptation against the new species, they succumb. Many of the invasive species have been introduced by humans.
Climate Change is impacting ecosystems in several ways, including via temperature shifts. These shifts are making it difficult or even impossible for many species to survive. As the climate changes more and more, biodiversity will face ever greater threats. Likewise, efforts to conserve biodiversity will face ever greater challenges. Indeed, some are starting to speak about conservation triage as a situation in which not all species can be saved, forcing conservationists to decide which species to protect. This use of the term triage is adapted from its use in medical crises, such as in emergency response to natural disasters.
The principal threat to biodiversity comes from the increased pressure on natural resources produced by high population growth and demands for increased standards of living. The process of economic development itself widens inequality and may force the poor to depend heavily on natural resources, while the development models followed, in most instances, have been incompatible with the sustainable use of natural resources.
They focus on the need for sustainable development and adequate use of coastal resources. Loss of biodiversity and biodiversity conservation are concepts that provide the basis for biodiversity management. The management of biodiversity is a complex matter that needs the involvement of many different partners ranging from governmental organizations to private companies, NGOs and volunteers. This aside, national and international commitment, legislation and enforcement offer an essential framework for promoting and maintaining biodiversity.