In the biosphere of earth, there is a huge diversity that exists at all levels of biological organisation. The variety that exists in the number and type of genes, the species, organisms and large biological communities or biome is known as Biodiversity. The loss resulting due to the decrease or reduction in this variety due to different factors can be called Biodiversity loss. Even in the smallest of the biological communities in a particular region the current loss of biodiversity is caused due to human activities. The loss of biodiversity in a region may lead to the extinction of certain species which can lead to the extinction of entire ecosystem in that particular area.
The idea of biodiversity is usually considered in terms of the variety or diversity of species called species richness. Hence, simplistically biodiversity loss is identified with the loss of species from a particular region, ecosystem or biome, but the consequences of biodiversity loss of a species will have adverse effects on the entire ecosystem or the biome. This is because the biodiversity decline leads to disruption of the food chain and nutritional dependence on a particular species.
Loss of Biodiversity
The loss of biodiversity definition can be given as the extinction and/or reduction of species in a certain habitat worldwide resulting in biodiversity depletion. This loss of biodiversity is caused due to various factors over periods of the earth’s timeline. But all of these factors have been a part of the natural order system of mass extinction. The loss of biodiversity and ecosystem loss or the mass extinction happening currently at 100 to 1000 more rate than the natural manner is due to human activities. Human activities have led to a huge aggravation of factors associated with mass extinction events.
The consequences of biodiversity loss in a given region may lead to a decline in plant production, lowered resistance to grievous environmental changes and increased variability in ecosystem processes, for example, plant productivity, water use and disease cycles. Other consequences of biodiversity loss are the coextinction of species because of disruption in the food chain and food web, destruction of alternative pathways for the ecosystem to withstand adverse conditions, and immediate danger of food security for humankind in a particular habitat.
Factors of Biodiversity Loss
As already mentioned above that the loss of biodiversity is caused due to human activities such as improper disposal and release of industrial waste and gases. The major causes of Biodiversity Loss are explained below.
1. Habitat Loss and Fragmentation: It is one of the major causes that drive the loss of diversity in an ecosystem. Habitat loss meaning is understood in simple terms as losing your own home. A very common cause or example of the reason for biodiversity depletion is reducing forest cover. The most drastic and dramatic example is the loss of tropical rainforests. They are being destroyed fast. Once they covered 14% of the earth’s land surface and now they cover only around 6%. Loss of biodiversity definition is exemplified by the biodiversity decline in populations of migratory birds, mammals unique to a particular region, etc. because of human activities and pollution leading to habitat loss meaning destruction of their natural living conditions.
2. Over-Exploitation: Natural resources which seemed infinite some thousand years ago now seem very much limited owing to the increased population of human beings alone. Also, the greed of many human enterprises and endeavours over the past centuries has led to overexploitation of natural resources which in turn has led to the destruction of biodiversity. Species like Steller's sea cow and passenger pigeon have gone extinct in the last 500 years because of overexploitation. Land-use intensification has been one of the major causes of biodiversity and ecosystem loss. Thus, the above-mentioned habitat loss meaning is exemplified by the over-exploitation of the land resources. On an alarming note, humans are using natural resources at 25% more than the planet.
3. Alien Species Invasion: Alien species for a particular region can be defined as the species that originally didn't inhabit the particular habitat or have not evolved in that particular habitat. When a foreign species is introduced knowingly or unknowingly in a given region, it can turn invasive and cause biodiversity loss. Biodiversity depletion or biodiversity decline of more than 200 species of cichlid fish in Lake Victoria of east Africa was caused due to the introduction of Nile perch. Not only necessarily do the new species become invasive but also when they compete for the niche with the indigenous species and replace them, the entire ecosystem based upon and surrounding the indigenous ones suffers. It is not only the loss of biodiversity introduction in the local area but also the simultaneous biodiversity and ecosystem loss.
4. Co-Extinctions: Loss of biodiversity is caused due to human activities that increase the rate of factors of biodiversity loss such as habitat loss because of overexploitation of the resources and invasion by foreign species. Biodiversity loss meaning, in this regard, is characterized by the loss of diversity in the ecosystem and the food web that is dependent on the native species in a given region. Loss of biodiversity meaning in this scenario says that when a species becomes extinct, the plant and the animal species that were associated with it also become extinct. Loss of biodiversity meaning in this case implies co-extinction. When a host fish species gets extinct, the assemblage of the parasite species also faces the same fate. Thus, loss of biodiversity in a region may lead to not only the extinction of one species but also coextinction due to a combination of biodiversity and ecosystem loss.
The biodiversity loss meaning is clear in the above mentioned short note. The consequences of biodiversity loss are dire. Scientific studies have shown that biologically diverse ecosystems are more productive even for human beings. It is well known that the high rates of modern extinctions are because of overexploitation, pollution, and habitat loss due to human activities. Nature's ability to provide essential products such as food, clean water and a stable survivable climate is reduced gravely because of these rates of extinction. Therefore, it is important to preserve biodiversity and many steps are being taken by various organizations around the world with that regard.