Loss of Species Diversity

Introduction

Loss of species diversity is also known as loss of biodiversity. Biodiversity is the total number of genes, species, or organisms of a given species within a given geographic area. Loss of biodiversity is a concern because the loss leads to the extinction of many species. This, in turn, leads to an imbalance in the ecosystem where the loss of biodiversity occurs.

Biodiversity loss is often considered as a loss of species richness in a given geographic area. However, the term species richness associated with biodiversity loss does not consider the long−term effects of the loss of species. Sudden upset in species diversity may lead to turmoil in the social structure of species, leading to an inability for males and females to find mates that leads to further decline of the population of the vulnerable species. Rapid falls in the population are often accompanied by a loss in genetic diversity which causes inbreeding or mating within a closely related population, which can further decrease the genetic diversity.

When the number of a species’ population reaches a certain level, its niche (the role played by the species in the ecosystem) gets affected. Therefore, although members of a species remain present in the geographic location of consideration, there may be significant changes in the ecosystem structure. For example, cutting down trees removes the shading, temperature, and moisture regulation of an area in which trees were located. This also affects animal habitat and nutrient availability provided by the trees in the ecosystem.

Natural Biodiversity Loss

Natural biodiversity loss occurs due to natural conditions. With the onset of spring, for example, there comes an opportunity for feeding and breeding. This increases the population of many species to rise. On the other hand, as winter begins, migrating animals leave their habitats, and warm−adapted insects die. Additionally, the seasonal increase and decrease of plant and invertebrate populations (insects and plankton for example) that act as food for other life forms also impact the biodiversity of an area.

Biodiversity loss is, however, related to more permanent ecological changes in an ecosystem. Natural calamities, such as wildfires, volcanoes, and floods change ecosystems by destroying the biodiversity present in them. These changes are however temporary because ecosystems have learned to adapt to these conditions and they recover from such cycles naturally over time.

Global state and trends figures for key elements of biodiversity important to food and agriculture

Human−driven Biodiversity Loss

In contrast to natural biodiversity loss, human−driven biodiversity loss is more widespread and effective. Humans have captured more than half of the inhabitable land area on Earth for agriculture. This roughly amounts to 51 million square kilometers. Out of this, nearly 40 million square kilometers are used for grazing by cattle, sheep, goats, and other livestock. This massive conversion of terrestrial ecosystems has resulted in a 60 percent decline in the number of vertebrates since 1970. The regions where most of the effect has been recorded are freshwater habitats (83 percent) and Central and South America (89 percent).

According to researchers, the current rate of species loss or loss of biodiversity varies between 100 and 10,000 times the background extinction rate (which is nearly one to five species per year when the complete fossil record is considered).

Scientists have identified five key drivers of biodiversity loss which are the following:

Habitat Loss and Degradation

This refers to any thinning, destruction, or fragmentation of an existing natural habitat that diminishes or removes the food resources and living space for most species. Species that cannot migrate are often killed in this process.

Overexploitation

This refers to the harvesting of game animals, fish, or other organisms that is more than the capacity for the surviving populations to replace their losses. This results in some species being reduced to very low numbers or others being converted to extinction.

Invasive species

In this process, non−native species colonize foreign ecosystems and drive out the local species, out−competing them with food and other resources. This results in the fast depletion of the population of native species. Invasive species may arrive in a new habitat through natural migration or via human introduction.

Pollution

Pollution may affect the growth of the population and eventually lead to extinction in some cases by harming the health of organisms. It may also impact the reproductive system and impair reproduction so that no new offspring is produced which may eventually lead to the extinction of a species in a given area.

Climate change

Global warming which occurs due to greenhouse gas accumulation in the atmosphere is leading to artificial changes in the environments at many locations, such as ice melting in Antarctica. This is affecting many species to leave their habitats and in many cases species are dying due to a complete reversal of their habitats’ living conditions.

According to scientists, habitat loss due to the conversion of forests, wetlands, grasslands, and other natural areas to urban locations, and invasive species are the most impactful reason for the loss of species diversity. However, they also acknowledge that climate change may become a major treason for biodiversity loss in the 21st century.

The tolerance limits and nutrient cycling procedures are related to the environmental temperatures of many species and they may not cope with the changes brought by global warming. Moreover, more invasive species may arise due to climate changes that may add more stress to the living conditions of the dying species. However, it has been observed that human activities which are not just limited to habitat loss and pollution affect all of the five key drivers increasingly, leading to the process of biodiversity loss in many parts of the world.

Conclusion

Biodiversity loss is an issue that must be taken seriously by human beings if they want to create a sustainable future for all living beings. Although steps are being taken, the measure of steps is very low till now. We must fasten the processes to keep biodiversity intact and for this mass awareness is necessary. Only then we can create a world full of diversity and biological balance.

Frequently Asked Questions

Qns 1. How much of the land area of the earth is used by human beings for agriculture? What portion of it is used for grazing?

Ans. Humans have captured more than half of the inhabitable land area on Earth for agriculture. This roughly amounts to 51 million square kilometers. Out of this, nearly 40 million square kilometers are used for grazing by cattle, sheep, goats, and other livestock.

Qns 2. What is the growth of the human population between 1970 to 2014?

Ans. Between 1970 and 2014, the human population boomed from 3.7 billion to 7.3 billion.

Qns 3. What could be the most impactful reason for biodiversity loss in the 21st century?

Ans. Climate change due to global warming could become the most impactful reason for biodiversity loss in the 21st century.