Threats to global biodiversity are a global concern these days. In recent years, extinction rates have increased dramatically. Human activity has led to the extinction of thousands of species and variations every year. Over the last 150 years, the rate of extinction has increased significantly. If current trends continue, we could lose 1/3rd to 2/3rd of our current biodiversity by the middle of the 21st century.

The main causes of biodiversity loss include invasive alien species, unsustainable natural resource use and exploitation, pollution, and land use changes. In this article, we will study what biodiversity is, how human activities affect biodiversity, climate change, and biodiversity, and the importance of biodiversity and its conservation.

What is Biodiversity?

The term biodiversity was coined by E.O. Wilson (father of biodiversity) in 1985. The word biodiversity is split into two parts bio (life) and diversity (variability). It includes organisms like plants, animals, and microorganisms, as well as the genes and ecosystems they generate. An area’s biological structure influences biodiversity and cannot be measured purely by numbers.

Whittaker (1972) identified three distinct categories of diversity: alpha, beta, and gamma. In the Convention of Biological Diversity (1992), biodiversity has been defined as the variability among living organisms from all sources including terrestrial, marine, and other aquatic ecosystems and the ecological complexes of which they are a part.

Human Activities Impacting Biodiversity

The major threats to biodiversity are Habitat loss or destruction, Invasive species, Pollution, Climate change, and Overexploitation.

Habitat Loss and Degradation

Habitat loss can be divided into two types. These are Habitat destruction and Habitat fragmentation.

• Habitat Destruction

It is the complete elimination of a localized or regional ecosystem as a result of either anthropogenic or natural activities. Anthropogenic activities that destroy the habitat are buildings, factories, or agricultural land as these require space and that space comes through the destruction of certain habitats. Natural activities are forest fires or Vulcans. All of this activity can destroy a regional ecosystem.

• Habitat Fragmentation

It is a secondary effect of habitat destruction and this happens because of the destruction of habitat patches due to which the remaining population are isolated from their group. E.g. We construct a road in the middle of a forest or grassland. Habitat fragmentation divides the resident species into two groups, leading to reduced reproductive ability and population decline.

Pollution

Pollution means any substance which is present in the environment having harmful effects. We have 3 types of pollution- air pollution, soil pollution, and water pollution.

• Air pollution is caused by solid and liquid particles and certain gases that are suspended in the air. These particles and gases often come from anthropogenic sources that as man-made sources like cars and trucks, exhaust factories, burning of waste in landfills, dust, and natural sources like that is pollen from flowers, mold spores fungal spores, volcanoes, and wildfires.
• Soil pollution is caused by the presence of xenobiotic chemicals or other alterations in the natural soil environment. Industrial waste, excessive use of fertilizers and pesticides, garbage pollution, leaching, and chemicals The presence of xenobiotic chemicals or other alterations in the natural soil environment causes soil pollution leads to soil pollution.
• Water pollution is the contamination of water bodies like lakes, rivers, and oceans usually as a result of human activities. Things that cause water pollution are the discharge of domestic and industrial effluent waste, leakage from water tanks, marine dumping, radioactive waste, atmospheric deposition, leaking of pesticides, etc.

Pollution produces polluting gases like sulfur dioxide, carbon dioxide, methane, carbon monoxide, oxides of nitrogen, etc. Excessive polluting gases lead to a highly polluted environment in which they are living.

Also read: Types of Pollution

Overexploitation of Natural Resources

Overexploitation of wildlife and natural resources is a major issue in conservation, despite its importance to human survival. Logging, hunting, and fishing can all reduce populations to extinction. Humans’ increasing need for wild species for food, fibre, ornamentation, and other things can lead to population reductions and extinction.

Overexploitation (unsustainable use) occurs when biodiversity is depleted faster than it can be replaced, leading to species extinction over time. For example, overfishing has led to the extinction of the cod fishery off the coast of Newfoundland, Canada. Encephalartos brevifoliolatus, a cycad, is now extinct in the wild due to overharvesting for horticulture. Overexploitation, combined with destructive harvesting practices, is a major cause of biodiversity loss in certain ecosystems.

Climate Change and Biodiversity

Small temperature rises typically lead to migration northward in latitude or higher in altitude. Changes will impact ecosystems, causing some to shrink and others to expand. Climate change can impact aquatic habitats, as some are sensitive to minor temperature fluctuations.

Rising Temperatures and Altered Precipitation

Rising ocean temperatures impact herbivores and their foraging behaviours. Rising temperatures lead to the spread of infections, increasing their virulence and decreasing host resilience in macroalgae. Climate change affects rainfall patterns, resulting in less sedimentation and nutrient run-off in low rainfall regions and more in high rainfall regions. In urbanised coastal areas, increased sedimentation and nutrient benefits encourage the growth of tiny, opportunistic algae species, leading to a change from canopy to algal-dominated blooms.

For example, cod are sensitive to temperature changes and require a restricted range of water temperatures to spawn successfully. Coral reef systems have had significant changes due to limited climate change in recent decades.

Also Read: Effect of Global Warming on Coral Reefs

Sea Level Rise and Ocean Acidification

Climate change, which is an accumulation of greenhouse gases like carbon dioxide in the earth’s atmosphere, is a rising threat. The ocean’s ability to absorb CO₂ declines as ocean acidification rises. More acidic oceans are less effective at mitigating climate change. Climate change limits the survival of species and their food sources.

Forests convert carbon dioxide into carbon and oxygen. The loss of forest cover and increased emissions from industrialization contribute to the ‘greenhouse effect’. Global warming melts ice caps, causing sea levels to rise and submerge low-lying places around the world. The worldwide average surface temperature has increased by 0.6 C (+/- 0.2 C ) in the last 140 years.

Also read: Climate Change and Its Impact

Invasive Species

Before we know what an invasive species is let us first understand what is an endemic species. Endemic species is an ecological state of a species being unique to a definite geographical location. That means that this particular species is defined by a geographical location. These are the actual inhabitants of an area, and these are the original native species of an area (the original inhabitants).

Invasive species are not native to a specific location and that is why they can grow outside their normal distribution. They tend to grow rapidly and hence these are also known as aggressive species. These compete with the endemic species for resources. This results in endemic species being depleted of the resources. This leads to the loss of endemic species and an increased spread of invasive species.

Invasive species are highly reproductive. They reproduce more rapidly due to which their progenies grow faster. Also, they are introduced by human activities often unintentionally. These are also known as exotic species because they have arrived from somewhere outside the environment.

Importance of Biodiversity

The Earth’s living species are diverse and important for human survival, supplying food, shelter, clothes, and medicines. Some important points are given below:

• Biodiversity provides a variety of products gathered from nature and sold in commercial markets.
• The consumptive value can be attributed to things such as fuel woods, leaves, forest products, etc. which may be consumed locally.
• The loss of biodiversity has a direct impact on the country’s social life, presumably by impacting ecological processes (energy flow and the biogeochemical cycle).
• Aesthetic values such as the refreshing aroma of flowers, the taste of berries, the softness of leaves, the melodic voices of birds, and so on drive humans to protect them.
• Any disruption in the precisely crafted ecological balance maintained by many organisms may result in serious issues, perhaps endangering human survival.
• Biodiversity has significant economic worth since economic progress is dependent on the efficient and cost-effective management of biotic resources.

Conservation of Biodiversity

The importance of biodiversity for genetic, commercial, medicinal, aesthetic, ecological, and other purposes highlights the need for conservation efforts. We are realising that wildlife is more than simply a game to be killed, but a natural treasure to be fostered and enjoyed. Global efforts are underway to conserve biodiversity, including plants and fauna.

There are two approaches to biodiversity conservation:

1. In situ conservation (within habitat): This is achieved by the protection of wild flora and fauna in nature itself. e.g. Biosphere Reserves, National Parks, Sanctuaries, Reserve Forests etc.
2. Ex-situ conservation (outside habitats): This is done by the establishment of gene banks, seed banks, zoos, botanical gardens, culture collections etc.

Also Read: In-Situ and Ex-Situ Conservation of Biodiversity

Conclusion: Threats to Biodiversity

Human activities, such as destroying native habitats and fragmenting them into smaller areas, have led to the destruction of global nitrogen, carbon, and water cycles, as well as climate change. This may be the most extreme extinction event in history. Despite significant biodiversity loss, individuals around the world are making choices and taking measures to protect biodiversity. Additional work is necessary to prevent further biodiversity loss. Consider the impact of your actions and encourage others, including corporations and governments, to follow suit.

Also Read

• Biological Diversity Act 2002
• Differentiate between Direct and Indirect Use of Biodiversity
• Biodiversity Conservation
• Pattern of Biodiversity

FAQs on Threats to Biodiversity

What are the 5 Main Threats to Biodiversity?

The five main threats to biodiversity are habitat loss, pollution, overexploitation, invasive species, and climate change.

How can we Mitigate Biodiversity Threats?

The ways to prevent biodiversity loss are- buying sustainable products, ditching lawn And garden chemicals, planting trees, protect ing local habitats, eating local and organic whenever possible.

Why is the Loss of Biodiversity a Problem?

The loss create the conditions responsible for morbidity or mortality. Biodiversity supports human and societal needs, including food and nutrition security, energy, development of medicines and pharmaceuticals and freshwater, which together underpin good health.

What are the top 4 Threats to Biodiversity?

According to the UN’s Convention on Biological Diversity, there are five main threats to biodiversity. These are changes in land and sea use, direct exploitation of natural resources, climate change, pollution,invasive species.

Is Habitat Loss a Threat to Biodiversity?

Habitat loss and fragmentation are the single greatest threats to biodiversity worldwide, and this certainly holds for mammals today.