Loss of Biodiversity - UPSC Environment Notes

Biodiversity loss refers to the decline in the variety of life within species, ecosystems, specific locations, and on a global scale.
When a species disappears from a particular area or experiences a reduction in both its numbers and genetic diversity, it is recognized as a loss of biodiversity.
Biodiversity loss occurs through the extinction of specific species or the degradation of their essential habitats. The latter is more prevalent, driven by the inevitable consequences of developmental activities.
Species extinction can be driven by economic exploitation, hunting for sport or food, as well as environmental factors like ecological substitutions, biological influences, and pathological causes, whether natural or human-induced.
Population overgrowth contributes significantly to biodiversity loss, leading to excessive resource exploitation and widespread deforestation.
The destruction of tropical regions has particularly devastating effects on natural habitats, impacting the entire biosphere.
Natural disasters, ranging from forest fires and droughts to floods, volcanic eruptions, and earthquakes, pose threats to both the flora and fauna of the Earth. Additionally, pollutants such as pesticides, toxic heavy metals, and hydrocarbons harm weaker and more vulnerable species.
The consequences of biodiversity loss in a given area may manifest as a decrease in plant production, reduced resilience to environmental disturbances, and an increase in variability in specific ecosystem aspects like water use, plant productivity, disease cycles, and pest prevalence.

Table of Contents

CAUSES OF BIODIVERSITY LOSS

HABITAT LOSS AND FRAGMENTATION

The alteration of land use has led to habitat loss and fragmentation, notably through the transformation of natural ecosystems into cropland, the expansion of infrastructure such as roads and railways, urbanization, and mining.
The Living Planet report highlights a 30% decline in wetlands over the past four decades, primarily due to reclamation for agricultural and urban purposes.
Additionally, about half of tropical and subtropical forests, along with 45% of temperate grasslands, have been converted for human use.
Beyond outright habitat loss, pollution-induced degradation further jeopardizes the survival of numerous species.
The fragmentation of large habitats, a consequence of diverse human activities, adversely affects mammals, birds with expansive territories, and species with migratory behaviors, contributing to population decline.

URBAN SPRAWL

As our global population expands, there is an unprecedented rate of land clearance for the construction of new homes, businesses, and infrastructure.
This activity leads to the destruction of habitats for native flora and fauna, resulting in the loss of entire ecosystems.
Surviving populations are now isolated from the rest of their species.
Urban expansion, in many instances, has led to the obliteration of pristine forests and ecosystems with unique roles, such as mangrove swamps and coral reefs.
These natural defenses, shielding the land from powerful winds and tidal surges while providing habitats for diverse life, have been lost.
The removal of these highly effective barriers has altered dynamics, subjecting adjacent terrestrial ecosystems to damage that would not have occurred without our impact.

OVEREXPLOITATION OF NATURAL RESOURCES

The extraction and refining processes produce toxic byproducts that harm the environment.
The burning of fossil fuels not only scorches the skies but also acidifies the oceans.
Petroleum byproducts like plastic contribute to a concerning issue of waste, obstructing waterways and endangering animals.
The over-exploitation of biodiversity and the unsustainable use of ecosystems stand out as significant contributors to biodiversity loss.
Overfishing, excessive harvesting of plant products, and activities like hunting or poaching can swiftly result in declining biodiversity.
Human consumption patterns are consistently identified as the primary driver of this unsustainable exploitation of natural resources.
Many species that faced extinction in the past five centuries, including Steller’s sea cow and the passenger pigeon, succumbed to over-exploitation by humans.

INTRODUCTION OF ALIEN SPECIES

The introduction of plants, animals, and microorganisms from different geographical regions, whether intentional or accidental, can pose substantial threats to native species.
This includes competition for resources such as food and shelter, the spread of unfamiliar diseases, genetic alterations through interbreeding with native species, and disruption of various elements within their food chains and physical environment.
A notable instance is the introduction of water hyacinth by the British in India for aesthetic purposes.
Regrettably, it has transformed into an invasive species, obstructing rivers, lakes, and other water bodies, hindering the growth and survival of aquatic life.

ENVIRONMENTAL POLLUTION

Environmental pollution refers to the gathering of pollutants, such as phosphorus and nitrogen, mainly originating from the runoff of excessive fertilizers in farmlands, harmful chemicals from urban and suburban runoff, industrial effluents, and similar sources that are released into natural water bodies.
An illustrative incident occurred in 2017 when an oil spill took place off the port of Ennore in Chennai, leading to adverse effects.
Likewise, the detrimental impact of plastic pollution on wildlife is evident.
Furthermore, air pollution from industrial and vehicular sources has contributed to the extinction of numerous bird species in urban environments.

CLIMATE CHANGE

Anticipated as a growing menace to biodiversity in the coming decades, climate change has already manifested observable alterations in flowering and migration patterns, as well as the global distribution of various species.
These shifts have disrupted food chains and led to imbalances in ecosystems where diverse species had previously developed synchronized interdependence.

UNSUSTAINABLE AGRICULTURE TECHNIQUE

Agricultural chemicals used for pest control pose a threat to birds, bees, and pollinators, with potential carcinogenic effects on humans.
Throughout the growing season, many essential crops undergo frequent pesticide applications, and some, like cotton, are even sprayed with defoliants for easier harvesting later in the season.
Unfortunately, these toxins and unsustainable agricultural practices have led to soil infertility, water pollution, the demise of aquatic life through runoff, and the introduction of substantial carcinogens into our food and drinking water, all while diminishing the nutritional value of crops.
The exploitation of lands solely for high-yielding crop varieties results in degraded landscapes incapable of supporting any life, contributing to the widespread loss of biodiversity and harm to living organisms.

CONSEQUENCE OF BIODIVERSITY LOSS

The repercussions of biodiversity loss are significant.
The presence of diverse life forms is crucial for the well-being and resilience of ecosystems.
These ecosystems, in turn, play a vital role in providing us with fresh, clean air, water, and fertile soil.
In addition to supporting basic life necessities, healthy ecosystems serve as effective absorbers of excess greenhouse gas emissions.
They contribute to the moderation of our climate, maintaining temperatures conducive to life as we know it.
However, when ecosystems experience a significant reduction in biodiversity, they become susceptible to destruction, weaken, and lose the capacity to deliver essential ecosystem services.
Mounting evidence strongly suggests that the ongoing decline in biodiversity will lead to subsequent disruptions in the functioning and stability of ecosystems.
The functionality of ecosystems often hinges on factors such as species richness, species composition, and the richness of functional groups.
Moreover, the evenness of species distribution and genetic diversity can also influence ecosystem functioning.
Changes in species richness and composition are frequently linked to alterations in stability, indicating that the current shifts in biodiversity are likely to bring about corresponding changes in various ecosystem properties.

HOW TO PREVENT BIODIVERSITY LOSS

There are various strategies to prevent biodiversity loss, and individuals, communities, and governments can play crucial roles in this endeavor:

Consumer Awareness and Preferences:

Foster awareness of the environmental consequences of consumer choices.
Advocate for transparency in product labeling, ensuring clear disclosure of all ingredients, especially those with potential environmental impacts like palm oil.

Sustainable Agriculture Practices:

Address the impact of agriculture expansion on biodiversity loss.
Promote sustainable farming practices that prioritize biodiversity conservation, emphasizing alternatives to intensive agriculture.

Certifications and Ethical Practices:

Support and prioritize products with certifications indicating sustainable environmental practices, such as fair trade, sustainable fishing, and zero waste initiatives.
Make informed choices based on environmentally friendly and ethical provider practices to influence market dynamics.

Local Sourcing and Community Initiatives:

Transition towards locally sourced and organic food options.
Promote community gardens in urban areas and support local organic farmers to reduce dependence on distant, environmentally taxing sources.

Reducing Fossil Fuel Dependency:

Minimize the use of fossil fuels and discourage overconsumption.
Advocate for sustainable energy alternatives and adopt practices that reduce carbon footprints.

Protection of Endangered Species:

Implement measures to protect endangered species from hunting and other threats to their survival.
Support conservation initiatives aimed at preserving the habitats of endangered species.

FAQs: Loss of Biodiversity

1. What is biodiversity loss?

A: Biodiversity loss refers to the decline in the variety of life within species, ecosystems, specific locations, and on a global scale. It occurs when a species disappears from an area or experiences a reduction in both its numbers and genetic diversity.

2. What are the primary causes of biodiversity loss?

A: The major causes include habitat loss and fragmentation, urban sprawl, overexploitation of natural resources, introduction of alien species, environmental pollution, climate change, and unsustainable agricultural practices.

3. How does habitat loss and fragmentation contribute to biodiversity loss?

A: Alteration of land use, conversion of natural ecosystems into cropland, infrastructure expansion, urbanization, and mining lead to habitat loss. Fragmentation, caused by human activities, negatively affects various species, contributing to population decline.

4. What role does urban sprawl play in biodiversity loss?

A: Urban expansion, driven by population growth, results in the destruction of habitats for native flora and fauna, isolating surviving populations. This activity often leads to the obliteration of vital ecosystems like mangrove swamps and coral reefs.

5. How does overexploitation of natural resources impact biodiversity?

A: Over-exploitation, including overfishing, excessive harvesting, and hunting, swiftly leads to declining biodiversity. The extraction and refining processes produce toxic byproducts, contributing to pollution and environmental harm.

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Loss of Biodiversity – UPSC Environment Notes