MEVE 014: Unit 05 - Human Impacts on Biodiversity

-

 UNIT 5: HUMAN IMPACTS ON BIODIVERSITY

5.0 Introduction

Biodiversity is the cornerstone of ecosystem health and function. However, with the growth of the human population and increased consumption of natural resources, biodiversity across the planet is under significant threat. Human-induced pressures are altering habitats, introducing invasive species, spreading diseases, and overexploiting resources. Understanding these impacts is essential to develop effective conservation and restoration strategies.

5.1 Objectives

After studying this unit, you should be able to:

  • Explain the relationship between human population growth and biodiversity loss.
  • Describe the various ways humans impact biodiversity.
  • Understand the consequences of habitat destruction, fragmentation, and degradation.
  • Identify how overexploitation, invasive species, and diseases affect ecosystems.
  • Recognize the urgency for conservation strategies and sustainable practices.

5.2 Human Population Growth and Its Impact

The exponential growth of the human population has led to increased demand for food, water, energy, and land. This demand accelerates land conversion, pollution, and exploitation of biological resources. The result is a decline in species diversity, disruption of ecological balance, and loss of ecosystem services.

Key impacts include:

  • Urban expansion into natural habitats.
  • Increased agricultural land leading to deforestation.
  • Pollution from industries and agriculture.
  • Higher carbon emissions contributing to climate change.

5.3 Habitat Destruction

Habitat destruction is the complete elimination of a habitat, making it impossible for local flora and fauna to survive. It is one of the most direct and irreversible causes of biodiversity loss.

Examples:

  • Deforestation for timber and agriculture.
  • Draining wetlands for urban development.
  • Mining and infrastructure projects.

5.4 Habitat Fragmentation

Fragmentation refers to the breaking up of large, continuous habitats into smaller, isolated patches. While some habitat remains, it becomes too small or disconnected to support viable populations.

Consequences:

  • Reduced genetic exchange between populations.
  • Increased edge effects that alter microclimates.
  • Higher vulnerability to external disturbances.

5.5 Habitat Transformation

Habitat transformation involves converting natural ecosystems into human-dominated landscapes such as urban areas, agricultural fields, or industrial zones.

Results:

  • Loss of original biodiversity.
  • Dominance of human-adapted or invasive species.
  • Disruption of ecological processes and nutrient cycles.

5.6 Habitat Degradation

Unlike outright destruction, degradation refers to the deterioration of habitat quality, making it less suitable for wildlife.

Causes include:

  • Pollution (air, water, soil).
  • Introduction of toxins and plastics.
  • Noise and light pollution.
  • Climate change impacts such as temperature shifts and altered rainfall patterns.

5.7 Overexploitation

Overexploitation is the excessive use of species and natural resources beyond their capacity to replenish. This includes overfishing, poaching, illegal logging, and unsustainable harvesting of medicinal plants.

Examples:

  • Collapse of marine fish stocks.
  • Decline in tiger and rhinoceros populations due to poaching.
  • Unsustainable collection of forest products.

5.8 Invasive Species

Invasive species are non-native organisms introduced by human activity that outcompete, prey on, or otherwise harm native species and ecosystems.

Impacts:

  • Displacement or extinction of native species.
  • Alteration of habitat structure and nutrient cycles.
  • Increased vulnerability to other stresses like disease and climate change.

Examples:

  • Lantana in Indian forests.
  • Zebra mussels in North American lakes.
  • Nile perch in African lakes.

5.9 Disease

Human activity also contributes to the spread of diseases that can affect wildlife populations and biodiversity.

How this happens:

  • Introduction of domestic animal diseases into wild populations.
  • Climate change expanding the range of disease vectors (e.g., mosquitoes).
  • Reduced immunity in fragmented populations due to genetic bottlenecks.

Examples:

  • Chytrid fungus affecting amphibians globally.
  • Canine distemper virus in carnivores like African wild dogs.

5.10 Let Us Sum Up

Human activities significantly affect biodiversity through population pressures, habitat alterations, resource exploitation, and biological introductions. These impacts not only threaten species survival but also destabilize ecosystem functions and services that humans depend on. Addressing these challenges requires coordinated conservation strategies, sustainable development, and global cooperation.

5.11 Keywords

  • Biodiversity: Variety of life in all forms—genetic, species, and ecosystem.
  • Habitat Destruction: Complete removal of a habitat.
  • Fragmentation: Division of habitat into smaller, isolated sections.
  • Degradation: Decline in habitat quality.
  • Overexploitation: Unsustainable harvesting of natural resources.
  • Invasive Species: Non-native species causing harm to native biodiversity.
  • Conservation: Protection and management of biodiversity.

 

Comments

Post a Comment

Popular Posts

Jcert Class 8 Daffodil Chapter 1a: The Naive Friends Solutions

-
Chapter 1a : The Naive Friends Answer the following questions: 1. Which questions made Keshav and Shyama curious about the egg? Ans.         How did the chick come out? How big would the eggs? How many? What colours would they? What did they eat? Such types of questions made Keshav and Shyama curious about the egg. 2. What three things did the children do to protect the eggs? Ans.         The children done three things are: (i)          Adjustment of food. (ii)        Adjustment of water. (iii)      Adjustment of roof. 3. Why did Keshav think of making a cushion for the eggs? Ans.         When Keshav saw the egg on direct sun light, he thaught making a cushion for the eggs. 4. What excuse did Keshav give for not showing the eggs to Shyama? Ans.     ...
Read more

Jcert Class 8 भाषा मंजरी Chapter 3 मित्रता Solutions

-
अध्याय - 3 : मित्रता 1. आप किस प्रकार कह सकते हैं कि मित्रों के चुनाव की उपयुक्तता पर हमारे जीवन की सफलता निर्भर करती है? उ. मित्रों के चुनाव की उपयुक्तता पर हमारे जीवन की सफलता निर्भर करती है क्योंकि संगति का गुप्त प्रभाव हमारे आचरण पर पड़ता है और यदि हमें अच्छी संगति, अच्छे मित्र मिलते हैं तो वे हमें सफलता की ओर ले जाते हैं जबकि बुरी संगति हमारे जीवन को खाक में मिला देती है।  2. 'विश्वासपात्र मित्र जीवन की एक औषध है।' आशय स्पष्ट कीजिए। उ. 'विश्वासपात्र मित्र जीवन की एक औषध है'- ऐसा इसलिए कहा गया है कि यदि हमें विश्वासी मित्र मिल गया तो हम अपने जीवन में चाहे जैसा भी कदम उठाएँ, उस कदम की आलोचना करके वह हमें सही दिशा की ओर उन्मुख करेगा। हम अपनी गलती रूपी बीमारी को उसकी आलोचना रूपी औषधि से दूर कर सकेंगे।  3. मित्र का चुनाव करते समय हमें किन बातों का ध्यान रखना चाहिए? उ. मित्र का चुनाव करते समय हमें निम्नलिखित बातों का ध्यान रखना चाहिए हमारे अच्छे विचारों (संकल्पों) को दृढ़ करने वाला हो। हमें दोषों और त्रुटियों से बचाए। हमारे सत्य, पवित्रता ...
Read more

Jcert Class 8 भाषा मंजरी Chapter 8 अमरूद का पेड Solutions

-
अध्याय - 8 : अमरूद का पेड 1. लेखक को क्यों लगता है कि इन सब पिछड़े खयालातों का हमारे घर में गुजर नहीं हो सकेगा। उ. अमरूद के पेड़ को देखकर सबसे पहले बाबू कन्हैयालाल की बूढ़ी पत्नी ने एक दिन टोका कि पश्चिम की तरफ अगर मकान का मुखड़ा हो और सामने ही अमरूद का पेड़ तो 'राम-राम बड़ा अशुभ होता है और माँ के चेहरे पर थोड़ा-सा भय दिखा पर लेखक को विश्वास था कि इन सब पिछड़े खयालातों का हमारे घर में गुजर नहीं हो सकेगा क्योंकि उसके घर के लोग आधुनिक विचारधारा के थे उसकी माँ सत्याग्रह के दिनों में अजमेर में लम्बा जेल कर चुकी है। पिताजी खुद राजनैतिक सामाजिक उदारता वाले आदमी थे। बुआ ने विवाह नहीं किया था, पढ़ने-लिखने में ही अपनी सम्पूर्ण जिन्दगी लगा दी और समाज कोई चुनौती देने का साहस नहीं कर सका। साथ ही परिवार के सभी लोगों में पिछड़ेपन के प्रति भर्त्सना का भाव था। 2. अमरूद के पेड़ की छाया किस प्रकार लेखक को उनके भाई-बहनों के साथ जोड़ती है ? उ. अमरूद के पेड़ की छाया लेखक को उसके भाई-बहनों के साथ जोड़ती है। वे सभी अमरूद की छाया में बेंत की कुर्सियों पर बैठ चर्चाएँ करते थे जिससे उनके बीच...
Read more