2 - Biodiversity and the Biodiversity Crisis F24

Page 1: Biodiversity Trends

• Graph shows changes in biodiversity over time from 1500 to 2014.

• Decline shown in mammals, birds, and other vertebrates.

• Indicates a biodiversity crisis with measurable impacts on vertebrates.

Page 2: Understanding Biodiversity

• Biodiversity Definition: Often equated with species diversity (variety of species in an area).

• It encompasses not only species diversity but also genetic and ecosystem diversity.

• Species Diversity Levels:

  • High Species Diversity

  • Medium Species Diversity

  • Low Species Diversity

Page 3: Types of Diversity

• Species Diversity:

  • Refers to the variety of species and their abundance in an area.

    • Variety = Number of different species.

    • Abundance = Total number of individuals of each species.

• Genetic Diversity:

  • Variety of heritable characteristics in a population of interbreeding individuals.

• Ecosystem Diversity:

  • Variety of ecosystems in the biosphere.

Page 4: Importance of Diversity

• Species diversity contributes to ecosystem resilience.

• Resilience: Ability of an ecosystem to remain stable under disturbances.

• High species diversity ecosystems withstand biotic and abiotic changes better than low diversity ecosystems.

Page 5: Resilience in Ecosystems

• Comparison: High species diversity ecosystems vs. low species diversity ecosystems.

• Higher resilience protects against threats like diseases.

• Example: A disease outbreak affects one species; more diverse ecosystems can adapt better.

Page 6: Genetic Diversity and Disease Resistance

• Critical for populations' survival against diseases.

• Low genetic diversity increases susceptibility to disease.

• Genetic diversity also aids in adapting to environmental changes.

Page 7: Importance of Ecosystem Diversity

• Influences the species diversity observed across the globe.

• Different environmental conditions are essential for speciation.

• Ecosystem diversity enhances the range of ecosystem services.

Page 8: Ecosystem Services Overview

• Ecosystem Services: Benefits from sustainable ecosystems.

• Essential for human and ecological welfare.

• Loss of ecosystem diversity would lead to the loss of vital services.

Page 9: Types of Ecosystem Services

• Atmospheric gas supply: Regulation of gases like carbon dioxide and oxygen.

• Climate regulation: Control over greenhouse gases.

• Water supply: Provision for irrigation and industrial needs.

• Pollination: Critical for food production.

• Ecological control: Management of pest populations.

• Wilderness habitats: Essential for wildlife sustainability.

• Food production: Crops and livestock.

• Raw materials: Sources for various industries.

• Genetic resources: Medicines and resistance genes.

• Recreation and Cultural benefits: Aesthetic and educational resources.

• Waste treatment: Natural purification processes.

• Soil erosion control: Retention of topsoil.

• Nutrient recycling: Essential cycles in ecosystems.

Page 10: Why Measure Biodiversity?

• Understanding biodiversity helps:

  1. Plan for land-use appropriately.

  2. Locate rare and sensitive species needing protection.

  3. Identify species critical for ecosystem interactions.

  4. Recognize biodiversity hotspots.

Page 11: Biodiversity Hotspots

• Definition: Areas with high species numbers in small zones.

• Examples:

  • Carolinian Canada: Small landmass yet has the highest biodiversity in Canada.

  • Leitrim Wetlands: Rich species variety, 200 plant species and 90 bird species.

• Some hotspots get special status to prevent development.

Page 12: Biodiversity in the Tropics

• Tropics host the highest biodiversity globally.

• 77% of vertebrate animals inhabit tropical hotspots.

• These regions comprise 16% of Earth’s surface, mainly in developing countries needing aid for ecosystem protection.

Page 13: Threats to Biodiversity

• Human actions lead to drastic ecological changes.

  • Examples: Deforestation, wetland drainage, invasive species.

• Such changes pose significant threats to biodiversity.

Page 14: Habitat Loss

• Definition: Destruction of habitats due to human activities or natural disasters.

• Habitat loss limits access to essential biotic and abiotic factors, leading to species loss.

Page 15: Deforestation

• The clearing of forests causes considerable habitat loss and reduces biodiversity.

• Particularly prevalent in tropical regions, impacting hotspots significantly.

Page 16: Draining Wetlands

• Wetlands are often drained for agriculture or development.

• Canada retains 24% of the world’s wetlands; hence, protection is vital for biodiversity.

Page 17: Habitat Fragmentation

• Occurs when human development divides habitats.

• Consequences of fragmentation:

  • Increased outside influence on habitats.

  • Reduced habitat connectivity.

  • Decreased species interactions and overall biodiversity.

Page 18: Invasive Species

• Definition: Species that disrupt native ecosystems.

• Invasive species hinder resource availability for native species, leading to biodiversity loss.

• Example: Purple loosestrife in Ontario.

Page 19: Overexploitation

• Refers to the excessive use of resources leading to depletion.

• Can cause dangerously low populations, increasing extinction risks and reducing biodiversity.

Page 20: Global Warming and Climate Change

• Rising global temperatures lead to climate changes affecting species adaptation.

• Species unable to adapt quickly will decline, reducing biodiversity.

Page 21: Key Drivers of Species Decline

• Findings from the Living Planet Report:

  • Habitat degradation, exploitation, invasive species, pollution, climate change.

• Species assessed: Birds, reptiles, mammals, fish.

Page 22: The Biodiversity Crisis

• Currently experiencing the 6th mass extinction (Holocene extinction).

• Sometimes referred to as the Anthropocene extinction due to human influences.

Page 23: Extinction Defined

• Extinction: End of all individuals of a species due to higher death rates than birth rates.

• Caused by factors:

  • Natural (biological/abiotic changes) or Human-induced.

• Results in reduced biodiversity.

Page 24: Types of Extinction

• Background Extinction:

  • Gradual, over long periods, with new species evolving.

• Mass Extinction:

  • Sudden and significant changes in ecosystems results in rapid declines in species.

Page 25: Current Extinction Rates

• Current rates are up to 1,000 times higher than normal background rates.

• Driven largely by human activity, contributing to the biodiversity crisis.