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:
Plan for land-use appropriately.
Locate rare and sensitive species needing protection.
Identify species critical for ecosystem interactions.
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.