Climate Change Effects on Biodiversity and Conservation Biology (lect. 10/09)

Climate Change and Its Impacts on Biodiversity

Overview of Climate Change Impacts

  • Discussion on species affected by climate change

  • Focus on critically endangered species and biodiversity

  • Transition to conservation biology methods and interventions

Conservation Biology

  • Definition: Application of population ecology, ecosystem ecology, and community ecology to prioritize conservation efforts

  • Importance of selecting which species or ecosystems to preserve

  • Examples of actions taken by conservation biologists to mitigate issues

Effects of Climate Change on Biodiversity

Abiotic Impacts

  • Reduction in ice and snow due to rising temperatures which decreases albedo (reflectivity of surfaces)

    • More sunlight absorbed leads to further warming

    • Positive feedback loop: Higher temperatures result in more snow and ice melt

  • Desertification as regions become hotter and drier

    • Transformation of biomes (e.g., grasslands to deserts), decreases photosynthesis, increases atmospheric CO₂ levels

  • Biochemical reactions and cellular respiration increase with temperature, affecting the cycles of greenhouse gases

  • Changes in patterns of fire in various ecosystems due to drier conditions, leading to greater CO₂ release from burning biomass

Positive and Negative Feedback Mechanisms

  • Positive Feedback: Increased temperatures lead to more evaporation and greenhouse gases (e.g., methane from bacteria)

    • Example: Warmer oceans can release more CO₂ reducing solubility which continues the cycle of warming

  • Negative Feedback: Increased clouds and evaporative cooling can reflect sunlight and mitigate temperatures

    • Example: Tundra replacing with boreal forests increases photosynthesis, absorbing CO₂

  • Variability of feedback loops based on geographical contexts (deserts, tundra)

Identification of Positive/Negative Feedback in Examples

  • Breakdown of tundra to forest as both positive (more CO₂ absorption) and negative feedback (reduction of snow albedo)

  • Effects of stratification in oceans on nutrient upwelling hindering marine primary productivity

Shift in Species Distributions

  • Range Shifts: Many species are adjusting their ranges due to changing climate conditions

    • Average movement of about 11 meters per year observed for some species such as damselflies and dragonflies

    • Potential drawbacks for new ecosystems: Increased competition, pathogens, and predation risks

Extinction Events

  • Two notable extinctions:

    • Golden Toad: Specialized species impacted by climate and disease

    • Bramble Cay Mouse: Habitat loss due to rising sea levels

  • Ongoing concern: By 2100, up to 14-32% of species could face extinction due to climate change effects

Phenological Shifts and Mismatches

  • Organisms depend on environmental cues for key life events (breeding, migration)

    • Example: Laying eggs and peak caterpillar populations not coinciding results in offspring survival issues

Coral Reefs and Climate Change

  • Importance of coral-algae mutualism in ecosystem health

  • Coral bleaching due to temperature and ocean acidification resulting from climate change—experiencing increased mortality rates and habitat degradation

Predictions for Future Climate Change

  • Current models project significant temperature increases leading to enhanced desertification and habitat loss

  • Rising sea levels: Projected to be approximately $7.2$ feet by 2100 due to melting glaciers, affecting coastal ecosystems

  • Inequitable impacts on precipitation patterns globally, varying effect on different geographical areas

Habitat Destruction and Its Consequences

  • Habitat destruction reports and cause of large declines in biodiversity due to deforestation for agriculture (specifically palm oil) and illegal logging

  • Monocultures leading to lesser quality habitats affecting native species availability

Global Monitoring of Species' Status

  • Utilization of IUCN data to monitor species' endangerment

    • Categories: Critically endangered, endangered, vulnerable, and extinct status

  • North America vs. South America: Highlighting the differences in biodiversity and threats to species

Conclusion

  • Climate change exacerbates existing pressures on biodiversity, highlighting the need for sustained conservation efforts and global collaborations to mitigate effects.