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Ecosystems

Ecosystems. Primary Source: IPCC WG-2 Chapter 4 - Ecosystems, their properties, goods and services (Plus parts of WG-2 Chapters 9-16). Ecosystem . From WG-2 Chapter 4:

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Ecosystems

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  1. Ecosystems Primary Source: IPCC WG-2 Chapter 4 - Ecosystems, their properties, goods and services (Plus parts of WG-2 Chapters 9-16)

  2. Ecosystem  From WG-2 Chapter 4: • “a dynamic complex of plant, animal and micro-organism communities, and the non-living environment, interacting as a functional unit” • “strong interactions between components within their boundaries and weak interactions across boundaries”

  3. Ecosystem Goods & Services - 1 • Supporting services • Primary and secondary production • Biodiversity • Provisioning services • Food • Fibre • Medicinal and cosmetic products

  4. Ecosystem Goods & Services - 2 • Regulating services • Carbon sequestration • Climate and water regulation • Buffering natural hazards (e.g., floods) • Water and air purification • Disease and pest regulation • Cultural services • Human spiritual & aesthetic appreciation

  5. Major Ecosystems: Areas and Carbon Stocks Transformed by land use

  6. Key Issues - Resilience Resilience  disturbance tolerated before shifting to a different state (e.g., forest  prairie) - also: ability to adapt naturally Expectation that ecosystems will tolerate some level of climate change and persist - Speed of (“stable”) transient responses?

  7. Key Issues - Other Human Pressures • Extractive use of goods • Increased degradation of natural habitats • Increased fragmentation of natural habitats Climate change can amplify these pressures

  8. Key Issues - Critical Thresholds Exceding critical threshold  positive feedbacks  novel states, poorly understood “Climate future and direct human pressures ‘virtually certain’ to be unprecedented vs. past 100s millenia”

  9. Key Issues - Time Lags Time needed for broad-scale biospheric responses or shifts in geographical ranges: poorly understood E.G.: • centuries for vegetation • millennia for soil formation Further understanding needed: How do ecosystems respond to continuously changing conditions (esp. on human time scales)?

  10. Key Issues - Species Extinctions Global extinction is a critical issue: Biodiversity is “very likely” linked to ecosystem functioning and maintenance of ecosystem services. What extinctions are critical for ecosystem functioning? How do they reduce societal options for adaptation?

  11. Example: “Hot Spots” in Australia & New Zealand Criteria: large impacts, low adaptive capacity, substantial population, economically important, substantial exposed infrastructure, and subject to other major stresses

  12. Example: Europe’s Key Vulnerabilities Colors: Main biogeographic regions (EEA, 2004) Criteria: large impacts, low adaptive capacity, substantial population, economically important, substantial exposed infrastructure, and subject to other major stresses

  13. Example: Europe - Change in Species Richness(Amphibians and Reptiles) Criteria: large impacts, low adaptive capacity, substantial population, economically important, substantial exposed infrastructure, and subject to other major stresses Richness   Green  Richness  Purple  (Using HadCM3, A1F1 Scenario)

  14. Latin America: Deforestation Predicted 2000-2100 Deforestation Areas Latin America GHG emissions = ~ 4% of global total ( ~ 50% from land-use change) Up to 40% loss of mammalian habitats by 2050. Important driver: soybean planting [38 Mha (2003/04)  59 Mha (2019/20)]

  15. North America: Forest Fires Effect of projected precipitation and (precipitation - evaporation) changes? Other stresses (e.g., pests)?

  16. North America: Bud Burst Effect on other parts of ecosystem (e.g., pollinating insects)?

  17. Arctic: Ecosystem Changes Dynamic vegetation model driven by HadCM2 (2090-2100)

  18. Coral Bleaching Threats from pollution, development, fishing, sediments, nutrients Low: Blue High: Red • Stresses include: • Increased ocean acidity (pH) • Stronger storms • Over-fishing • Pollution • Cycles such as ENSO & Warmer SST

  19. Future Coral Bleaching • Stresses: • Increased ocean acidity (pH): No current link • Stronger storms: Possible in future • Others: over-fishing, pollution, cycles such as ENSO • Warmer SST: T > ~ 1 ˚C above summer max. for 4+ weeks • expulsion of symbiotic zooxanthellae • fast-growing, bleaching-resistant genera dominate recovery Challenge for projections: How much does coral adapt?

  20. Coral Bleaching Events vs. SST

  21. Projected Risks vs. T Not Included: Effects of over-harvesting, pollution, land-use change, habitat fragmentation

  22. END Ecosystems

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