(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Ecosystems (from IPCC WG-2, Chapters 4,9-16) Ecosystems Primary Source: IPCC WG-2 Chapter 4 - Ecosystems, their properties, goods and services (Plus parts of WG-2 Chapters 9-16)

(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Ecosystems (from IPCC WG-2, Chapters 4,9-16) 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”

(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Ecosystems (from IPCC WG-2, Chapters 4,9-16) Ecosystem Goods & Services - 1  Supporting services Primary and secondary production Primary and secondary production Biodiversity Biodiversity  Provisioning services Food Food Fibre Fibre Medicinal and cosmetic products Medicinal and cosmetic products

(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Ecosystems (from IPCC WG-2, Chapters 4,9-16) Ecosystem Goods & Services - 2  Regulating services Carbon sequestration Carbon sequestration Climate and water regulation Climate and water regulation Buffering natural hazards (e.g., floods) Buffering natural hazards (e.g., floods) Water and air purification Water and air purification Disease and pest regulation Disease and pest regulation  Cultural services Human spiritual & aesthetic appreciation Human spiritual & aesthetic appreciation

(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Ecosystems (from IPCC WG-2, Chapters 4,9-16) Major Ecosystems: Areas and Carbon Stocks Transformed by land use

(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Ecosystems (from IPCC WG-2, Chapters 4,9-16) 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?

(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Ecosystems (from IPCC WG-2, Chapters 4,9-16) 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

(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Ecosystems (from IPCC WG-2, Chapters 4,9-16) Key Issues - Critical Thresholds Exceding critical threshold  positive feedbacks  novel states, poorly understood  novel states, poorly understood “Climate future and direct human pressures ‘virtually certain’ to be unprecedented vs. past 100s millenia”

(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Ecosystems (from IPCC WG-2, Chapters 4,9-16) 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)?

(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Ecosystems (from IPCC WG-2, Chapters 4,9-16) 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?

(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Ecosystems (from IPCC WG-2, Chapters 4,9-16) 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

(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Ecosystems (from IPCC WG-2, Chapters 4,9-16) Example: Europe’s Key Vulnerabilities Criteria: large impacts, low adaptive capacity, substantial population, economically important, substantial exposed infrastructure, and subject to other major stresses Colors: Main biogeographic regions (EEA, 2004)

(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Ecosystems (from IPCC WG-2, Chapters 4,9-16) 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 (Using HadCM3, A1F1 Scenario) Richness   Green  Richness   Purple 

(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Ecosystems (from IPCC WG-2, Chapters 4,9-16) Latin America: Deforestation Predicted Deforestation Areas Latin America GHG emissions = ~ 4% of global total ( ~ 50% from land-use change) Up to 40% loss of mammalian habitats by Important driver: soybean planting [38 Mha (2003/04)  59 Mha (2019/20)]

(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Ecosystems (from IPCC WG-2, Chapters 4,9-16) North America: Forest Fires Effect of projected precipitation and (precipitation - evaporation) changes? Other stresses (e.g., pests)?

(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Ecosystems (from IPCC WG-2, Chapters 4,9-16) North America: Bud Burst Effect on other parts of ecosystem (e.g., pollinating insects)?

(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Ecosystems (from IPCC WG-2, Chapters 4,9-16) Arctic: Ecosystem Changes Dynamic vegetation model driven by HadCM2 ( )

(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Ecosystems (from IPCC WG-2, Chapters 4,9-16) Coral Bleaching Stresses include: Increased ocean acidity (pH) Increased ocean acidity (pH) Stronger storms Stronger storms Over-fishing Over-fishing Pollution Pollution Cycles such as ENSO & Warmer SST Cycles such as ENSO & Warmer SST Threats from pollution, development, fishing, sediments, nutrients Low: Blue High: Red

(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Ecosystems (from IPCC WG-2, Chapters 4,9-16) Future Coral Bleaching Stresses: Increased ocean acidity (pH): No current link Increased ocean acidity (pH): No current link Stronger storms: Possible in future Stronger storms: Possible in future Others: over-fishing, pollution, cycles such as ENSO Others: over-fishing, pollution, cycles such as ENSO Warmer SST:  T > ~ 1 ˚C above summer max. for 4+ weeks 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?

(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Ecosystems (from IPCC WG-2, Chapters 4,9-16) Coral Bleaching Events vs. SST

(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Ecosystems (from IPCC WG-2, Chapters 4,9-16) Projected Risks vs.  T Not Included: Effects of over-harvesting, pollution, land-use change, habitat fragmentation

(Mt/Ag/EnSc/EnSt 404/504 - Global Change) Ecosystems (from IPCC WG-2, Chapters 4,9-16) END Ecosystems