Premise Three Basic Forms of Uncertainty - Level of Change - Process Impacts - Time and Space 1

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Premise Three Basic Forms of Uncertainty - Level of Change - Process Impacts - Time and Space 3

Simulated Temperature over the US Source: Climate Change Impacts on the US, NAST,

Premise Three Basic Forms of Uncertainty - Level of Change - Process Impacts - Time and Space 5

ha Landscape Region 1/10 ha Week Month Year Decade Century Landscape Dynamics Forest Selection Tree Disease Forest Competition Species Selection Species Competition Biome Selection Biome Competitio n Insect Scale Uncertainty 6

Global Change Certainty across Southeastern United States Ecosystems: Impacts and Implications Steven McNulty Research Ecologist USDA Forest Service Raleigh, NC 7

Global change impacts range from the certain to the unknown 8

Certain change Increased atmospheric CO 2 9

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Very Likely Impacts In Southeastern Forests (independent of climate change) Increased Population Increased Fuel loads 11

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This will lead to… Further forest fragmentation Further restrictions in forest management options Increase Fire Severity and Frequency 16

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Likely Impacts In Southeastern Forests (with and without climate change) Inter-annual precipitation variability 18

Percent of the continental USA with a much above normal proportion of total annual precipitation from 1-day extreme events (more than 2 inches or 50.8mm) Karl et al BW 7 19

= +119% 20

= +232% 21

Uwharrie National Forest Current Soil Erosion Map 22

Areas of Soil Erosion By 2030 On UNF 23

American beech Iverson et. al GTR NE265 24

Sugar maple Iverson et. al GTR NE265 25

Likely Impacts In Southeastern Forests (with and without climate change) Inter-annual precipitation variability Extended growing season and warming 26

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> 25% DECLINE 5%-25% DECLINE <5% CHANGE 5%-25% INCREASE Timberland Acreage Shift 1993 – 2040: No Climate Change Baseline 30

Timberland Acreage Shifts by 2040 Due to Hadley Climate Change 5%-25% DECLINE <5% CHANGE 5%-25% INCREASE 31

Unlikely Impacts In Southeastern Forests (dependent of climate change) 32

Loblolly pine Iverson et. al GTR NE265 33

Sweetgum Iverson et. al GTR NE265 34

Unknown Impacts In Southeastern Forests (dependent of climate change) Increasing CO 2 on forest growth Insect and disease impacts Integrated stress impacts 35

How a different critical nitrogen load could be determined within the same ecosystem N dep = 10 kg/ha/yr N leaching = 0 Mortality = 0% Critical N > 10 kg Load N dep = 10 kg/ha/yr N leaching = 1 Mortality = 10% Critical = 10 kg Load + 3 yr Drought Stress N dep = 10 kg/ha/yr N leaching = 15 Mortality = 75% Critical = 8 kg Load + 3 yr Drought Stress + insects N dep = 10 kg/ha/yr N leaching = 25 Mortality = 100% Critical < 5 kg Load + 3 yr Drought Stress + insects S dep = 10 kg/ha/yr 36

Conclusions There is sufficient certainty regarding several areas of global change for assessing probable ecosystem impacts across the southern US during the next 50 years Other less certain impacts need to be prioritized for future research study based on cost and potential impact Synergistic impacts will be very difficult, if not impossible to predict 37

Conclusions (cont.) Thresholds and positive feedback impacts are poorly understood and could have the greatest potential for catastrophic change More emphasis should be placed on coping and mitigating those impact which have a high probability of occurrence while time and funding exist to address these issues 38