locations of coral reef bleaching bleaching of coral reefs by ocean temps > 85deg f (29 deg c)

Locations of Coral Reef Bleaching

BLEACHING OF CORAL REEFS BY OCEAN TEMPS > 85deg F (29 deg C)

Spring bud-burst dates for Aspen in Edmonton,

Beaubien and Freeland I.J.Biomet 44:53-59, 2000

The increase in growing season length over the last 50 years averaged for eight stations in Alaska having the longest and most consistent temperature records.

Area of thaw and refreeze

Area of thaw only

Border of dieback area

Birch Decline 1930-1960 and thaw-refreeze zone

What’s Going On?

Climate Change and Other Environmental Stressimpacts on North American

Forests and Rangelands

Steven McNulty, USDA FS

Presented to the North American Forestry Commission Integration Workshop

March, 2008

400,000 Years of Antarctic CO2 and Temperature Change

Source: Climate Change Impacts on the US, NAST, 2001

Northern Hemisphere Carbon Emissions


Atmospheric CO2 Concentrations


Northern Hemisphere Surface Temperature


What Will Happen Next?

Presented in Order from Most to Least Likely

Denial!!!(The current going rate is $1000 for any presentation against Global warming, but even at that rate, the conference could notMeet its target of 500 participants)

Certain

Certain change

Atmospheric CO2 will continue to increase

Extremely Likely

Water and air temperature will continue to increase

“Simulations of the response to natural forcings alone … do not explain the warming in the second half of the century” SPM

Stott et al, Science 2000

“..model estimates that take into account both greenhouse gases and sulphate aerosols are consistent with observations over this period” SPM

Stott et al, Science 2000

Management Strategy for Coping withIncreased Sea Level Rise

Coastal forests will be inundated and coastal beach erosion will increase. Forest managersshould work with land owners at a local scale to plant mangroves and other soil retention vegetation to delay terrestrial loss for a long as reasonably possible.

Likely Impacts

Changing Patterns in Wildfire Occurrence

Average Annual CO2 Emitted to Atmosphere Due to Fire, Projected to 2050

050

100150200250300350400

Decade

TgC

O2

Fire (lower 48)

Fire (AK)

total

Large scale (> 400 ac) Wildfires and Air Temperature

From Westerling et al. 2005

Average Yearly Gross CO2 Emitted to Atmosphere Due to Fire Disturbance in Alaska by Decade

0

5

10

15

20

25

1920s 1930s 1940s 1950s 1960s 1970s 1980s 1990s 2000s

Decade

TgC

O2

Management Strategy for Coping withIncreased Wild Fire

Manage for and encourage more fire tolerant grass and tree species

Increase public education and preparedness regarding wild fire prevention and individual preparation and control

Compared to climatic drivers, fuel reduction controlmeasures will be largely ineffectual

Likely Impacts

Inter-annual precipitation variability and soil erosion

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. 1996

BW 7

Areas of Soil Erosion By 2030 On UNF

Management Strategy for Coping withIncreased Soil Erosion

Continue to encourage standard soil erosion control practices such as contour plowing, winter cropping, shelter belts, and buffer strips

Relocate trails away from streams

Use bridge mats and culverts at stream crossings

Likely Impacts

Changes in Productivity and Economic Value

> 25% DECLINE

5%-25% DECLINE

<5% CHANGE

5%-25% INCREASE

Timberland Acreage Shift 1993 – 2040: No Climate Change Baseline

Timberland Acreage Shifts by 2040 Due to Hadley Climate Change

5%-25% DECLINE

<5% CHANGE

5%-25% INCREASE

Management Strategy for Coping withChanging Rangeland and Forest Productivity

Work with local land owners to examine alternativecrops (e.g., shift from red pine to loblolly pine plantations or from corn to wheat) as climate shifts occur

Examine options for changing management strategy for exists crops (e.g., wider tree planting,fewer head per acre)

Less Likely Impacts

Gradual Ecosystem Shifts

American beech

Iverson et. al GTR NE265

Sugar maple


Loblolly pine


Sweetgum


Less Likely Impacts

Increasing western North American water crisis

Unknown Impacts of Climate Change

Integrated stress impacts

2004 Canadian Acid Deposition Science Assessment

Example of Critical Load Calculated for N Across Canada

Examples of Critical Loads in the US

How a different critical nitrogen load could be determined within the same ecosystem

N dep = 10 kg/ha/yr

N leaching = 0Mortality = 0%

Critical N > 10 kgLoad

N dep = 10 kg/ha/yr


Critical = 10 kgLoad

+ 3 yr Drought Stress

N dep = 10 kg/ha/yrS dep = 10 kg/ha/yr


Critical = 8 kgLoad

+ 3 yr Drought Stress

N dep = 10 kg/ha/yr


Critical < 5 kgLoad

+ 3 yr Drought Stress+ fire

S dep = 10 kg/ha/yr

Conclusions

There is much we understand about climate changeand the impacts it is having and will continue to have onNorth American rangelands and forests.

There are also management strategies that can be usedto minimize some of the negative impacts of climate change

However, while we have great confidence in the direction of climate change, there remains uncertainly regarding therate and ultimate level of climate change. Much of this uncertainty is due to the uncertainty of society to addressfuture green house gas emissions.

locations of coral reef bleaching bleaching of coral reefs by ocean temps > 85deg f (29 deg c)

Documents