locations of coral reef bleaching bleaching of coral reefs by ocean temps > 85deg f (29 deg c)
TRANSCRIPT
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
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
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
“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.
Average Annual CO2 Emitted to Atmosphere Due to Fire, Projected to 2050
050
100150200250300350400
Decade
TgC
O2
Fire (lower 48)
Fire (AK)
total
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
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
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
> 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)
2004 Canadian Acid Deposition Science Assessment
Example of Critical Load Calculated for N Across Canada
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
N leaching = 1Mortality = 10%
Critical = 10 kgLoad
+ 3 yr Drought Stress
N dep = 10 kg/ha/yrS dep = 10 kg/ha/yr
N leaching = 15Mortality = 75%
Critical = 8 kgLoad
+ 3 yr Drought Stress
N dep = 10 kg/ha/yr
N leaching = 25Mortality = 100%
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.