Locations of Coral Reef Bleaching
BLEACHING OF CORAL REEFS BY OCEAN TEMPS > 85 deg 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.
Birch Decline 1930 -1960 and thaw-refreeze zone Area of thaw and refreeze Area of thaw only Border of dieback area
What’s Going On?
Climate Change and Other Environmental Stress impacts on North American Forests and Rangelands Presented to the North American Forestry Commission Integration Workshop March, 2008 Steven Mc. Nulty, USDA FS
400, 000 Years of Antarctic CO 2 and Temperature Change Source: Climate Change Impacts on the US, NAST, 2001
Northern Hemisphere Carbon Emissions Source: Climate Change Impacts on the US, NAST, 2000
Atmospheric CO 2 Concentrations Source: Climate Change Impacts on the US, NAST, 2000
Northern Hemisphere Surface Temperature Source: Climate Change Impacts on the US, NAST, 2000
What Will Happen Next? Presented in Order from Most to Least Likely
Certain Denial!!! (The current going rate is $1000 for any presentation against Global warming, but even at that rate, the conference could not Meet its target of 500 participants)
Certain change Atmospheric CO 2 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 with Increased Sea Level Rise Coastal forests will be inundated and coastal beach erosion will increase. Forest managers should 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
Large scale (> 400 ac) Wildfires and Air Temperature From Westerling et al. 2005
Management Strategy for Coping with Increased 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 control measures 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. 8 mm) BW 7 Karl et al. 1996
Areas of Soil Erosion By 2030 On UNF
Management Strategy for Coping with Increased 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
Timberland Acreage Shift 1993 – 2040: No Climate Change Baseline > 25% DECLINE 5%-25% DECLINE <5% CHANGE 5%-25% INCREASE
Timberland Acreage Shifts by 2040 Due to Hadley Climate Change 5%-25% DECLINE <5% CHANGE 5%-25% INCREASE
Management Strategy for Coping with Changing Rangeland Forest Productivity Work with local land owners to examine alternative crops (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 NE 265
Sugar maple Iverson et. al GTR NE 265
Loblolly pine Iverson et. al GTR NE 265
Sweetgum Iverson et. al GTR NE 265
Less Likely Impacts Increasing western North American water crisis
Unknown Impacts of Climate Change Integrated stress impacts
Example of Critical Load Calculated for N Across Canada 2004 Canadian Acid Deposition Science Assessment
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 = 0 Mortality = 0% + 3 yr Drought Stress N dep = 10 kg/ha/yr S dep = 10 kg/ha/yr + 3 yr Drought Stress + fire Critical N > 10 kg Load N leaching = 1 Mortality = 10% N leaching = 15 Mortality = 75% Critical = 10 kg Load Critical = 8 kg Load N leaching = 25 Mortality = 100% Critical < 5 kg Load
Conclusions There is much we understand about climate change and the impacts it is having and will continue to have on North American rangelands and forests. There also management strategies that can be used to 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 the rate and ultimate level of climate change. Much of this uncertainty is due to the uncertainty of society to address future green house gas emissions.
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