Global climate change is now a fact of life. There is now unequivocal evidence that the earth is warming faster than at any other time in recorded history (IPCC, 2007). The predicted impacts include changes in weather patterns, increases in mean temperatures, changes in patterns of precipitation, increasing evidence of extreme climatic events, and increasing sea levels (Harris, et al, 2006).
The Midwestern Drought of 2012
For Wisconsin, predicted climate changes include, as much as a 25% increase in winter precipitation and “summer precipitation could decrease by as much as 20% by the end of this century,” (Kling et al, 2003, cited in Glass, Herrick, and Kucharik, 2009.) We may be on the way toward reaching that dubious milestone. In 2012 as of September 24, the Madison rainfall deficit for the year is 9.1 inches, or 33% below normal. The NWS reported on September 20, that for various locations across southern Wisconsin, including Madison, for the period June to mid-September the rainfall deficit ranged from 4″ to 9″, which “is generally 25% to 50% below normal.” (NWS)
Yet, the human scale perception of these changes, and their possible impacts on our everyday lives, has not caught up with this new reality. When I think of this perceptual gap, I’m reminded of an interpretive sign at the Moraine Park Visitor Center in Rocky Mountain National Park. In a display about weather and climate, the park rangers offered this definition: “Climate is what you expect, weather is what you get.” But, most of us are, in fact, still expecting that old climate. This outlook represents something between optimism and inattention, and evidence of its strong hold on us is everywhere. A few examples:
1. There is a steady drumbeat of “happy talk” by our local TV and radio weather forecasters about nice sunny skies, and cool days in the face of the fact (according to the National Weather Service) that Dane County and southern Wisconsin are in a “severe drought” while much of the rest of Wisconsin is in either “moderate or extreme drought?”
2. Some few citizens are conscientiously deep watering their trees and shrubs with the aim of easing the stress and coaxing them through till next year, but many others are only watering their dormant lawns or doing nothing at all.
3. You are not likely to receive coverage of the drought or climate change from local newspapers. If you want to know why you should be concerned and why you should water your trees and shrubs from now until the ground is frozen, you should take note of this report from the NWS:
“SOIL MOISTURE CONDITIONS…CALCULATED SOIL MOISTURE CONDITIONS…AS
OF SEPTEMBER 17…REMAINED VERY DRY IN THE 0 TO 4 INCH LAYER.
MOISTURE VALUES BETWEEN 0.125 AND 0.50 INCHES WERE PREVALENT OVER
SOUTHERN WISCONSIN. IN ADDITION…THE AVERAGE SOIL MOISTURE ANOMALY
IN THE TOP 40 INCHES OF SOIL IS 4 TO 6 INCHES BELOW NORMAL…WHICH
IS EXTREMELY DRY.”
I present it here because this information was ignored by the Wisconsin State Journal (Crop Report, Tuesday September 25, 2012, Section D, Page 1) but reported on the equally serious impacts of the drought on Wisconsin’s agricultural economy.
How can one explain this apparent obliviousness to the rest of the natural world?
Restoration and Management Concerns
But if we worry about effects of the current drought on our street and yard trees, we should be really concerned about our native ecosystems and restoration projects. What’s happening in the urban environment is nothing compared to the likely impacts on our woodlands, wetlands, prairies, and wetlands. For those of us planting new restorations, will we be able to keep young trees, shrubs, wildflower plants alive? Under what circumstances will it make sense to seed new grasslands? What will be the survival rate during this drought of immature restorations initiated just a few years ago?
Another major restoration and management challenge in Madison, Dane County and southern Wisconsin include likely wide swings in precipitation amounts: either drought or increased precipitation from increased frequency of intense severe events–or maybe both but no middle ground. Increased severity of precipitation events will mean higher peak flows from storm water, leading to erosion of native soils, introduction of seeds of pest plants, and aid the spread invasive pest plants through sedimentation, flooding, and runoff containing nitrogen and road salts (Kercher, et al, 2007.)
Another restoration challenge we could face is the potential reduction in effectiveness of standard restoration techniques such as prescribed burning. Given the possibility of an increasingly warmer and drier Wisconsin over the next century, prescribed burning may become increasingly dangerous with extremely low relative-humidity levels, fewer appropriate air-quality days, and drier, more combustible fuel loads. More planning and resources may be necessary to conduct safe burns, which in certain cases may need to be supplemented or replaced altogether with other, and, depending upon the situation and restoration goals, potentially less effective techniques such as mowing or rotational grazing. (Glass, et al, 2009).
New Approaches Needed
The effects of climate change combined with existing habitat fragmentation, continued urbanization, pest species, and hydrological modifications are strong incentives to use adaptive restoration and management techniques in planning for long-term restoration projects. This will mean that restoration targets will be dynamic instead of rigidly based upon a historic reference condition (Harris, et al, 2006).
Rather than working toward a single community type, a restoration may have moving end points, such that as climatic conditions change, so too does the target community. This approach will need using all the tools in the restoration toolbox, as well as new tools that will be developed through field research and lessons learned.
“Unpredictable dimensions of global climate change add layers of uncertainty to the already complicated and difficult job of restoration. But restoration is well equipped for this uncertainty. As restorationists, we understand that natural systems are variable in space and time and that each natural community has a unique history in terms of first conditions, disturbances and land use histories.” (Glass, Herrick, and Kucharik, 2009). With this awareness restorationists will be able to create a range of flexible project goals that respond to unanticipated situations.
Glass, S.B., B.M. Herrick, and C.J. Kucharik, 2009. Climate Change and Ecological Restoration at the University of Wisconsin-Madison Arboretum. Ecological Restoration 27: 3
Harris, J.A., R.J. Hobbs, E. Higgs, and J. Aronson, 2006. Ecological restoration and global climate change. Restoration Ecology 14: 170-176.
Intergovernmental Panel on Climate Change (IPCC). 2007. Climate change 2007: Synthesis report: Summary for policy-makers. Valencia, Spain: IPCC. www.ipcc.ch/pdf/assessmeny-report/ar4/syr/ar4_syr_spm.pdf
Kercher, S.M., A. Herr-Turoff and J.B. Zedler. 2007. Understanding invasion as a process: The case of Phalaris arundinacea in wet prairies. Biological Invasions 9: 657-665.
Kling, G.W., K. Hayhoe, L.B. Johnson, J.J. Magnuson, S. Polasky et. al. 2003. Confronting climate change in the Great Lakes region: Impacts on our communities and ecosystems. Union of Concerned Scientists and Ecological Society of America. www.ucsusa.org/greatlakes/glchallengereport.html