Campuses:
By Becky Beyers
Editor’s note: Because of its location and traditions, some of CFANS’ best-known research deals with cold climates. But what happens to that research if, as experts expect, temperatures rise even a few degrees over the next decades? We asked five CFANS scientists to explain how a warmer climate might affect their research.
Dan Erkkila (’77–B.S., forest science; ’82–M.S., ’91–Ph.D., forest management), head of the North Central Research and Outreach Center in Grand Rapids, which has long been known for its work in breeding cold-hardy fruits, vegetables and wild rice, as well as for its forestry work:
Over time, NCROC researchers will definitely move their research work in new directions if the climate changes that we are hearing about do occur. Most of our research programs involve, in one way or another, growing agricultural or forest crops in the existing climate of northeast Minnesota. Rising mean temperatures and dewpoints, along with significant long-term changes in precipitation amounts and timing, will directly affect growth.
One of our competitive advantages as a research site has been our traditionally cooler, northern location. Our facility remains the only cold-weather hardiness evaluation site in the lower 48 states for fruit and vegetable crops. If, as a consequence of warming, the USDA plant hardiness zones move north, our ability to study cold-hardiness may cease. On the other hand, warming may produce longer growing seasons, meaning horticultural crops typically requiring warmer, southern locations may find new homes here. For example, northeastern Minnesota sites may be able to support more than cold-climate varieties for Minnesota’s growing grape industry.
Warming effects leading to longer growing seasons would likely have a positive effect on commercial wild rice production (California is now the largest producer of commercial wild rice in the U.S.). But we could also face new or variant diseases arising from moisture and humidity changes, and we would need to breed varieties with the shorter seed dormancy required for the changing dormant/growing seasons.
Forest geneticists and silviculturalists already are looking at how to address new disease and pest issues, as well as the ecologic changes that will alter the landscape. But we don’t yet know which species will survive as the coniferous forest biome transitions into a deciduous biome. 
Neil Anderson (’85– M.S., ’89–Ph.D., horticulture), professor in the Department of Horticultural Science who works in breeding ornamental and flowering plants for cold climates:
Recent shifts in climate have made breeding and selecting for cold tolerance (winter hardiness) a challenge. Snowfall cover, low soil and air temperatures, soil moisture levels, and frost heaving have varied widely each year since 2000, creating a quandary for focused research. While each winter is highly variable for all of these environmental extremes, the possibility still exists that one winter with a cold temperature dip could kill non-hardy plant materials.
In breeding for winter-hardy herbaceous plants, such as garden mums, lilies or gladioli, the standard procedure has always been to conduct extensive, replicated field testing over years and locations in order to select potential new cultivars with proven hardiness and outstanding garden performance. But with such unpredictable winters, our program has had to modify our selection procedures, expanding beyond field tests to include laboratory freezing tests and nondestructive phenotypic selection of other growth traits.
It may take years before the climatic shifts have adjusted and maintain consistency in summer and winter temperature ranges. Until this happens, however, flower breeding programs must stay vigilant in ensuring that the “winter hardy” selections are widely adaptable to the environmental variations and respond accordingly.
Patrick Huelman, associate professor in the Department of Bioproducts and Biosystems Engineering, and coordinator of the department’s Cold Climate Housing Center:
The climate would have to change a lot to affect what we look at in terms of heating and indoor air quality. But our increasingly warmer and more humid summer weather is creating some new challenges.
In this part of the world we haven’t really devoted a great deal of the housing research effort to how houses are affected by air conditioning. People use AC more frequently now, partly because of warm, humid summers but also because they’re just used to having it, at work and in their cars. So they’re running their home air conditioners more often and for longer stretches of time.
That affects buildings because of how moisture goes in and out through the walls (or more generically, the “building envelope.”) If you’re only worried about heating, you’d build the walls so the vapor barriers are on the inside of the walls and the outside part of the walls allows moisture to dissipate. But if you take that same wall with air conditioning on a hot, humid day—you may get moisture condensing on the inner side of the wall. We’re starting to see this problem today; as you run air conditioning more, that humidity collects inside the walls, and eventually can lead to problems with mold.
That’s the transition we’re in—it’s not so much because of climate change itself, but because of strong air conditioning use for indoor humidity control or perhaps for other reasons like allergens. We’re looking at ways to develop a building envelope that can be more responsive to both heating and cooling needs, and in newer houses there’s much more thought being given to how air conditioning is affecting that moisture flow now and in the future.
Tracy Twine, assistant professor in the Department of Soil, Water and Climate, who studies climate change and ecosystems at the Earth’s surface level:
It’s complicated, because the crops that grow in Iowa and places south of here are grown here too—corn and soybeans, for example. It’s going to get warmer everywhere, and that may help us because we’ll have a longer growing season. Crops like warm weather, so if anything our climate getting a few degrees warmer could benefit corn and soybeans. On the other hand, greater corn yields have been associated with cooler summers. So a warmer spring or fall might be better than a warmer summer.
But you also have to consider precipitation. In the last 20 years or so there’s been more precipitation, so if that continues we’d be in good shape. But we don’t have a lot of confidence that recent precipitation trends will necessarily continue.
Even predicting what will happen just in Minnesota is difficult—you have to consider the whole planet. We’re starting to look at what happens to vegetation as the levels of carbon dioxide and ozone increase at the ground level, and those factors may have just as big an effect on our crops and plants as temperature and precipitation trends. 
Jim Luby (’82–Ph.D., plant breeding and genetics), professor in the Department of Horticultural Science and one of the scientists who developed the Honeycrisp apple and cold-hardy Minnesota wine grapes:
I guess it will depend on when it gets warmer—in all seasons? More so in winter or summer?—and on how much warmer.
As for winter, I think with fruit and any perennial plant we need to remember that we still live in a continental climate with nothing but a couple thousand miles of cold, dark Canadian prairie and taiga between us and the Arctic—nothing to moderate winter temperatures. I am thinking that although climate change may result in warmer average winter temperatures, we will still be subject to occasional very cold Arctic air masses. They may not be as frequent as in years past, but even if one of them comes it could be quite damaging. If we have less persistent snow cover, we may actually see more injury to crowns and roots of perennial fruit plants.
One thing we seem to be seeing already, regardless of global climate change, is a more substantial effect of the Twin Cities heat island. People in Minneapolis-St. Paul and many of the inner ring suburbs are probably seeing a shift of one USDA hardiness zone already from 20 to 25 years ago, compared to the outer suburbs and greater Minnesota.
If we have more summer heat, that could lead to more consistent ripening of grapes and may allow us to grow some different varieties currently grown further south. We may also be able to plant varieties of apples that need a longer season to mature.
But don’t plant these just yet—the winter of 2007-08, which was just an average winter, caused extensive damage to these more tender varieties and species.
