Agriculture

Oregon agriculture is as diverse as the geography and climate of the state. However, while this diversity is an economic strength, it creates a wide range of sensitivity issues to climate change factors that does not produce a ‘one size fits all’ assessment protocol or universal response. Oregon ranks in the top five of states producing crops as varied as potatoes, sweet cherries, plums for prunes, onions, hops, pears, hazelnuts, grass seeds, dried herbs, nursery plants, berries, and winegrapes. Furthermore, Oregon has large commodity output in Christmas trees, livestock, wheat, and Dungeness crab. Each of these crops or commodities has quite different climate requirements and thresholds that need to be better understood to adequately assess climate change impacts.

Depending on the crop/commodity and its current climatic equilibrium, temperature and/or precipitation changes can either reduce or increase yields and/or quality. Few if any direct studies on production and quality for Oregon’s major crops have been done. Most of the work that has been done is largely speculative, indicating that if a given crop/commodity exists within today’s climatic thresholds, that projected changes would push them outside what is suitable. What is needed is much more direct and controlled studies of plant/animal growth characteristics, optimum climate requirements and variability thresholds for economic sustainability. For example, Lobell et al (2006) and Lobell et al (2007) have conducted studies on the major crops in California revealing historical impacts and future sensitivities. These kind of studies need to be replicated to Oregon’s climate and crops.

Winegrapes and orchard crops are two examples of Oregon agricultural crops that may experience impacts based on climate change. For winegrapes, research globally has shown that each variety has a relative narrow climatic optimum for both quality and economically sustainable production. For Oregon, no crop better illustrates the climate sensitivity and risk associated with climate change than Pinot Noir, the state’s marquee winegrape. Changes in the climate of Oregon’s wine growing regions since 1950 (especially the Willamette Valley) have provided longer and warmer growing seasons and less risk of frost (Jones, 2003; Jones, 2005). These changes have taken the region from a marginal wine climate to one producing globally-recognized high quality wines. Similar changes have been seen in other wine regions worldwide (Nemani et al. 2001; Jones et al. 2005; Jones, 2006; White et al. 2006; Jones and Goodrich, 2008; White et al. 2008). However, due to the narrow niche that Pinot Noir requires for optimum quality, further increases in temperature will likely move much of current acreage planted in the Willamette Valley outside of what is considered suitable. This would necessitate costly adaptation processes of replanting to different, warmer climate varieties, or moving to higher elevations, more toward the coast, or further north in latitude. Additional risks comes the marketing side, where changes in varieties or wine styles would require a substantial effort to inform consumers.

Orchard-based crops provide another example of the potential economic impacts of climate change associated with rising temperatures. Like many crops, orchard fruits mature more quickly at higher temperatures. Earlier maturity, however, brings issues of both crop quality and its timing to market. Oregon apples and pears, for example, are sold into a global market in which crop quality and availability provide comparative advantages. Observations in Jackson County, where pears represent a large portion of the crop land, show that pear bloom dates in the spring have been earlier in the year with lower frost impacts. However, when frosts do occur, the trees are not as accustomed to the low temperatures as they used to be and minor frosts can be more problematic. In addition, the earlier start to the season has been followed by earlier harvests, which impact when the fruit can make it to the market. Furthermore, winter chilling requirements for orchard crops in Oregon appear to still be sufficient, unlike California where chilling hours during the winter have declined in some parts of the central valley to the point of not making some orchard crops viable (Lobell et al. 2006). However, as climates continue to change similar winter dormancy issues could spell trouble for Oregon. Further shifts to earlier and earlier harvests during warmer summers could both lower the quality of the fruit and shift the competitive environment in which Oregon producers must sell their crop.

Probably the biggest advantage that Oregon agricultural producers have relative to changes in climate is that those in agribusiness continually adapt to variations in climate, otherwise they would not be successful. As a result adaptation by farmers should allow them to maintain quality and production levels in the face of short-term and modest warming. However, if warming is very rapid and compounded by less and less availability of water, then the ability to adapt is much lower. This has been seen in Australia where a multi-year drought episode and government policies that failed to manage water appropriately and inform stakeholders, has brought near collapse to the wine industry in many regions. Surveys out of California and Australia, reveal that growers deem that site factors are essential to quality and these include climate and access to irrigation. They also believe that their ability to adapt to changes in climate becomes increasingly difficult with greater warming without better understanding of their system and government policies that are proactive.

References

Jones, G., 2003, Trends in Frost Occurrence and the Frost-Free Growing Season Length in Oregon Grape-Growing Regions, Proceedings from the 117th Annual Meeting of the Oregon Horticultural Society, Portland, Oregon, January 2003

Jones, G., White, M, Cooper, O. Storchmann, K., 2005, Climate Change and Global Wine Quality, Climate Change 73(3), 319-343.

Jones, G., 2006, Climate and Terroir: Impacts of Climate Variability and Change on Wine, In Fine Wine and Terroir – The Geoscience Perspective. Macqueen, R.W., and Meinert, L.D., (eds.), Geoscience Canada Reprint Series Number 9, Geological Association of Canada, St. John’s, Newfoundland, 247 pages.

Jones, G. and Goodrich, G., 2008, Influence of Climate Variability on Wine Region in the Western USA and on Wine Quality in the Napa Valley. Climate Research, 35: 241-254.

Lobell, D.B., Field, C.B., Cahill, K.N. and Bonfils, C., 2006, Impacts of future climate change on California perennial crop yields: Model projections with climate and crop uncertainties. Agricultural and Forest Meteorology 141: 208-218.

Lobell, D., Field, C., 2007, Global scale climate–crop yield relationships and the impacts of recent warming, Environ. Res. Lett. 2 014002.

Nemani, R. R., White, M. A., Cayan, D. R., Jones, G. V., Running, S. W., and J. C. Coughlan, 2001, Asymmetric climatic warming improves California vintages, Climate Research, Nov. 22, 19(1):25-34.

White, M., Diffenbaugh, N., Jones, G., Pal, J., and F. Giorgi 2006, Extreme heat reduces and shifts United States premium wine production in the 21st century, Proceedings of the National Academy of Sciences, 103(30): 11217–11222.

White, M., Jones, G., and N.S. Diffenbaugh, 2008, “Climate Variability, Climate Change, and Wine Production in the Western United States”. In Warming in Western North America/Evidence and Environmental Effects. Eds. Wagner, F.H., University of Utah Press (Accepted)