HR: 11:54h
AN: A42A-07    [Abstracts]
TI: Climate Change in the Western United States Grape Growing Regions and its Impact on Wine Quality
AU: * Jones, G
EM: gjones@sou.edu
AF: Southern Oregon University, 101A Taylor Hall 1250 Siskiyou Blvd, Ashland, OR 97520 United States
AB: Understanding climate change and the potential impacts on natural and human-based systems has become increasingly important as changing levels of greenhouse gases and alterations in earth surface characteristics bring about planetary energy, temperature, and hydrologic changes. Observed trends and potential changes in temperatures exert strong influences on virtually every form of agriculture where production viability may be altered due to changes in winter hardening potential, frost occurrence, growing season lengths, and heat accumulation for ripening potential. The importance of understanding climate change impacts on agriculture is never more evident than with viticulture where many years of experience has resulted in the finest wines being made from grapes grown in geographically distinct regions. However, grapevines are generally grown in regions and under conditions that are considered narrow for a specific variety's optimum quality, ultimately putting it at a greater potential risk from climatic variations and change. Therefore, this research examines trends from 1948-2002 in annual and seasonal frost frequencies, the dates of last spring and first fall frost occurrence, the length of the frost-free period, and growing season average temperatures and degree-days for the principal grape growing regions in California, Oregon, and Washington. Results reveal that, on average, most regions have experienced a decline in frost frequency, earlier last spring frosts, later first fall frosts, longer frost-free periods, and warmer growing seasons with greater heat accumulation. The observed changes in growing season climates are also related to higher average grape sugar concentrations, the resulting potential alcohol levels, and vintage ratings. However, an examination of possible future climate change in these same regions indicate an average growing season warming of 2 degC in the next 50 years. The magnitude of the projected changes will potentially bring about geographical shifts in production viability or cause growers and winemakers to consider varietal or management adaptations to maintain current wine styles and quality.
DE: 4215 Climate and interannual variability (3309)
DE: 3309 Climatology (1620)
DE: 1600 GLOBAL CHANGE (New category)
DE: 0315 Biosphere/atmosphere interactions
DE: 0614 Biological effects
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting