GSA Annual Meeting in Seattle, Washington, USA - 2017

Paper No. 240-9
Presentation Time: 3:35 PM


BERSHAW, John1, CARDER, Bethany2, BURNS, Scott F.2 and CARLSON, Tessa B.2, (1)Department of Geology, Portland State University, Portland, OR 97201, (2)Department of Geology, Portland State University, 1721 SW Broadway, Portland, OR 97201,

Terroir, which describes how the soil, climate, and other characteristics of a particular location or region affect the plants grown there, has a strong tradition in wine, coffee, hops, maple syrup, and cheese. Appellations (AVAs) have long existed in the wine industry to protect a region's terroir and brand identity. Cannabis is now legal to grow in numerous states and like wine and beer, consumers are becoming more discerning in their choices, including where and how it was grown.

Thousands of years ago, ancestral varieties of cannabis evolved independently across Asia, a direct response to diverse environments. Human cultivation of the plant has resulted in a proliferation of cannabis strains selected for specific genetic traits. While the genotype determines the range of possible traits that a plant may have, growth conditions determine where they will be on the spectrum of possibilities. It is expected that clones with the same genetics grown by multiple farmers will express different phenotypes because of epigenetic changes that take place as plants adapt to their unique environment, the essence of terroir. We are testing this in cannabis by looking at the chemistry of mature clones grown on outdoor and indoor farms across southern Oregon. Soil chemistry and climate data are being correlated with plant chemistry. While the presence of specific organic compounds seems tied to genetics, preliminary data suggest that the relative abundance of those compounds among plants from unique farms may be related to differences in growing methods and terroir. This research is an important step towards determining if there is a scientific basis for cannabis appellations based on terroir in southern Oregon.