“A Dahurian Larch’s Way of Knowing: Little Larix gmelinii thriving in small-town Ohio"

1. Figure 3: Sample detrending using ARStan to create chronology Figure 5: The master standardized chronology Picture 5: Wooster Tree Ring Lab Picture 6: Wooster Tree Ring Lab Preparation Room “A Dahurian Larch’s Way of Knowing: Little Larix gmelinii thriving in small-town Ohio" Tyler Moore tmoore@wooster.edu, Department of Geology, The College of Wooster, Wooster, OH 44691 Results and Conclusions Background and Introduction Dahurian Larch (Larix gmelinii) are native to eastern Siberia, Mongolia, northeast China, and North Korea. Larix gmelinii is one of the hardiest species of tree in the world, growing at both the most northern latitude of any tree, 72º 30’N, and withstands the coldest temperature, -70ºC. In 1929 the Secrest Arboretum of the Ohio Agricultural Development and Research Center received a set of Prince Rupprecht’s Larch (Larix principis-rupprechtii) that grows in the Wutai Shan mountains of China. They are generaly found on rocky slopes in an area receiving on average 600-900mm per year, a level northeast Ohio often surpasses in a month. In the fall of 2006, the Larch growing in the Secrest Arboretum were cored to determine what would be the primary growth limitation in a climate as drastically different from its native habitat as Ohio. Figure 6: Raw data v. June and July precipitation A standardized chronology was created, correlating well with summer precipitation, most specifically June and July. However, the meteorological data correlates best with the raw measurements The Larch growth shows the highest correlation between the raw data and precipitation in June and July which correlates at 0.48. Correlation with temperature in June is strongly negative, -0.28, but the overall annual and summer temperature correlation is low, and statistically insignificant, at -0.13 and -.01 respectively. The negative temperature correlation is likely due to the negative impact of high temperatures on available precipitation for the trees due to evapotranspiration. It is also possible that are not comfortable growing in conditions so drastically different than their native Siberia. Picture 3. Dahurian Larch growing in the Kolyma Region of the arctic northeast Siberia Picture 4: Dahurian Larch in Secrest Arboretum Figure 1. Map of OARDC Figure 2: Map of Secrest Arboretum • Dendroclimatology: • -Tree growth is largely impacted by both the temperature and precipitation levels of its habitat, mostly throughout the growing season. Narrow rings are indicative of unfavorable growing conditions, while wide rings indicate climatic conditions that are more favorable for growth. • -Radial growth is strongly impacted by precipitation and temperature during the growing season. Narrow rings are indicative of cold, dry years or periods of prolonged/heavy snow pack. Wide rings indicate wet/warm periods favorable for growth. • -Measuring the rings of various trees in an area allows for the creation of a chronology for that specie in that area. Various statistical techniques can be used to eliminate irrelevant growth trends, allowing the resultant standardized curve to be plotted against meteorological data, determining which factors are most important in the growth of the tree • Methodology • 7 Dahurian Larch were cored at the Secrest Arboretum, resulting in 28 cores. • Cores were mounted and prepared for measuring at the Wooster Tree Ring Lab • Tree rings were measured within .001mm using the software MeasureJ2X, crossdated with Cofecha, and the chronology was created using ARSTAN Figure 7. Monthly temperature and precipitation correlations over the 20-month dendroclimatic year The correlations over the dendroclimatic year show that the Larch retain a strong memory of past growing conditions, likely a carryover from the extreme conditions in which it evolved. Picture 1: Coring the Larch at the Secrest Arboretum The strong precipitation correlation, together with a weak correlation for temperature patterns, indicate that as temperatures rise in Siberia, the Larch will become less sensitive to seasonal temperature variations, and will be primarily limited in growth by fluctuations in precipitation. The impact of global warming on precipitation levels throughout Russia and Mongolia will have a greater effect on the health and activities of the northern boreal forests. Reference: Gymnosperm Database, 2004, Larix gmelinii var. pincipis-rupprechtii description [WWW Document]. URL: http://www.conifers.org/pi/la/gmelinii3.htm Accessed December, 2006. Figure 4: Plot of each individual index, showing high correlation within the site Acknowledgements: I would like to thank the Secrest Arboretum for allowing us to core their trees Picture 2: Coring on the Secrest Arboretum site