Varying Tree Response to Pluvial Conditions by Natural and Exotic Species, Northeast Ohio, USA

Abstract:

Northeast Ohio is experiencing a dramatic wetting over the past several decades, presenting a challenge for managing the increased runoff and flooding. This steady rise is also an opportunity to investigate the response of trees to the increase in moisture. We examined ring-width records from exotic stands of Dawn Redwood (Metasequoia glyptostroboides) and European Larch (Larix decidua) in Secrest Aboretum, Wooster, Ohio and the response of native White Oak (Quercus alba) from the region. The Dawn Redwood tree growth is significantly correlated with increasing summer moisture, but at the same time it is negatively influenced by summer temperatures. The overall healthy growth rates noted for this species suggest that the precipitation driver is at least keeping pace with the increased evapotranspiration demands of warming summers. The European Larch shows a loss of year-to-year sensitivity to summer precipitation as well as a general decrease in ring-widths possibly linked to summer warming. The utility of examining the climate response of these exotic species may be useful in anticipating future changes in the native range of the trees with a changing climate. Additionally, the European Larch are an important species used in dendroclimatology in its native range and thus can be examined in a different climate zone. Recent studies in the Midwest have also shown a decreasing sensitivity to year-to-year changes in moisture as the overall precipitation increases. However, at other oak sites, tree growth is tracking the low frequency (multi-decadal to century-scale) increase in moisture; responding with a steady increase in ring-width.