Rapid leaf trait response to growing-season meteorology in Vitis: Implications for leaf physiognomic paleoclimate reconstructions

PREMISE OF THE STUDYThe size and shape (physiognomy) of woody, dicotyledonous angiosperm leaves are correlated with climate and these relationships have been used to develop. proxies. These proxies assume that leaf morphology plastically responds to meteorological conditions and that leaf traits change isometrically through development.\n\nMETHODSWe used Digital Leaf Physiognomy (DiLP) to measure leaf characters of multiple Vitis species from the USDA Germplasm Repository in Geneva, NY from the 2012-2013 and 2014-2015 growing seasons. These growing seasons had different temperature and precipitation.\n\nKEY RESULTSWe found three primary results: (1) there were predictable significant differences in leaf characters in leaves of different developmental stages along the vine, (2) there were significant differences in leaf characters in leaves of the same developmental stage between the growing seasons, and (3) there were significant differences in leaf characters between growing seasons.\n\nCONCLUSIONSWe found that Vitis leaf shape had the strongest relationship with growing season meteorological conditions in taxa growing in their native range. In addition, leaves have variable phenotypic plasticity along the vine. We interpret that the meteorological signal was strongest in those leaves that have completed allometric expansion. This is significant for leaf physiognomic-paleoclimate proxies because these leaves are most likely to be preserved in leaf litter and reflect the type of leaves included in paleoclimate reconstructions. We found that leaf development does have the potential to be a confounding factor, but it is unlikely to exert a significant influence on analysis due to differential preservation potential.