Liming improves sap characteristics of sugar maple over the long term

• Published in: Forest ecology and management 2020-05, Vol.464, p.118044, Article 118044
• Main Authors: Moore, Jean-David, Duchesne, Louis, Ouimet, Rock, Deschênes, Marie-Lou
• Format: Article
• Language: English
• Subjects: Liming; Maple syrup; Sap; Sugar maple
• ISSN: 0378-1127; 1872-7042
• DOI: 10.1016/j.foreco.2020.118044

•Sugar maple sap was collected in a base-poor SM stand, 18 years after liming.•We show that healthier limed trees could produce more and sweeter sap in the long term.•We suggest that liming can enhance maple syrup yield, both in the short and longer term. Sugar maple (SM, Acer saccharum Marsh.) sap was collected over one spring period in a base-poor SM stand, 18 years after an experimental liming. We wanted to test whether the healthier limed trees could produce more and sweeter sap in the long term than control (non-limed) trees. Results show that liming increased sap sweetness by up to 20%. No direct effect of liming was observed for sap and syrup yield. However, a path analysis showed that the effect of liming on SM syrup yield was indirect and by means of enhanced tree-ring growth. Moreover, our results confirm those of previous studies showing that diameter at breast height (DBH) and tree-ring growth could be good predictors of sap characteristics and syrup yield. These results, combined with the previously documented positive effects of liming on SM nutrition, crown health, growth, and regeneration, strongly suggest that liming can, ultimately, enhance maple syrup yield in base-poor SM stands, both in the short and longer term.