Liming impacts Fagus sylvatica leaf traits and litter decomposition 25 years after amendment

Liming is a common technique used to restore forest health in acidified areas but little is known on the remanence of this amendment in forest ecosystems. We thus investigated how calcareous amendments impact internal biogeochemical cycling of beech stands (Fagus sylvatica), especially the chemistry and traits of leaves and leaf litter and the subsequent rate of litter decomposition 25 years after applications. We also wanted to know if leaf features provide easy predictive tools of litter quality. In both limed and unlimed stands, we compared functional traits (SLA, LDMC, stomatal density), nutrients and fiber contents (hemicellulose, cellulose and lignin) of green and senescent leaves. Additionally, litter bags were used to infer litter decomposition rate. Our results clearly showed that liming impacts leaf chemistry but not morphological leaf traits many years after treatment. In limed stands, green leaves had significantly higher content of Ca and lignin, but lower Mg and cellulose. For senescent leaves, limed stands had greater Ca, Na and cellulose, but lower K, Mn, and N. Resorption rates of K, Na and Mg, in senescent leaves were also affected by limed treatment. We also found a higher litter decomposition rate in limed stands than in unlimed stands. We thus demonstrated that the effect of liming on soil nutrient availability was weak but that changes in beech leaf quality could be recorded 25 years after treatment. These mid-term liming effects on leaf litter quality likely alter soil properties, soil biota and their interactions and thus litter decomposition rate. Lastly, the use of functional leaf traits as a proxy of ecosystem functioning (such as litter decay) is not sufficiently sensitive to detect changes in sites with smooth environmental stress variation. (C) 2015 Elsevier B.V. All rights reserved.